tests: Use single test file for unit and functional parser tests

3 files changed, 8241 insertions, 15256 deletions

diff --git a/test/functional/api/vim_spec.lua b/test/functional/api/vim_spec.lua
index 714b1988fb..3939bc9b52 100644
--- a/test/functional/api/vim_spec.lua
+++ b/test/functional/api/vim_spec.lua
@@ -766,6 +766,11 @@ describe('api', function()
       elseif typ == 'Environment' then
         typ = ('%s(ident=%s)'):format(typ, east_api_node.ident)
         east_api_node.ident = nil
+      elseif typ == 'Assignment' then
+        local aug = east_api_node.augmentation
+        if aug == '' then aug = 'Plain' end
+        typ = ('%s(%s)'):format(typ, aug)
+        east_api_node.augmentation = nil
       end
       typ = ('%s:%u:%u:%s'):format(
         typ, east_api_node.start[1], east_api_node.start[2],
@@ -798,6 +803,9 @@ describe('api', function()
       end
       if east_api.ast then
         east_api.ast = {simplify_east_api_node(line, east_api.ast)}
+        if #east_api.ast == 0 then
+          east_api.ast = nil
+        end
       end
       if east_api.len == #line then
         east_api.len = nil
@@ -819,11 +827,19 @@ describe('api', function()
       [1] = "m",
       [2] = "E",
       [3] = "mE",
+      [4] = "l",
+      [5] = "lm",
+      [6] = "lE",
+      [7] = "lmE",
     }
-    local function check_parsing(str, exp_ast, exp_highlighting_fs,
-                                 nz_flags_exps)
+    local function _check_parsing(opts, str, exp_ast, exp_highlighting_fs,
+                                  nz_flags_exps)
+      if type(str) ~= 'string' then
+        return
+      end
+      local zflags = opts.flags[1]
       nz_flags_exps = nz_flags_exps or {}
-      for _, flags in ipairs({0, 1, 2, 3}) do
+      for _, flags in ipairs(opts.flags) do
         local err, msg = pcall(function()
           local east_api = meths.parse_expression(str, FLAGS_TO_STR[flags], true)
           local east_hl = east_api.highlight
@@ -835,8 +851,8 @@ describe('api', function()
             hl_fs = exp_highlighting_fs,
           }
           local add_exps = nz_flags_exps[flags]
-          if not add_exps and flags == 3 then
-            add_exps = nz_flags_exps[1] or nz_flags_exps[2]
+          if not add_exps and flags == 3 + zflags then
+            add_exps = nz_flags_exps[1 + zflags] or nz_flags_exps[2 + zflags]
           end
           if add_exps then
             if add_exps.ast then
@@ -873,7096 +889,22 @@ describe('api', function()
           str)), (col + #str)
       end
     end
-    it('works with + and @a', function()
-      check_parsing('@a', {
-        ast = {
-          'Register(name=a):0:0:@a',
-        },
-      }, {
-        hl('Register', '@a'),
-      })
-      check_parsing('+@a', {
-        ast = {
-          {
-            'UnaryPlus:0:0:+',
-            children = {
-              'Register(name=a):0:1:@a',
-            },
-          },
-        },
-      }, {
-        hl('UnaryPlus', '+'),
-        hl('Register', '@a'),
-      })
-      check_parsing('@a+@b', {
-        ast = {
-          {
-            'BinaryPlus:0:2:+',
-            children = {
-              'Register(name=a):0:0:@a',
-              'Register(name=b):0:3:@b',
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-        hl('Register', '@b'),
-      })
-      check_parsing('@a+@b+@c', {
-        ast = {
-          {
-            'BinaryPlus:0:5:+',
-            children = {
-              {
-                'BinaryPlus:0:2:+',
-                children = {
-                  'Register(name=a):0:0:@a',
-                  'Register(name=b):0:3:@b',
-                },
-              },
-              'Register(name=c):0:6:@c',
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-        hl('Register', '@b'),
-        hl('BinaryPlus', '+'),
-        hl('Register', '@c'),
-      })
-      check_parsing('+@a+@b', {
-        ast = {
-          {
-            'BinaryPlus:0:3:+',
-            children = {
-              {
-                'UnaryPlus:0:0:+',
-                children = {
-                  'Register(name=a):0:1:@a',
-                },
-              },
-              'Register(name=b):0:4:@b',
-            },
-          },
-        },
-      }, {
-        hl('UnaryPlus', '+'),
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-        hl('Register', '@b'),
-      })
-      check_parsing('+@a++@b', {
-        ast = {
-          {
-            'BinaryPlus:0:3:+',
-            children = {
-              {
-                'UnaryPlus:0:0:+',
-                children = {
-                  'Register(name=a):0:1:@a',
-                },
-              },
-              {
-                'UnaryPlus:0:4:+',
-                children = {
-                  'Register(name=b):0:5:@b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('UnaryPlus', '+'),
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-        hl('UnaryPlus', '+'),
-        hl('Register', '@b'),
-      })
-      check_parsing('@a@b', {
-        ast = {
-          {
-            'OpMissing:0:2:',
-            children = {
-              'Register(name=a):0:0:@a',
-              'Register(name=b):0:2:@b',
-            },
-          },
-        },
-        err = {
-          arg = '@b',
-          msg = 'E15: Missing operator: %.*s',
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('InvalidRegister', '@b'),
-      }, {
-        [1] = {
-          ast = {
-            len = 2,
-            err = REMOVE_THIS,
-            ast = {
-              'Register(name=a):0:0:@a'
-            },
-          },
-          hl_fs = {
-            [2] = REMOVE_THIS,
-          },
-        },
-      })
-      check_parsing(' @a \t @b', {
-        ast = {
-          {
-            'OpMissing:0:3:',
-            children = {
-              'Register(name=a):0:0: @a',
-              'Register(name=b):0:3: \t @b',
-            },
-          },
-        },
-        err = {
-          arg = '@b',
-          msg = 'E15: Missing operator: %.*s',
-        },
-      }, {
-        hl('Register', '@a', 1),
-        hl('InvalidSpacing', ' \t '),
-        hl('Register', '@b'),
-      }, {
-        [1] = {
-          ast = {
-            len = 6,
-            err = REMOVE_THIS,
-            ast = {
-              'Register(name=a):0:0: @a'
-            },
-          },
-          hl_fs = {
-            [2] = REMOVE_THIS,
-            [3] = REMOVE_THIS,
-          },
-        },
-      })
-      check_parsing('+', {
-        ast = {
-          'UnaryPlus:0:0:+',
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('UnaryPlus', '+'),
-      })
-      check_parsing(' +', {
-        ast = {
-          'UnaryPlus:0:0: +',
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('UnaryPlus', '+', 1),
-      })
-      check_parsing('@a+  ', {
-        ast = {
-          {
-            'BinaryPlus:0:2:+',
-            children = {
-              'Register(name=a):0:0:@a',
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-      })
-    end)
-    it('works with @a, + and parenthesis', function()
-      check_parsing('(@a)', {
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              'Register(name=a):0:1:@a',
-            },
-          },
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Register', '@a'),
-        hl('NestingParenthesis', ')'),
-      })
-      check_parsing('()', {
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              'Missing:0:1:',
-            },
-          },
-        },
-        err = {
-          arg = ')',
-          msg = 'E15: Expected value, got parenthesis: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('InvalidNestingParenthesis', ')'),
-      })
-      check_parsing(')', {
-        ast = {
-          {
-            'Nested:0:0:',
-            children = {
-              'Missing:0:0:',
-            },
-          },
-        },
-        err = {
-          arg = ')',
-          msg = 'E15: Expected value, got parenthesis: %.*s',
-        },
-      }, {
-        hl('InvalidNestingParenthesis', ')'),
-      })
-      check_parsing('+)', {
-        ast = {
-          {
-            'Nested:0:1:',
-            children = {
-              {
-                'UnaryPlus:0:0:+',
-                children = {
-                  'Missing:0:1:',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ')',
-          msg = 'E15: Expected value, got parenthesis: %.*s',
-        },
-      }, {
-        hl('UnaryPlus', '+'),
-        hl('InvalidNestingParenthesis', ')'),
-      })
-      check_parsing('+@a(@b)', {
-        ast = {
-          {
-            'UnaryPlus:0:0:+',
-            children = {
-              {
-                'Call:0:3:(',
-                children = {
-                  'Register(name=a):0:1:@a',
-                  'Register(name=b):0:4:@b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('UnaryPlus', '+'),
-        hl('Register', '@a'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@b'),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('@a+@b(@c)', {
-        ast = {
-          {
-            'BinaryPlus:0:2:+',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Call:0:5:(',
-                children = {
-                  'Register(name=b):0:3:@b',
-                  'Register(name=c):0:6:@c',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-        hl('Register', '@b'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@c'),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('@a()', {
-        ast = {
-          {
-            'Call:0:2:(',
-            children = {
-              'Register(name=a):0:0:@a',
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('CallingParenthesis', '('),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('@a ()', {
-        ast = {
-          {
-            'OpMissing:0:2:',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Nested:0:2: (',
-                children = {
-                  'Missing:0:4:',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '()',
-          msg = 'E15: Missing operator: %.*s',
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('InvalidSpacing', ' '),
-        hl('NestingParenthesis', '('),
-        hl('InvalidNestingParenthesis', ')'),
-      }, {
-        [1] = {
-          ast = {
-            len = 3,
-            err = REMOVE_THIS,
-            ast = {
-              'Register(name=a):0:0:@a',
-            },
-          },
-          hl_fs = {
-            [2] = REMOVE_THIS,
-            [3] = REMOVE_THIS,
-            [4] = REMOVE_THIS,
-          },
-        },
-      })
-      check_parsing('@a + (@b)', {
-        ast = {
-          {
-            'BinaryPlus:0:2: +',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Nested:0:4: (',
-                children = {
-                  'Register(name=b):0:6:@b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+', 1),
-        hl('NestingParenthesis', '(', 1),
-        hl('Register', '@b'),
-        hl('NestingParenthesis', ')'),
-      })
-      check_parsing('@a + (+@b)', {
-        ast = {
-          {
-            'BinaryPlus:0:2: +',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Nested:0:4: (',
-                children = {
-                  {
-                    'UnaryPlus:0:6:+',
-                    children = {
-                      'Register(name=b):0:7:@b',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+', 1),
-        hl('NestingParenthesis', '(', 1),
-        hl('UnaryPlus', '+'),
-        hl('Register', '@b'),
-        hl('NestingParenthesis', ')'),
-      })
-      check_parsing('@a + (@b + @c)', {
-        ast = {
-          {
-            'BinaryPlus:0:2: +',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Nested:0:4: (',
-                children = {
-                  {
-                    'BinaryPlus:0:8: +',
-                    children = {
-                      'Register(name=b):0:6:@b',
-                      'Register(name=c):0:10: @c',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+', 1),
-        hl('NestingParenthesis', '(', 1),
-        hl('Register', '@b'),
-        hl('BinaryPlus', '+', 1),
-        hl('Register', '@c', 1),
-        hl('NestingParenthesis', ')'),
-      })
-      check_parsing('(@a)+@b', {
-        ast = {
-          {
-            'BinaryPlus:0:4:+',
-            children = {
-              {
-                'Nested:0:0:(',
-                children = {
-                  'Register(name=a):0:1:@a',
-                },
-              },
-              'Register(name=b):0:5:@b',
-            },
-          },
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Register', '@a'),
-        hl('NestingParenthesis', ')'),
-        hl('BinaryPlus', '+'),
-        hl('Register', '@b'),
-      })
-      check_parsing('@a+(@b)(@c)', {
-        --           01234567890
-        ast = {
-          {
-            'BinaryPlus:0:2:+',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Call:0:7:(',
-                children = {
-                  {
-                    'Nested:0:3:(',
-                    children = { 'Register(name=b):0:4:@b' },
-                  },
-                  'Register(name=c):0:8:@c',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-        hl('NestingParenthesis', '('),
-        hl('Register', '@b'),
-        hl('NestingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@c'),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('@a+((@b))(@c)', {
-        --           01234567890123456890123456789
-        --           0         1        2
-        ast = {
-          {
-            'BinaryPlus:0:2:+',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Call:0:9:(',
-                children = {
-                  {
-                    'Nested:0:3:(',
-                    children = {
-                      {
-                        'Nested:0:4:(',
-                        children = { 'Register(name=b):0:5:@b' }
-                      },
-                    },
-                  },
-                  'Register(name=c):0:10:@c',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-        hl('NestingParenthesis', '('),
-        hl('NestingParenthesis', '('),
-        hl('Register', '@b'),
-        hl('NestingParenthesis', ')'),
-        hl('NestingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@c'),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('@a+((@b))+@c', {
-        --           01234567890123456890123456789
-        --           0         1        2
-        ast = {
-          {
-            'BinaryPlus:0:9:+',
-            children = {
-              {
-                'BinaryPlus:0:2:+',
-                children = {
-                  'Register(name=a):0:0:@a',
-                  {
-                    'Nested:0:3:(',
-                    children = {
-                      {
-                        'Nested:0:4:(',
-                        children = { 'Register(name=b):0:5:@b' }
-                      },
-                    },
-                  },
-                },
-              },
-              'Register(name=c):0:10:@c',
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-        hl('NestingParenthesis', '('),
-        hl('NestingParenthesis', '('),
-        hl('Register', '@b'),
-        hl('NestingParenthesis', ')'),
-        hl('NestingParenthesis', ')'),
-        hl('BinaryPlus', '+'),
-        hl('Register', '@c'),
-      })
-      check_parsing(
-        '@a + (@b + @c) + @d(@e) + (+@f) + ((+@g(@h))(@j)(@k))(@l)', {--[[
-         | | | | | |   | |  ||  | | ||  | | ||| ||   ||  ||   ||
-         000000000011111111112222222222333333333344444444445555555
-         012345678901234567890123456789012345678901234567890123456
-        ]]
-          ast = {{
-            'BinaryPlus:0:31: +',
-            children = {
-              {
-                'BinaryPlus:0:23: +',
-                children = {
-                  {
-                    'BinaryPlus:0:14: +',
-                    children = {
-                      {
-                        'BinaryPlus:0:2: +',
-                        children = {
-                          'Register(name=a):0:0:@a',
-                          {
-                            'Nested:0:4: (',
-                            children = {
-                              {
-                                'BinaryPlus:0:8: +',
-                                children = {
-                                  'Register(name=b):0:6:@b',
-                                  'Register(name=c):0:10: @c',
-                                },
-                              },
-                            },
-                          },
-                        },
-                      },
-                      {
-                        'Call:0:19:(',
-                        children = {
-                          'Register(name=d):0:16: @d',
-                          'Register(name=e):0:20:@e',
-                        },
-                      },
-                    },
-                  },
-                  {
-                    'Nested:0:25: (',
-                    children = {
-                      {
-                        'UnaryPlus:0:27:+',
-                        children = {
-                          'Register(name=f):0:28:@f',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-              {
-                'Call:0:53:(',
-                children = {
-                  {
-                    'Nested:0:33: (',
-                    children = {
-                      {
-                        'Call:0:48:(',
-                        children = {
-                          {
-                            'Call:0:44:(',
-                            children = {
-                              {
-                                'Nested:0:35:(',
-                                children = {
-                                  {
-                                    'UnaryPlus:0:36:+',
-                                    children = {
-                                      {
-                                        'Call:0:39:(',
-                                        children = {
-                                          'Register(name=g):0:37:@g',
-                                          'Register(name=h):0:40:@h',
-                                        },
-                                      },
-                                    },
-                                  },
-                                },
-                              },
-                              'Register(name=j):0:45:@j',
-                            },
-                          },
-                          'Register(name=k):0:49:@k',
-                        },
-                      },
-                    },
-                  },
-                  'Register(name=l):0:54:@l',
-                },
-              },
-            },
-          }},
-        }, {
-          hl('Register', '@a'),
-          hl('BinaryPlus', '+', 1),
-          hl('NestingParenthesis', '(', 1),
-          hl('Register', '@b'),
-          hl('BinaryPlus', '+', 1),
-          hl('Register', '@c', 1),
-          hl('NestingParenthesis', ')'),
-          hl('BinaryPlus', '+', 1),
-          hl('Register', '@d', 1),
-          hl('CallingParenthesis', '('),
-          hl('Register', '@e'),
-          hl('CallingParenthesis', ')'),
-          hl('BinaryPlus', '+', 1),
-          hl('NestingParenthesis', '(', 1),
-          hl('UnaryPlus', '+'),
-          hl('Register', '@f'),
-          hl('NestingParenthesis', ')'),
-          hl('BinaryPlus', '+', 1),
-          hl('NestingParenthesis', '(', 1),
-          hl('NestingParenthesis', '('),
-          hl('UnaryPlus', '+'),
-          hl('Register', '@g'),
-          hl('CallingParenthesis', '('),
-          hl('Register', '@h'),
-          hl('CallingParenthesis', ')'),
-          hl('NestingParenthesis', ')'),
-          hl('CallingParenthesis', '('),
-          hl('Register', '@j'),
-          hl('CallingParenthesis', ')'),
-          hl('CallingParenthesis', '('),
-          hl('Register', '@k'),
-          hl('CallingParenthesis', ')'),
-          hl('NestingParenthesis', ')'),
-          hl('CallingParenthesis', '('),
-          hl('Register', '@l'),
-          hl('CallingParenthesis', ')'),
-        })
-      check_parsing('@a)', {
-        --           012
-        ast = {
-          {
-            'Nested:0:2:',
-            children = {
-              'Register(name=a):0:0:@a',
-            },
-          },
-        },
-        err = {
-          arg = ')',
-          msg = 'E15: Unexpected closing parenthesis: %.*s',
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('InvalidNestingParenthesis', ')'),
-      })
-      check_parsing('(@a', {
-        --           012
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              'Register(name=a):0:1:@a',
-            },
-          },
-        },
-        err = {
-          arg = '(@a',
-          msg = 'E110: Missing closing parenthesis for nested expression: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Register', '@a'),
-      })
-      check_parsing('@a(@b', {
-        --           01234
-        ast = {
-          {
-            'Call:0:2:(',
-            children = {
-              'Register(name=a):0:0:@a',
-              'Register(name=b):0:3:@b',
-            },
-          },
-        },
-        err = {
-          arg = '(@b',
-          msg = 'E116: Missing closing parenthesis for function call: %.*s',
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@b'),
-      })
-      check_parsing('@a(@b, @c, @d, @e)', {
-        --           012345678901234567
-        --           0         1
-        ast = {
-          {
-            'Call:0:2:(',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Comma:0:5:,',
-                children = {
-                  'Register(name=b):0:3:@b',
-                  {
-                    'Comma:0:9:,',
-                    children = {
-                      'Register(name=c):0:6: @c',
-                      {
-                        'Comma:0:13:,',
-                        children = {
-                          'Register(name=d):0:10: @d',
-                          'Register(name=e):0:14: @e',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@b'),
-        hl('Comma', ','),
-        hl('Register', '@c', 1),
-        hl('Comma', ','),
-        hl('Register', '@d', 1),
-        hl('Comma', ','),
-        hl('Register', '@e', 1),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('@a(@b(@c))', {
-        --           01234567890123456789012345678901234567
-        --           0         1         2         3
-        ast = {
-          {
-            'Call:0:2:(',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Call:0:5:(',
-                children = {
-                  'Register(name=b):0:3:@b',
-                  'Register(name=c):0:6:@c',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@b'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@c'),
-        hl('CallingParenthesis', ')'),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('@a(@b(@c(@d(@e), @f(@g(@h), @i(@j)))))', {
-        --           01234567890123456789012345678901234567
-        --           0         1         2         3
-        ast = {
-          {
-            'Call:0:2:(',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'Call:0:5:(',
-                children = {
-                  'Register(name=b):0:3:@b',
-                  {
-                    'Call:0:8:(',
-                    children = {
-                      'Register(name=c):0:6:@c',
-                      {
-                        'Comma:0:15:,',
-                        children = {
-                          {
-                            'Call:0:11:(',
-                            children = {
-                              'Register(name=d):0:9:@d',
-                              'Register(name=e):0:12:@e',
-                            },
-                          },
-                          {
-                            'Call:0:19:(',
-                            children = {
-                              'Register(name=f):0:16: @f',
-                              {
-                                'Comma:0:26:,',
-                                children = {
-                                  {
-                                    'Call:0:22:(',
-                                    children = {
-                                      'Register(name=g):0:20:@g',
-                                      'Register(name=h):0:23:@h',
-                                    },
-                                  },
-                                  {
-                                    'Call:0:30:(',
-                                    children = {
-                                      'Register(name=i):0:27: @i',
-                                      'Register(name=j):0:31:@j',
-                                    },
-                                  },
-                                },
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@b'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@c'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@d'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@e'),
-        hl('CallingParenthesis', ')'),
-        hl('Comma', ','),
-        hl('Register', '@f', 1),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@g'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@h'),
-        hl('CallingParenthesis', ')'),
-        hl('Comma', ','),
-        hl('Register', '@i', 1),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@j'),
-        hl('CallingParenthesis', ')'),
-        hl('CallingParenthesis', ')'),
-        hl('CallingParenthesis', ')'),
-        hl('CallingParenthesis', ')'),
-        hl('CallingParenthesis', ')'),
-      })
-    end)
-    it('works with variable names, including curly braces ones', function()
-      check_parsing('var', {
-          ast = {
-            'PlainIdentifier(scope=0,ident=var):0:0:var',
-          },
-      }, {
-        hl('IdentifierName', 'var'),
-      })
-      check_parsing('g:var', {
-          ast = {
-            'PlainIdentifier(scope=g,ident=var):0:0:g:var',
-          },
-      }, {
-        hl('IdentifierScope', 'g'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('IdentifierName', 'var'),
-      })
-      check_parsing('g:', {
-          ast = {
-            'PlainIdentifier(scope=g,ident=):0:0:g:',
-          },
-      }, {
-        hl('IdentifierScope', 'g'),
-        hl('IdentifierScopeDelimiter', ':'),
-      })
-      check_parsing('{a}', {
-        --           012
-        ast = {
-          {
-            'CurlyBracesIdentifier:0:0:{',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:1:a',
-            },
-          },
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Curly', '}'),
-      })
-      check_parsing('{a:b}', {
-        --           012
-        ast = {
-          {
-            'CurlyBracesIdentifier:0:0:{',
-            children = {
-              'PlainIdentifier(scope=a,ident=b):0:1:a:b',
-            },
-          },
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('IdentifierScope', 'a'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('IdentifierName', 'b'),
-        hl('Curly', '}'),
-      })
-      check_parsing('{a:@b}', {
-        --           012345
-        ast = {
-          {
-            'CurlyBracesIdentifier:0:0:{',
-            children = {
-              {
-                'OpMissing:0:3:',
-                children={
-                  'PlainIdentifier(scope=a,ident=):0:1:a:',
-                  'Register(name=b):0:3:@b',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '@b}',
-          msg = 'E15: Missing operator: %.*s',
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('IdentifierScope', 'a'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('InvalidRegister', '@b'),
-        hl('Curly', '}'),
-      })
-      check_parsing('{@a}', {
-        ast = {
-          {
-            'CurlyBracesIdentifier:0:0:{',
-            children = {
-              'Register(name=a):0:1:@a',
-            },
-          },
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('Register', '@a'),
-        hl('Curly', '}'),
-      })
-      check_parsing('{@a}{@b}', {
-        --           01234567
-        ast = {
-          {
-            'ComplexIdentifier:0:4:',
-            children = {
-              {
-                'CurlyBracesIdentifier:0:0:{',
-                children = {
-                  'Register(name=a):0:1:@a',
-                },
-              },
-              {
-                'CurlyBracesIdentifier:0:4:{',
-                children = {
-                  'Register(name=b):0:5:@b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('Register', '@a'),
-        hl('Curly', '}'),
-        hl('Curly', '{'),
-        hl('Register', '@b'),
-        hl('Curly', '}'),
-      })
-      check_parsing('g:{@a}', {
-        --           01234567
-        ast = {
-          {
-            'ComplexIdentifier:0:2:',
-            children = {
-              'PlainIdentifier(scope=g,ident=):0:0:g:',
-              {
-                'CurlyBracesIdentifier:0:2:{',
-                children = {
-                  'Register(name=a):0:3:@a',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierScope', 'g'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('Curly', '{'),
-        hl('Register', '@a'),
-        hl('Curly', '}'),
-      })
-      check_parsing('{@a}_test', {
-        --           012345678
-        ast = {
-          {
-            'ComplexIdentifier:0:4:',
-            children = {
-              {
-                'CurlyBracesIdentifier:0:0:{',
-                children = {
-                  'Register(name=a):0:1:@a',
-                },
-              },
-              'PlainIdentifier(scope=0,ident=_test):0:4:_test',
-            },
-          },
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('Register', '@a'),
-        hl('Curly', '}'),
-        hl('IdentifierName', '_test'),
-      })
-      check_parsing('g:{@a}_test', {
-        --           01234567890
-        ast = {
-          {
-            'ComplexIdentifier:0:2:',
-            children = {
-              'PlainIdentifier(scope=g,ident=):0:0:g:',
-              {
-                'ComplexIdentifier:0:6:',
-                children = {
-                  {
-                    'CurlyBracesIdentifier:0:2:{',
-                    children = {
-                      'Register(name=a):0:3:@a',
-                    },
-                  },
-                  'PlainIdentifier(scope=0,ident=_test):0:6:_test',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierScope', 'g'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('Curly', '{'),
-        hl('Register', '@a'),
-        hl('Curly', '}'),
-        hl('IdentifierName', '_test'),
-      })
-      check_parsing('g:{@a}_test()', {
-        --           0123456789012
-        ast = {
-          {
-            'Call:0:11:(',
-            children = {
-              {
-                'ComplexIdentifier:0:2:',
-                children = {
-                  'PlainIdentifier(scope=g,ident=):0:0:g:',
-                  {
-                    'ComplexIdentifier:0:6:',
-                    children = {
-                      {
-                        'CurlyBracesIdentifier:0:2:{',
-                        children = {
-                          'Register(name=a):0:3:@a',
-                        },
-                      },
-                      'PlainIdentifier(scope=0,ident=_test):0:6:_test',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierScope', 'g'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('Curly', '{'),
-        hl('Register', '@a'),
-        hl('Curly', '}'),
-        hl('IdentifierName', '_test'),
-        hl('CallingParenthesis', '('),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('{@a} ()', {
-        --           0123456789012
-        ast = {
-          {
-            'Call:0:4: (',
-            children = {
-              {
-                'CurlyBracesIdentifier:0:0:{',
-                children = {
-                  'Register(name=a):0:1:@a',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('Register', '@a'),
-        hl('Curly', '}'),
-        hl('CallingParenthesis', '(', 1),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('g:{@a} ()', {
-        --           0123456789012
-        ast = {
-          {
-            'Call:0:6: (',
-            children = {
-              {
-                'ComplexIdentifier:0:2:',
-                children = {
-                  'PlainIdentifier(scope=g,ident=):0:0:g:',
-                  {
-                    'CurlyBracesIdentifier:0:2:{',
-                    children = {
-                      'Register(name=a):0:3:@a',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierScope', 'g'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('Curly', '{'),
-        hl('Register', '@a'),
-        hl('Curly', '}'),
-        hl('CallingParenthesis', '(', 1),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('{@a', {
-        --           012
-        ast = {
-          {
-            'UnknownFigure:0:0:{',
-            children = {
-              'Register(name=a):0:1:@a',
-            },
-          },
-        },
-        err = {
-          arg = '{@a',
-          msg = 'E15: Missing closing figure brace: %.*s',
-        },
-      }, {
-        hl('FigureBrace', '{'),
-        hl('Register', '@a'),
-      })
-    end)
-    it('works with lambdas and dictionaries', function()
-      check_parsing('{}', {
-        ast = {
-          'DictLiteral:0:0:{',
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('Dict', '}'),
-      })
-      check_parsing('{->@a}', {
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Arrow:0:1:->',
-                children = {
-                  'Register(name=a):0:3:@a',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('Arrow', '->'),
-        hl('Register', '@a'),
-        hl('Lambda', '}'),
-      })
-      check_parsing('{->@a+@b}', {
-        --           012345678
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Arrow:0:1:->',
-                children = {
-                  {
-                    'BinaryPlus:0:5:+',
-                    children = {
-                      'Register(name=a):0:3:@a',
-                      'Register(name=b):0:6:@b',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('Arrow', '->'),
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+'),
-        hl('Register', '@b'),
-        hl('Lambda', '}'),
-      })
-      check_parsing('{a->@a}', {
-        --           012345678
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:1:a',
-              {
-                'Arrow:0:2:->',
-                children = {
-                  'Register(name=a):0:4:@a',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Arrow', '->'),
-        hl('Register', '@a'),
-        hl('Lambda', '}'),
-      })
-      check_parsing('{a,b->@a}', {
-        --           012345678
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'PlainIdentifier(scope=0,ident=b):0:3:b',
-                },
-              },
-              {
-                'Arrow:0:4:->',
-                children = {
-                  'Register(name=a):0:6:@a',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-        hl('Arrow', '->'),
-        hl('Register', '@a'),
-        hl('Lambda', '}'),
-      })
-      check_parsing('{a,b,c->@a}', {
-        --           01234567890
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  {
-                    'Comma:0:4:,',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=b):0:3:b',
-                      'PlainIdentifier(scope=0,ident=c):0:5:c',
-                    },
-                  },
-                },
-              },
-              {
-                'Arrow:0:6:->',
-                children = {
-                  'Register(name=a):0:8:@a',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'c'),
-        hl('Arrow', '->'),
-        hl('Register', '@a'),
-        hl('Lambda', '}'),
-      })
-      check_parsing('{a,b,c,d->@a}', {
-        --           0123456789012
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  {
-                    'Comma:0:4:,',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=b):0:3:b',
-                      {
-                        'Comma:0:6:,',
-                        children = {
-                          'PlainIdentifier(scope=0,ident=c):0:5:c',
-                          'PlainIdentifier(scope=0,ident=d):0:7:d',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-              {
-                'Arrow:0:8:->',
-                children = {
-                  'Register(name=a):0:10:@a',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'c'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'd'),
-        hl('Arrow', '->'),
-        hl('Register', '@a'),
-        hl('Lambda', '}'),
-      })
-      check_parsing('{a,b,c,d,->@a}', {
-        --           01234567890123
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  {
-                    'Comma:0:4:,',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=b):0:3:b',
-                      {
-                        'Comma:0:6:,',
-                        children = {
-                          'PlainIdentifier(scope=0,ident=c):0:5:c',
-                          {
-                            'Comma:0:8:,',
-                            children = {
-                              'PlainIdentifier(scope=0,ident=d):0:7:d',
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-              {
-                'Arrow:0:9:->',
-                children = {
-                  'Register(name=a):0:11:@a',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'c'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'd'),
-        hl('Comma', ','),
-        hl('Arrow', '->'),
-        hl('Register', '@a'),
-        hl('Lambda', '}'),
-      })
-      check_parsing('{a,b->{c,d->{e,f->@a}}}', {
-        --           01234567890123456789012
-        --           0         1         2
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'PlainIdentifier(scope=0,ident=b):0:3:b',
-                },
-              },
-              {
-                'Arrow:0:4:->',
-                children = {
-                  {
-                    'Lambda:0:6:{',
-                    children = {
-                      {
-                        'Comma:0:8:,',
-                        children = {
-                          'PlainIdentifier(scope=0,ident=c):0:7:c',
-                          'PlainIdentifier(scope=0,ident=d):0:9:d',
-                        },
-                      },
-                      {
-                        'Arrow:0:10:->',
-                        children = {
-                          {
-                            'Lambda:0:12:{',
-                            children = {
-                              {
-                                'Comma:0:14:,',
-                                children = {
-                                  'PlainIdentifier(scope=0,ident=e):0:13:e',
-                                  'PlainIdentifier(scope=0,ident=f):0:15:f',
-                                },
-                              },
-                              {
-                                'Arrow:0:16:->',
-                                children = {
-                                  'Register(name=a):0:18:@a',
-                                },
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-        hl('Arrow', '->'),
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'c'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'd'),
-        hl('Arrow', '->'),
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'e'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'f'),
-        hl('Arrow', '->'),
-        hl('Register', '@a'),
-        hl('Lambda', '}'),
-        hl('Lambda', '}'),
-        hl('Lambda', '}'),
-      })
-      check_parsing('{a,b->c,d}', {
-        --           0123456789
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'PlainIdentifier(scope=0,ident=b):0:3:b',
-                },
-              },
-              {
-                'Arrow:0:4:->',
-                children = {
-                  {
-                    'Comma:0:7:,',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=c):0:6:c',
-                      'PlainIdentifier(scope=0,ident=d):0:8:d',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ',d}',
-          msg = 'E15: Comma outside of call, lambda or literal: %.*s',
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-        hl('Arrow', '->'),
-        hl('IdentifierName', 'c'),
-        hl('InvalidComma', ','),
-        hl('IdentifierName', 'd'),
-        hl('Lambda', '}'),
-      })
-      check_parsing('a,b,c,d', {
-        --           0123456789
-        ast = {
-          {
-            'Comma:0:1:,',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'Comma:0:3:,',
-                children = {
-                'PlainIdentifier(scope=0,ident=b):0:2:b',
-                  {
-                    'Comma:0:5:,',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=c):0:4:c',
-                      'PlainIdentifier(scope=0,ident=d):0:6:d',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ',b,c,d',
-          msg = 'E15: Comma outside of call, lambda or literal: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('InvalidComma', ','),
-        hl('IdentifierName', 'b'),
-        hl('InvalidComma', ','),
-        hl('IdentifierName', 'c'),
-        hl('InvalidComma', ','),
-        hl('IdentifierName', 'd'),
-      })
-      check_parsing('a,b,c,d,', {
-        --           0123456789
-        ast = {
-          {
-            'Comma:0:1:,',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'Comma:0:3:,',
-                children = {
-                'PlainIdentifier(scope=0,ident=b):0:2:b',
-                  {
-                    'Comma:0:5:,',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=c):0:4:c',
-                      {
-                        'Comma:0:7:,',
-                        children = {
-                          'PlainIdentifier(scope=0,ident=d):0:6:d',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ',b,c,d,',
-          msg = 'E15: Comma outside of call, lambda or literal: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('InvalidComma', ','),
-        hl('IdentifierName', 'b'),
-        hl('InvalidComma', ','),
-        hl('IdentifierName', 'c'),
-        hl('InvalidComma', ','),
-        hl('IdentifierName', 'd'),
-        hl('InvalidComma', ','),
-      })
-      check_parsing(',', {
-        --           0123456789
-        ast = {
-          {
-            'Comma:0:0:,',
-            children = {
-              'Missing:0:0:',
-            },
-          },
-        },
-        err = {
-          arg = ',',
-          msg = 'E15: Expected value, got comma: %.*s',
-        },
-      }, {
-        hl('InvalidComma', ','),
-      })
-      check_parsing('{,a->@a}', {
-        --           0123456789
-        ast = {
-          {
-            'CurlyBracesIdentifier:0:0:{',
-            children = {
-              {
-                'Arrow:0:3:->',
-                children = {
-                  {
-                    'Comma:0:1:,',
-                    children = {
-                      'Missing:0:1:',
-                      'PlainIdentifier(scope=0,ident=a):0:2:a',
-                    },
-                  },
-                  'Register(name=a):0:5:@a',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ',a->@a}',
-          msg = 'E15: Expected value, got comma: %.*s',
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('InvalidComma', ','),
-        hl('IdentifierName', 'a'),
-        hl('InvalidArrow', '->'),
-        hl('Register', '@a'),
-        hl('Curly', '}'),
-      })
-      check_parsing('}', {
-        --           0123456789
-        ast = {
-          'UnknownFigure:0:0:',
-        },
-        err = {
-          arg = '}',
-          msg = 'E15: Unexpected closing figure brace: %.*s',
-        },
-      }, {
-        hl('InvalidFigureBrace', '}'),
-      })
-      check_parsing('{->}', {
-        --           0123456789
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              'Arrow:0:1:->',
-            },
-          },
-        },
-        err = {
-          arg = '}',
-          msg = 'E15: Expected value, got closing figure brace: %.*s',
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('Arrow', '->'),
-        hl('InvalidLambda', '}'),
-      })
-      check_parsing('{a,b}', {
-        --           0123456789
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'PlainIdentifier(scope=0,ident=b):0:3:b',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '}',
-          msg = 'E15: Expected lambda arguments list or arrow: %.*s',
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-        hl('InvalidLambda', '}'),
-      })
-      check_parsing('{a,}', {
-        --           0123456789
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '}',
-          msg = 'E15: Expected lambda arguments list or arrow: %.*s',
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('InvalidLambda', '}'),
-      })
-      check_parsing('{@a:@b}', {
-        --           0123456789
-        ast = {
-          {
-            'DictLiteral:0:0:{',
-            children = {
-              {
-                'Colon:0:3::',
-                children = {
-                  'Register(name=a):0:1:@a',
-                  'Register(name=b):0:4:@b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('Register', '@a'),
-        hl('Colon', ':'),
-        hl('Register', '@b'),
-        hl('Dict', '}'),
-      })
-      check_parsing('{@a:@b,@c:@d}', {
-        --           0123456789012
-        --           0         1
-        ast = {
-          {
-            'DictLiteral:0:0:{',
-            children = {
-              {
-                'Comma:0:6:,',
-                children = {
-                  {
-                    'Colon:0:3::',
-                    children = {
-                      'Register(name=a):0:1:@a',
-                      'Register(name=b):0:4:@b',
-                    },
-                  },
-                  {
-                    'Colon:0:9::',
-                    children = {
-                      'Register(name=c):0:7:@c',
-                      'Register(name=d):0:10:@d',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('Register', '@a'),
-        hl('Colon', ':'),
-        hl('Register', '@b'),
-        hl('Comma', ','),
-        hl('Register', '@c'),
-        hl('Colon', ':'),
-        hl('Register', '@d'),
-        hl('Dict', '}'),
-      })
-      check_parsing('{@a:@b,@c:@d,@e:@f,}', {
-        --           01234567890123456789
-        --           0         1
-        ast = {
-          {
-            'DictLiteral:0:0:{',
-            children = {
-              {
-                'Comma:0:6:,',
-                children = {
-                  {
-                    'Colon:0:3::',
-                    children = {
-                      'Register(name=a):0:1:@a',
-                      'Register(name=b):0:4:@b',
-                    },
-                  },
-                  {
-                    'Comma:0:12:,',
-                    children = {
-                      {
-                        'Colon:0:9::',
-                        children = {
-                          'Register(name=c):0:7:@c',
-                          'Register(name=d):0:10:@d',
-                        },
-                      },
-                      {
-                        'Comma:0:18:,',
-                        children = {
-                          {
-                            'Colon:0:15::',
-                            children = {
-                              'Register(name=e):0:13:@e',
-                              'Register(name=f):0:16:@f',
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('Register', '@a'),
-        hl('Colon', ':'),
-        hl('Register', '@b'),
-        hl('Comma', ','),
-        hl('Register', '@c'),
-        hl('Colon', ':'),
-        hl('Register', '@d'),
-        hl('Comma', ','),
-        hl('Register', '@e'),
-        hl('Colon', ':'),
-        hl('Register', '@f'),
-        hl('Comma', ','),
-        hl('Dict', '}'),
-      })
-      check_parsing('{@a:@b,@c:@d,@e:@f,@g:}', {
-        --           01234567890123456789012
-        --           0         1         2
-        ast = {
-          {
-            'DictLiteral:0:0:{',
-            children = {
-              {
-                'Comma:0:6:,',
-                children = {
-                  {
-                    'Colon:0:3::',
-                    children = {
-                      'Register(name=a):0:1:@a',
-                      'Register(name=b):0:4:@b',
-                    },
-                  },
-                  {
-                    'Comma:0:12:,',
-                    children = {
-                      {
-                        'Colon:0:9::',
-                        children = {
-                          'Register(name=c):0:7:@c',
-                          'Register(name=d):0:10:@d',
-                        },
-                      },
-                      {
-                        'Comma:0:18:,',
-                        children = {
-                          {
-                            'Colon:0:15::',
-                            children = {
-                              'Register(name=e):0:13:@e',
-                              'Register(name=f):0:16:@f',
-                            },
-                          },
-                          {
-                            'Colon:0:21::',
-                            children = {
-                              'Register(name=g):0:19:@g',
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '}',
-          msg = 'E15: Expected value, got closing figure brace: %.*s',
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('Register', '@a'),
-        hl('Colon', ':'),
-        hl('Register', '@b'),
-        hl('Comma', ','),
-        hl('Register', '@c'),
-        hl('Colon', ':'),
-        hl('Register', '@d'),
-        hl('Comma', ','),
-        hl('Register', '@e'),
-        hl('Colon', ':'),
-        hl('Register', '@f'),
-        hl('Comma', ','),
-        hl('Register', '@g'),
-        hl('Colon', ':'),
-        hl('InvalidDict', '}'),
-      })
-      check_parsing('{@a:@b,}', {
-        --           01234567890123
-        --           0         1
-        ast = {
-          {
-            'DictLiteral:0:0:{',
-            children = {
-              {
-                'Comma:0:6:,',
-                children = {
-                  {
-                    'Colon:0:3::',
-                    children = {
-                      'Register(name=a):0:1:@a',
-                      'Register(name=b):0:4:@b',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('Register', '@a'),
-        hl('Colon', ':'),
-        hl('Register', '@b'),
-        hl('Comma', ','),
-        hl('Dict', '}'),
-      })
-      check_parsing('{({f -> g})(@h)(@i)}', {
-        --           01234567890123456789
-        --           0         1
-        ast = {
-          {
-            'CurlyBracesIdentifier:0:0:{',
-            children = {
-              {
-                'Call:0:15:(',
-                children = {
-                  {
-                    'Call:0:11:(',
-                    children = {
-                      {
-                        'Nested:0:1:(',
-                        children = {
-                          {
-                            'Lambda:0:2:{',
-                            children = {
-                              'PlainIdentifier(scope=0,ident=f):0:3:f',
-                              {
-                                'Arrow:0:4: ->',
-                                children = {
-                                  'PlainIdentifier(scope=0,ident=g):0:7: g',
-                                },
-                              },
-                            },
-                          },
-                        },
-                      },
-                      'Register(name=h):0:12:@h',
-                    },
-                  },
-                  'Register(name=i):0:16:@i',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('NestingParenthesis', '('),
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'f'),
-        hl('Arrow', '->', 1),
-        hl('IdentifierName', 'g', 1),
-        hl('Lambda', '}'),
-        hl('NestingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@h'),
-        hl('CallingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@i'),
-        hl('CallingParenthesis', ')'),
-        hl('Curly', '}'),
-      })
-      check_parsing('a:{b()}c', {
-        --           01234567
-        ast = {
-          {
-            'ComplexIdentifier:0:2:',
-            children = {
-              'PlainIdentifier(scope=a,ident=):0:0:a:',
-              {
-                'ComplexIdentifier:0:7:',
-                children = {
-                  {
-                    'CurlyBracesIdentifier:0:2:{',
-                    children = {
-                      {
-                        'Call:0:4:(',
-                        children = {
-                          'PlainIdentifier(scope=0,ident=b):0:3:b',
-                        },
-                      },
-                    },
-                  },
-                  'PlainIdentifier(scope=0,ident=c):0:7:c',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierScope', 'a'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('Curly', '{'),
-        hl('IdentifierName', 'b'),
-        hl('CallingParenthesis', '('),
-        hl('CallingParenthesis', ')'),
-        hl('Curly', '}'),
-        hl('IdentifierName', 'c'),
-      })
-      check_parsing('a:{{b, c -> @d + @e + ({f -> g})(@h)}(@i)}j', {
-        --           01234567890123456789012345678901234567890123456
-        --           0         1         2         3         4
-        ast = {
-          {
-            'ComplexIdentifier:0:2:',
-            children = {
-              'PlainIdentifier(scope=a,ident=):0:0:a:',
-              {
-                'ComplexIdentifier:0:42:',
-                children = {
-                  {
-                    'CurlyBracesIdentifier:0:2:{',
-                    children = {
-                      {
-                        'Call:0:37:(',
-                        children = {
-                          {
-                            'Lambda:0:3:{',
-                            children = {
-                              {
-                                'Comma:0:5:,',
-                                children = {
-                                  'PlainIdentifier(scope=0,ident=b):0:4:b',
-                                  'PlainIdentifier(scope=0,ident=c):0:6: c',
-                                },
-                              },
-                              {
-                                'Arrow:0:8: ->',
-                                children = {
-                                  {
-                                    'BinaryPlus:0:19: +',
-                                    children = {
-                                      {
-                                        'BinaryPlus:0:14: +',
-                                        children = {
-                                          'Register(name=d):0:11: @d',
-                                          'Register(name=e):0:16: @e',
-                                        },
-                                      },
-                                      {
-                                        'Call:0:32:(',
-                                        children = {
-                                          {
-                                            'Nested:0:21: (',
-                                            children = {
-                                              {
-                                                'Lambda:0:23:{',
-                                                children = {
-                                                  'PlainIdentifier(scope=0,ident=f):0:24:f',
-                                                  {
-                                                    'Arrow:0:25: ->',
-                                                    children = {
-                                                      'PlainIdentifier(scope=0,ident=g):0:28: g',
-                                                    },
-                                                  },
-                                                },
-                                              },
-                                            },
-                                          },
-                                          'Register(name=h):0:33:@h',
-                                        },
-                                      },
-                                    },
-                                  },
-                                },
-                              },
-                            },
-                          },
-                          'Register(name=i):0:38:@i',
-                        },
-                      },
-                    },
-                  },
-                  'PlainIdentifier(scope=0,ident=j):0:42:j',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierScope', 'a'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('Curly', '{'),
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'b'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'c', 1),
-        hl('Arrow', '->', 1),
-        hl('Register', '@d', 1),
-        hl('BinaryPlus', '+', 1),
-        hl('Register', '@e', 1),
-        hl('BinaryPlus', '+', 1),
-        hl('NestingParenthesis', '(', 1),
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'f'),
-        hl('Arrow', '->', 1),
-        hl('IdentifierName', 'g', 1),
-        hl('Lambda', '}'),
-        hl('NestingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@h'),
-        hl('CallingParenthesis', ')'),
-        hl('Lambda', '}'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@i'),
-        hl('CallingParenthesis', ')'),
-        hl('Curly', '}'),
-        hl('IdentifierName', 'j'),
-      })
-      check_parsing('{@a + @b : @c + @d, @e + @f : @g + @i}', {
-        --           01234567890123456789012345678901234567
-        --           0         1         2         3
-        ast = {
-          {
-            'DictLiteral:0:0:{',
-            children = {
-              {
-                'Comma:0:18:,',
-                children = {
-                  {
-                    'Colon:0:8: :',
-                    children = {
-                      {
-                        'BinaryPlus:0:3: +',
-                        children = {
-                          'Register(name=a):0:1:@a',
-                          'Register(name=b):0:5: @b',
-                        },
-                      },
-                      {
-                        'BinaryPlus:0:13: +',
-                        children = {
-                          'Register(name=c):0:10: @c',
-                          'Register(name=d):0:15: @d',
-                        },
-                      },
-                    },
-                  },
-                  {
-                    'Colon:0:27: :',
-                    children = {
-                      {
-                        'BinaryPlus:0:22: +',
-                        children = {
-                          'Register(name=e):0:19: @e',
-                          'Register(name=f):0:24: @f',
-                        },
-                      },
-                      {
-                        'BinaryPlus:0:32: +',
-                        children = {
-                          'Register(name=g):0:29: @g',
-                          'Register(name=i):0:34: @i',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+', 1),
-        hl('Register', '@b', 1),
-        hl('Colon', ':', 1),
-        hl('Register', '@c', 1),
-        hl('BinaryPlus', '+', 1),
-        hl('Register', '@d', 1),
-        hl('Comma', ','),
-        hl('Register', '@e', 1),
-        hl('BinaryPlus', '+', 1),
-        hl('Register', '@f', 1),
-        hl('Colon', ':', 1),
-        hl('Register', '@g', 1),
-        hl('BinaryPlus', '+', 1),
-        hl('Register', '@i', 1),
-        hl('Dict', '}'),
-      })
-      check_parsing('-> -> ->', {
-        --           01234567
-        ast = {
-          {
-            'Arrow:0:0:->',
-            children = {
-              'Missing:0:0:',
-              {
-                'Arrow:0:2: ->',
-                children = {
-                  'Missing:0:2:',
-                  {
-                    'Arrow:0:5: ->',
-                    children = {
-                      'Missing:0:5:',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '-> -> ->',
-          msg = 'E15: Unexpected arrow: %.*s',
-        },
-      }, {
-        hl('InvalidArrow', '->'),
-        hl('InvalidArrow', '->', 1),
-        hl('InvalidArrow', '->', 1),
-      })
-      check_parsing('a -> b -> c -> d', {
-        --           0123456789012345
-        --           0         1
-        ast = {
-          {
-            'Arrow:0:1: ->',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'Arrow:0:6: ->',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:4: b',
-                  {
-                    'Arrow:0:11: ->',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=c):0:9: c',
-                      'PlainIdentifier(scope=0,ident=d):0:14: d',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '-> b -> c -> d',
-          msg = 'E15: Arrow outside of lambda: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('InvalidArrow', '->', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('InvalidArrow', '->', 1),
-        hl('IdentifierName', 'c', 1),
-        hl('InvalidArrow', '->', 1),
-        hl('IdentifierName', 'd', 1),
-      })
-      check_parsing('{a -> b -> c}', {
-        --           0123456789012
-        --           0         1
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:1:a',
-              {
-                'Arrow:0:2: ->',
-                children = {
-                  {
-                    'Arrow:0:7: ->',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=b):0:5: b',
-                      'PlainIdentifier(scope=0,ident=c):0:10: c',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '-> c}',
-          msg = 'E15: Arrow outside of lambda: %.*s',
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Arrow', '->', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('InvalidArrow', '->', 1),
-        hl('IdentifierName', 'c', 1),
-        hl('Lambda', '}'),
-      })
-      check_parsing('{a: -> b}', {
-        --           012345678
-        ast = {
-          {
-            'CurlyBracesIdentifier:0:0:{',
-            children = {
-              {
-                'Arrow:0:3: ->',
-                children = {
-                  'PlainIdentifier(scope=a,ident=):0:1:a:',
-                  'PlainIdentifier(scope=0,ident=b):0:6: b',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '-> b}',
-          msg = 'E15: Arrow outside of lambda: %.*s',
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('IdentifierScope', 'a'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('InvalidArrow', '->', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('Curly', '}'),
-      })
-
-      check_parsing('{a:b -> b}', {
-        --           0123456789
-        ast = {
-          {
-            'CurlyBracesIdentifier:0:0:{',
-            children = {
-              {
-                'Arrow:0:4: ->',
-                children = {
-                  'PlainIdentifier(scope=a,ident=b):0:1:a:b',
-                  'PlainIdentifier(scope=0,ident=b):0:7: b',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '-> b}',
-          msg = 'E15: Arrow outside of lambda: %.*s',
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('IdentifierScope', 'a'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('IdentifierName', 'b'),
-        hl('InvalidArrow', '->', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('Curly', '}'),
-      })
-
-      check_parsing('{a#b -> b}', {
-        --           0123456789
-        ast = {
-          {
-            'CurlyBracesIdentifier:0:0:{',
-            children = {
-              {
-                'Arrow:0:4: ->',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a#b):0:1:a#b',
-                  'PlainIdentifier(scope=0,ident=b):0:7: b',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '-> b}',
-          msg = 'E15: Arrow outside of lambda: %.*s',
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('IdentifierName', 'a#b'),
-        hl('InvalidArrow', '->', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('Curly', '}'),
-      })
-      check_parsing('{a : b : c}', {
-        --           01234567890
-        --           0         1
-        ast = {
-          {
-            'DictLiteral:0:0:{',
-            children = {
-              {
-                'Colon:0:2: :',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  {
-                    'Colon:0:6: :',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=b):0:4: b',
-                      'PlainIdentifier(scope=0,ident=c):0:8: c',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ': c}',
-          msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Colon', ':', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('InvalidColon', ':', 1),
-        hl('IdentifierName', 'c', 1),
-        hl('Dict', '}'),
-      })
-      check_parsing('{', {
-        --           0
-        ast = {
-          'UnknownFigure:0:0:{',
-        },
-        err = {
-          arg = '{',
-          msg = 'E15: Missing closing figure brace: %.*s',
-        },
-      }, {
-        hl('FigureBrace', '{'),
-      })
-      check_parsing('{a', {
-        --           01
-        ast = {
-          {
-            'UnknownFigure:0:0:{',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:1:a',
-            },
-          },
-        },
-        err = {
-          arg = '{a',
-          msg = 'E15: Missing closing figure brace: %.*s',
-        },
-      }, {
-        hl('FigureBrace', '{'),
-        hl('IdentifierName', 'a'),
-      })
-      check_parsing('{a,b', {
-        --           0123
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'PlainIdentifier(scope=0,ident=b):0:3:b',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '{a,b',
-          msg = 'E15: Missing closing figure brace for lambda: %.*s',
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-      })
-      check_parsing('{a,b->', {
-        --           012345
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'PlainIdentifier(scope=0,ident=b):0:3:b',
-                },
-              },
-              'Arrow:0:4:->',
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-        hl('Arrow', '->'),
-      })
-      check_parsing('{a,b->c', {
-        --           0123456
-        ast = {
-          {
-            'Lambda:0:0:{',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'PlainIdentifier(scope=0,ident=b):0:3:b',
-                },
-              },
-              {
-                'Arrow:0:4:->',
-                children = {
-                  'PlainIdentifier(scope=0,ident=c):0:6:c',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '{a,b->c',
-          msg = 'E15: Missing closing figure brace for lambda: %.*s',
-        },
-      }, {
-        hl('Lambda', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b'),
-        hl('Arrow', '->'),
-        hl('IdentifierName', 'c'),
-      })
-      check_parsing('{a : b', {
-        --           012345
-        ast = {
-          {
-            'DictLiteral:0:0:{',
-            children = {
-              {
-                'Colon:0:2: :',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'PlainIdentifier(scope=0,ident=b):0:4: b',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '{a : b',
-          msg = 'E723: Missing end of Dictionary \'}\': %.*s',
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Colon', ':', 1),
-        hl('IdentifierName', 'b', 1),
-      })
-      check_parsing('{a : b,', {
-        --           0123456
-        ast = {
-          {
-            'DictLiteral:0:0:{',
-            children = {
-              {
-                'Comma:0:6:,',
-                children = {
-                  {
-                    'Colon:0:2: :',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=a):0:1:a',
-                      'PlainIdentifier(scope=0,ident=b):0:4: b',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('Dict', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Colon', ':', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('Comma', ','),
-      })
-    end)
-    it('works with ternary operator', function()
-      check_parsing('a ? b : c', {
-        --           012345678
-        ast = {
-          {
-            'Ternary:0:1: ?',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'TernaryValue:0:5: :',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:3: b',
-                  'PlainIdentifier(scope=0,ident=c):0:7: c',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Ternary', '?', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('TernaryColon', ':', 1),
-        hl('IdentifierName', 'c', 1),
-      })
-      check_parsing('@a?@b?@c:@d:@e', {
-        --           01234567890123
-        --           0         1
-        ast = {
-          {
-            'Ternary:0:2:?',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'TernaryValue:0:11::',
-                children = {
-                  {
-                    'Ternary:0:5:?',
-                    children = {
-                      'Register(name=b):0:3:@b',
-                      {
-                        'TernaryValue:0:8::',
-                        children = {
-                          'Register(name=c):0:6:@c',
-                          'Register(name=d):0:9:@d',
-                        },
-                      },
-                    },
-                  },
-                  'Register(name=e):0:12:@e',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('Ternary', '?'),
-        hl('Register', '@b'),
-        hl('Ternary', '?'),
-        hl('Register', '@c'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@d'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@e'),
-      })
-      check_parsing('@a?@b:@c?@d:@e', {
-        --           01234567890123
-        --           0         1
-        ast = {
-          {
-            'Ternary:0:2:?',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'TernaryValue:0:5::',
-                children = {
-                  'Register(name=b):0:3:@b',
-                  {
-                    'Ternary:0:8:?',
-                    children = {
-                      'Register(name=c):0:6:@c',
-                      {
-                        'TernaryValue:0:11::',
-                        children = {
-                          'Register(name=d):0:9:@d',
-                          'Register(name=e):0:12:@e',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('Ternary', '?'),
-        hl('Register', '@b'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@c'),
-        hl('Ternary', '?'),
-        hl('Register', '@d'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@e'),
-      })
-      check_parsing('@a?@b?@c?@d:@e?@f:@g:@h?@i:@j:@k', {
-        --           01234567890123456789012345678901
-        --           0         1         2         3
-        ast = {
-          {
-            'Ternary:0:2:?',
-            children = {
-              'Register(name=a):0:0:@a',
-              {
-                'TernaryValue:0:29::',
-                children = {
-                  {
-                    'Ternary:0:5:?',
-                    children = {
-                      'Register(name=b):0:3:@b',
-                      {
-                        'TernaryValue:0:20::',
-                        children = {
-                          {
-                            'Ternary:0:8:?',
-                            children = {
-                              'Register(name=c):0:6:@c',
-                              {
-                                'TernaryValue:0:11::',
-                                children = {
-                                  'Register(name=d):0:9:@d',
-                                  {
-                                    'Ternary:0:14:?',
-                                    children = {
-                                      'Register(name=e):0:12:@e',
-                                      {
-                                        'TernaryValue:0:17::',
-                                        children = {
-                                          'Register(name=f):0:15:@f',
-                                          'Register(name=g):0:18:@g',
-                                        },
-                                      },
-                                    },
-                                  },
-                                },
-                              },
-                            },
-                          },
-                          {
-                            'Ternary:0:23:?',
-                            children = {
-                              'Register(name=h):0:21:@h',
-                              {
-                                'TernaryValue:0:26::',
-                                children = {
-                                  'Register(name=i):0:24:@i',
-                                  'Register(name=j):0:27:@j',
-                                },
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                  'Register(name=k):0:30:@k',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('Ternary', '?'),
-        hl('Register', '@b'),
-        hl('Ternary', '?'),
-        hl('Register', '@c'),
-        hl('Ternary', '?'),
-        hl('Register', '@d'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@e'),
-        hl('Ternary', '?'),
-        hl('Register', '@f'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@g'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@h'),
-        hl('Ternary', '?'),
-        hl('Register', '@i'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@j'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@k'),
-      })
-      check_parsing('?', {
-        --           0
-        ast = {
-          {
-            'Ternary:0:0:?',
-            children = {
-              'Missing:0:0:',
-              'TernaryValue:0:0:?',
-            },
-          },
-        },
-        err = {
-          arg = '?',
-          msg = 'E15: Expected value, got question mark: %.*s',
-        },
-      }, {
-        hl('InvalidTernary', '?'),
-      })
-
-      check_parsing('?:', {
-        --           01
-        ast = {
-          {
-            'Ternary:0:0:?',
-            children = {
-              'Missing:0:0:',
-              {
-                'TernaryValue:0:1::',
-                children = {
-                  'Missing:0:1:',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '?:',
-          msg = 'E15: Expected value, got question mark: %.*s',
-        },
-      }, {
-        hl('InvalidTernary', '?'),
-        hl('InvalidTernaryColon', ':'),
-      })
-
-      check_parsing('?::', {
-        --           012
-        ast = {
-          {
-            'Colon:0:2::',
-            children = {
-              {
-                'Ternary:0:0:?',
-                children = {
-                  'Missing:0:0:',
-                  {
-                    'TernaryValue:0:1::',
-                    children = {
-                      'Missing:0:1:',
-                      'Missing:0:2:',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '?::',
-          msg = 'E15: Expected value, got question mark: %.*s',
-        },
-      }, {
-        hl('InvalidTernary', '?'),
-        hl('InvalidTernaryColon', ':'),
-        hl('InvalidColon', ':'),
-      })
-
-      check_parsing('a?b', {
-        --           012
-        ast = {
-          {
-            'Ternary:0:1:?',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'TernaryValue:0:1:?',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:2:b',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '?b',
-          msg = 'E109: Missing \':\' after \'?\': %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Ternary', '?'),
-        hl('IdentifierName', 'b'),
-      })
-      check_parsing('a?b:', {
-        --           0123
-        ast = {
-          {
-            'Ternary:0:1:?',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'TernaryValue:0:1:?',
-                children = {
-                  'PlainIdentifier(scope=b,ident=):0:2:b:',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '?b:',
-          msg = 'E109: Missing \':\' after \'?\': %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Ternary', '?'),
-        hl('IdentifierScope', 'b'),
-        hl('IdentifierScopeDelimiter', ':'),
-      })
-
-      check_parsing('a?b::c', {
-        --           012345
-        ast = {
-          {
-            'Ternary:0:1:?',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'TernaryValue:0:4::',
-                children = {
-                  'PlainIdentifier(scope=b,ident=):0:2:b:',
-                  'PlainIdentifier(scope=0,ident=c):0:5:c',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Ternary', '?'),
-        hl('IdentifierScope', 'b'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('TernaryColon', ':'),
-        hl('IdentifierName', 'c'),
-      })
-
-      check_parsing('a?b :', {
-        --           01234
-        ast = {
-          {
-            'Ternary:0:1:?',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'TernaryValue:0:3: :',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:2:b',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Ternary', '?'),
-        hl('IdentifierName', 'b'),
-        hl('TernaryColon', ':', 1),
-      })
-
-      check_parsing('(@a?@b:@c)?@d:@e', {
-        --           0123456789012345
-        --           0         1
-        ast = {
-          {
-            'Ternary:0:10:?',
-            children = {
-              {
-                'Nested:0:0:(',
-                children = {
-                  {
-                    'Ternary:0:3:?',
-                    children = {
-                      'Register(name=a):0:1:@a',
-                      {
-                        'TernaryValue:0:6::',
-                        children = {
-                          'Register(name=b):0:4:@b',
-                          'Register(name=c):0:7:@c',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-              {
-                'TernaryValue:0:13::',
-                children = {
-                  'Register(name=d):0:11:@d',
-                  'Register(name=e):0:14:@e',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Register', '@a'),
-        hl('Ternary', '?'),
-        hl('Register', '@b'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@c'),
-        hl('NestingParenthesis', ')'),
-        hl('Ternary', '?'),
-        hl('Register', '@d'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@e'),
-      })
-
-      check_parsing('(@a?@b:@c)?(@d?@e:@f):(@g?@h:@i)', {
-        --           01234567890123456789012345678901
-        --           0         1         2         3
-        ast = {
-          {
-            'Ternary:0:10:?',
-            children = {
-              {
-                'Nested:0:0:(',
-                children = {
-                  {
-                    'Ternary:0:3:?',
-                    children = {
-                      'Register(name=a):0:1:@a',
-                      {
-                        'TernaryValue:0:6::',
-                        children = {
-                          'Register(name=b):0:4:@b',
-                          'Register(name=c):0:7:@c',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-              {
-                'TernaryValue:0:21::',
-                children = {
-                  {
-                    'Nested:0:11:(',
-                    children = {
-                      {
-                        'Ternary:0:14:?',
-                        children = {
-                          'Register(name=d):0:12:@d',
-                          {
-                            'TernaryValue:0:17::',
-                            children = {
-                              'Register(name=e):0:15:@e',
-                              'Register(name=f):0:18:@f',
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                  {
-                    'Nested:0:22:(',
-                    children = {
-                      {
-                        'Ternary:0:25:?',
-                        children = {
-                          'Register(name=g):0:23:@g',
-                          {
-                            'TernaryValue:0:28::',
-                            children = {
-                              'Register(name=h):0:26:@h',
-                              'Register(name=i):0:29:@i',
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Register', '@a'),
-        hl('Ternary', '?'),
-        hl('Register', '@b'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@c'),
-        hl('NestingParenthesis', ')'),
-        hl('Ternary', '?'),
-        hl('NestingParenthesis', '('),
-        hl('Register', '@d'),
-        hl('Ternary', '?'),
-        hl('Register', '@e'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@f'),
-        hl('NestingParenthesis', ')'),
-        hl('TernaryColon', ':'),
-        hl('NestingParenthesis', '('),
-        hl('Register', '@g'),
-        hl('Ternary', '?'),
-        hl('Register', '@h'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@i'),
-        hl('NestingParenthesis', ')'),
-      })
-
-      check_parsing('(@a?@b:@c)?@d?@e:@f:@g?@h:@i', {
-        --           0123456789012345678901234567
-        --           0         1         2
-        ast = {
-          {
-            'Ternary:0:10:?',
-            children = {
-              {
-                'Nested:0:0:(',
-                children = {
-                  {
-                    'Ternary:0:3:?',
-                    children = {
-                      'Register(name=a):0:1:@a',
-                      {
-                        'TernaryValue:0:6::',
-                        children = {
-                          'Register(name=b):0:4:@b',
-                          'Register(name=c):0:7:@c',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-              {
-                'TernaryValue:0:19::',
-                children = {
-                  {
-                    'Ternary:0:13:?',
-                    children = {
-                      'Register(name=d):0:11:@d',
-                      {
-                        'TernaryValue:0:16::',
-                        children = {
-                          'Register(name=e):0:14:@e',
-                          'Register(name=f):0:17:@f',
-                        },
-                      },
-                    },
-                  },
-                  {
-                    'Ternary:0:22:?',
-                    children = {
-                      'Register(name=g):0:20:@g',
-                      {
-                        'TernaryValue:0:25::',
-                        children = {
-                          'Register(name=h):0:23:@h',
-                          'Register(name=i):0:26:@i',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Register', '@a'),
-        hl('Ternary', '?'),
-        hl('Register', '@b'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@c'),
-        hl('NestingParenthesis', ')'),
-        hl('Ternary', '?'),
-        hl('Register', '@d'),
-        hl('Ternary', '?'),
-        hl('Register', '@e'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@f'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@g'),
-        hl('Ternary', '?'),
-        hl('Register', '@h'),
-        hl('TernaryColon', ':'),
-        hl('Register', '@i'),
-      })
-      check_parsing('a?b{cdef}g:h', {
-        --           012345678901
-        --           0         1
-        ast = {
-          {
-            'Ternary:0:1:?',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'TernaryValue:0:10::',
-                children = {
-                  {
-                    'ComplexIdentifier:0:3:',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=b):0:2:b',
-                      {
-                        'ComplexIdentifier:0:9:',
-                        children = {
-                          {
-                            'CurlyBracesIdentifier:0:3:{',
-                            children = {
-                              'PlainIdentifier(scope=0,ident=cdef):0:4:cdef',
-                            },
-                          },
-                          'PlainIdentifier(scope=0,ident=g):0:9:g',
-                        },
-                      },
-                    },
-                  },
-                  'PlainIdentifier(scope=0,ident=h):0:11:h',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Ternary', '?'),
-        hl('IdentifierName', 'b'),
-        hl('Curly', '{'),
-        hl('IdentifierName', 'cdef'),
-        hl('Curly', '}'),
-        hl('IdentifierName', 'g'),
-        hl('TernaryColon', ':'),
-        hl('IdentifierName', 'h'),
-      })
-      check_parsing('a ? b : c : d', {
-        --           0123456789012
-        --           0         1
-        ast = {
-          {
-            'Colon:0:9: :',
-            children = {
-              {
-                'Ternary:0:1: ?',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:0:a',
-                  {
-                    'TernaryValue:0:5: :',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=b):0:3: b',
-                      'PlainIdentifier(scope=0,ident=c):0:7: c',
-                    },
-                  },
-                },
-              },
-              'PlainIdentifier(scope=0,ident=d):0:11: d',
-            },
-          },
-        },
-        err = {
-          arg = ': d',
-          msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Ternary', '?', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('TernaryColon', ':', 1),
-        hl('IdentifierName', 'c', 1),
-        hl('InvalidColon', ':', 1),
-        hl('IdentifierName', 'd', 1),
-      })
-    end)
-    it('works with comparison operators', function()
-      check_parsing('a == b', {
-        --           012345
-        ast = {
-          {
-            'Comparison(type=Equal,inv=0,ccs=UseOption):0:1: ==',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:4: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '==', 1),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a ==? b', {
-        --           0123456
-        ast = {
-          {
-            'Comparison(type=Equal,inv=0,ccs=IgnoreCase):0:1: ==?',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:5: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '==', 1),
-        hl('ComparisonModifier', '?'),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a ==# b', {
-        --           0123456
-        ast = {
-          {
-            'Comparison(type=Equal,inv=0,ccs=MatchCase):0:1: ==#',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:5: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '==', 1),
-        hl('ComparisonModifier', '#'),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a !=# b', {
-        --           0123456
-        ast = {
-          {
-            'Comparison(type=Equal,inv=1,ccs=MatchCase):0:1: !=#',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:5: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '!=', 1),
-        hl('ComparisonModifier', '#'),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a <=# b', {
-        --           0123456
-        ast = {
-          {
-            'Comparison(type=Greater,inv=1,ccs=MatchCase):0:1: <=#',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:5: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '<=', 1),
-        hl('ComparisonModifier', '#'),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a >=# b', {
-        --           0123456
-        ast = {
-          {
-            'Comparison(type=GreaterOrEqual,inv=0,ccs=MatchCase):0:1: >=#',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:5: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '>=', 1),
-        hl('ComparisonModifier', '#'),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a ># b', {
-        --           012345
-        ast = {
-          {
-            'Comparison(type=Greater,inv=0,ccs=MatchCase):0:1: >#',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:4: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '>', 1),
-        hl('ComparisonModifier', '#'),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a <# b', {
-        --           012345
-        ast = {
-          {
-            'Comparison(type=GreaterOrEqual,inv=1,ccs=MatchCase):0:1: <#',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:4: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '<', 1),
-        hl('ComparisonModifier', '#'),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a is#b', {
-        --           012345
-        ast = {
-          {
-            'Comparison(type=Identical,inv=0,ccs=MatchCase):0:1: is#',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:5:b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', 'is', 1),
-        hl('ComparisonModifier', '#'),
-        hl('IdentifierName', 'b'),
-      })
-
-      check_parsing('a is?b', {
-        --           012345
-        ast = {
-          {
-            'Comparison(type=Identical,inv=0,ccs=IgnoreCase):0:1: is?',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:5:b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', 'is', 1),
-        hl('ComparisonModifier', '?'),
-        hl('IdentifierName', 'b'),
-      })
-
-      check_parsing('a isnot b', {
-        --           012345678
-        ast = {
-          {
-            'Comparison(type=Identical,inv=1,ccs=UseOption):0:1: isnot',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:7: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', 'isnot', 1),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a < b < c', {
-        --           012345678
-        ast = {
-          {
-            'Comparison(type=GreaterOrEqual,inv=1,ccs=UseOption):0:1: <',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'Comparison(type=GreaterOrEqual,inv=1,ccs=UseOption):0:5: <',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:3: b',
-                  'PlainIdentifier(scope=0,ident=c):0:7: c',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ' < c',
-          msg = 'E15: Operator is not associative: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '<', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('InvalidComparison', '<', 1),
-        hl('IdentifierName', 'c', 1),
-      })
-
-      check_parsing('a < b <# c', {
-        --           012345678
-        ast = {
-          {
-            'Comparison(type=GreaterOrEqual,inv=1,ccs=UseOption):0:1: <',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'Comparison(type=GreaterOrEqual,inv=1,ccs=MatchCase):0:5: <#',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:3: b',
-                  'PlainIdentifier(scope=0,ident=c):0:8: c',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ' <# c',
-          msg = 'E15: Operator is not associative: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Comparison', '<', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('InvalidComparison', '<', 1),
-        hl('InvalidComparisonModifier', '#'),
-        hl('IdentifierName', 'c', 1),
-      })
-
-      check_parsing('a += b', {
-        --           012345
-        ast = {
-          {
-            'Comparison(type=Equal,inv=0,ccs=UseOption):0:3:=',
-            children = {
-              {
-                'BinaryPlus:0:1: +',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:0:a',
-                  'Missing:0:3:',
-                },
-              },
-              'PlainIdentifier(scope=0,ident=b):0:4: b',
-            },
-          },
-        },
-        err = {
-          arg = '= b',
-          msg = 'E15: Expected == or =~: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('BinaryPlus', '+', 1),
-        hl('InvalidComparison', '='),
-        hl('IdentifierName', 'b', 1),
-      })
-      check_parsing('a + b == c + d', {
-        --           01234567890123
-        --           0         1
-        ast = {
-          {
-            'Comparison(type=Equal,inv=0,ccs=UseOption):0:5: ==',
-            children = {
-              {
-                'BinaryPlus:0:1: +',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:0:a',
-                  'PlainIdentifier(scope=0,ident=b):0:3: b',
-                },
-              },
-              {
-                'BinaryPlus:0:10: +',
-                children = {
-                  'PlainIdentifier(scope=0,ident=c):0:8: c',
-                  'PlainIdentifier(scope=0,ident=d):0:12: d',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('BinaryPlus', '+', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('Comparison', '==', 1),
-        hl('IdentifierName', 'c', 1),
-        hl('BinaryPlus', '+', 1),
-        hl('IdentifierName', 'd', 1),
-      })
-      check_parsing('+ a == + b', {
-        --           0123456789
-        ast = {
-          {
-            'Comparison(type=Equal,inv=0,ccs=UseOption):0:3: ==',
-            children = {
-              {
-                'UnaryPlus:0:0:+',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1: a',
-                },
-              },
-              {
-                'UnaryPlus:0:6: +',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:8: b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('UnaryPlus', '+'),
-        hl('IdentifierName', 'a', 1),
-        hl('Comparison', '==', 1),
-        hl('UnaryPlus', '+', 1),
-        hl('IdentifierName', 'b', 1),
-      })
-    end)
-    it('works with concat/subscript', function()
-      check_parsing('.', {
-        --           0
-        ast = {
-          {
-            'ConcatOrSubscript:0:0:.',
-            children = {
-              'Missing:0:0:',
-            },
-          },
-        },
-        err = {
-          arg = '.',
-          msg = 'E15: Unexpected dot: %.*s',
-        },
-      }, {
-        hl('InvalidConcatOrSubscript', '.'),
-      })
-
-      check_parsing('a.', {
-        --           01
-        ast = {
-          {
-            'ConcatOrSubscript:0:1:.',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('ConcatOrSubscript', '.'),
-      })
-
-      check_parsing('a.b', {
-        --           012
-        ast = {
-          {
-            'ConcatOrSubscript:0:1:.',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainKey(key=b):0:2:b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('ConcatOrSubscript', '.'),
-        hl('IdentifierKey', 'b'),
-      })
-
-      check_parsing('1.2', {
-        --           012
-        ast = {
-          'Float(val=1.200000e+00):0:0:1.2',
-        },
-      }, {
-        hl('Float', '1.2'),
-      })
-
-      check_parsing('1.2 + 1.3e-5', {
-        --           012345678901
-        --           0         1
-        ast = {
-          {
-            'BinaryPlus:0:3: +',
-            children = {
-              'Float(val=1.200000e+00):0:0:1.2',
-              'Float(val=1.300000e-05):0:5: 1.3e-5',
-            },
-          },
-        },
-      }, {
-        hl('Float', '1.2'),
-        hl('BinaryPlus', '+', 1),
-        hl('Float', '1.3e-5', 1),
-      })
-
-      check_parsing('a . 1.2 + 1.3e-5', {
-        --           0123456789012345
-        --           0         1
-        ast = {
-          {
-            'BinaryPlus:0:7: +',
-            children = {
-              {
-                'Concat:0:1: .',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:0:a',
-                  {
-                    'ConcatOrSubscript:0:5:.',
-                    children = {
-                      'Integer(val=1):0:3: 1',
-                      'PlainKey(key=2):0:6:2',
-                    },
-                  },
-                },
-              },
-              'Float(val=1.300000e-05):0:9: 1.3e-5',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Concat', '.', 1),
-        hl('Number', '1', 1),
-        hl('ConcatOrSubscript', '.'),
-        hl('IdentifierKey', '2'),
-        hl('BinaryPlus', '+', 1),
-        hl('Float', '1.3e-5', 1),
-      })
-
-      check_parsing('1.3e-5 + 1.2 . a', {
-        --           0123456789012345
-        --           0         1
-        ast = {
-          {
-            'Concat:0:12: .',
-            children = {
-              {
-                'BinaryPlus:0:6: +',
-                children = {
-                  'Float(val=1.300000e-05):0:0:1.3e-5',
-                  'Float(val=1.200000e+00):0:8: 1.2',
-                },
-              },
-              'PlainIdentifier(scope=0,ident=a):0:14: a',
-            },
-          },
-        },
-      }, {
-        hl('Float', '1.3e-5'),
-        hl('BinaryPlus', '+', 1),
-        hl('Float', '1.2', 1),
-        hl('Concat', '.', 1),
-        hl('IdentifierName', 'a', 1),
-      })
-
-      check_parsing('1.3e-5 + a . 1.2', {
-        --           0123456789012345
-        --           0         1
-        ast = {
-          {
-            'Concat:0:10: .',
-            children = {
-              {
-                'BinaryPlus:0:6: +',
-                children = {
-                  'Float(val=1.300000e-05):0:0:1.3e-5',
-                  'PlainIdentifier(scope=0,ident=a):0:8: a',
-                },
-              },
-              {
-                'ConcatOrSubscript:0:14:.',
-                children = {
-                  'Integer(val=1):0:12: 1',
-                  'PlainKey(key=2):0:15:2',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Float', '1.3e-5'),
-        hl('BinaryPlus', '+', 1),
-        hl('IdentifierName', 'a', 1),
-        hl('Concat', '.', 1),
-        hl('Number', '1', 1),
-        hl('ConcatOrSubscript', '.'),
-        hl('IdentifierKey', '2'),
-      })
-
-      check_parsing('1.2.3', {
-        --           01234
-        ast = {
-          {
-            'ConcatOrSubscript:0:3:.',
-            children = {
-              {
-                'ConcatOrSubscript:0:1:.',
-                children = {
-                  'Integer(val=1):0:0:1',
-                  'PlainKey(key=2):0:2:2',
-                },
-              },
-              'PlainKey(key=3):0:4:3',
-            },
-          },
-        },
-      }, {
-        hl('Number', '1'),
-        hl('ConcatOrSubscript', '.'),
-        hl('IdentifierKey', '2'),
-        hl('ConcatOrSubscript', '.'),
-        hl('IdentifierKey', '3'),
-      })
-
-      check_parsing('a.1.2', {
-        --           01234
-        ast = {
-          {
-            'ConcatOrSubscript:0:3:.',
-            children = {
-              {
-                'ConcatOrSubscript:0:1:.',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:0:a',
-                  'PlainKey(key=1):0:2:1',
-                },
-              },
-              'PlainKey(key=2):0:4:2',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('ConcatOrSubscript', '.'),
-        hl('IdentifierKey', '1'),
-        hl('ConcatOrSubscript', '.'),
-        hl('IdentifierKey', '2'),
-      })
-
-      check_parsing('a . 1.2', {
-        --           0123456
-        ast = {
-          {
-            'Concat:0:1: .',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'ConcatOrSubscript:0:5:.',
-                children = {
-                  'Integer(val=1):0:3: 1',
-                  'PlainKey(key=2):0:6:2',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Concat', '.', 1),
-        hl('Number', '1', 1),
-        hl('ConcatOrSubscript', '.'),
-        hl('IdentifierKey', '2'),
-      })
-
-      check_parsing('+a . +b', {
-        --           0123456
-        ast = {
-          {
-            'Concat:0:2: .',
-            children = {
-              {
-                'UnaryPlus:0:0:+',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                },
-              },
-              {
-                'UnaryPlus:0:4: +',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:6:b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('UnaryPlus', '+'),
-        hl('IdentifierName', 'a'),
-        hl('Concat', '.', 1),
-        hl('UnaryPlus', '+', 1),
-        hl('IdentifierName', 'b'),
-      })
-
-      check_parsing('a. b', {
-        --           0123
-        ast = {
-          {
-            'Concat:0:1:.',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=0,ident=b):0:2: b',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('ConcatOrSubscript', '.'),
-        hl('IdentifierName', 'b', 1),
-      })
-
-      check_parsing('a. 1', {
-        --           0123
-        ast = {
-          {
-            'Concat:0:1:.',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'Integer(val=1):0:2: 1',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('ConcatOrSubscript', '.'),
-        hl('Number', '1', 1),
-      })
-    end)
-    it('works with bracket subscripts', function()
-      check_parsing(':', {
-        --           0
-        ast = {
-          {
-            'Colon:0:0::',
-            children = {
-              'Missing:0:0:',
-            },
-          },
-        },
-        err = {
-          arg = ':',
-          msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-        },
-      }, {
-        hl('InvalidColon', ':'),
-      })
-      check_parsing('a[]', {
-        --           012
-        ast = {
-          {
-            'Subscript:0:1:[',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-            },
-          },
-        },
-        err = {
-          arg = ']',
-          msg = 'E15: Expected value, got closing bracket: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('SubscriptBracket', '['),
-        hl('InvalidSubscriptBracket', ']'),
-      })
-      check_parsing('a[b:]', {
-        --           01234
-        ast = {
-          {
-            'Subscript:0:1:[',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=b,ident=):0:2:b:',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierScope', 'b'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('SubscriptBracket', ']'),
-      })
-
-      check_parsing('a[b:c]', {
-        --           012345
-        ast = {
-          {
-            'Subscript:0:1:[',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              'PlainIdentifier(scope=b,ident=c):0:2:b:c',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierScope', 'b'),
-        hl('IdentifierScopeDelimiter', ':'),
-        hl('IdentifierName', 'c'),
-        hl('SubscriptBracket', ']'),
-      })
-      check_parsing('a[b : c]', {
-        --           01234567
-        ast = {
-          {
-            'Subscript:0:1:[',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'Colon:0:3: :',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:2:b',
-                  'PlainIdentifier(scope=0,ident=c):0:5: c',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierName', 'b'),
-        hl('SubscriptColon', ':', 1),
-        hl('IdentifierName', 'c', 1),
-        hl('SubscriptBracket', ']'),
-      })
-
-      check_parsing('a[: b]', {
-        --           012345
-        ast = {
-          {
-            'Subscript:0:1:[',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'Colon:0:2::',
-                children = {
-                  'Missing:0:2:',
-                  'PlainIdentifier(scope=0,ident=b):0:3: b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('SubscriptBracket', '['),
-        hl('SubscriptColon', ':'),
-        hl('IdentifierName', 'b', 1),
-        hl('SubscriptBracket', ']'),
-      })
-
-      check_parsing('a[b :]', {
-        --           012345
-        ast = {
-          {
-            'Subscript:0:1:[',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-              {
-                'Colon:0:3: :',
-                children = {
-                  'PlainIdentifier(scope=0,ident=b):0:2:b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierName', 'b'),
-        hl('SubscriptColon', ':', 1),
-        hl('SubscriptBracket', ']'),
-      })
-      check_parsing('a[b][c][d](e)(f)(g)', {
-        --           0123456789012345678
-        --           0         1
-        ast = {
-          {
-            'Call:0:16:(',
-            children = {
-              {
-                'Call:0:13:(',
-                children = {
-                  {
-                    'Call:0:10:(',
-                    children = {
-                      {
-                        'Subscript:0:7:[',
-                        children = {
-                          {
-                            'Subscript:0:4:[',
-                            children = {
-                              {
-                                'Subscript:0:1:[',
-                                children = {
-                                  'PlainIdentifier(scope=0,ident=a):0:0:a',
-                                  'PlainIdentifier(scope=0,ident=b):0:2:b',
-                                },
-                              },
-                              'PlainIdentifier(scope=0,ident=c):0:5:c',
-                            },
-                          },
-                          'PlainIdentifier(scope=0,ident=d):0:8:d',
-                        },
-                      },
-                      'PlainIdentifier(scope=0,ident=e):0:11:e',
-                    },
-                  },
-                  'PlainIdentifier(scope=0,ident=f):0:14:f',
-                },
-              },
-              'PlainIdentifier(scope=0,ident=g):0:17:g',
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierName', 'b'),
-        hl('SubscriptBracket', ']'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierName', 'c'),
-        hl('SubscriptBracket', ']'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierName', 'd'),
-        hl('SubscriptBracket', ']'),
-        hl('CallingParenthesis', '('),
-        hl('IdentifierName', 'e'),
-        hl('CallingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('IdentifierName', 'f'),
-        hl('CallingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('IdentifierName', 'g'),
-        hl('CallingParenthesis', ')'),
-      })
-      check_parsing('{a}{b}{c}[d][e][f]', {
-        --           012345678901234567
-        --           0         1
-        ast = {
-          {
-            'Subscript:0:15:[',
-            children = {
-              {
-                'Subscript:0:12:[',
-                children = {
-                  {
-                    'Subscript:0:9:[',
-                    children = {
-                      {
-                        'ComplexIdentifier:0:3:',
-                        children = {
-                          {
-                            'CurlyBracesIdentifier:0:0:{',
-                            children = {
-                              'PlainIdentifier(scope=0,ident=a):0:1:a',
-                            },
-                          },
-                          {
-                            'ComplexIdentifier:0:6:',
-                            children = {
-                              {
-                                'CurlyBracesIdentifier:0:3:{',
-                                children = {
-                                  'PlainIdentifier(scope=0,ident=b):0:4:b',
-                                },
-                              },
-                              {
-                                'CurlyBracesIdentifier:0:6:{',
-                                children = {
-                                  'PlainIdentifier(scope=0,ident=c):0:7:c',
-                                },
-                              },
-                            },
-                          },
-                        },
-                      },
-                      'PlainIdentifier(scope=0,ident=d):0:10:d',
-                    },
-                  },
-                  'PlainIdentifier(scope=0,ident=e):0:13:e',
-                },
-              },
-              'PlainIdentifier(scope=0,ident=f):0:16:f',
-            },
-          },
-        },
-      }, {
-        hl('Curly', '{'),
-        hl('IdentifierName', 'a'),
-        hl('Curly', '}'),
-        hl('Curly', '{'),
-        hl('IdentifierName', 'b'),
-        hl('Curly', '}'),
-        hl('Curly', '{'),
-        hl('IdentifierName', 'c'),
-        hl('Curly', '}'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierName', 'd'),
-        hl('SubscriptBracket', ']'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierName', 'e'),
-        hl('SubscriptBracket', ']'),
-        hl('SubscriptBracket', '['),
-        hl('IdentifierName', 'f'),
-        hl('SubscriptBracket', ']'),
-      })
-    end)
-    it('supports list literals', function()
-      check_parsing('[]', {
-        --           01
-        ast = {
-          'ListLiteral:0:0:[',
-        },
-      }, {
-        hl('List', '['),
-        hl('List', ']'),
-      })
-
-      check_parsing('[a]', {
-        --           012
-        ast = {
-          {
-            'ListLiteral:0:0:[',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:1:a',
-            },
-          },
-        },
-      }, {
-        hl('List', '['),
-        hl('IdentifierName', 'a'),
-        hl('List', ']'),
-      })
-
-      check_parsing('[a, b]', {
-        --           012345
-        ast = {
-          {
-            'ListLiteral:0:0:[',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'PlainIdentifier(scope=0,ident=b):0:3: b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('List', '['),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b', 1),
-        hl('List', ']'),
-      })
-
-      check_parsing('[a, b, c]', {
-        --           012345678
-        ast = {
-          {
-            'ListLiteral:0:0:[',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  {
-                    'Comma:0:5:,',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=b):0:3: b',
-                      'PlainIdentifier(scope=0,ident=c):0:6: c',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('List', '['),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b', 1),
-        hl('Comma', ','),
-        hl('IdentifierName', 'c', 1),
-        hl('List', ']'),
-      })
-
-      check_parsing('[a, b, c, ]', {
-        --           01234567890
-        --           0         1
-        ast = {
-          {
-            'ListLiteral:0:0:[',
-            children = {
-              {
-                'Comma:0:2:,',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  {
-                    'Comma:0:5:,',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=b):0:3: b',
-                      {
-                        'Comma:0:8:,',
-                        children = {
-                          'PlainIdentifier(scope=0,ident=c):0:6: c',
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('List', '['),
-        hl('IdentifierName', 'a'),
-        hl('Comma', ','),
-        hl('IdentifierName', 'b', 1),
-        hl('Comma', ','),
-        hl('IdentifierName', 'c', 1),
-        hl('Comma', ','),
-        hl('List', ']', 1),
-      })
-
-      check_parsing('[a : b, c : d]', {
-        --           01234567890123
-        --           0         1
-        ast = {
-          {
-            'ListLiteral:0:0:[',
-            children = {
-              {
-                'Comma:0:6:,',
-                children = {
-                  {
-                    'Colon:0:2: :',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=a):0:1:a',
-                      'PlainIdentifier(scope=0,ident=b):0:4: b',
-                    },
-                  },
-                  {
-                    'Colon:0:9: :',
-                    children = {
-                      'PlainIdentifier(scope=0,ident=c):0:7: c',
-                      'PlainIdentifier(scope=0,ident=d):0:11: d',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ': b, c : d]',
-          msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-        },
-      }, {
-        hl('List', '['),
-        hl('IdentifierName', 'a'),
-        hl('InvalidColon', ':', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('Comma', ','),
-        hl('IdentifierName', 'c', 1),
-        hl('InvalidColon', ':', 1),
-        hl('IdentifierName', 'd', 1),
-        hl('List', ']'),
-      })
-
-      check_parsing(']', {
-        --           0
-        ast = {
-          'ListLiteral:0:0:',
-        },
-        err = {
-          arg = ']',
-          msg = 'E15: Unexpected closing figure brace: %.*s',
-        },
-      }, {
-        hl('InvalidList', ']'),
-      })
-
-      check_parsing('a]', {
-        --           01
-        ast = {
-          {
-            'ListLiteral:0:1:',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-            },
-          },
-        },
-        err = {
-          arg = ']',
-          msg = 'E15: Unexpected closing figure brace: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('InvalidList', ']'),
-      })
-
-      check_parsing('[] []', {
-        --           01234
-        ast = {
-          {
-            'OpMissing:0:2:',
-            children = {
-              'ListLiteral:0:0:[',
-              'ListLiteral:0:2: [',
-            },
-          },
-        },
-        err = {
-          arg = '[]',
-          msg = 'E15: Missing operator: %.*s',
-        },
-      }, {
-        hl('List', '['),
-        hl('List', ']'),
-        hl('InvalidSpacing', ' '),
-        hl('List', '['),
-        hl('List', ']'),
-      }, {
-        [1] = {
-          ast = {
-            len = 3,
-            err = REMOVE_THIS,
-            ast = {
-              'ListLiteral:0:0:[',
-            },
-          },
-          hl_fs = {
-            [3] = REMOVE_THIS,
-            [4] = REMOVE_THIS,
-            [5] = REMOVE_THIS,
-          },
-        },
-      })
-
-      check_parsing('[][]', {
-        --           0123
-        ast = {
-          {
-            'Subscript:0:2:[',
-            children = {
-              'ListLiteral:0:0:[',
-            },
-          },
-        },
-        err = {
-          arg = ']',
-          msg = 'E15: Expected value, got closing bracket: %.*s',
-        },
-      }, {
-        hl('List', '['),
-        hl('List', ']'),
-        hl('SubscriptBracket', '['),
-        hl('InvalidSubscriptBracket', ']'),
-      })
-
-      check_parsing('[', {
-        --           0
-        ast = {
-          'ListLiteral:0:0:[',
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('List', '['),
-      })
-
-      check_parsing('[1', {
-        --           01
-        ast = {
-          {
-            'ListLiteral:0:0:[',
-            children = {
-              'Integer(val=1):0:1:1',
-            },
-          },
-        },
-        err = {
-          arg = '[1',
-          msg = 'E697: Missing end of List \']\': %.*s',
-        },
-      }, {
-        hl('List', '['),
-        hl('Number', '1'),
-      })
-    end)
-    it('works with strings', function()
-      check_parsing('\'abc\'', {
-        --           01234
-        ast = {
-          'SingleQuotedString(val="abc"):0:0:\'abc\'',
-        },
-      }, {
-        hl('SingleQuote', '\''),
-        hl('SingleQuotedBody', 'abc'),
-        hl('SingleQuote', '\''),
-      })
-      check_parsing('"abc"', {
-        --           01234
-        ast = {
-          'DoubleQuotedString(val="abc"):0:0:"abc"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedBody', 'abc'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('\'\'', {
-        --           01
-        ast = {
-          'SingleQuotedString(val=""):0:0:\'\'',
-        },
-      }, {
-        hl('SingleQuote', '\''),
-        hl('SingleQuote', '\''),
-      })
-      check_parsing('""', {
-        --           01
-        ast = {
-          'DoubleQuotedString(val=""):0:0:""',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"', {
-        --           0
-        ast = {
-          'DoubleQuotedString(val=""):0:0:"',
-        },
-        err = {
-          arg = '"',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-      })
-      check_parsing('\'', {
-        --           0
-        ast = {
-          'SingleQuotedString(val=""):0:0:\'',
-        },
-        err = {
-          arg = '\'',
-          msg = 'E115: Missing single quote: %.*s',
-        },
-      }, {
-        hl('InvalidSingleQuote', '\''),
-      })
-      check_parsing('"a', {
-        --           01
-        ast = {
-          'DoubleQuotedString(val="a"):0:0:"a',
-        },
-        err = {
-          arg = '"a',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedBody', 'a'),
-      })
-      check_parsing('\'a', {
-        --           01
-        ast = {
-          'SingleQuotedString(val="a"):0:0:\'a',
-        },
-        err = {
-          arg = '\'a',
-          msg = 'E115: Missing single quote: %.*s',
-        },
-      }, {
-        hl('InvalidSingleQuote', '\''),
-        hl('InvalidSingleQuotedBody', 'a'),
-      })
-      check_parsing('\'abc\'\'def\'', {
-        --           0123456789
-        ast = {
-          'SingleQuotedString(val="abc\'def"):0:0:\'abc\'\'def\'',
-        },
-      }, {
-        hl('SingleQuote', '\''),
-        hl('SingleQuotedBody', 'abc'),
-        hl('SingleQuotedQuote', '\'\''),
-        hl('SingleQuotedBody', 'def'),
-        hl('SingleQuote', '\''),
-      })
-      check_parsing('\'abc\'\'', {
-        --           012345
-        ast = {
-          'SingleQuotedString(val="abc\'"):0:0:\'abc\'\'',
-        },
-        err = {
-          arg = '\'abc\'\'',
-          msg = 'E115: Missing single quote: %.*s',
-        },
-      }, {
-        hl('InvalidSingleQuote', '\''),
-        hl('InvalidSingleQuotedBody', 'abc'),
-        hl('InvalidSingleQuotedQuote', '\'\''),
-      })
-      check_parsing('\'\'\'\'\'\'\'\'', {
-        --           01234567
-        ast = {
-          'SingleQuotedString(val="\'\'\'"):0:0:\'\'\'\'\'\'\'\'',
-        },
-      }, {
-        hl('SingleQuote', '\''),
-        hl('SingleQuotedQuote', '\'\''),
-        hl('SingleQuotedQuote', '\'\''),
-        hl('SingleQuotedQuote', '\'\''),
-        hl('SingleQuote', '\''),
-      })
-      check_parsing('\'\'\'a\'\'\'\'bc\'', {
-        --           01234567890
-        --           0         1
-        ast = {
-          'SingleQuotedString(val="\'a\'\'bc"):0:0:\'\'\'a\'\'\'\'bc\'',
-        },
-      }, {
-        hl('SingleQuote', '\''),
-        hl('SingleQuotedQuote', '\'\''),
-        hl('SingleQuotedBody', 'a'),
-        hl('SingleQuotedQuote', '\'\''),
-        hl('SingleQuotedQuote', '\'\''),
-        hl('SingleQuotedBody', 'bc'),
-        hl('SingleQuote', '\''),
-      })
-      check_parsing('"\\"\\"\\"\\""', {
-        --           0123456789
-        ast = {
-          'DoubleQuotedString(val="\\"\\"\\"\\""):0:0:"\\"\\"\\"\\""',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\"'),
-        hl('DoubleQuotedEscape', '\\"'),
-        hl('DoubleQuotedEscape', '\\"'),
-        hl('DoubleQuotedEscape', '\\"'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"abc\\"def\\"ghi\\"jkl\\"mno"', {
-        --           0123456789012345678901234
-        --           0         1         2
-        ast = {
-          'DoubleQuotedString(val="abc\\"def\\"ghi\\"jkl\\"mno"):0:0:"abc\\"def\\"ghi\\"jkl\\"mno"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedBody', 'abc'),
-        hl('DoubleQuotedEscape', '\\"'),
-        hl('DoubleQuotedBody', 'def'),
-        hl('DoubleQuotedEscape', '\\"'),
-        hl('DoubleQuotedBody', 'ghi'),
-        hl('DoubleQuotedEscape', '\\"'),
-        hl('DoubleQuotedBody', 'jkl'),
-        hl('DoubleQuotedEscape', '\\"'),
-        hl('DoubleQuotedBody', 'mno'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"\\b\\e\\f\\r\\t\\\\"', {
-        --           0123456789012345
-        --           0         1
-        ast = {
-          [[DoubleQuotedString(val="\8\27\12\13\9\\"):0:0:"\b\e\f\r\t\\"]],
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\b'),
-        hl('DoubleQuotedEscape', '\\e'),
-        hl('DoubleQuotedEscape', '\\f'),
-        hl('DoubleQuotedEscape', '\\r'),
-        hl('DoubleQuotedEscape', '\\t'),
-        hl('DoubleQuotedEscape', '\\\\'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"\\n\n"', {
-        --           01234
-        ast = {
-          'DoubleQuotedString(val="\\\n\\\n"):0:0:"\\n\n"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\n'),
-        hl('DoubleQuotedBody', '\n'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"\\x00"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\0"):0:0:"\\x00"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\x00'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"\\xFF"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\255"):0:0:"\\xFF"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\xFF'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"\\xF"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\15"):0:0:"\\xF"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\xF'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"\\u00AB"', {
-        --           01234567
-        ast = {
-          'DoubleQuotedString(val="«"):0:0:"\\u00AB"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\u00AB'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"\\U000000AB"', {
-        --           01234567
-        ast = {
-          'DoubleQuotedString(val="«"):0:0:"\\U000000AB"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U000000AB'),
-        hl('DoubleQuote', '"'),
-      })
-      check_parsing('"\\x"', {
-        --           0123
-        ast = {
-          'DoubleQuotedString(val="x"):0:0:"\\x"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\x'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\x', {
-        --           012
-        ast = {
-          'DoubleQuotedString(val="x"):0:0:"\\x',
-        },
-        err = {
-          arg = '"\\x',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedUnknownEscape', '\\x'),
-      })
-
-      check_parsing('"\\xF', {
-        --           0123
-        ast = {
-          'DoubleQuotedString(val="\\15"):0:0:"\\xF',
-        },
-        err = {
-          arg = '"\\xF',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedEscape', '\\xF'),
-      })
-
-      check_parsing('"\\u"', {
-        --           0123
-        ast = {
-          'DoubleQuotedString(val="u"):0:0:"\\u"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\u'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\u', {
-        --           012
-        ast = {
-          'DoubleQuotedString(val="u"):0:0:"\\u',
-        },
-        err = {
-          arg = '"\\u',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedUnknownEscape', '\\u'),
-      })
-
-      check_parsing('"\\U', {
-        --           012
-        ast = {
-          'DoubleQuotedString(val="U"):0:0:"\\U',
-        },
-        err = {
-          arg = '"\\U',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
-      })
-
-      check_parsing('"\\U"', {
-        --           0123
-        ast = {
-          'DoubleQuotedString(val="U"):0:0:"\\U"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\U'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\xFX"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\15X"):0:0:"\\xFX"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\xF'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\XFX"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\15X"):0:0:"\\XFX"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\XF'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\xX"', {
-        --           01234
-        ast = {
-          'DoubleQuotedString(val="xX"):0:0:"\\xX"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\x'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\XX"', {
-        --           01234
-        ast = {
-          'DoubleQuotedString(val="XX"):0:0:"\\XX"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\X'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\uX"', {
-        --           01234
-        ast = {
-          'DoubleQuotedString(val="uX"):0:0:"\\uX"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\u'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\UX"', {
-        --           01234
-        ast = {
-          'DoubleQuotedString(val="UX"):0:0:"\\UX"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\U'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\x0X"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\x0X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\x0'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\X0X"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\X0X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\X0'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\u0X"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\u0X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\u0'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\U0X"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\U0X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U0'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\x00X"', {
-        --           0123456
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\x00X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\x00'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\X00X"', {
-        --           0123456
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\X00X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\X00'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\u00X"', {
-        --           0123456
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\u00X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\u00'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\U00X"', {
-        --           0123456
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\U00X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U00'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\u000X"', {
-        --           01234567
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\u000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\u000'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\U000X"', {
-        --           01234567
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\U000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U000'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\u0000X"', {
-        --           012345678
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\u0000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\u0000'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\U0000X"', {
-        --           012345678
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\U0000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U0000'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\U00000X"', {
-        --           0123456789
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\U00000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U00000'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\U000000X"', {
-        --           01234567890
-        --           0         1
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\U000000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U000000'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\U0000000X"', {
-        --           012345678901
-        --           0         1
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\U0000000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U0000000'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\U00000000X"', {
-        --           0123456789012
-        --           0         1
-        ast = {
-          'DoubleQuotedString(val="\\0X"):0:0:"\\U00000000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U00000000'),
-        hl('DoubleQuotedBody', 'X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\x000X"', {
-        --           01234567
-        ast = {
-          'DoubleQuotedString(val="\\0000X"):0:0:"\\x000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\x00'),
-        hl('DoubleQuotedBody', '0X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\X000X"', {
-        --           01234567
-        ast = {
-          'DoubleQuotedString(val="\\0000X"):0:0:"\\X000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\X00'),
-        hl('DoubleQuotedBody', '0X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\u00000X"', {
-        --           0123456789
-        ast = {
-          'DoubleQuotedString(val="\\0000X"):0:0:"\\u00000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\u0000'),
-        hl('DoubleQuotedBody', '0X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\U000000000X"', {
-        --           01234567890123
-        --           0         1
-        ast = {
-          'DoubleQuotedString(val="\\0000X"):0:0:"\\U000000000X"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\U00000000'),
-        hl('DoubleQuotedBody', '0X'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\0"', {
-        --           0123
-        ast = {
-          'DoubleQuotedString(val="\\0"):0:0:"\\0"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\0'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\00"', {
-        --           01234
-        ast = {
-          'DoubleQuotedString(val="\\0"):0:0:"\\00"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\00'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\000"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\0"):0:0:"\\000"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\000'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\0000"', {
-        --           0123456
-        ast = {
-          'DoubleQuotedString(val="\\0000"):0:0:"\\0000"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\000'),
-        hl('DoubleQuotedBody', '0'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\8"', {
-        --           0123
-        ast = {
-          'DoubleQuotedString(val="8"):0:0:"\\8"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\8'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\08"', {
-        --           01234
-        ast = {
-          'DoubleQuotedString(val="\\0008"):0:0:"\\08"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\0'),
-        hl('DoubleQuotedBody', '8'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\008"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\0008"):0:0:"\\008"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\00'),
-        hl('DoubleQuotedBody', '8'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\0008"', {
-        --           0123456
-        ast = {
-          'DoubleQuotedString(val="\\0008"):0:0:"\\0008"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\000'),
-        hl('DoubleQuotedBody', '8'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\777"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\255"):0:0:"\\777"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\777'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\050"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\40"):0:0:"\\050"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\050'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\<C-u>"', {
-        --           012345
-        ast = {
-          'DoubleQuotedString(val="\\21"):0:0:"\\<C-u>"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedEscape', '\\<C-u>'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\<', {
-        --           012
-        ast = {
-          'DoubleQuotedString(val="<"):0:0:"\\<',
-        },
-        err = {
-          arg = '"\\<',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedUnknownEscape', '\\<'),
-      })
-
-      check_parsing('"\\<"', {
-        --           0123
-        ast = {
-          'DoubleQuotedString(val="<"):0:0:"\\<"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\<'),
-        hl('DoubleQuote', '"'),
-      })
-
-      check_parsing('"\\<C-u"', {
-        --           0123456
-        ast = {
-          'DoubleQuotedString(val="<C-u"):0:0:"\\<C-u"',
-        },
-      }, {
-        hl('DoubleQuote', '"'),
-        hl('DoubleQuotedUnknownEscape', '\\<'),
-        hl('DoubleQuotedBody', 'C-u'),
-        hl('DoubleQuote', '"'),
-      })
-    end)
-    it('works with multiplication-like operators', function()
-      check_parsing('2+2*2', {
-        --           01234
-        ast = {
-          {
-            'BinaryPlus:0:1:+',
-            children = {
-              'Integer(val=2):0:0:2',
-              {
-                'Multiplication:0:3:*',
-                children = {
-                  'Integer(val=2):0:2:2',
-                  'Integer(val=2):0:4:2',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Number', '2'),
-        hl('BinaryPlus', '+'),
-        hl('Number', '2'),
-        hl('Multiplication', '*'),
-        hl('Number', '2'),
-      })
-
-      check_parsing('2+2*', {
-        --           0123
-        ast = {
-          {
-            'BinaryPlus:0:1:+',
-            children = {
-              'Integer(val=2):0:0:2',
-              {
-                'Multiplication:0:3:*',
-                children = {
-                  'Integer(val=2):0:2:2',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('Number', '2'),
-        hl('BinaryPlus', '+'),
-        hl('Number', '2'),
-        hl('Multiplication', '*'),
-      })
-
-      check_parsing('2+*2', {
-        --           0123
-        ast = {
-          {
-            'BinaryPlus:0:1:+',
-            children = {
-              'Integer(val=2):0:0:2',
-              {
-                'Multiplication:0:2:*',
-                children = {
-                  'Missing:0:2:',
-                  'Integer(val=2):0:3:2',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '*2',
-          msg = 'E15: Unexpected multiplication-like operator: %.*s',
-        },
-      }, {
-        hl('Number', '2'),
-        hl('BinaryPlus', '+'),
-        hl('InvalidMultiplication', '*'),
-        hl('Number', '2'),
-      })
-
-      check_parsing('2+2/2', {
-        --           01234
-        ast = {
-          {
-            'BinaryPlus:0:1:+',
-            children = {
-              'Integer(val=2):0:0:2',
-              {
-                'Division:0:3:/',
-                children = {
-                  'Integer(val=2):0:2:2',
-                  'Integer(val=2):0:4:2',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Number', '2'),
-        hl('BinaryPlus', '+'),
-        hl('Number', '2'),
-        hl('Division', '/'),
-        hl('Number', '2'),
-      })
-
-      check_parsing('2+2/', {
-        --           0123
-        ast = {
-          {
-            'BinaryPlus:0:1:+',
-            children = {
-              'Integer(val=2):0:0:2',
-              {
-                'Division:0:3:/',
-                children = {
-                  'Integer(val=2):0:2:2',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('Number', '2'),
-        hl('BinaryPlus', '+'),
-        hl('Number', '2'),
-        hl('Division', '/'),
-      })
-
-      check_parsing('2+/2', {
-        --           0123
-        ast = {
-          {
-            'BinaryPlus:0:1:+',
-            children = {
-              'Integer(val=2):0:0:2',
-              {
-                'Division:0:2:/',
-                children = {
-                  'Missing:0:2:',
-                  'Integer(val=2):0:3:2',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '/2',
-          msg = 'E15: Unexpected multiplication-like operator: %.*s',
-        },
-      }, {
-        hl('Number', '2'),
-        hl('BinaryPlus', '+'),
-        hl('InvalidDivision', '/'),
-        hl('Number', '2'),
-      })
-
-      check_parsing('2+2%2', {
-        --           01234
-        ast = {
-          {
-            'BinaryPlus:0:1:+',
-            children = {
-              'Integer(val=2):0:0:2',
-              {
-                'Mod:0:3:%',
-                children = {
-                  'Integer(val=2):0:2:2',
-                  'Integer(val=2):0:4:2',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Number', '2'),
-        hl('BinaryPlus', '+'),
-        hl('Number', '2'),
-        hl('Mod', '%'),
-        hl('Number', '2'),
-      })
-
-      check_parsing('2+2%', {
-        --           0123
-        ast = {
-          {
-            'BinaryPlus:0:1:+',
-            children = {
-              'Integer(val=2):0:0:2',
-              {
-                'Mod:0:3:%',
-                children = {
-                  'Integer(val=2):0:2:2',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('Number', '2'),
-        hl('BinaryPlus', '+'),
-        hl('Number', '2'),
-        hl('Mod', '%'),
-      })
-
-      check_parsing('2+%2', {
-        --           0123
-        ast = {
-          {
-            'BinaryPlus:0:1:+',
-            children = {
-              'Integer(val=2):0:0:2',
-              {
-                'Mod:0:2:%',
-                children = {
-                  'Missing:0:2:',
-                  'Integer(val=2):0:3:2',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '%2',
-          msg = 'E15: Unexpected multiplication-like operator: %.*s',
-        },
-      }, {
-        hl('Number', '2'),
-        hl('BinaryPlus', '+'),
-        hl('InvalidMod', '%'),
-        hl('Number', '2'),
-      })
-    end)
-    it('works with -', function()
-      check_parsing('@a', {
-        ast = {
-          'Register(name=a):0:0:@a',
-        },
-      }, {
-        hl('Register', '@a'),
-      })
-      check_parsing('-@a', {
-        ast = {
-          {
-            'UnaryMinus:0:0:-',
-            children = {
-              'Register(name=a):0:1:@a',
-            },
-          },
-        },
-      }, {
-        hl('UnaryMinus', '-'),
-        hl('Register', '@a'),
-      })
-      check_parsing('@a-@b', {
-        ast = {
-          {
-            'BinaryMinus:0:2:-',
-            children = {
-              'Register(name=a):0:0:@a',
-              'Register(name=b):0:3:@b',
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryMinus', '-'),
-        hl('Register', '@b'),
-      })
-      check_parsing('@a-@b-@c', {
-        ast = {
-          {
-            'BinaryMinus:0:5:-',
-            children = {
-              {
-                'BinaryMinus:0:2:-',
-                children = {
-                  'Register(name=a):0:0:@a',
-                  'Register(name=b):0:3:@b',
-                },
-              },
-              'Register(name=c):0:6:@c',
-            },
-          },
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryMinus', '-'),
-        hl('Register', '@b'),
-        hl('BinaryMinus', '-'),
-        hl('Register', '@c'),
-      })
-      check_parsing('-@a-@b', {
-        ast = {
-          {
-            'BinaryMinus:0:3:-',
-            children = {
-              {
-                'UnaryMinus:0:0:-',
-                children = {
-                  'Register(name=a):0:1:@a',
-                },
-              },
-              'Register(name=b):0:4:@b',
-            },
-          },
-        },
-      }, {
-        hl('UnaryMinus', '-'),
-        hl('Register', '@a'),
-        hl('BinaryMinus', '-'),
-        hl('Register', '@b'),
-      })
-      check_parsing('-@a--@b', {
-        ast = {
-          {
-            'BinaryMinus:0:3:-',
-            children = {
-              {
-                'UnaryMinus:0:0:-',
-                children = {
-                  'Register(name=a):0:1:@a',
-                },
-              },
-              {
-                'UnaryMinus:0:4:-',
-                children = {
-                  'Register(name=b):0:5:@b',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('UnaryMinus', '-'),
-        hl('Register', '@a'),
-        hl('BinaryMinus', '-'),
-        hl('UnaryMinus', '-'),
-        hl('Register', '@b'),
-      })
-      check_parsing('-', {
-        ast = {
-          'UnaryMinus:0:0:-',
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('UnaryMinus', '-'),
-      })
-      check_parsing(' -', {
-        ast = {
-          'UnaryMinus:0:0: -',
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('UnaryMinus', '-', 1),
-      })
-      check_parsing('@a-  ', {
-        ast = {
-          {
-            'BinaryMinus:0:2:-',
-            children = {
-              'Register(name=a):0:0:@a',
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryMinus', '-'),
-      })
-    end)
-    it('works with logical operators', function()
-      check_parsing('a && b || c && d', {
-        --           0123456789012345
-        --           0         1
-        ast = {
-          {
-            'Or:0:6: ||',
-            children = {
-              {
-                'And:0:1: &&',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:0:a',
-                  'PlainIdentifier(scope=0,ident=b):0:4: b',
-                },
-              },
-              {
-                'And:0:11: &&',
-                children = {
-                  'PlainIdentifier(scope=0,ident=c):0:9: c',
-                  'PlainIdentifier(scope=0,ident=d):0:14: d',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('And', '&&', 1),
-        hl('IdentifierName', 'b', 1),
-        hl('Or', '||', 1),
-        hl('IdentifierName', 'c', 1),
-        hl('And', '&&', 1),
-        hl('IdentifierName', 'd', 1),
-      })
-
-      check_parsing('&& a', {
-        --           0123
-        ast = {
-          {
-            'And:0:0:&&',
-            children = {
-              'Missing:0:0:',
-              'PlainIdentifier(scope=0,ident=a):0:2: a',
-            },
-          },
-        },
-        err = {
-          arg = '&& a',
-          msg = 'E15: Unexpected and operator: %.*s',
-        },
-      }, {
-        hl('InvalidAnd', '&&'),
-        hl('IdentifierName', 'a', 1),
-      })
-
-      check_parsing('|| a', {
-        --           0123
-        ast = {
-          {
-            'Or:0:0:||',
-            children = {
-              'Missing:0:0:',
-              'PlainIdentifier(scope=0,ident=a):0:2: a',
-            },
-          },
-        },
-        err = {
-          arg = '|| a',
-          msg = 'E15: Unexpected or operator: %.*s',
-        },
-      }, {
-        hl('InvalidOr', '||'),
-        hl('IdentifierName', 'a', 1),
-      })
-
-      check_parsing('a||', {
-        --           012
-        ast = {
-          {
-            'Or:0:1:||',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('Or', '||'),
-      })
-
-      check_parsing('a&&', {
-        --           012
-        ast = {
-          {
-            'And:0:1:&&',
-            children = {
-              'PlainIdentifier(scope=0,ident=a):0:0:a',
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('IdentifierName', 'a'),
-        hl('And', '&&'),
-      })
-
-      check_parsing('(&&)', {
-        --           0123
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'And:0:1:&&',
-                children = {
-                  'Missing:0:1:',
-                  'Missing:0:3:',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '&&)',
-          msg = 'E15: Unexpected and operator: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('InvalidAnd', '&&'),
-        hl('InvalidNestingParenthesis', ')'),
-      })
-
-      check_parsing('(||)', {
-        --           0123
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'Or:0:1:||',
-                children = {
-                  'Missing:0:1:',
-                  'Missing:0:3:',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '||)',
-          msg = 'E15: Unexpected or operator: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('InvalidOr', '||'),
-        hl('InvalidNestingParenthesis', ')'),
-      })
-
-      check_parsing('(a||)', {
-        --           01234
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'Or:0:2:||',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'Missing:0:4:',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ')',
-          msg = 'E15: Expected value, got parenthesis: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('IdentifierName', 'a'),
-        hl('Or', '||'),
-        hl('InvalidNestingParenthesis', ')'),
-      })
-
-      check_parsing('(a&&)', {
-        --           01234
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'And:0:2:&&',
-                children = {
-                  'PlainIdentifier(scope=0,ident=a):0:1:a',
-                  'Missing:0:4:',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ')',
-          msg = 'E15: Expected value, got parenthesis: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('IdentifierName', 'a'),
-        hl('And', '&&'),
-        hl('InvalidNestingParenthesis', ')'),
-      })
-
-      check_parsing('(&&a)', {
-        --           01234
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'And:0:1:&&',
-                children = {
-                  'Missing:0:1:',
-                  'PlainIdentifier(scope=0,ident=a):0:3:a',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '&&a)',
-          msg = 'E15: Unexpected and operator: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('InvalidAnd', '&&'),
-        hl('IdentifierName', 'a'),
-        hl('NestingParenthesis', ')'),
-      })
-
-      check_parsing('(||a)', {
-        --           01234
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'Or:0:1:||',
-                children = {
-                  'Missing:0:1:',
-                  'PlainIdentifier(scope=0,ident=a):0:3:a',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '||a)',
-          msg = 'E15: Unexpected or operator: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('InvalidOr', '||'),
-        hl('IdentifierName', 'a'),
-        hl('NestingParenthesis', ')'),
-      })
-    end)
-    it('works with &opt', function()
-      check_parsing('&', {
-        --           0
-        ast = {
-          'Option(scope=0,ident=):0:0:&',
-        },
-        err = {
-          arg = '&',
-          msg = 'E112: Option name missing: %.*s',
-        },
-      }, {
-        hl('InvalidOptionSigil', '&'),
-      })
-
-      check_parsing('&opt', {
-        --           0123
-        ast = {
-          'Option(scope=0,ident=opt):0:0:&opt',
-        },
-      }, {
-        hl('OptionSigil', '&'),
-        hl('OptionName', 'opt'),
-      })
-
-      check_parsing('&l:opt', {
-        --           012345
-        ast = {
-          'Option(scope=l,ident=opt):0:0:&l:opt',
-        },
-      }, {
-        hl('OptionSigil', '&'),
-        hl('OptionScope', 'l'),
-        hl('OptionScopeDelimiter', ':'),
-        hl('OptionName', 'opt'),
-      })
-
-      check_parsing('&g:opt', {
-        --           012345
-        ast = {
-          'Option(scope=g,ident=opt):0:0:&g:opt',
-        },
-      }, {
-        hl('OptionSigil', '&'),
-        hl('OptionScope', 'g'),
-        hl('OptionScopeDelimiter', ':'),
-        hl('OptionName', 'opt'),
-      })
-
-      check_parsing('&s:opt', {
-        --           012345
-        ast = {
-          {
-            'Colon:0:2::',
-            children = {
-              'Option(scope=0,ident=s):0:0:&s',
-              'PlainIdentifier(scope=0,ident=opt):0:3:opt',
-            },
-          },
-        },
-        err = {
-          arg = ':opt',
-          msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-        },
-      }, {
-        hl('OptionSigil', '&'),
-        hl('OptionName', 's'),
-        hl('InvalidColon', ':'),
-        hl('IdentifierName', 'opt'),
-      })
-
-      check_parsing('& ', {
-        --           01
-        ast = {
-          'Option(scope=0,ident=):0:0:&',
-        },
-        err = {
-          arg = '& ',
-          msg = 'E112: Option name missing: %.*s',
-        },
-      }, {
-        hl('InvalidOptionSigil', '&'),
-      })
-
-      check_parsing('&-', {
-        --           01
-        ast = {
-          {
-            'BinaryMinus:0:1:-',
-            children = {
-              'Option(scope=0,ident=):0:0:&',
-            },
-          },
-        },
-        err = {
-          arg = '&-',
-          msg = 'E112: Option name missing: %.*s',
-        },
-      }, {
-        hl('InvalidOptionSigil', '&'),
-        hl('BinaryMinus', '-'),
-      })
-
-      check_parsing('&A', {
-        --           01
-        ast = {
-          'Option(scope=0,ident=A):0:0:&A',
-        },
-      }, {
-        hl('OptionSigil', '&'),
-        hl('OptionName', 'A'),
-      })
-
-      check_parsing('&xxx_yyy', {
-        --           01234567
-        ast = {
-          {
-            'OpMissing:0:4:',
-            children = {
-              'Option(scope=0,ident=xxx):0:0:&xxx',
-              'PlainIdentifier(scope=0,ident=_yyy):0:4:_yyy',
-            },
-          },
-        },
-        err = {
-          arg = '_yyy',
-          msg = 'E15: Missing operator: %.*s',
-        },
-      }, {
-        hl('OptionSigil', '&'),
-        hl('OptionName', 'xxx'),
-        hl('InvalidIdentifierName', '_yyy'),
-      }, {
-        [1] = {
-          ast = {
-            len = 4,
-            err = REMOVE_THIS,
-            ast = {
-              'Option(scope=0,ident=xxx):0:0:&xxx',
-            },
-          },
-          hl_fs = {
-            [3] = REMOVE_THIS,
-          },
-        },
-      })
-
-      check_parsing('(1+&)', {
-        --           01234
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'BinaryPlus:0:2:+',
-                children = {
-                  'Integer(val=1):0:1:1',
-                  'Option(scope=0,ident=):0:3:&',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '&)',
-          msg = 'E112: Option name missing: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Number', '1'),
-        hl('BinaryPlus', '+'),
-        hl('InvalidOptionSigil', '&'),
-        hl('NestingParenthesis', ')'),
-      })
-
-      check_parsing('(&+1)', {
-        --           01234
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'BinaryPlus:0:2:+',
-                children = {
-                  'Option(scope=0,ident=):0:1:&',
-                  'Integer(val=1):0:3:1',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '&+1)',
-          msg = 'E112: Option name missing: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('InvalidOptionSigil', '&'),
-        hl('BinaryPlus', '+'),
-        hl('Number', '1'),
-        hl('NestingParenthesis', ')'),
-      })
-    end)
-    it('works with $ENV', function()
-      check_parsing('$', {
-        --           0
-        ast = {
-          'Environment(ident=):0:0:$',
-        },
-        err = {
-          arg = '$',
-          msg = 'E15: Environment variable name missing',
-        },
-      }, {
-        hl('InvalidEnvironmentSigil', '$'),
-      })
-
-      check_parsing('$g:A', {
-        --           0123
-        ast = {
-          {
-            'Colon:0:2::',
-            children = {
-              'Environment(ident=g):0:0:$g',
-              'PlainIdentifier(scope=0,ident=A):0:3:A',
-            },
-          },
-        },
-        err = {
-          arg = ':A',
-          msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-        },
-      }, {
-        hl('EnvironmentSigil', '$'),
-        hl('EnvironmentName', 'g'),
-        hl('InvalidColon', ':'),
-        hl('IdentifierName', 'A'),
-      })
-
-      check_parsing('$A', {
-        --           01
-        ast = {
-          'Environment(ident=A):0:0:$A',
-        },
-      }, {
-        hl('EnvironmentSigil', '$'),
-        hl('EnvironmentName', 'A'),
-      })
-
-      check_parsing('$ABC', {
-        --           0123
-        ast = {
-          'Environment(ident=ABC):0:0:$ABC',
-        },
-      }, {
-        hl('EnvironmentSigil', '$'),
-        hl('EnvironmentName', 'ABC'),
-      })
-
-      check_parsing('(1+$)', {
-        --           01234
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'BinaryPlus:0:2:+',
-                children = {
-                  'Integer(val=1):0:1:1',
-                  'Environment(ident=):0:3:$',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '$)',
-          msg = 'E15: Environment variable name missing',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Number', '1'),
-        hl('BinaryPlus', '+'),
-        hl('InvalidEnvironmentSigil', '$'),
-        hl('NestingParenthesis', ')'),
-      })
-
-      check_parsing('($+1)', {
-        --           01234
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'BinaryPlus:0:2:+',
-                children = {
-                  'Environment(ident=):0:1:$',
-                  'Integer(val=1):0:3:1',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '$+1)',
-          msg = 'E15: Environment variable name missing',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('InvalidEnvironmentSigil', '$'),
-        hl('BinaryPlus', '+'),
-        hl('Number', '1'),
-        hl('NestingParenthesis', ')'),
-      })
-
-      check_parsing('$_ABC', {
-        --           01234
-        ast = {
-          'Environment(ident=_ABC):0:0:$_ABC',
-        },
-      }, {
-        hl('EnvironmentSigil', '$'),
-        hl('EnvironmentName', '_ABC'),
-      })
-
-      check_parsing('$_', {
-        --           01
-        ast = {
-          'Environment(ident=_):0:0:$_',
-        },
-      }, {
-        hl('EnvironmentSigil', '$'),
-        hl('EnvironmentName', '_'),
-      })
-
-      check_parsing('$ABC_DEF', {
-        --           01234567
-        ast = {
-          'Environment(ident=ABC_DEF):0:0:$ABC_DEF',
-        },
-      }, {
-        hl('EnvironmentSigil', '$'),
-        hl('EnvironmentName', 'ABC_DEF'),
-      })
-    end)
-    it('works with unary !', function()
-      check_parsing('!', {
-        --           0
-        ast = {
-          'Not:0:0:!',
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('Not', '!'),
-      })
-
-      check_parsing('!!', {
-        --           01
-        ast = {
-          {
-            'Not:0:0:!',
-            children = {
-              'Not:0:1:!',
-            },
-          },
-        },
-        err = {
-          arg = '',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-        hl('Not', '!'),
-        hl('Not', '!'),
-      })
-
-      check_parsing('!!1', {
-        --           012
-        ast = {
-          {
-            'Not:0:0:!',
-            children = {
-              {
-                'Not:0:1:!',
-                children = {
-                  'Integer(val=1):0:2:1',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('Not', '!'),
-        hl('Not', '!'),
-        hl('Number', '1'),
-      })
-
-      check_parsing('!1', {
-        --           01
-        ast = {
-          {
-            'Not:0:0:!',
-            children = {
-              'Integer(val=1):0:1:1',
-            },
-          },
-        },
-      }, {
-        hl('Not', '!'),
-        hl('Number', '1'),
-      })
-
-      check_parsing('(!1)', {
-        --           0123
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'Not:0:1:!',
-                children = {
-                  'Integer(val=1):0:2:1',
-                },
-              },
-            },
-          },
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Not', '!'),
-        hl('Number', '1'),
-        hl('NestingParenthesis', ')'),
-      })
-
-      check_parsing('(!)', {
-        --           012
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'Not:0:1:!',
-                children = {
-                  'Missing:0:2:',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = ')',
-          msg = 'E15: Expected value, got parenthesis: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Not', '!'),
-        hl('InvalidNestingParenthesis', ')'),
-      })
-
-      check_parsing('(1!2)', {
-        --           01234
-        ast = {
-          {
-            'Nested:0:0:(',
-            children = {
-              {
-                'OpMissing:0:2:',
-                children = {
-                  'Integer(val=1):0:1:1',
-                  {
-                    'Not:0:2:!',
-                    children = {
-                      'Integer(val=2):0:3:2',
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '!2)',
-          msg = 'E15: Missing operator: %.*s',
-        },
-      }, {
-        hl('NestingParenthesis', '('),
-        hl('Number', '1'),
-        hl('InvalidNot', '!'),
-        hl('Number', '2'),
-        hl('NestingParenthesis', ')'),
-      })
-
-      check_parsing('1!2', {
-        --           012
-        ast = {
-          {
-            'OpMissing:0:1:',
-            children = {
-              'Integer(val=1):0:0:1',
-              {
-                'Not:0:1:!',
-                children = {
-                  'Integer(val=2):0:2:2',
-                },
-              },
-            },
-          },
-        },
-        err = {
-          arg = '!2',
-          msg = 'E15: Missing operator: %.*s',
-        },
-      }, {
-        hl('Number', '1'),
-        hl('InvalidNot', '!'),
-        hl('Number', '2'),
-      }, {
-        [1] = {
-          ast = {
-            len = 1,
-            err = REMOVE_THIS,
-            ast = {
-              'Integer(val=1):0:0:1',
-            },
-          },
-          hl_fs = {
-            [2] = REMOVE_THIS,
-            [3] = REMOVE_THIS,
-          },
-        },
-      })
-    end)
-    it('highlights numbers with prefix', function()
-      check_parsing('0xABCDEF', {
-        --           01234567
-        ast = {
-          'Integer(val=11259375):0:0:0xABCDEF',
-        },
-      }, {
-        hl('NumberPrefix', '0x'),
-        hl('Number', 'ABCDEF'),
-      })
-
-      check_parsing('0Xabcdef', {
-        --           01234567
-        ast = {
-          'Integer(val=11259375):0:0:0Xabcdef',
-        },
-      }, {
-        hl('NumberPrefix', '0X'),
-        hl('Number', 'abcdef'),
-      })
-
-      check_parsing('0XABCDEF', {
-        --           01234567
-        ast = {
-          'Integer(val=11259375):0:0:0XABCDEF',
-        },
-      }, {
-        hl('NumberPrefix', '0X'),
-        hl('Number', 'ABCDEF'),
-      })
-
-      check_parsing('0xabcdef', {
-        --           01234567
-        ast = {
-          'Integer(val=11259375):0:0:0xabcdef',
-        },
-      }, {
-        hl('NumberPrefix', '0x'),
-        hl('Number', 'abcdef'),
-      })
-
-      check_parsing('0b001', {
-        --           01234
-        ast = {
-          'Integer(val=1):0:0:0b001',
-        },
-      }, {
-        hl('NumberPrefix', '0b'),
-        hl('Number', '001'),
-      })
-
-      check_parsing('0B001', {
-        --           01234
-        ast = {
-          'Integer(val=1):0:0:0B001',
-        },
-      }, {
-        hl('NumberPrefix', '0B'),
-        hl('Number', '001'),
-      })
-
-      check_parsing('0B00', {
-        --           0123
-        ast = {
-          'Integer(val=0):0:0:0B00',
-        },
-      }, {
-        hl('NumberPrefix', '0B'),
-        hl('Number', '00'),
-      })
-
-      check_parsing('00', {
-        --           01
-        ast = {
-          'Integer(val=0):0:0:00',
-        },
-      }, {
-        hl('NumberPrefix', '0'),
-        hl('Number', '0'),
-      })
-
-      check_parsing('001', {
-        --           012
-        ast = {
-          'Integer(val=1):0:0:001',
-        },
-      }, {
-        hl('NumberPrefix', '0'),
-        hl('Number', '01'),
-      })
-
-      check_parsing('01', {
-        --           01
-        ast = {
-          'Integer(val=1):0:0:01',
-        },
-      }, {
-        hl('NumberPrefix', '0'),
-        hl('Number', '1'),
-      })
-
-      check_parsing('1', {
-        --           0
-        ast = {
-          'Integer(val=1):0:0:1',
-        },
-      }, {
-        hl('Number', '1'),
-      })
-    end)
-    it('errors out on unknown flags', function()
-      eq({false, 'Invalid flag: \'F\' (70)'},
-         meth_pcall(meths.parse_expression, '', 'F', true))
-      eq({false, 'Invalid flag: \'\\0\' (0)'},
-         meth_pcall(meths.parse_expression, '', '\0', true))
-      eq({false, 'Invalid flag: \'\1\' (1)'},
-         meth_pcall(meths.parse_expression, '', 'm\1E', true))
-    end)
-    it('respects highlight argument', function()
-      eq({
-        len = 1,
-        ast = {
-          ivalue = 1,
-          len = 1,
-          start = {0, 0},
-          type = 'Integer'
-        },
-      }, meths.parse_expression('1', '', false))
-      eq({
-        len = 1,
-        ast = {
-          ivalue = 1,
-          len = 1,
-          start = {0, 0},
-          type = 'Integer'
-        },
-        highlight = {
-          {0, 0, 1, 'NVimNumber'}
-        },
-      }, meths.parse_expression('1', '', true))
-    end)
-    it('works (KLEE tests)', function()
-      check_parsing('\0002&A:\000', {
-        ast = {},
-        len = 0,
-        err = {
-          arg = '\0002&A:\0',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-      }, {
-        [2] = {
-          ast = {
-            len = REMOVE_THIS,
-            ast = {
-              {
-                'Colon:0:4::',
-                children = {
-                  {
-                    'OpMissing:0:2:',
-                    children = {
-                      'Integer(val=2):0:1:2',
-                      'Option(scope=0,ident=A):0:2:&A',
-                    },
-                  },
-                },
-              },
-            },
-            err = {
-              msg = 'E15: Unexpected EOC character: %.*s',
-            },
-          },
-          hl_fs = {
-            hl('InvalidSpacing', '\0'),
-            hl('Number', '2'),
-            hl('InvalidOptionSigil', '&'),
-            hl('InvalidOptionName', 'A'),
-            hl('InvalidColon', ':'),
-            hl('InvalidSpacing', '\0'),
-          },
-        },
-        [3] = {
-          ast = {
-            len = 2,
-            ast = {
-              'Integer(val=2):0:1:2',
-            },
-            err = {
-              msg = 'E15: Unexpected EOC character: %.*s',
-            },
-          },
-          hl_fs = {
-            hl('InvalidSpacing', '\0'),
-            hl('Number', '2'),
-          },
-        },
-      })
-      check_parsing('"\\U\\', {
-        --           0123
-        ast = {
-          [[DoubleQuotedString(val="U\\"):0:0:"\U\]],
-        },
-        err = {
-          arg = '"\\U\\',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
-        hl('InvalidDoubleQuotedBody', '\\'),
-      })
-      check_parsing('"\\U', {
-        --           012
-        ast = {
-          'DoubleQuotedString(val="U"):0:0:"\\U',
-        },
-        err = {
-          arg = '"\\U',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
-      })
-      check_parsing('|"\\U\\', {
-        --           01234
-        ast = {},
-        len = 0,
-        err = {
-          arg = '|"\\U\\',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-      }, {
-        [2] = {
-          ast = {
-            len = REMOVE_THIS,
-            ast = {
-              {
-                'Or:0:0:|',
-                children = {
-                  'Missing:0:0:',
-                  'DoubleQuotedString(val="U\\\\"):0:1:"\\U\\',
-                },
-              },
-            },
-            err = {
-              msg = 'E15: Unexpected EOC character: %.*s',
-            },
-          },
-          hl_fs = {
-            hl('InvalidOr', '|'),
-            hl('InvalidDoubleQuote', '"'),
-            hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
-            hl('InvalidDoubleQuotedBody', '\\'),
-          },
-        },
-      })
-      check_parsing('|"\\e"', {
-        --           01234
-        ast = {},
-        len = 0,
-        err = {
-          arg = '|"\\e"',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-      }, {
-        [2] = {
-          ast = {
-            len = REMOVE_THIS,
-            ast = {
-              {
-                'Or:0:0:|',
-                children = {
-                  'Missing:0:0:',
-                  'DoubleQuotedString(val="\\27"):0:1:"\\e"',
-                },
-              },
-            },
-            err = {
-              msg = 'E15: Unexpected EOC character: %.*s',
-            },
-          },
-          hl_fs = {
-            hl('InvalidOr', '|'),
-            hl('DoubleQuote', '"'),
-            hl('DoubleQuotedEscape', '\\e'),
-            hl('DoubleQuote', '"'),
-          },
-        },
-      })
-      check_parsing('|\029', {
-        --           01
-        ast = {},
-        len = 0,
-        err = {
-          arg = '|\029',
-          msg = 'E15: Expected value, got EOC: %.*s',
-        },
-      }, {
-      }, {
-        [2] = {
-          ast = {
-            len = REMOVE_THIS,
-            ast = {
-              {
-                'Or:0:0:|',
-                children = {
-                  'Missing:0:0:',
-                  'PlainIdentifier(scope=0,ident=\029):0:1:\029',
-                },
-              },
-            },
-            err = {
-              msg = 'E15: Unexpected EOC character: %.*s',
-            },
-          },
-          hl_fs = {
-            hl('InvalidOr', '|'),
-            hl('InvalidIdentifierName', '\029'),
-          },
-        },
-      })
-      check_parsing('"\\<', {
-        --           012
-        ast = {
-          'DoubleQuotedString(val="<"):0:0:"\\<',
-        },
-        err = {
-          arg = '"\\<',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedUnknownEscape', '\\<'),
-      })
-      check_parsing('"\\1', {
-        --           012
-        ast = {
-          'DoubleQuotedString(val="\\1"):0:0:"\\1',
-        },
-        err = {
-          arg = '"\\1',
-          msg = 'E114: Missing double quote: %.*s',
-        },
-      }, {
-        hl('InvalidDoubleQuote', '"'),
-        hl('InvalidDoubleQuotedEscape', '\\1'),
-      })
-      check_parsing('}l', {
-        --           01
-        ast = {
-          {
-            'OpMissing:0:1:',
-            children = {
-              'UnknownFigure:0:0:',
-              'PlainIdentifier(scope=0,ident=l):0:1:l',
-            },
-          },
-        },
-        err = {
-          arg = '}l',
-          msg = 'E15: Unexpected closing figure brace: %.*s',
-        },
-      }, {
-        hl('InvalidFigureBrace', '}'),
-        hl('InvalidIdentifierName', 'l'),
-      }, {
-        [1] = {
-          ast = {
-            len = 1,
-            ast = {
-              'UnknownFigure:0:0:',
-            },
-          },
-          hl_fs = {
-            [2] = REMOVE_THIS,
-          },
-        },
-      })
-      check_parsing(':?\000\000\000\000\000\000\000', {
-        ast = {
-          {
-            'Colon:0:0::',
-            children = {
-              'Missing:0:0:',
-              {
-                'Ternary:0:1:?',
-                children = {
-                  'Missing:0:1:',
-                  'TernaryValue:0:1:?',
-                },
-              },
-            },
-          },
-        },
-        len = 2,
-        err = {
-          arg = ':?\000\000\000\000\000\000\000',
-          msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-        },
-      }, {
-        hl('InvalidColon', ':'),
-        hl('InvalidTernary', '?'),
-      }, {
-        [2] = {
-          ast = {
-            len = REMOVE_THIS,
-          },
-          hl_fs = {
-            [3] = hl('InvalidSpacing', '\0'),
-            [4] = hl('InvalidSpacing', '\0'),
-            [5] = hl('InvalidSpacing', '\0'),
-            [6] = hl('InvalidSpacing', '\0'),
-            [7] = hl('InvalidSpacing', '\0'),
-            [8] = hl('InvalidSpacing', '\0'),
-            [9] = hl('InvalidSpacing', '\0'),
-          },
-        },
-      })
-    end)
+    local function fmtn(typ, args, rest)
+      if (typ == 'UnknownFigure'
+          or typ == 'DictLiteral'
+          or typ == 'CurlyBracesIdentifier'
+          or typ == 'Lambda') then
+        return ('%s%s'):format(typ, rest)
+      elseif typ == 'DoubleQuotedString' or typ == 'SingleQuotedString' then
+        if args:sub(-4) == 'NULL' then
+          args = args:sub(1, -5) .. '""'
+        end
+        return ('%s(%s)%s'):format(typ, args, rest)
+      end
+    end
+    assert:set_parameter('TableFormatLevel', 1000000)
+    require('test.unit.viml.expressions.parser_tests')(
+        it, _check_parsing, hl, fmtn)
   end)
 
 end)
diff --git a/test/unit/viml/expressions/parser_spec.lua b/test/unit/viml/expressions/parser_spec.lua
index eca76aa9cd..24f681f438 100644
--- a/test/unit/viml/expressions/parser_spec.lua
+++ b/test/unit/viml/expressions/parser_spec.lua
@@ -226,6 +226,9 @@ local function format_check(expr, format_check_data, opts)
   if #expr > 10 then
     print(digits2)
   end
+  if zdata.ast.len then
+    print(('  len = %u,'):format(zdata.ast.len))
+  end
   print('  ast = ' .. format_luav(zdata.ast.ast, '  ') .. ',')
   if zdata.ast.err then
     print('  err = {')
@@ -414,14 +417,21 @@ eastnodelist2lua = function(pstate, eastnode, checked_nodes)
   return ret
 end
 
-local function east2lua(pstate, east)
+local function east2lua(str, pstate, east)
   local checked_nodes = {}
+  local len = tonumber(pstate.pos.col)
+  if pstate.pos.line == 1 then
+    len = tonumber(pstate.reader.lines.items[0].size)
+  end
+  if type(str) == 'string' and len == #str then
+    len = nil
+  end
   return {
     err = east.err.msg ~= nil and {
       msg = ffi.string(east.err.msg),
-      arg = ('%s'):format(
-        ffi.string(east.err.arg, east.err.arg_len)),
+      arg = ffi.string(east.err.arg, east.err.arg_len),
     } or nil,
+    len = len,
     ast = eastnodelist2lua(pstate, east.root, checked_nodes),
   }
 end
@@ -463,7 +473,7 @@ describe('Expressions parser', function()
 
         local pstate = new_pstate({str})
         local east = lib.viml_pexpr_parse(pstate, flags)
-        local ast = east2lua(pstate, east)
+        local ast = east2lua(str, pstate, east)
         local hls = phl2lua(pstate)
         if exp_ast == nil then
           format_check_data[flags] = {ast=ast, hl_fs=hls_to_hl_fs(hls)}
@@ -509,15 +519,6 @@ describe('Expressions parser', function()
       format_check(str, format_check_data, opts)
     end
   end
-  local function check_parsing(...)
-    return _check_parsing({flags={0, 1, 2, 3}, funcname='check_parsing'}, ...)
-  end
-  local function check_asgn_parsing(...)
-    return _check_parsing({
-      flags={4, 5, 6, 7},
-      funcname='check_asgn_parsing',
-    }, ...)
-  end
   local function hl(group, str, shift)
     return function(next_col)
       if nvim_hl_defs['NVim' .. group] == nil then
@@ -531,8152 +532,9 @@ describe('Expressions parser', function()
         str)), (col + #str)
     end
   end
-  itp('works with + and @a', function()
-    check_parsing('@a', {
-      ast = {
-        'Register(name=a):0:0:@a',
-      },
-    }, {
-      hl('Register', '@a'),
-    })
-    check_parsing('+@a', {
-      ast = {
-        {
-          'UnaryPlus:0:0:+',
-          children = {
-            'Register(name=a):0:1:@a',
-          },
-        },
-      },
-    }, {
-      hl('UnaryPlus', '+'),
-      hl('Register', '@a'),
-    })
-    check_parsing('@a+@b', {
-      ast = {
-        {
-          'BinaryPlus:0:2:+',
-          children = {
-            'Register(name=a):0:0:@a',
-            'Register(name=b):0:3:@b',
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-      hl('Register', '@b'),
-    })
-    check_parsing('@a+@b+@c', {
-      ast = {
-        {
-          'BinaryPlus:0:5:+',
-          children = {
-            {
-              'BinaryPlus:0:2:+',
-              children = {
-                'Register(name=a):0:0:@a',
-                'Register(name=b):0:3:@b',
-              },
-            },
-            'Register(name=c):0:6:@c',
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-      hl('Register', '@b'),
-      hl('BinaryPlus', '+'),
-      hl('Register', '@c'),
-    })
-    check_parsing('+@a+@b', {
-      ast = {
-        {
-          'BinaryPlus:0:3:+',
-          children = {
-            {
-              'UnaryPlus:0:0:+',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-            'Register(name=b):0:4:@b',
-          },
-        },
-      },
-    }, {
-      hl('UnaryPlus', '+'),
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-      hl('Register', '@b'),
-    })
-    check_parsing('+@a++@b', {
-      ast = {
-        {
-          'BinaryPlus:0:3:+',
-          children = {
-            {
-              'UnaryPlus:0:0:+',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-            {
-              'UnaryPlus:0:4:+',
-              children = {
-                'Register(name=b):0:5:@b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('UnaryPlus', '+'),
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-      hl('UnaryPlus', '+'),
-      hl('Register', '@b'),
-    })
-    check_parsing('@a@b', {
-      ast = {
-        {
-          'OpMissing:0:2:',
-          children = {
-            'Register(name=a):0:0:@a',
-            'Register(name=b):0:2:@b',
-          },
-        },
-      },
-      err = {
-        arg = '@b',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('InvalidRegister', '@b'),
-    }, {
-      [1] = {
-        ast = {
-          err = REMOVE_THIS,
-          ast = {
-            'Register(name=a):0:0:@a'
-          },
-        },
-        hl_fs = {
-          [2] = REMOVE_THIS,
-        },
-      },
-    })
-    check_parsing(' @a \t @b', {
-      ast = {
-        {
-          'OpMissing:0:3:',
-          children = {
-            'Register(name=a):0:0: @a',
-            'Register(name=b):0:3: \t @b',
-          },
-        },
-      },
-      err = {
-        arg = '@b',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('Register', '@a', 1),
-      hl('InvalidSpacing', ' \t '),
-      hl('Register', '@b'),
-    }, {
-      [1] = {
-        ast = {
-          err = REMOVE_THIS,
-          ast = {
-            'Register(name=a):0:0: @a'
-          },
-        },
-        hl_fs = {
-          [2] = REMOVE_THIS,
-          [3] = REMOVE_THIS,
-        },
-      },
-    })
-    check_parsing('+', {
-      ast = {
-        'UnaryPlus:0:0:+',
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('UnaryPlus', '+'),
-    })
-    check_parsing(' +', {
-      ast = {
-        'UnaryPlus:0:0: +',
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('UnaryPlus', '+', 1),
-    })
-    check_parsing('@a+  ', {
-      ast = {
-        {
-          'BinaryPlus:0:2:+',
-          children = {
-            'Register(name=a):0:0:@a',
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-    })
-  end)
-  itp('works with @a, + and parenthesis', function()
-    check_parsing('(@a)', {
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            'Register(name=a):0:1:@a',
-          },
-        },
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Register', '@a'),
-      hl('NestingParenthesis', ')'),
-    })
-    check_parsing('()', {
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            'Missing:0:1:',
-          },
-        },
-      },
-      err = {
-        arg = ')',
-        msg = 'E15: Expected value, got parenthesis: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('InvalidNestingParenthesis', ')'),
-    })
-    check_parsing(')', {
-      ast = {
-        {
-          'Nested:0:0:',
-          children = {
-            'Missing:0:0:',
-          },
-        },
-      },
-      err = {
-        arg = ')',
-        msg = 'E15: Expected value, got parenthesis: %.*s',
-      },
-    }, {
-      hl('InvalidNestingParenthesis', ')'),
-    })
-    check_parsing('+)', {
-      ast = {
-        {
-          'Nested:0:1:',
-          children = {
-            {
-              'UnaryPlus:0:0:+',
-              children = {
-                'Missing:0:1:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ')',
-        msg = 'E15: Expected value, got parenthesis: %.*s',
-      },
-    }, {
-      hl('UnaryPlus', '+'),
-      hl('InvalidNestingParenthesis', ')'),
-    })
-    check_parsing('+@a(@b)', {
-      ast = {
-        {
-          'UnaryPlus:0:0:+',
-          children = {
-            {
-              'Call:0:3:(',
-              children = {
-                'Register(name=a):0:1:@a',
-                'Register(name=b):0:4:@b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('UnaryPlus', '+'),
-      hl('Register', '@a'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@b'),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('@a+@b(@c)', {
-      ast = {
-        {
-          'BinaryPlus:0:2:+',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Call:0:5:(',
-              children = {
-                'Register(name=b):0:3:@b',
-                'Register(name=c):0:6:@c',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-      hl('Register', '@b'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@c'),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('@a()', {
-      ast = {
-        {
-          'Call:0:2:(',
-          children = {
-            'Register(name=a):0:0:@a',
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('CallingParenthesis', '('),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('@a ()', {
-      ast = {
-        {
-          'OpMissing:0:2:',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Nested:0:2: (',
-              children = {
-                'Missing:0:4:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '()',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('InvalidSpacing', ' '),
-      hl('NestingParenthesis', '('),
-      hl('InvalidNestingParenthesis', ')'),
-    }, {
-      [1] = {
-        ast = {
-          err = REMOVE_THIS,
-          ast = {
-            'Register(name=a):0:0:@a',
-          },
-        },
-        hl_fs = {
-          [2] = REMOVE_THIS,
-          [3] = REMOVE_THIS,
-          [4] = REMOVE_THIS,
-        },
-      },
-    })
-    check_parsing('@a + (@b)', {
-      ast = {
-        {
-          'BinaryPlus:0:2: +',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Nested:0:4: (',
-              children = {
-                'Register(name=b):0:6:@b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+', 1),
-      hl('NestingParenthesis', '(', 1),
-      hl('Register', '@b'),
-      hl('NestingParenthesis', ')'),
-    })
-    check_parsing('@a + (+@b)', {
-      ast = {
-        {
-          'BinaryPlus:0:2: +',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Nested:0:4: (',
-              children = {
-                {
-                  'UnaryPlus:0:6:+',
-                  children = {
-                    'Register(name=b):0:7:@b',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+', 1),
-      hl('NestingParenthesis', '(', 1),
-      hl('UnaryPlus', '+'),
-      hl('Register', '@b'),
-      hl('NestingParenthesis', ')'),
-    })
-    check_parsing('@a + (@b + @c)', {
-      ast = {
-        {
-          'BinaryPlus:0:2: +',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Nested:0:4: (',
-              children = {
-                {
-                  'BinaryPlus:0:8: +',
-                  children = {
-                    'Register(name=b):0:6:@b',
-                    'Register(name=c):0:10: @c',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+', 1),
-      hl('NestingParenthesis', '(', 1),
-      hl('Register', '@b'),
-      hl('BinaryPlus', '+', 1),
-      hl('Register', '@c', 1),
-      hl('NestingParenthesis', ')'),
-    })
-    check_parsing('(@a)+@b', {
-      ast = {
-        {
-          'BinaryPlus:0:4:+',
-          children = {
-            {
-              'Nested:0:0:(',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-            'Register(name=b):0:5:@b',
-          },
-        },
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Register', '@a'),
-      hl('NestingParenthesis', ')'),
-      hl('BinaryPlus', '+'),
-      hl('Register', '@b'),
-    })
-    check_parsing('@a+(@b)(@c)', {
-      --           01234567890
-      ast = {
-        {
-          'BinaryPlus:0:2:+',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Call:0:7:(',
-              children = {
-                {
-                  'Nested:0:3:(',
-                  children = { 'Register(name=b):0:4:@b' },
-                },
-                'Register(name=c):0:8:@c',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-      hl('NestingParenthesis', '('),
-      hl('Register', '@b'),
-      hl('NestingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@c'),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('@a+((@b))(@c)', {
-      --           01234567890123456890123456789
-      --           0         1        2
-      ast = {
-        {
-          'BinaryPlus:0:2:+',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Call:0:9:(',
-              children = {
-                {
-                  'Nested:0:3:(',
-                  children = {
-                    {
-                      'Nested:0:4:(',
-                      children = { 'Register(name=b):0:5:@b' }
-                    },
-                  },
-                },
-                'Register(name=c):0:10:@c',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-      hl('NestingParenthesis', '('),
-      hl('NestingParenthesis', '('),
-      hl('Register', '@b'),
-      hl('NestingParenthesis', ')'),
-      hl('NestingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@c'),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('@a+((@b))+@c', {
-      --           01234567890123456890123456789
-      --           0         1        2
-      ast = {
-        {
-          'BinaryPlus:0:9:+',
-          children = {
-            {
-              'BinaryPlus:0:2:+',
-              children = {
-                'Register(name=a):0:0:@a',
-                {
-                  'Nested:0:3:(',
-                  children = {
-                    {
-                      'Nested:0:4:(',
-                      children = { 'Register(name=b):0:5:@b' }
-                    },
-                  },
-                },
-              },
-            },
-            'Register(name=c):0:10:@c',
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-      hl('NestingParenthesis', '('),
-      hl('NestingParenthesis', '('),
-      hl('Register', '@b'),
-      hl('NestingParenthesis', ')'),
-      hl('NestingParenthesis', ')'),
-      hl('BinaryPlus', '+'),
-      hl('Register', '@c'),
-    })
-    check_parsing(
-      '@a + (@b + @c) + @d(@e) + (+@f) + ((+@g(@h))(@j)(@k))(@l)', {--[[
-       | | | | | |   | |  ||  | | ||  | | ||| ||   ||  ||   ||
-       000000000011111111112222222222333333333344444444445555555
-       012345678901234567890123456789012345678901234567890123456
-      ]]
-        ast = {{
-          'BinaryPlus:0:31: +',
-          children = {
-            {
-              'BinaryPlus:0:23: +',
-              children = {
-                {
-                  'BinaryPlus:0:14: +',
-                  children = {
-                    {
-                      'BinaryPlus:0:2: +',
-                      children = {
-                        'Register(name=a):0:0:@a',
-                        {
-                          'Nested:0:4: (',
-                          children = {
-                            {
-                              'BinaryPlus:0:8: +',
-                              children = {
-                                'Register(name=b):0:6:@b',
-                                'Register(name=c):0:10: @c',
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                    {
-                      'Call:0:19:(',
-                      children = {
-                        'Register(name=d):0:16: @d',
-                        'Register(name=e):0:20:@e',
-                      },
-                    },
-                  },
-                },
-                {
-                  'Nested:0:25: (',
-                  children = {
-                    {
-                      'UnaryPlus:0:27:+',
-                      children = {
-                        'Register(name=f):0:28:@f',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-            {
-              'Call:0:53:(',
-              children = {
-                {
-                  'Nested:0:33: (',
-                  children = {
-                    {
-                      'Call:0:48:(',
-                      children = {
-                        {
-                          'Call:0:44:(',
-                          children = {
-                            {
-                              'Nested:0:35:(',
-                              children = {
-                                {
-                                  'UnaryPlus:0:36:+',
-                                  children = {
-                                    {
-                                      'Call:0:39:(',
-                                      children = {
-                                        'Register(name=g):0:37:@g',
-                                        'Register(name=h):0:40:@h',
-                                      },
-                                    },
-                                  },
-                                },
-                              },
-                            },
-                            'Register(name=j):0:45:@j',
-                          },
-                        },
-                        'Register(name=k):0:49:@k',
-                      },
-                    },
-                  },
-                },
-                'Register(name=l):0:54:@l',
-              },
-            },
-          },
-        }},
-      }, {
-        hl('Register', '@a'),
-        hl('BinaryPlus', '+', 1),
-        hl('NestingParenthesis', '(', 1),
-        hl('Register', '@b'),
-        hl('BinaryPlus', '+', 1),
-        hl('Register', '@c', 1),
-        hl('NestingParenthesis', ')'),
-        hl('BinaryPlus', '+', 1),
-        hl('Register', '@d', 1),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@e'),
-        hl('CallingParenthesis', ')'),
-        hl('BinaryPlus', '+', 1),
-        hl('NestingParenthesis', '(', 1),
-        hl('UnaryPlus', '+'),
-        hl('Register', '@f'),
-        hl('NestingParenthesis', ')'),
-        hl('BinaryPlus', '+', 1),
-        hl('NestingParenthesis', '(', 1),
-        hl('NestingParenthesis', '('),
-        hl('UnaryPlus', '+'),
-        hl('Register', '@g'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@h'),
-        hl('CallingParenthesis', ')'),
-        hl('NestingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@j'),
-        hl('CallingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@k'),
-        hl('CallingParenthesis', ')'),
-        hl('NestingParenthesis', ')'),
-        hl('CallingParenthesis', '('),
-        hl('Register', '@l'),
-        hl('CallingParenthesis', ')'),
-      })
-    check_parsing('@a)', {
-      --           012
-      ast = {
-        {
-          'Nested:0:2:',
-          children = {
-            'Register(name=a):0:0:@a',
-          },
-        },
-      },
-      err = {
-        arg = ')',
-        msg = 'E15: Unexpected closing parenthesis: %.*s',
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('InvalidNestingParenthesis', ')'),
-    })
-    check_parsing('(@a', {
-      --           012
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            'Register(name=a):0:1:@a',
-          },
-        },
-      },
-      err = {
-        arg = '(@a',
-        msg = 'E110: Missing closing parenthesis for nested expression: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Register', '@a'),
-    })
-    check_parsing('@a(@b', {
-      --           01234
-      ast = {
-        {
-          'Call:0:2:(',
-          children = {
-            'Register(name=a):0:0:@a',
-            'Register(name=b):0:3:@b',
-          },
-        },
-      },
-      err = {
-        arg = '(@b',
-        msg = 'E116: Missing closing parenthesis for function call: %.*s',
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@b'),
-    })
-    check_parsing('@a(@b, @c, @d, @e)', {
-      --           012345678901234567
-      --           0         1
-      ast = {
-        {
-          'Call:0:2:(',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Comma:0:5:,',
-              children = {
-                'Register(name=b):0:3:@b',
-                {
-                  'Comma:0:9:,',
-                  children = {
-                    'Register(name=c):0:6: @c',
-                    {
-                      'Comma:0:13:,',
-                      children = {
-                        'Register(name=d):0:10: @d',
-                        'Register(name=e):0:14: @e',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@b'),
-      hl('Comma', ','),
-      hl('Register', '@c', 1),
-      hl('Comma', ','),
-      hl('Register', '@d', 1),
-      hl('Comma', ','),
-      hl('Register', '@e', 1),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('@a(@b(@c))', {
-      --           01234567890123456789012345678901234567
-      --           0         1         2         3
-      ast = {
-        {
-          'Call:0:2:(',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Call:0:5:(',
-              children = {
-                'Register(name=b):0:3:@b',
-                'Register(name=c):0:6:@c',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@b'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@c'),
-      hl('CallingParenthesis', ')'),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('@a(@b(@c(@d(@e), @f(@g(@h), @i(@j)))))', {
-      --           01234567890123456789012345678901234567
-      --           0         1         2         3
-      ast = {
-        {
-          'Call:0:2:(',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'Call:0:5:(',
-              children = {
-                'Register(name=b):0:3:@b',
-                {
-                  'Call:0:8:(',
-                  children = {
-                    'Register(name=c):0:6:@c',
-                    {
-                      'Comma:0:15:,',
-                      children = {
-                        {
-                          'Call:0:11:(',
-                          children = {
-                            'Register(name=d):0:9:@d',
-                            'Register(name=e):0:12:@e',
-                          },
-                        },
-                        {
-                          'Call:0:19:(',
-                          children = {
-                            'Register(name=f):0:16: @f',
-                            {
-                              'Comma:0:26:,',
-                              children = {
-                                {
-                                  'Call:0:22:(',
-                                  children = {
-                                    'Register(name=g):0:20:@g',
-                                    'Register(name=h):0:23:@h',
-                                  },
-                                },
-                                {
-                                  'Call:0:30:(',
-                                  children = {
-                                    'Register(name=i):0:27: @i',
-                                    'Register(name=j):0:31:@j',
-                                  },
-                                },
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@b'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@c'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@d'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@e'),
-      hl('CallingParenthesis', ')'),
-      hl('Comma', ','),
-      hl('Register', '@f', 1),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@g'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@h'),
-      hl('CallingParenthesis', ')'),
-      hl('Comma', ','),
-      hl('Register', '@i', 1),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@j'),
-      hl('CallingParenthesis', ')'),
-      hl('CallingParenthesis', ')'),
-      hl('CallingParenthesis', ')'),
-      hl('CallingParenthesis', ')'),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('()()', {
-      --           0123
-      ast = {
-        {
-          'Call:0:2:(',
-          children = {
-            {
-              'Nested:0:0:(',
-              children = {
-                'Missing:0:1:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ')()',
-        msg = 'E15: Expected value, got parenthesis: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('InvalidNestingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('(@a)()', {
-      --           012345
-      ast = {
-        {
-          'Call:0:4:(',
-          children = {
-            {
-              'Nested:0:0:(',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Register', '@a'),
-      hl('NestingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('(@a)(@b)', {
-      --           01234567
-      ast = {
-        {
-          'Call:0:4:(',
-          children = {
-            {
-              'Nested:0:0:(',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-            'Register(name=b):0:5:@b',
-          },
-        },
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Register', '@a'),
-      hl('NestingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@b'),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('(@a) (@b)', {
-      --           012345678
-      ast = {
-        {
-          'OpMissing:0:4:',
-          children = {
-            {
-              'Nested:0:0:(',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-            {
-              'Nested:0:4: (',
-              children = {
-                'Register(name=b):0:6:@b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '(@b)',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Register', '@a'),
-      hl('NestingParenthesis', ')'),
-      hl('InvalidSpacing', ' '),
-      hl('NestingParenthesis', '('),
-      hl('Register', '@b'),
-      hl('NestingParenthesis', ')'),
-    }, {
-      [1] = {
-        ast = {
-          ast = {
-            {
-              'Nested:0:0:(',
-              children = {
-                'Register(name=a):0:1:@a',
-                REMOVE_THIS,
-              },
-            },
-          },
-          err = REMOVE_THIS,
-        },
-        hl_fs = {
-          [4] = REMOVE_THIS,
-          [5] = REMOVE_THIS,
-          [6] = REMOVE_THIS,
-          [7] = REMOVE_THIS,
-        },
-      },
-    })
-  end)
-  itp('works with variable names, including curly braces ones', function()
-    check_parsing('var', {
-        ast = {
-          'PlainIdentifier(scope=0,ident=var):0:0:var',
-        },
-    }, {
-      hl('IdentifierName', 'var'),
-    })
-    check_parsing('g:var', {
-        ast = {
-          'PlainIdentifier(scope=g,ident=var):0:0:g:var',
-        },
-    }, {
-      hl('IdentifierScope', 'g'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('IdentifierName', 'var'),
-    })
-    check_parsing('g:', {
-        ast = {
-          'PlainIdentifier(scope=g,ident=):0:0:g:',
-        },
-    }, {
-      hl('IdentifierScope', 'g'),
-      hl('IdentifierScopeDelimiter', ':'),
-    })
-    check_parsing('{a}', {
-      --           012
-      ast = {
-        {
-          'CurlyBracesIdentifier(-di):0:0:{',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:1:a',
-          },
-        },
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Curly', '}'),
-    })
-    check_parsing('{a:b}', {
-      --           012
-      ast = {
-        {
-          'CurlyBracesIdentifier(-di):0:0:{',
-          children = {
-            'PlainIdentifier(scope=a,ident=b):0:1:a:b',
-          },
-        },
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('IdentifierScope', 'a'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '}'),
-    })
-    check_parsing('{a:@b}', {
-      --           012345
-      ast = {
-        {
-          'CurlyBracesIdentifier(-di):0:0:{',
-          children = {
-            {
-              'OpMissing:0:3:',
-              children={
-                'PlainIdentifier(scope=a,ident=):0:1:a:',
-                'Register(name=b):0:3:@b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '@b}',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('IdentifierScope', 'a'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('InvalidRegister', '@b'),
-      hl('Curly', '}'),
-    })
-    check_parsing('{@a}', {
-      ast = {
-        {
-          'CurlyBracesIdentifier(-di):0:0:{',
-          children = {
-            'Register(name=a):0:1:@a',
-          },
-        },
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('Register', '@a'),
-      hl('Curly', '}'),
-    })
-    check_parsing('{@a}{@b}', {
-      --           01234567
-      ast = {
-        {
-          'ComplexIdentifier:0:4:',
-          children = {
-            {
-              'CurlyBracesIdentifier(-di):0:0:{',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-            {
-              'CurlyBracesIdentifier(--i):0:4:{',
-              children = {
-                'Register(name=b):0:5:@b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('Register', '@a'),
-      hl('Curly', '}'),
-      hl('Curly', '{'),
-      hl('Register', '@b'),
-      hl('Curly', '}'),
-    })
-    check_parsing('g:{@a}', {
-      --           01234567
-      ast = {
-        {
-          'ComplexIdentifier:0:2:',
-          children = {
-            'PlainIdentifier(scope=g,ident=):0:0:g:',
-            {
-              'CurlyBracesIdentifier(--i):0:2:{',
-              children = {
-                'Register(name=a):0:3:@a',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierScope', 'g'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('Curly', '{'),
-      hl('Register', '@a'),
-      hl('Curly', '}'),
-    })
-    check_parsing('{@a}_test', {
-      --           012345678
-      ast = {
-        {
-          'ComplexIdentifier:0:4:',
-          children = {
-            {
-              'CurlyBracesIdentifier(-di):0:0:{',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-            'PlainIdentifier(scope=0,ident=_test):0:4:_test',
-          },
-        },
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('Register', '@a'),
-      hl('Curly', '}'),
-      hl('IdentifierName', '_test'),
-    })
-    check_parsing('g:{@a}_test', {
-      --           01234567890
-      ast = {
-        {
-          'ComplexIdentifier:0:2:',
-          children = {
-            'PlainIdentifier(scope=g,ident=):0:0:g:',
-            {
-              'ComplexIdentifier:0:6:',
-              children = {
-                {
-                  'CurlyBracesIdentifier(--i):0:2:{',
-                  children = {
-                    'Register(name=a):0:3:@a',
-                  },
-                },
-                'PlainIdentifier(scope=0,ident=_test):0:6:_test',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierScope', 'g'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('Curly', '{'),
-      hl('Register', '@a'),
-      hl('Curly', '}'),
-      hl('IdentifierName', '_test'),
-    })
-    check_parsing('g:{@a}_test()', {
-      --           0123456789012
-      ast = {
-        {
-          'Call:0:11:(',
-          children = {
-            {
-              'ComplexIdentifier:0:2:',
-              children = {
-                'PlainIdentifier(scope=g,ident=):0:0:g:',
-                {
-                  'ComplexIdentifier:0:6:',
-                  children = {
-                    {
-                      'CurlyBracesIdentifier(--i):0:2:{',
-                      children = {
-                        'Register(name=a):0:3:@a',
-                      },
-                    },
-                    'PlainIdentifier(scope=0,ident=_test):0:6:_test',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierScope', 'g'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('Curly', '{'),
-      hl('Register', '@a'),
-      hl('Curly', '}'),
-      hl('IdentifierName', '_test'),
-      hl('CallingParenthesis', '('),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('{@a} ()', {
-      --           0123456789012
-      ast = {
-        {
-          'Call:0:4: (',
-          children = {
-            {
-              'CurlyBracesIdentifier(-di):0:0:{',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('Register', '@a'),
-      hl('Curly', '}'),
-      hl('CallingParenthesis', '(', 1),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('g:{@a} ()', {
-      --           0123456789012
-      ast = {
-        {
-          'Call:0:6: (',
-          children = {
-            {
-              'ComplexIdentifier:0:2:',
-              children = {
-                'PlainIdentifier(scope=g,ident=):0:0:g:',
-                {
-                  'CurlyBracesIdentifier(--i):0:2:{',
-                  children = {
-                    'Register(name=a):0:3:@a',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierScope', 'g'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('Curly', '{'),
-      hl('Register', '@a'),
-      hl('Curly', '}'),
-      hl('CallingParenthesis', '(', 1),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('{@a', {
-      --           012
-      ast = {
-        {
-          'UnknownFigure(-di):0:0:{',
-          children = {
-            'Register(name=a):0:1:@a',
-          },
-        },
-      },
-      err = {
-        arg = '{@a',
-        msg = 'E15: Missing closing figure brace: %.*s',
-      },
-    }, {
-      hl('FigureBrace', '{'),
-      hl('Register', '@a'),
-    })
-    check_parsing('a ()', {
-      --           0123
-      ast = {
-        {
-          'Call:0:1: (',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('CallingParenthesis', '(', 1),
-      hl('CallingParenthesis', ')'),
-    })
-  end)
-  itp('works with lambdas and dictionaries', function()
-    check_parsing('{}', {
-      ast = {
-        'DictLiteral(-di):0:0:{',
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('Dict', '}'),
-    })
-    check_parsing('{->@a}', {
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Arrow:0:1:->',
-              children = {
-                'Register(name=a):0:3:@a',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('Arrow', '->'),
-      hl('Register', '@a'),
-      hl('Lambda', '}'),
-    })
-    check_parsing('{->@a+@b}', {
-      --           012345678
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Arrow:0:1:->',
-              children = {
-                {
-                  'BinaryPlus:0:5:+',
-                  children = {
-                    'Register(name=a):0:3:@a',
-                    'Register(name=b):0:6:@b',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('Arrow', '->'),
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+'),
-      hl('Register', '@b'),
-      hl('Lambda', '}'),
-    })
-    check_parsing('{a->@a}', {
-      --           012345678
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:1:a',
-            {
-              'Arrow:0:2:->',
-              children = {
-                'Register(name=a):0:4:@a',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Arrow', '->'),
-      hl('Register', '@a'),
-      hl('Lambda', '}'),
-    })
-    check_parsing('{a,b->@a}', {
-      --           012345678
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:3:b',
-              },
-            },
-            {
-              'Arrow:0:4:->',
-              children = {
-                'Register(name=a):0:6:@a',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-      hl('Arrow', '->'),
-      hl('Register', '@a'),
-      hl('Lambda', '}'),
-    })
-    check_parsing('{a,b,c->@a}', {
-      --           01234567890
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                {
-                  'Comma:0:4:,',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:3:b',
-                    'PlainIdentifier(scope=0,ident=c):0:5:c',
-                  },
-                },
-              },
-            },
-            {
-              'Arrow:0:6:->',
-              children = {
-                'Register(name=a):0:8:@a',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'c'),
-      hl('Arrow', '->'),
-      hl('Register', '@a'),
-      hl('Lambda', '}'),
-    })
-    check_parsing('{a,b,c,d->@a}', {
-      --           0123456789012
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                {
-                  'Comma:0:4:,',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:3:b',
-                    {
-                      'Comma:0:6:,',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=c):0:5:c',
-                        'PlainIdentifier(scope=0,ident=d):0:7:d',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-            {
-              'Arrow:0:8:->',
-              children = {
-                'Register(name=a):0:10:@a',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'c'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'd'),
-      hl('Arrow', '->'),
-      hl('Register', '@a'),
-      hl('Lambda', '}'),
-    })
-    check_parsing('{a,b,c,d,->@a}', {
-      --           01234567890123
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                {
-                  'Comma:0:4:,',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:3:b',
-                    {
-                      'Comma:0:6:,',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=c):0:5:c',
-                        {
-                          'Comma:0:8:,',
-                          children = {
-                            'PlainIdentifier(scope=0,ident=d):0:7:d',
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-            {
-              'Arrow:0:9:->',
-              children = {
-                'Register(name=a):0:11:@a',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'c'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'd'),
-      hl('Comma', ','),
-      hl('Arrow', '->'),
-      hl('Register', '@a'),
-      hl('Lambda', '}'),
-    })
-    check_parsing('{a,b->{c,d->{e,f->@a}}}', {
-      --           01234567890123456789012
-      --           0         1         2
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:3:b',
-              },
-            },
-            {
-              'Arrow:0:4:->',
-              children = {
-                {
-                  'Lambda(\\di):0:6:{',
-                  children = {
-                    {
-                      'Comma:0:8:,',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=c):0:7:c',
-                        'PlainIdentifier(scope=0,ident=d):0:9:d',
-                      },
-                    },
-                    {
-                      'Arrow:0:10:->',
-                      children = {
-                        {
-                          'Lambda(\\di):0:12:{',
-                          children = {
-                            {
-                              'Comma:0:14:,',
-                              children = {
-                                'PlainIdentifier(scope=0,ident=e):0:13:e',
-                                'PlainIdentifier(scope=0,ident=f):0:15:f',
-                              },
-                            },
-                            {
-                              'Arrow:0:16:->',
-                              children = {
-                                'Register(name=a):0:18:@a',
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-      hl('Arrow', '->'),
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'c'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'd'),
-      hl('Arrow', '->'),
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'e'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'f'),
-      hl('Arrow', '->'),
-      hl('Register', '@a'),
-      hl('Lambda', '}'),
-      hl('Lambda', '}'),
-      hl('Lambda', '}'),
-    })
-    check_parsing('{a,b->c,d}', {
-      --           0123456789
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:3:b',
-              },
-            },
-            {
-              'Arrow:0:4:->',
-              children = {
-                {
-                  'Comma:0:7:,',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=c):0:6:c',
-                    'PlainIdentifier(scope=0,ident=d):0:8:d',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ',d}',
-        msg = 'E15: Comma outside of call, lambda or literal: %.*s',
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-      hl('Arrow', '->'),
-      hl('IdentifierName', 'c'),
-      hl('InvalidComma', ','),
-      hl('IdentifierName', 'd'),
-      hl('Lambda', '}'),
-    })
-    check_parsing('a,b,c,d', {
-      --           0123456789
-      ast = {
-        {
-          'Comma:0:1:,',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'Comma:0:3:,',
-              children = {
-              'PlainIdentifier(scope=0,ident=b):0:2:b',
-                {
-                  'Comma:0:5:,',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=c):0:4:c',
-                    'PlainIdentifier(scope=0,ident=d):0:6:d',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ',b,c,d',
-        msg = 'E15: Comma outside of call, lambda or literal: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('InvalidComma', ','),
-      hl('IdentifierName', 'b'),
-      hl('InvalidComma', ','),
-      hl('IdentifierName', 'c'),
-      hl('InvalidComma', ','),
-      hl('IdentifierName', 'd'),
-    })
-    check_parsing('a,b,c,d,', {
-      --           0123456789
-      ast = {
-        {
-          'Comma:0:1:,',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'Comma:0:3:,',
-              children = {
-              'PlainIdentifier(scope=0,ident=b):0:2:b',
-                {
-                  'Comma:0:5:,',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=c):0:4:c',
-                    {
-                      'Comma:0:7:,',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=d):0:6:d',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ',b,c,d,',
-        msg = 'E15: Comma outside of call, lambda or literal: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('InvalidComma', ','),
-      hl('IdentifierName', 'b'),
-      hl('InvalidComma', ','),
-      hl('IdentifierName', 'c'),
-      hl('InvalidComma', ','),
-      hl('IdentifierName', 'd'),
-      hl('InvalidComma', ','),
-    })
-    check_parsing(',', {
-      --           0123456789
-      ast = {
-        {
-          'Comma:0:0:,',
-          children = {
-            'Missing:0:0:',
-          },
-        },
-      },
-      err = {
-        arg = ',',
-        msg = 'E15: Expected value, got comma: %.*s',
-      },
-    }, {
-      hl('InvalidComma', ','),
-    })
-    check_parsing('{,a->@a}', {
-      --           0123456789
-      ast = {
-        {
-          'CurlyBracesIdentifier(-di):0:0:{',
-          children = {
-            {
-              'Arrow:0:3:->',
-              children = {
-                {
-                  'Comma:0:1:,',
-                  children = {
-                    'Missing:0:1:',
-                    'PlainIdentifier(scope=0,ident=a):0:2:a',
-                  },
-                },
-                'Register(name=a):0:5:@a',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ',a->@a}',
-        msg = 'E15: Expected value, got comma: %.*s',
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('InvalidComma', ','),
-      hl('IdentifierName', 'a'),
-      hl('InvalidArrow', '->'),
-      hl('Register', '@a'),
-      hl('Curly', '}'),
-    })
-    check_parsing('}', {
-      --           0123456789
-      ast = {
-        'UnknownFigure(---):0:0:',
-      },
-      err = {
-        arg = '}',
-        msg = 'E15: Unexpected closing figure brace: %.*s',
-      },
-    }, {
-      hl('InvalidFigureBrace', '}'),
-    })
-    check_parsing('{->}', {
-      --           0123456789
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            'Arrow:0:1:->',
-          },
-        },
-      },
-      err = {
-        arg = '}',
-        msg = 'E15: Expected value, got closing figure brace: %.*s',
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('Arrow', '->'),
-      hl('InvalidLambda', '}'),
-    })
-    check_parsing('{a,b}', {
-      --           0123456789
-      ast = {
-        {
-          'Lambda(-di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:3:b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '}',
-        msg = 'E15: Expected lambda arguments list or arrow: %.*s',
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-      hl('InvalidLambda', '}'),
-    })
-    check_parsing('{a,}', {
-      --           0123456789
-      ast = {
-        {
-          'Lambda(-di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '}',
-        msg = 'E15: Expected lambda arguments list or arrow: %.*s',
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('InvalidLambda', '}'),
-    })
-    check_parsing('{@a:@b}', {
-      --           0123456789
-      ast = {
-        {
-          'DictLiteral(-di):0:0:{',
-          children = {
-            {
-              'Colon:0:3::',
-              children = {
-                'Register(name=a):0:1:@a',
-                'Register(name=b):0:4:@b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('Register', '@a'),
-      hl('Colon', ':'),
-      hl('Register', '@b'),
-      hl('Dict', '}'),
-    })
-    check_parsing('{@a:@b,@c:@d}', {
-      --           0123456789012
-      --           0         1
-      ast = {
-        {
-          'DictLiteral(-di):0:0:{',
-          children = {
-            {
-              'Comma:0:6:,',
-              children = {
-                {
-                  'Colon:0:3::',
-                  children = {
-                    'Register(name=a):0:1:@a',
-                    'Register(name=b):0:4:@b',
-                  },
-                },
-                {
-                  'Colon:0:9::',
-                  children = {
-                    'Register(name=c):0:7:@c',
-                    'Register(name=d):0:10:@d',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('Register', '@a'),
-      hl('Colon', ':'),
-      hl('Register', '@b'),
-      hl('Comma', ','),
-      hl('Register', '@c'),
-      hl('Colon', ':'),
-      hl('Register', '@d'),
-      hl('Dict', '}'),
-    })
-    check_parsing('{@a:@b,@c:@d,@e:@f,}', {
-      --           01234567890123456789
-      --           0         1
-      ast = {
-        {
-          'DictLiteral(-di):0:0:{',
-          children = {
-            {
-              'Comma:0:6:,',
-              children = {
-                {
-                  'Colon:0:3::',
-                  children = {
-                    'Register(name=a):0:1:@a',
-                    'Register(name=b):0:4:@b',
-                  },
-                },
-                {
-                  'Comma:0:12:,',
-                  children = {
-                    {
-                      'Colon:0:9::',
-                      children = {
-                        'Register(name=c):0:7:@c',
-                        'Register(name=d):0:10:@d',
-                      },
-                    },
-                    {
-                      'Comma:0:18:,',
-                      children = {
-                        {
-                          'Colon:0:15::',
-                          children = {
-                            'Register(name=e):0:13:@e',
-                            'Register(name=f):0:16:@f',
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('Register', '@a'),
-      hl('Colon', ':'),
-      hl('Register', '@b'),
-      hl('Comma', ','),
-      hl('Register', '@c'),
-      hl('Colon', ':'),
-      hl('Register', '@d'),
-      hl('Comma', ','),
-      hl('Register', '@e'),
-      hl('Colon', ':'),
-      hl('Register', '@f'),
-      hl('Comma', ','),
-      hl('Dict', '}'),
-    })
-    check_parsing('{@a:@b,@c:@d,@e:@f,@g:}', {
-      --           01234567890123456789012
-      --           0         1         2
-      ast = {
-        {
-          'DictLiteral(-di):0:0:{',
-          children = {
-            {
-              'Comma:0:6:,',
-              children = {
-                {
-                  'Colon:0:3::',
-                  children = {
-                    'Register(name=a):0:1:@a',
-                    'Register(name=b):0:4:@b',
-                  },
-                },
-                {
-                  'Comma:0:12:,',
-                  children = {
-                    {
-                      'Colon:0:9::',
-                      children = {
-                        'Register(name=c):0:7:@c',
-                        'Register(name=d):0:10:@d',
-                      },
-                    },
-                    {
-                      'Comma:0:18:,',
-                      children = {
-                        {
-                          'Colon:0:15::',
-                          children = {
-                            'Register(name=e):0:13:@e',
-                            'Register(name=f):0:16:@f',
-                          },
-                        },
-                        {
-                          'Colon:0:21::',
-                          children = {
-                            'Register(name=g):0:19:@g',
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '}',
-        msg = 'E15: Expected value, got closing figure brace: %.*s',
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('Register', '@a'),
-      hl('Colon', ':'),
-      hl('Register', '@b'),
-      hl('Comma', ','),
-      hl('Register', '@c'),
-      hl('Colon', ':'),
-      hl('Register', '@d'),
-      hl('Comma', ','),
-      hl('Register', '@e'),
-      hl('Colon', ':'),
-      hl('Register', '@f'),
-      hl('Comma', ','),
-      hl('Register', '@g'),
-      hl('Colon', ':'),
-      hl('InvalidDict', '}'),
-    })
-    check_parsing('{@a:@b,}', {
-      --           01234567890123
-      --           0         1
-      ast = {
-        {
-          'DictLiteral(-di):0:0:{',
-          children = {
-            {
-              'Comma:0:6:,',
-              children = {
-                {
-                  'Colon:0:3::',
-                  children = {
-                    'Register(name=a):0:1:@a',
-                    'Register(name=b):0:4:@b',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('Register', '@a'),
-      hl('Colon', ':'),
-      hl('Register', '@b'),
-      hl('Comma', ','),
-      hl('Dict', '}'),
-    })
-    check_parsing('{({f -> g})(@h)(@i)}', {
-      --           01234567890123456789
-      --           0         1
-      ast = {
-        {
-          'CurlyBracesIdentifier(-di):0:0:{',
-          children = {
-            {
-              'Call:0:15:(',
-              children = {
-                {
-                  'Call:0:11:(',
-                  children = {
-                    {
-                      'Nested:0:1:(',
-                      children = {
-                        {
-                          'Lambda(\\di):0:2:{',
-                          children = {
-                            'PlainIdentifier(scope=0,ident=f):0:3:f',
-                            {
-                              'Arrow:0:4: ->',
-                              children = {
-                                'PlainIdentifier(scope=0,ident=g):0:7: g',
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                    'Register(name=h):0:12:@h',
-                  },
-                },
-                'Register(name=i):0:16:@i',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('NestingParenthesis', '('),
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'f'),
-      hl('Arrow', '->', 1),
-      hl('IdentifierName', 'g', 1),
-      hl('Lambda', '}'),
-      hl('NestingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@h'),
-      hl('CallingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@i'),
-      hl('CallingParenthesis', ')'),
-      hl('Curly', '}'),
-    })
-    check_parsing('a:{b()}c', {
-      --           01234567
-      ast = {
-        {
-          'ComplexIdentifier:0:2:',
-          children = {
-            'PlainIdentifier(scope=a,ident=):0:0:a:',
-            {
-              'ComplexIdentifier:0:7:',
-              children = {
-                {
-                  'CurlyBracesIdentifier(--i):0:2:{',
-                  children = {
-                    {
-                      'Call:0:4:(',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=b):0:3:b',
-                      },
-                    },
-                  },
-                },
-                'PlainIdentifier(scope=0,ident=c):0:7:c',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierScope', 'a'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'b'),
-      hl('CallingParenthesis', '('),
-      hl('CallingParenthesis', ')'),
-      hl('Curly', '}'),
-      hl('IdentifierName', 'c'),
-    })
-    check_parsing('a:{{b, c -> @d + @e + ({f -> g})(@h)}(@i)}j', {
-      --           01234567890123456789012345678901234567890123456
-      --           0         1         2         3         4
-      ast = {
-        {
-          'ComplexIdentifier:0:2:',
-          children = {
-            'PlainIdentifier(scope=a,ident=):0:0:a:',
-            {
-              'ComplexIdentifier:0:42:',
-              children = {
-                {
-                  'CurlyBracesIdentifier(--i):0:2:{',
-                  children = {
-                    {
-                      'Call:0:37:(',
-                      children = {
-                        {
-                          'Lambda(\\di):0:3:{',
-                          children = {
-                            {
-                              'Comma:0:5:,',
-                              children = {
-                                'PlainIdentifier(scope=0,ident=b):0:4:b',
-                                'PlainIdentifier(scope=0,ident=c):0:6: c',
-                              },
-                            },
-                            {
-                              'Arrow:0:8: ->',
-                              children = {
-                                {
-                                  'BinaryPlus:0:19: +',
-                                  children = {
-                                    {
-                                      'BinaryPlus:0:14: +',
-                                      children = {
-                                        'Register(name=d):0:11: @d',
-                                        'Register(name=e):0:16: @e',
-                                      },
-                                    },
-                                    {
-                                      'Call:0:32:(',
-                                      children = {
-                                        {
-                                          'Nested:0:21: (',
-                                          children = {
-                                            {
-                                              'Lambda(\\di):0:23:{',
-                                              children = {
-                                                'PlainIdentifier(scope=0,ident=f):0:24:f',
-                                                {
-                                                  'Arrow:0:25: ->',
-                                                  children = {
-                                                    'PlainIdentifier(scope=0,ident=g):0:28: g',
-                                                  },
-                                                },
-                                              },
-                                            },
-                                          },
-                                        },
-                                        'Register(name=h):0:33:@h',
-                                      },
-                                    },
-                                  },
-                                },
-                              },
-                            },
-                          },
-                        },
-                        'Register(name=i):0:38:@i',
-                      },
-                    },
-                  },
-                },
-                'PlainIdentifier(scope=0,ident=j):0:42:j',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierScope', 'a'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('Curly', '{'),
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'b'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'c', 1),
-      hl('Arrow', '->', 1),
-      hl('Register', '@d', 1),
-      hl('BinaryPlus', '+', 1),
-      hl('Register', '@e', 1),
-      hl('BinaryPlus', '+', 1),
-      hl('NestingParenthesis', '(', 1),
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'f'),
-      hl('Arrow', '->', 1),
-      hl('IdentifierName', 'g', 1),
-      hl('Lambda', '}'),
-      hl('NestingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@h'),
-      hl('CallingParenthesis', ')'),
-      hl('Lambda', '}'),
-      hl('CallingParenthesis', '('),
-      hl('Register', '@i'),
-      hl('CallingParenthesis', ')'),
-      hl('Curly', '}'),
-      hl('IdentifierName', 'j'),
-    })
-    check_parsing('{@a + @b : @c + @d, @e + @f : @g + @i}', {
-      --           01234567890123456789012345678901234567
-      --           0         1         2         3
-      ast = {
-        {
-          'DictLiteral(-di):0:0:{',
-          children = {
-            {
-              'Comma:0:18:,',
-              children = {
-                {
-                  'Colon:0:8: :',
-                  children = {
-                    {
-                      'BinaryPlus:0:3: +',
-                      children = {
-                        'Register(name=a):0:1:@a',
-                        'Register(name=b):0:5: @b',
-                      },
-                    },
-                    {
-                      'BinaryPlus:0:13: +',
-                      children = {
-                        'Register(name=c):0:10: @c',
-                        'Register(name=d):0:15: @d',
-                      },
-                    },
-                  },
-                },
-                {
-                  'Colon:0:27: :',
-                  children = {
-                    {
-                      'BinaryPlus:0:22: +',
-                      children = {
-                        'Register(name=e):0:19: @e',
-                        'Register(name=f):0:24: @f',
-                      },
-                    },
-                    {
-                      'BinaryPlus:0:32: +',
-                      children = {
-                        'Register(name=g):0:29: @g',
-                        'Register(name=i):0:34: @i',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('Register', '@a'),
-      hl('BinaryPlus', '+', 1),
-      hl('Register', '@b', 1),
-      hl('Colon', ':', 1),
-      hl('Register', '@c', 1),
-      hl('BinaryPlus', '+', 1),
-      hl('Register', '@d', 1),
-      hl('Comma', ','),
-      hl('Register', '@e', 1),
-      hl('BinaryPlus', '+', 1),
-      hl('Register', '@f', 1),
-      hl('Colon', ':', 1),
-      hl('Register', '@g', 1),
-      hl('BinaryPlus', '+', 1),
-      hl('Register', '@i', 1),
-      hl('Dict', '}'),
-    })
-    check_parsing('-> -> ->', {
-      --           01234567
-      ast = {
-        {
-          'Arrow:0:0:->',
-          children = {
-            'Missing:0:0:',
-            {
-              'Arrow:0:2: ->',
-              children = {
-                'Missing:0:2:',
-                {
-                  'Arrow:0:5: ->',
-                  children = {
-                    'Missing:0:5:',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '-> -> ->',
-        msg = 'E15: Unexpected arrow: %.*s',
-      },
-    }, {
-      hl('InvalidArrow', '->'),
-      hl('InvalidArrow', '->', 1),
-      hl('InvalidArrow', '->', 1),
-    })
-    check_parsing('a -> b -> c -> d', {
-      --           0123456789012345
-      --           0         1
-      ast = {
-        {
-          'Arrow:0:1: ->',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'Arrow:0:6: ->',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:4: b',
-                {
-                  'Arrow:0:11: ->',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=c):0:9: c',
-                    'PlainIdentifier(scope=0,ident=d):0:14: d',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '-> b -> c -> d',
-        msg = 'E15: Arrow outside of lambda: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('InvalidArrow', '->', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('InvalidArrow', '->', 1),
-      hl('IdentifierName', 'c', 1),
-      hl('InvalidArrow', '->', 1),
-      hl('IdentifierName', 'd', 1),
-    })
-    check_parsing('{a -> b -> c}', {
-      --           0123456789012
-      --           0         1
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:1:a',
-            {
-              'Arrow:0:2: ->',
-              children = {
-                {
-                  'Arrow:0:7: ->',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:5: b',
-                    'PlainIdentifier(scope=0,ident=c):0:10: c',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '-> c}',
-        msg = 'E15: Arrow outside of lambda: %.*s',
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Arrow', '->', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('InvalidArrow', '->', 1),
-      hl('IdentifierName', 'c', 1),
-      hl('Lambda', '}'),
-    })
-    check_parsing('{a: -> b}', {
-      --           012345678
-      ast = {
-        {
-          'CurlyBracesIdentifier(-di):0:0:{',
-          children = {
-            {
-              'Arrow:0:3: ->',
-              children = {
-                'PlainIdentifier(scope=a,ident=):0:1:a:',
-                'PlainIdentifier(scope=0,ident=b):0:6: b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '-> b}',
-        msg = 'E15: Arrow outside of lambda: %.*s',
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('IdentifierScope', 'a'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('InvalidArrow', '->', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('Curly', '}'),
-    })
-
-    check_parsing('{a:b -> b}', {
-      --           0123456789
-      ast = {
-        {
-          'CurlyBracesIdentifier(-di):0:0:{',
-          children = {
-            {
-              'Arrow:0:4: ->',
-              children = {
-                'PlainIdentifier(scope=a,ident=b):0:1:a:b',
-                'PlainIdentifier(scope=0,ident=b):0:7: b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '-> b}',
-        msg = 'E15: Arrow outside of lambda: %.*s',
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('IdentifierScope', 'a'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('IdentifierName', 'b'),
-      hl('InvalidArrow', '->', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('Curly', '}'),
-    })
-
-    check_parsing('{a#b -> b}', {
-      --           0123456789
-      ast = {
-        {
-          'CurlyBracesIdentifier(-di):0:0:{',
-          children = {
-            {
-              'Arrow:0:4: ->',
-              children = {
-                'PlainIdentifier(scope=0,ident=a#b):0:1:a#b',
-                'PlainIdentifier(scope=0,ident=b):0:7: b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '-> b}',
-        msg = 'E15: Arrow outside of lambda: %.*s',
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('IdentifierName', 'a#b'),
-      hl('InvalidArrow', '->', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('Curly', '}'),
-    })
-    check_parsing('{a : b : c}', {
-      --           01234567890
-      --           0         1
-      ast = {
-        {
-          'DictLiteral(-di):0:0:{',
-          children = {
-            {
-              'Colon:0:2: :',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                {
-                  'Colon:0:6: :',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:4: b',
-                    'PlainIdentifier(scope=0,ident=c):0:8: c',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ': c}',
-        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Colon', ':', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('InvalidColon', ':', 1),
-      hl('IdentifierName', 'c', 1),
-      hl('Dict', '}'),
-    })
-    check_parsing('{', {
-      --           0
-      ast = {
-        'UnknownFigure(\\di):0:0:{',
-      },
-      err = {
-        arg = '{',
-        msg = 'E15: Missing closing figure brace: %.*s',
-      },
-    }, {
-      hl('FigureBrace', '{'),
-    })
-    check_parsing('{a', {
-      --           01
-      ast = {
-        {
-          'UnknownFigure(\\di):0:0:{',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:1:a',
-          },
-        },
-      },
-      err = {
-        arg = '{a',
-        msg = 'E15: Missing closing figure brace: %.*s',
-      },
-    }, {
-      hl('FigureBrace', '{'),
-      hl('IdentifierName', 'a'),
-    })
-    check_parsing('{a,b', {
-      --           0123
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:3:b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '{a,b',
-        msg = 'E15: Missing closing figure brace for lambda: %.*s',
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-    })
-    check_parsing('{a,b->', {
-      --           012345
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:3:b',
-              },
-            },
-            'Arrow:0:4:->',
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-      hl('Arrow', '->'),
-    })
-    check_parsing('{a,b->c', {
-      --           0123456
-      ast = {
-        {
-          'Lambda(\\di):0:0:{',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:3:b',
-              },
-            },
-            {
-              'Arrow:0:4:->',
-              children = {
-                'PlainIdentifier(scope=0,ident=c):0:6:c',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '{a,b->c',
-        msg = 'E15: Missing closing figure brace for lambda: %.*s',
-      },
-    }, {
-      hl('Lambda', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b'),
-      hl('Arrow', '->'),
-      hl('IdentifierName', 'c'),
-    })
-    check_parsing('{a : b', {
-      --           012345
-      ast = {
-        {
-          'DictLiteral(-di):0:0:{',
-          children = {
-            {
-              'Colon:0:2: :',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:4: b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '{a : b',
-        msg = 'E723: Missing end of Dictionary \'}\': %.*s',
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Colon', ':', 1),
-      hl('IdentifierName', 'b', 1),
-    })
-    check_parsing('{a : b,', {
-      --           0123456
-      ast = {
-        {
-          'DictLiteral(-di):0:0:{',
-          children = {
-            {
-              'Comma:0:6:,',
-              children = {
-                {
-                  'Colon:0:2: :',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=a):0:1:a',
-                    'PlainIdentifier(scope=0,ident=b):0:4: b',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('Dict', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Colon', ':', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('Comma', ','),
-    })
-  end)
-  itp('works with ternary operator', function()
-    check_parsing('a ? b : c', {
-      --           012345678
-      ast = {
-        {
-          'Ternary:0:1: ?',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'TernaryValue:0:5: :',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:3: b',
-                'PlainIdentifier(scope=0,ident=c):0:7: c',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Ternary', '?', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('TernaryColon', ':', 1),
-      hl('IdentifierName', 'c', 1),
-    })
-    check_parsing('@a?@b?@c:@d:@e', {
-      --           01234567890123
-      --           0         1
-      ast = {
-        {
-          'Ternary:0:2:?',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'TernaryValue:0:11::',
-              children = {
-                {
-                  'Ternary:0:5:?',
-                  children = {
-                    'Register(name=b):0:3:@b',
-                    {
-                      'TernaryValue:0:8::',
-                      children = {
-                        'Register(name=c):0:6:@c',
-                        'Register(name=d):0:9:@d',
-                      },
-                    },
-                  },
-                },
-                'Register(name=e):0:12:@e',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('Ternary', '?'),
-      hl('Register', '@b'),
-      hl('Ternary', '?'),
-      hl('Register', '@c'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@d'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@e'),
-    })
-    check_parsing('@a?@b:@c?@d:@e', {
-      --           01234567890123
-      --           0         1
-      ast = {
-        {
-          'Ternary:0:2:?',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'TernaryValue:0:5::',
-              children = {
-                'Register(name=b):0:3:@b',
-                {
-                  'Ternary:0:8:?',
-                  children = {
-                    'Register(name=c):0:6:@c',
-                    {
-                      'TernaryValue:0:11::',
-                      children = {
-                        'Register(name=d):0:9:@d',
-                        'Register(name=e):0:12:@e',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('Ternary', '?'),
-      hl('Register', '@b'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@c'),
-      hl('Ternary', '?'),
-      hl('Register', '@d'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@e'),
-    })
-    check_parsing('@a?@b?@c?@d:@e?@f:@g:@h?@i:@j:@k', {
-      --           01234567890123456789012345678901
-      --           0         1         2         3
-      ast = {
-        {
-          'Ternary:0:2:?',
-          children = {
-            'Register(name=a):0:0:@a',
-            {
-              'TernaryValue:0:29::',
-              children = {
-                {
-                  'Ternary:0:5:?',
-                  children = {
-                    'Register(name=b):0:3:@b',
-                    {
-                      'TernaryValue:0:20::',
-                      children = {
-                        {
-                          'Ternary:0:8:?',
-                          children = {
-                            'Register(name=c):0:6:@c',
-                            {
-                              'TernaryValue:0:11::',
-                              children = {
-                                'Register(name=d):0:9:@d',
-                                {
-                                  'Ternary:0:14:?',
-                                  children = {
-                                    'Register(name=e):0:12:@e',
-                                    {
-                                      'TernaryValue:0:17::',
-                                      children = {
-                                        'Register(name=f):0:15:@f',
-                                        'Register(name=g):0:18:@g',
-                                      },
-                                    },
-                                  },
-                                },
-                              },
-                            },
-                          },
-                        },
-                        {
-                          'Ternary:0:23:?',
-                          children = {
-                            'Register(name=h):0:21:@h',
-                            {
-                              'TernaryValue:0:26::',
-                              children = {
-                                'Register(name=i):0:24:@i',
-                                'Register(name=j):0:27:@j',
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-                'Register(name=k):0:30:@k',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('Ternary', '?'),
-      hl('Register', '@b'),
-      hl('Ternary', '?'),
-      hl('Register', '@c'),
-      hl('Ternary', '?'),
-      hl('Register', '@d'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@e'),
-      hl('Ternary', '?'),
-      hl('Register', '@f'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@g'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@h'),
-      hl('Ternary', '?'),
-      hl('Register', '@i'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@j'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@k'),
-    })
-    check_parsing('?', {
-      --           0
-      ast = {
-        {
-          'Ternary:0:0:?',
-          children = {
-            'Missing:0:0:',
-            'TernaryValue:0:0:?',
-          },
-        },
-      },
-      err = {
-        arg = '?',
-        msg = 'E15: Expected value, got question mark: %.*s',
-      },
-    }, {
-      hl('InvalidTernary', '?'),
-    })
-
-    check_parsing('?:', {
-      --           01
-      ast = {
-        {
-          'Ternary:0:0:?',
-          children = {
-            'Missing:0:0:',
-            {
-              'TernaryValue:0:1::',
-              children = {
-                'Missing:0:1:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '?:',
-        msg = 'E15: Expected value, got question mark: %.*s',
-      },
-    }, {
-      hl('InvalidTernary', '?'),
-      hl('InvalidTernaryColon', ':'),
-    })
-
-    check_parsing('?::', {
-      --           012
-      ast = {
-        {
-          'Colon:0:2::',
-          children = {
-            {
-              'Ternary:0:0:?',
-              children = {
-                'Missing:0:0:',
-                {
-                  'TernaryValue:0:1::',
-                  children = {
-                    'Missing:0:1:',
-                    'Missing:0:2:',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '?::',
-        msg = 'E15: Expected value, got question mark: %.*s',
-      },
-    }, {
-      hl('InvalidTernary', '?'),
-      hl('InvalidTernaryColon', ':'),
-      hl('InvalidColon', ':'),
-    })
-
-    check_parsing('a?b', {
-      --           012
-      ast = {
-        {
-          'Ternary:0:1:?',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'TernaryValue:0:1:?',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:2:b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '?b',
-        msg = 'E109: Missing \':\' after \'?\': %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Ternary', '?'),
-      hl('IdentifierName', 'b'),
-    })
-    check_parsing('a?b:', {
-      --           0123
-      ast = {
-        {
-          'Ternary:0:1:?',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'TernaryValue:0:1:?',
-              children = {
-                'PlainIdentifier(scope=b,ident=):0:2:b:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '?b:',
-        msg = 'E109: Missing \':\' after \'?\': %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Ternary', '?'),
-      hl('IdentifierScope', 'b'),
-      hl('IdentifierScopeDelimiter', ':'),
-    })
-
-    check_parsing('a?b::c', {
-      --           012345
-      ast = {
-        {
-          'Ternary:0:1:?',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'TernaryValue:0:4::',
-              children = {
-                'PlainIdentifier(scope=b,ident=):0:2:b:',
-                'PlainIdentifier(scope=0,ident=c):0:5:c',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Ternary', '?'),
-      hl('IdentifierScope', 'b'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('TernaryColon', ':'),
-      hl('IdentifierName', 'c'),
-    })
-
-    check_parsing('a?b :', {
-      --           01234
-      ast = {
-        {
-          'Ternary:0:1:?',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'TernaryValue:0:3: :',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:2:b',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Ternary', '?'),
-      hl('IdentifierName', 'b'),
-      hl('TernaryColon', ':', 1),
-    })
-
-    check_parsing('(@a?@b:@c)?@d:@e', {
-      --           0123456789012345
-      --           0         1
-      ast = {
-        {
-          'Ternary:0:10:?',
-          children = {
-            {
-              'Nested:0:0:(',
-              children = {
-                {
-                  'Ternary:0:3:?',
-                  children = {
-                    'Register(name=a):0:1:@a',
-                    {
-                      'TernaryValue:0:6::',
-                      children = {
-                        'Register(name=b):0:4:@b',
-                        'Register(name=c):0:7:@c',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-            {
-              'TernaryValue:0:13::',
-              children = {
-                'Register(name=d):0:11:@d',
-                'Register(name=e):0:14:@e',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Register', '@a'),
-      hl('Ternary', '?'),
-      hl('Register', '@b'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@c'),
-      hl('NestingParenthesis', ')'),
-      hl('Ternary', '?'),
-      hl('Register', '@d'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@e'),
-    })
-
-    check_parsing('(@a?@b:@c)?(@d?@e:@f):(@g?@h:@i)', {
-      --           01234567890123456789012345678901
-      --           0         1         2         3
-      ast = {
-        {
-          'Ternary:0:10:?',
-          children = {
-            {
-              'Nested:0:0:(',
-              children = {
-                {
-                  'Ternary:0:3:?',
-                  children = {
-                    'Register(name=a):0:1:@a',
-                    {
-                      'TernaryValue:0:6::',
-                      children = {
-                        'Register(name=b):0:4:@b',
-                        'Register(name=c):0:7:@c',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-            {
-              'TernaryValue:0:21::',
-              children = {
-                {
-                  'Nested:0:11:(',
-                  children = {
-                    {
-                      'Ternary:0:14:?',
-                      children = {
-                        'Register(name=d):0:12:@d',
-                        {
-                          'TernaryValue:0:17::',
-                          children = {
-                            'Register(name=e):0:15:@e',
-                            'Register(name=f):0:18:@f',
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-                {
-                  'Nested:0:22:(',
-                  children = {
-                    {
-                      'Ternary:0:25:?',
-                      children = {
-                        'Register(name=g):0:23:@g',
-                        {
-                          'TernaryValue:0:28::',
-                          children = {
-                            'Register(name=h):0:26:@h',
-                            'Register(name=i):0:29:@i',
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Register', '@a'),
-      hl('Ternary', '?'),
-      hl('Register', '@b'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@c'),
-      hl('NestingParenthesis', ')'),
-      hl('Ternary', '?'),
-      hl('NestingParenthesis', '('),
-      hl('Register', '@d'),
-      hl('Ternary', '?'),
-      hl('Register', '@e'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@f'),
-      hl('NestingParenthesis', ')'),
-      hl('TernaryColon', ':'),
-      hl('NestingParenthesis', '('),
-      hl('Register', '@g'),
-      hl('Ternary', '?'),
-      hl('Register', '@h'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@i'),
-      hl('NestingParenthesis', ')'),
-    })
-
-    check_parsing('(@a?@b:@c)?@d?@e:@f:@g?@h:@i', {
-      --           0123456789012345678901234567
-      --           0         1         2
-      ast = {
-        {
-          'Ternary:0:10:?',
-          children = {
-            {
-              'Nested:0:0:(',
-              children = {
-                {
-                  'Ternary:0:3:?',
-                  children = {
-                    'Register(name=a):0:1:@a',
-                    {
-                      'TernaryValue:0:6::',
-                      children = {
-                        'Register(name=b):0:4:@b',
-                        'Register(name=c):0:7:@c',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-            {
-              'TernaryValue:0:19::',
-              children = {
-                {
-                  'Ternary:0:13:?',
-                  children = {
-                    'Register(name=d):0:11:@d',
-                    {
-                      'TernaryValue:0:16::',
-                      children = {
-                        'Register(name=e):0:14:@e',
-                        'Register(name=f):0:17:@f',
-                      },
-                    },
-                  },
-                },
-                {
-                  'Ternary:0:22:?',
-                  children = {
-                    'Register(name=g):0:20:@g',
-                    {
-                      'TernaryValue:0:25::',
-                      children = {
-                        'Register(name=h):0:23:@h',
-                        'Register(name=i):0:26:@i',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Register', '@a'),
-      hl('Ternary', '?'),
-      hl('Register', '@b'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@c'),
-      hl('NestingParenthesis', ')'),
-      hl('Ternary', '?'),
-      hl('Register', '@d'),
-      hl('Ternary', '?'),
-      hl('Register', '@e'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@f'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@g'),
-      hl('Ternary', '?'),
-      hl('Register', '@h'),
-      hl('TernaryColon', ':'),
-      hl('Register', '@i'),
-    })
-    check_parsing('a?b{cdef}g:h', {
-      --           012345678901
-      --           0         1
-      ast = {
-        {
-          'Ternary:0:1:?',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'TernaryValue:0:10::',
-              children = {
-                {
-                  'ComplexIdentifier:0:3:',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:2:b',
-                    {
-                      'ComplexIdentifier:0:9:',
-                      children = {
-                        {
-                          'CurlyBracesIdentifier(--i):0:3:{',
-                          children = {
-                            'PlainIdentifier(scope=0,ident=cdef):0:4:cdef',
-                          },
-                        },
-                        'PlainIdentifier(scope=0,ident=g):0:9:g',
-                      },
-                    },
-                  },
-                },
-                'PlainIdentifier(scope=0,ident=h):0:11:h',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Ternary', '?'),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'cdef'),
-      hl('Curly', '}'),
-      hl('IdentifierName', 'g'),
-      hl('TernaryColon', ':'),
-      hl('IdentifierName', 'h'),
-    })
-    check_parsing('a ? b : c : d', {
-      --           0123456789012
-      --           0         1
-      ast = {
-        {
-          'Colon:0:9: :',
-          children = {
-            {
-              'Ternary:0:1: ?',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                {
-                  'TernaryValue:0:5: :',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:3: b',
-                    'PlainIdentifier(scope=0,ident=c):0:7: c',
-                  },
-                },
-              },
-            },
-            'PlainIdentifier(scope=0,ident=d):0:11: d',
-          },
-        },
-      },
-      err = {
-        arg = ': d',
-        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Ternary', '?', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('TernaryColon', ':', 1),
-      hl('IdentifierName', 'c', 1),
-      hl('InvalidColon', ':', 1),
-      hl('IdentifierName', 'd', 1),
-    })
-  end)
-  itp('works with comparison operators', function()
-    check_parsing('a == b', {
-      --           012345
-      ast = {
-        {
-          'Comparison(type=Equal,inv=0,ccs=UseOption):0:1: ==',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:4: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '==', 1),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a ==? b', {
-      --           0123456
-      ast = {
-        {
-          'Comparison(type=Equal,inv=0,ccs=IgnoreCase):0:1: ==?',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:5: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '==', 1),
-      hl('ComparisonModifier', '?'),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a ==# b', {
-      --           0123456
-      ast = {
-        {
-          'Comparison(type=Equal,inv=0,ccs=MatchCase):0:1: ==#',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:5: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '==', 1),
-      hl('ComparisonModifier', '#'),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a !=# b', {
-      --           0123456
-      ast = {
-        {
-          'Comparison(type=Equal,inv=1,ccs=MatchCase):0:1: !=#',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:5: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '!=', 1),
-      hl('ComparisonModifier', '#'),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a <=# b', {
-      --           0123456
-      ast = {
-        {
-          'Comparison(type=Greater,inv=1,ccs=MatchCase):0:1: <=#',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:5: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '<=', 1),
-      hl('ComparisonModifier', '#'),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a >=# b', {
-      --           0123456
-      ast = {
-        {
-          'Comparison(type=GreaterOrEqual,inv=0,ccs=MatchCase):0:1: >=#',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:5: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '>=', 1),
-      hl('ComparisonModifier', '#'),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a ># b', {
-      --           012345
-      ast = {
-        {
-          'Comparison(type=Greater,inv=0,ccs=MatchCase):0:1: >#',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:4: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '>', 1),
-      hl('ComparisonModifier', '#'),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a <# b', {
-      --           012345
-      ast = {
-        {
-          'Comparison(type=GreaterOrEqual,inv=1,ccs=MatchCase):0:1: <#',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:4: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '<', 1),
-      hl('ComparisonModifier', '#'),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a is#b', {
-      --           012345
-      ast = {
-        {
-          'Comparison(type=Identical,inv=0,ccs=MatchCase):0:1: is#',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:5:b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', 'is', 1),
-      hl('ComparisonModifier', '#'),
-      hl('IdentifierName', 'b'),
-    })
-
-    check_parsing('a is?b', {
-      --           012345
-      ast = {
-        {
-          'Comparison(type=Identical,inv=0,ccs=IgnoreCase):0:1: is?',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:5:b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', 'is', 1),
-      hl('ComparisonModifier', '?'),
-      hl('IdentifierName', 'b'),
-    })
-
-    check_parsing('a isnot b', {
-      --           012345678
-      ast = {
-        {
-          'Comparison(type=Identical,inv=1,ccs=UseOption):0:1: isnot',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:7: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', 'isnot', 1),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a < b < c', {
-      --           012345678
-      ast = {
-        {
-          'Comparison(type=GreaterOrEqual,inv=1,ccs=UseOption):0:1: <',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'Comparison(type=GreaterOrEqual,inv=1,ccs=UseOption):0:5: <',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:3: b',
-                'PlainIdentifier(scope=0,ident=c):0:7: c',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ' < c',
-        msg = 'E15: Operator is not associative: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '<', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('InvalidComparison', '<', 1),
-      hl('IdentifierName', 'c', 1),
-    })
-
-    check_parsing('a < b <# c', {
-      --           012345678
-      ast = {
-        {
-          'Comparison(type=GreaterOrEqual,inv=1,ccs=UseOption):0:1: <',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'Comparison(type=GreaterOrEqual,inv=1,ccs=MatchCase):0:5: <#',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:3: b',
-                'PlainIdentifier(scope=0,ident=c):0:8: c',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ' <# c',
-        msg = 'E15: Operator is not associative: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Comparison', '<', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('InvalidComparison', '<', 1),
-      hl('InvalidComparisonModifier', '#'),
-      hl('IdentifierName', 'c', 1),
-    })
-
-    check_parsing('a += b', {
-      --           012345
-      ast = {
-        {
-          'Assignment(Add):0:1: +=',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:4: b',
-          },
-        },
-      },
-      err = {
-        arg = '+= b',
-        msg = 'E15: Misplaced assignment: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('InvalidAssignmentWithAddition', '+=', 1),
-      hl('IdentifierName', 'b', 1),
-    })
-    check_parsing('a + b == c + d', {
-      --           01234567890123
-      --           0         1
-      ast = {
-        {
-          'Comparison(type=Equal,inv=0,ccs=UseOption):0:5: ==',
-          children = {
-            {
-              'BinaryPlus:0:1: +',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                'PlainIdentifier(scope=0,ident=b):0:3: b',
-              },
-            },
-            {
-              'BinaryPlus:0:10: +',
-              children = {
-                'PlainIdentifier(scope=0,ident=c):0:8: c',
-                'PlainIdentifier(scope=0,ident=d):0:12: d',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('BinaryPlus', '+', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('Comparison', '==', 1),
-      hl('IdentifierName', 'c', 1),
-      hl('BinaryPlus', '+', 1),
-      hl('IdentifierName', 'd', 1),
-    })
-    check_parsing('+ a == + b', {
-      --           0123456789
-      ast = {
-        {
-          'Comparison(type=Equal,inv=0,ccs=UseOption):0:3: ==',
-          children = {
-            {
-              'UnaryPlus:0:0:+',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1: a',
-              },
-            },
-            {
-              'UnaryPlus:0:6: +',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:8: b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('UnaryPlus', '+'),
-      hl('IdentifierName', 'a', 1),
-      hl('Comparison', '==', 1),
-      hl('UnaryPlus', '+', 1),
-      hl('IdentifierName', 'b', 1),
-    })
-  end)
-  itp('works with concat/subscript', function()
-    check_parsing('.', {
-      --           0
-      ast = {
-        {
-          'ConcatOrSubscript:0:0:.',
-          children = {
-            'Missing:0:0:',
-          },
-        },
-      },
-      err = {
-        arg = '.',
-        msg = 'E15: Unexpected dot: %.*s',
-      },
-    }, {
-      hl('InvalidConcatOrSubscript', '.'),
-    })
-
-    check_parsing('a.', {
-      --           01
-      ast = {
-        {
-          'ConcatOrSubscript:0:1:.',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('ConcatOrSubscript', '.'),
-    })
-
-    check_parsing('a.b', {
-      --           012
-      ast = {
-        {
-          'ConcatOrSubscript:0:1:.',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainKey(key=b):0:2:b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', 'b'),
-    })
-
-    check_parsing('1.2', {
-      --           012
-      ast = {
-        'Float(val=1.200000e+00):0:0:1.2',
-      },
-    }, {
-      hl('Float', '1.2'),
-    })
-
-    check_parsing('1.2 + 1.3e-5', {
-      --           012345678901
-      --           0         1
-      ast = {
-        {
-          'BinaryPlus:0:3: +',
-          children = {
-            'Float(val=1.200000e+00):0:0:1.2',
-            'Float(val=1.300000e-05):0:5: 1.3e-5',
-          },
-        },
-      },
-    }, {
-      hl('Float', '1.2'),
-      hl('BinaryPlus', '+', 1),
-      hl('Float', '1.3e-5', 1),
-    })
-
-    check_parsing('a . 1.2 + 1.3e-5', {
-      --           0123456789012345
-      --           0         1
-      ast = {
-        {
-          'BinaryPlus:0:7: +',
-          children = {
-            {
-              'Concat:0:1: .',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                {
-                  'ConcatOrSubscript:0:5:.',
-                  children = {
-                    'Integer(val=1):0:3: 1',
-                    'PlainKey(key=2):0:6:2',
-                  },
-                },
-              },
-            },
-            'Float(val=1.300000e-05):0:9: 1.3e-5',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Concat', '.', 1),
-      hl('Number', '1', 1),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '2'),
-      hl('BinaryPlus', '+', 1),
-      hl('Float', '1.3e-5', 1),
-    })
-
-    check_parsing('1.3e-5 + 1.2 . a', {
-      --           0123456789012345
-      --           0         1
-      ast = {
-        {
-          'Concat:0:12: .',
-          children = {
-            {
-              'BinaryPlus:0:6: +',
-              children = {
-                'Float(val=1.300000e-05):0:0:1.3e-5',
-                'Float(val=1.200000e+00):0:8: 1.2',
-              },
-            },
-            'PlainIdentifier(scope=0,ident=a):0:14: a',
-          },
-        },
-      },
-    }, {
-      hl('Float', '1.3e-5'),
-      hl('BinaryPlus', '+', 1),
-      hl('Float', '1.2', 1),
-      hl('Concat', '.', 1),
-      hl('IdentifierName', 'a', 1),
-    })
-
-    check_parsing('1.3e-5 + a . 1.2', {
-      --           0123456789012345
-      --           0         1
-      ast = {
-        {
-          'Concat:0:10: .',
-          children = {
-            {
-              'BinaryPlus:0:6: +',
-              children = {
-                'Float(val=1.300000e-05):0:0:1.3e-5',
-                'PlainIdentifier(scope=0,ident=a):0:8: a',
-              },
-            },
-            {
-              'ConcatOrSubscript:0:14:.',
-              children = {
-                'Integer(val=1):0:12: 1',
-                'PlainKey(key=2):0:15:2',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Float', '1.3e-5'),
-      hl('BinaryPlus', '+', 1),
-      hl('IdentifierName', 'a', 1),
-      hl('Concat', '.', 1),
-      hl('Number', '1', 1),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '2'),
-    })
-
-    check_parsing('1.2.3', {
-      --           01234
-      ast = {
-        {
-          'ConcatOrSubscript:0:3:.',
-          children = {
-            {
-              'ConcatOrSubscript:0:1:.',
-              children = {
-                'Integer(val=1):0:0:1',
-                'PlainKey(key=2):0:2:2',
-              },
-            },
-            'PlainKey(key=3):0:4:3',
-          },
-        },
-      },
-    }, {
-      hl('Number', '1'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '2'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '3'),
-    })
-
-    check_parsing('a.1.2', {
-      --           01234
-      ast = {
-        {
-          'ConcatOrSubscript:0:3:.',
-          children = {
-            {
-              'ConcatOrSubscript:0:1:.',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                'PlainKey(key=1):0:2:1',
-              },
-            },
-            'PlainKey(key=2):0:4:2',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '1'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '2'),
-    })
-
-    check_parsing('a . 1.2', {
-      --           0123456
-      ast = {
-        {
-          'Concat:0:1: .',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'ConcatOrSubscript:0:5:.',
-              children = {
-                'Integer(val=1):0:3: 1',
-                'PlainKey(key=2):0:6:2',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Concat', '.', 1),
-      hl('Number', '1', 1),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '2'),
-    })
-
-    check_parsing('+a . +b', {
-      --           0123456
-      ast = {
-        {
-          'Concat:0:2: .',
-          children = {
-            {
-              'UnaryPlus:0:0:+',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-              },
-            },
-            {
-              'UnaryPlus:0:4: +',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:6:b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('UnaryPlus', '+'),
-      hl('IdentifierName', 'a'),
-      hl('Concat', '.', 1),
-      hl('UnaryPlus', '+', 1),
-      hl('IdentifierName', 'b'),
-    })
-
-    check_parsing('a. b', {
-      --           0123
-      ast = {
-        {
-          'Concat:0:1:.',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:2: b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierName', 'b', 1),
-    })
-
-    check_parsing('a. 1', {
-      --           0123
-      ast = {
-        {
-          'Concat:0:1:.',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'Integer(val=1):0:2: 1',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('ConcatOrSubscript', '.'),
-      hl('Number', '1', 1),
-    })
-  end)
-  itp('works with bracket subscripts', function()
-    check_parsing(':', {
-      --           0
-      ast = {
-        {
-          'Colon:0:0::',
-          children = {
-            'Missing:0:0:',
-          },
-        },
-      },
-      err = {
-        arg = ':',
-        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-      },
-    }, {
-      hl('InvalidColon', ':'),
-    })
-    check_parsing('a[]', {
-      --           012
-      ast = {
-        {
-          'Subscript:0:1:[',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-          },
-        },
-      },
-      err = {
-        arg = ']',
-        msg = 'E15: Expected value, got closing bracket: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('InvalidSubscriptBracket', ']'),
-    })
-    check_parsing('a[b:]', {
-      --           01234
-      ast = {
-        {
-          'Subscript:0:1:[',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=b,ident=):0:2:b:',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierScope', 'b'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('SubscriptBracket', ']'),
-    })
-
-    check_parsing('a[b:c]', {
-      --           012345
-      ast = {
-        {
-          'Subscript:0:1:[',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=b,ident=c):0:2:b:c',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierScope', 'b'),
-      hl('IdentifierScopeDelimiter', ':'),
-      hl('IdentifierName', 'c'),
-      hl('SubscriptBracket', ']'),
-    })
-    check_parsing('a[b : c]', {
-      --           01234567
-      ast = {
-        {
-          'Subscript:0:1:[',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'Colon:0:3: :',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:2:b',
-                'PlainIdentifier(scope=0,ident=c):0:5: c',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierName', 'b'),
-      hl('SubscriptColon', ':', 1),
-      hl('IdentifierName', 'c', 1),
-      hl('SubscriptBracket', ']'),
-    })
-
-    check_parsing('a[: b]', {
-      --           012345
-      ast = {
-        {
-          'Subscript:0:1:[',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'Colon:0:2::',
-              children = {
-                'Missing:0:2:',
-                'PlainIdentifier(scope=0,ident=b):0:3: b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('SubscriptColon', ':'),
-      hl('IdentifierName', 'b', 1),
-      hl('SubscriptBracket', ']'),
-    })
-
-    check_parsing('a[b :]', {
-      --           012345
-      ast = {
-        {
-          'Subscript:0:1:[',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'Colon:0:3: :',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:2:b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierName', 'b'),
-      hl('SubscriptColon', ':', 1),
-      hl('SubscriptBracket', ']'),
-    })
-    check_parsing('a[b][c][d](e)(f)(g)', {
-      --           0123456789012345678
-      --           0         1
-      ast = {
-        {
-          'Call:0:16:(',
-          children = {
-            {
-              'Call:0:13:(',
-              children = {
-                {
-                  'Call:0:10:(',
-                  children = {
-                    {
-                      'Subscript:0:7:[',
-                      children = {
-                        {
-                          'Subscript:0:4:[',
-                          children = {
-                            {
-                              'Subscript:0:1:[',
-                              children = {
-                                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                                'PlainIdentifier(scope=0,ident=b):0:2:b',
-                              },
-                            },
-                            'PlainIdentifier(scope=0,ident=c):0:5:c',
-                          },
-                        },
-                        'PlainIdentifier(scope=0,ident=d):0:8:d',
-                      },
-                    },
-                    'PlainIdentifier(scope=0,ident=e):0:11:e',
-                  },
-                },
-                'PlainIdentifier(scope=0,ident=f):0:14:f',
-              },
-            },
-            'PlainIdentifier(scope=0,ident=g):0:17:g',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierName', 'b'),
-      hl('SubscriptBracket', ']'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierName', 'c'),
-      hl('SubscriptBracket', ']'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierName', 'd'),
-      hl('SubscriptBracket', ']'),
-      hl('CallingParenthesis', '('),
-      hl('IdentifierName', 'e'),
-      hl('CallingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('IdentifierName', 'f'),
-      hl('CallingParenthesis', ')'),
-      hl('CallingParenthesis', '('),
-      hl('IdentifierName', 'g'),
-      hl('CallingParenthesis', ')'),
-    })
-    check_parsing('{a}{b}{c}[d][e][f]', {
-      --           012345678901234567
-      --           0         1
-      ast = {
-        {
-          'Subscript:0:15:[',
-          children = {
-            {
-              'Subscript:0:12:[',
-              children = {
-                {
-                  'Subscript:0:9:[',
-                  children = {
-                    {
-                      'ComplexIdentifier:0:3:',
-                      children = {
-                        {
-                          'CurlyBracesIdentifier(-di):0:0:{',
-                          children = {
-                            'PlainIdentifier(scope=0,ident=a):0:1:a',
-                          },
-                        },
-                        {
-                          'ComplexIdentifier:0:6:',
-                          children = {
-                            {
-                              'CurlyBracesIdentifier(--i):0:3:{',
-                              children = {
-                                'PlainIdentifier(scope=0,ident=b):0:4:b',
-                              },
-                            },
-                            {
-                              'CurlyBracesIdentifier(--i):0:6:{',
-                              children = {
-                                'PlainIdentifier(scope=0,ident=c):0:7:c',
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                    'PlainIdentifier(scope=0,ident=d):0:10:d',
-                  },
-                },
-                'PlainIdentifier(scope=0,ident=e):0:13:e',
-              },
-            },
-            'PlainIdentifier(scope=0,ident=f):0:16:f',
-          },
-        },
-      },
-    }, {
-      hl('Curly', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Curly', '}'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '}'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'c'),
-      hl('Curly', '}'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierName', 'd'),
-      hl('SubscriptBracket', ']'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierName', 'e'),
-      hl('SubscriptBracket', ']'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierName', 'f'),
-      hl('SubscriptBracket', ']'),
-    })
-  end)
-  itp('supports list literals', function()
-    check_parsing('[]', {
-      --           01
-      ast = {
-        'ListLiteral:0:0:[',
-      },
-    }, {
-      hl('List', '['),
-      hl('List', ']'),
-    })
-
-    check_parsing('[a]', {
-      --           012
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:1:a',
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('List', ']'),
-    })
-
-    check_parsing('[a, b]', {
-      --           012345
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:3: b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b', 1),
-      hl('List', ']'),
-    })
-
-    check_parsing('[a, b, c]', {
-      --           012345678
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                {
-                  'Comma:0:5:,',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:3: b',
-                    'PlainIdentifier(scope=0,ident=c):0:6: c',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b', 1),
-      hl('Comma', ','),
-      hl('IdentifierName', 'c', 1),
-      hl('List', ']'),
-    })
-
-    check_parsing('[a, b, c, ]', {
-      --           01234567890
-      --           0         1
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                {
-                  'Comma:0:5:,',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:3: b',
-                    {
-                      'Comma:0:8:,',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=c):0:6: c',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b', 1),
-      hl('Comma', ','),
-      hl('IdentifierName', 'c', 1),
-      hl('Comma', ','),
-      hl('List', ']', 1),
-    })
-
-    check_parsing('[a : b, c : d]', {
-      --           01234567890123
-      --           0         1
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            {
-              'Comma:0:6:,',
-              children = {
-                {
-                  'Colon:0:2: :',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=a):0:1:a',
-                    'PlainIdentifier(scope=0,ident=b):0:4: b',
-                  },
-                },
-                {
-                  'Colon:0:9: :',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=c):0:7: c',
-                    'PlainIdentifier(scope=0,ident=d):0:11: d',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ': b, c : d]',
-        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('InvalidColon', ':', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('Comma', ','),
-      hl('IdentifierName', 'c', 1),
-      hl('InvalidColon', ':', 1),
-      hl('IdentifierName', 'd', 1),
-      hl('List', ']'),
-    })
-
-    check_parsing(']', {
-      --           0
-      ast = {
-        'ListLiteral:0:0:',
-      },
-      err = {
-        arg = ']',
-        msg = 'E15: Unexpected closing figure brace: %.*s',
-      },
-    }, {
-      hl('InvalidList', ']'),
-    })
-
-    check_parsing('a]', {
-      --           01
-      ast = {
-        {
-          'ListLiteral:0:1:',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-          },
-        },
-      },
-      err = {
-        arg = ']',
-        msg = 'E15: Unexpected closing figure brace: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('InvalidList', ']'),
-    })
-
-    check_parsing('[] []', {
-      --           01234
-      ast = {
-        {
-          'OpMissing:0:2:',
-          children = {
-            'ListLiteral:0:0:[',
-            'ListLiteral:0:2: [',
-          },
-        },
-      },
-      err = {
-        arg = '[]',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('List', '['),
-      hl('List', ']'),
-      hl('InvalidSpacing', ' '),
-      hl('List', '['),
-      hl('List', ']'),
-    }, {
-      [1] = {
-        ast = {
-          err = REMOVE_THIS,
-          ast = {
-            'ListLiteral:0:0:[',
-          },
-        },
-        hl_fs = {
-          [3] = REMOVE_THIS,
-          [4] = REMOVE_THIS,
-          [5] = REMOVE_THIS,
-        },
-      },
-    })
-
-    check_parsing('[][]', {
-      --           0123
-      ast = {
-        {
-          'Subscript:0:2:[',
-          children = {
-            'ListLiteral:0:0:[',
-          },
-        },
-      },
-      err = {
-        arg = ']',
-        msg = 'E15: Expected value, got closing bracket: %.*s',
-      },
-    }, {
-      hl('List', '['),
-      hl('List', ']'),
-      hl('SubscriptBracket', '['),
-      hl('InvalidSubscriptBracket', ']'),
-    })
-
-    check_parsing('[', {
-      --           0
-      ast = {
-        'ListLiteral:0:0:[',
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('List', '['),
-    })
-
-    check_parsing('[1', {
-      --           01
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            'Integer(val=1):0:1:1',
-          },
-        },
-      },
-      err = {
-        arg = '[1',
-        msg = 'E697: Missing end of List \']\': %.*s',
-      },
-    }, {
-      hl('List', '['),
-      hl('Number', '1'),
-    })
-  end)
-  itp('works with strings', function()
-    check_parsing('\'abc\'', {
-      --           01234
-      ast = {
-        'SingleQuotedString(val="abc"):0:0:\'abc\'',
-      },
-    }, {
-      hl('SingleQuote', '\''),
-      hl('SingleQuotedBody', 'abc'),
-      hl('SingleQuote', '\''),
-    })
-    check_parsing('"abc"', {
-      --           01234
-      ast = {
-        'DoubleQuotedString(val="abc"):0:0:"abc"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedBody', 'abc'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('\'\'', {
-      --           01
-      ast = {
-        'SingleQuotedString(val=NULL):0:0:\'\'',
-      },
-    }, {
-      hl('SingleQuote', '\''),
-      hl('SingleQuote', '\''),
-    })
-    check_parsing('""', {
-      --           01
-      ast = {
-        'DoubleQuotedString(val=NULL):0:0:""',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"', {
-      --           0
-      ast = {
-        'DoubleQuotedString(val=NULL):0:0:"',
-      },
-      err = {
-        arg = '"',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-    })
-    check_parsing('\'', {
-      --           0
-      ast = {
-        'SingleQuotedString(val=NULL):0:0:\'',
-      },
-      err = {
-        arg = '\'',
-        msg = 'E115: Missing single quote: %.*s',
-      },
-    }, {
-      hl('InvalidSingleQuote', '\''),
-    })
-    check_parsing('"a', {
-      --           01
-      ast = {
-        'DoubleQuotedString(val="a"):0:0:"a',
-      },
-      err = {
-        arg = '"a',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedBody', 'a'),
-    })
-    check_parsing('\'a', {
-      --           01
-      ast = {
-        'SingleQuotedString(val="a"):0:0:\'a',
-      },
-      err = {
-        arg = '\'a',
-        msg = 'E115: Missing single quote: %.*s',
-      },
-    }, {
-      hl('InvalidSingleQuote', '\''),
-      hl('InvalidSingleQuotedBody', 'a'),
-    })
-    check_parsing('\'abc\'\'def\'', {
-      --           0123456789
-      ast = {
-        'SingleQuotedString(val="abc\'def"):0:0:\'abc\'\'def\'',
-      },
-    }, {
-      hl('SingleQuote', '\''),
-      hl('SingleQuotedBody', 'abc'),
-      hl('SingleQuotedQuote', '\'\''),
-      hl('SingleQuotedBody', 'def'),
-      hl('SingleQuote', '\''),
-    })
-    check_parsing('\'abc\'\'', {
-      --           012345
-      ast = {
-        'SingleQuotedString(val="abc\'"):0:0:\'abc\'\'',
-      },
-      err = {
-        arg = '\'abc\'\'',
-        msg = 'E115: Missing single quote: %.*s',
-      },
-    }, {
-      hl('InvalidSingleQuote', '\''),
-      hl('InvalidSingleQuotedBody', 'abc'),
-      hl('InvalidSingleQuotedQuote', '\'\''),
-    })
-    check_parsing('\'\'\'\'\'\'\'\'', {
-      --           01234567
-      ast = {
-        'SingleQuotedString(val="\'\'\'"):0:0:\'\'\'\'\'\'\'\'',
-      },
-    }, {
-      hl('SingleQuote', '\''),
-      hl('SingleQuotedQuote', '\'\''),
-      hl('SingleQuotedQuote', '\'\''),
-      hl('SingleQuotedQuote', '\'\''),
-      hl('SingleQuote', '\''),
-    })
-    check_parsing('\'\'\'a\'\'\'\'bc\'', {
-      --           01234567890
-      --           0         1
-      ast = {
-        'SingleQuotedString(val="\'a\'\'bc"):0:0:\'\'\'a\'\'\'\'bc\'',
-      },
-    }, {
-      hl('SingleQuote', '\''),
-      hl('SingleQuotedQuote', '\'\''),
-      hl('SingleQuotedBody', 'a'),
-      hl('SingleQuotedQuote', '\'\''),
-      hl('SingleQuotedQuote', '\'\''),
-      hl('SingleQuotedBody', 'bc'),
-      hl('SingleQuote', '\''),
-    })
-    check_parsing('"\\"\\"\\"\\""', {
-      --           0123456789
-      ast = {
-        'DoubleQuotedString(val="\\"\\"\\"\\""):0:0:"\\"\\"\\"\\""',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\"'),
-      hl('DoubleQuotedEscape', '\\"'),
-      hl('DoubleQuotedEscape', '\\"'),
-      hl('DoubleQuotedEscape', '\\"'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"abc\\"def\\"ghi\\"jkl\\"mno"', {
-      --           0123456789012345678901234
-      --           0         1         2
-      ast = {
-        'DoubleQuotedString(val="abc\\"def\\"ghi\\"jkl\\"mno"):0:0:"abc\\"def\\"ghi\\"jkl\\"mno"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedBody', 'abc'),
-      hl('DoubleQuotedEscape', '\\"'),
-      hl('DoubleQuotedBody', 'def'),
-      hl('DoubleQuotedEscape', '\\"'),
-      hl('DoubleQuotedBody', 'ghi'),
-      hl('DoubleQuotedEscape', '\\"'),
-      hl('DoubleQuotedBody', 'jkl'),
-      hl('DoubleQuotedEscape', '\\"'),
-      hl('DoubleQuotedBody', 'mno'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"\\b\\e\\f\\r\\t\\\\"', {
-      --           0123456789012345
-      --           0         1
-      ast = {
-        [[DoubleQuotedString(val="\8\27\12\13\9\\"):0:0:"\b\e\f\r\t\\"]],
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\b'),
-      hl('DoubleQuotedEscape', '\\e'),
-      hl('DoubleQuotedEscape', '\\f'),
-      hl('DoubleQuotedEscape', '\\r'),
-      hl('DoubleQuotedEscape', '\\t'),
-      hl('DoubleQuotedEscape', '\\\\'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"\\n\n"', {
-      --           01234
-      ast = {
-        'DoubleQuotedString(val="\\\n\\\n"):0:0:"\\n\n"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\n'),
-      hl('DoubleQuotedBody', '\n'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"\\x00"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\0"):0:0:"\\x00"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\x00'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"\\xFF"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\255"):0:0:"\\xFF"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\xFF'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"\\xF"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\15"):0:0:"\\xF"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\xF'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"\\u00AB"', {
-      --           01234567
-      ast = {
-        'DoubleQuotedString(val="«"):0:0:"\\u00AB"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\u00AB'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"\\U000000AB"', {
-      --           01234567
-      ast = {
-        'DoubleQuotedString(val="«"):0:0:"\\U000000AB"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U000000AB'),
-      hl('DoubleQuote', '"'),
-    })
-    check_parsing('"\\x"', {
-      --           0123
-      ast = {
-        'DoubleQuotedString(val="x"):0:0:"\\x"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\x'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\x', {
-      --           012
-      ast = {
-        'DoubleQuotedString(val="x"):0:0:"\\x',
-      },
-      err = {
-        arg = '"\\x',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedUnknownEscape', '\\x'),
-    })
-
-    check_parsing('"\\xF', {
-      --           0123
-      ast = {
-        'DoubleQuotedString(val="\\15"):0:0:"\\xF',
-      },
-      err = {
-        arg = '"\\xF',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedEscape', '\\xF'),
-    })
-
-    check_parsing('"\\u"', {
-      --           0123
-      ast = {
-        'DoubleQuotedString(val="u"):0:0:"\\u"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\u'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\u', {
-      --           012
-      ast = {
-        'DoubleQuotedString(val="u"):0:0:"\\u',
-      },
-      err = {
-        arg = '"\\u',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedUnknownEscape', '\\u'),
-    })
-
-    check_parsing('"\\U', {
-      --           012
-      ast = {
-        'DoubleQuotedString(val="U"):0:0:"\\U',
-      },
-      err = {
-        arg = '"\\U',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
-    })
-
-    check_parsing('"\\U"', {
-      --           0123
-      ast = {
-        'DoubleQuotedString(val="U"):0:0:"\\U"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\U'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\xFX"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\15X"):0:0:"\\xFX"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\xF'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\XFX"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\15X"):0:0:"\\XFX"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\XF'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\xX"', {
-      --           01234
-      ast = {
-        'DoubleQuotedString(val="xX"):0:0:"\\xX"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\x'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\XX"', {
-      --           01234
-      ast = {
-        'DoubleQuotedString(val="XX"):0:0:"\\XX"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\X'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\uX"', {
-      --           01234
-      ast = {
-        'DoubleQuotedString(val="uX"):0:0:"\\uX"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\u'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\UX"', {
-      --           01234
-      ast = {
-        'DoubleQuotedString(val="UX"):0:0:"\\UX"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\U'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\x0X"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\x0X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\x0'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\X0X"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\X0X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\X0'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\u0X"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\u0X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\u0'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\U0X"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\U0X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U0'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\x00X"', {
-      --           0123456
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\x00X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\x00'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\X00X"', {
-      --           0123456
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\X00X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\X00'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\u00X"', {
-      --           0123456
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\u00X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\u00'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\U00X"', {
-      --           0123456
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\U00X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U00'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\u000X"', {
-      --           01234567
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\u000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\u000'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\U000X"', {
-      --           01234567
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\U000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U000'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\u0000X"', {
-      --           012345678
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\u0000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\u0000'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\U0000X"', {
-      --           012345678
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\U0000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U0000'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\U00000X"', {
-      --           0123456789
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\U00000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U00000'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\U000000X"', {
-      --           01234567890
-      --           0         1
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\U000000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U000000'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\U0000000X"', {
-      --           012345678901
-      --           0         1
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\U0000000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U0000000'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\U00000000X"', {
-      --           0123456789012
-      --           0         1
-      ast = {
-        'DoubleQuotedString(val="\\0X"):0:0:"\\U00000000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U00000000'),
-      hl('DoubleQuotedBody', 'X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\x000X"', {
-      --           01234567
-      ast = {
-        'DoubleQuotedString(val="\\0000X"):0:0:"\\x000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\x00'),
-      hl('DoubleQuotedBody', '0X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\X000X"', {
-      --           01234567
-      ast = {
-        'DoubleQuotedString(val="\\0000X"):0:0:"\\X000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\X00'),
-      hl('DoubleQuotedBody', '0X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\u00000X"', {
-      --           0123456789
-      ast = {
-        'DoubleQuotedString(val="\\0000X"):0:0:"\\u00000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\u0000'),
-      hl('DoubleQuotedBody', '0X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\U000000000X"', {
-      --           01234567890123
-      --           0         1
-      ast = {
-        'DoubleQuotedString(val="\\0000X"):0:0:"\\U000000000X"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\U00000000'),
-      hl('DoubleQuotedBody', '0X'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\0"', {
-      --           0123
-      ast = {
-        'DoubleQuotedString(val="\\0"):0:0:"\\0"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\0'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\00"', {
-      --           01234
-      ast = {
-        'DoubleQuotedString(val="\\0"):0:0:"\\00"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\00'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\000"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\0"):0:0:"\\000"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\000'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\0000"', {
-      --           0123456
-      ast = {
-        'DoubleQuotedString(val="\\0000"):0:0:"\\0000"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\000'),
-      hl('DoubleQuotedBody', '0'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\8"', {
-      --           0123
-      ast = {
-        'DoubleQuotedString(val="8"):0:0:"\\8"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\8'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\08"', {
-      --           01234
-      ast = {
-        'DoubleQuotedString(val="\\0008"):0:0:"\\08"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\0'),
-      hl('DoubleQuotedBody', '8'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\008"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\0008"):0:0:"\\008"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\00'),
-      hl('DoubleQuotedBody', '8'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\0008"', {
-      --           0123456
-      ast = {
-        'DoubleQuotedString(val="\\0008"):0:0:"\\0008"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\000'),
-      hl('DoubleQuotedBody', '8'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\777"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\255"):0:0:"\\777"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\777'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\050"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\40"):0:0:"\\050"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\050'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\<C-u>"', {
-      --           012345
-      ast = {
-        'DoubleQuotedString(val="\\21"):0:0:"\\<C-u>"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedEscape', '\\<C-u>'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\<', {
-      --           012
-      ast = {
-        'DoubleQuotedString(val="<"):0:0:"\\<',
-      },
-      err = {
-        arg = '"\\<',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedUnknownEscape', '\\<'),
-    })
-
-    check_parsing('"\\<"', {
-      --           0123
-      ast = {
-        'DoubleQuotedString(val="<"):0:0:"\\<"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\<'),
-      hl('DoubleQuote', '"'),
-    })
-
-    check_parsing('"\\<C-u"', {
-      --           0123456
-      ast = {
-        'DoubleQuotedString(val="<C-u"):0:0:"\\<C-u"',
-      },
-    }, {
-      hl('DoubleQuote', '"'),
-      hl('DoubleQuotedUnknownEscape', '\\<'),
-      hl('DoubleQuotedBody', 'C-u'),
-      hl('DoubleQuote', '"'),
-    })
-  end)
-  itp('works with multiplication-like operators', function()
-    check_parsing('2+2*2', {
-      --           01234
-      ast = {
-        {
-          'BinaryPlus:0:1:+',
-          children = {
-            'Integer(val=2):0:0:2',
-            {
-              'Multiplication:0:3:*',
-              children = {
-                'Integer(val=2):0:2:2',
-                'Integer(val=2):0:4:2',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Number', '2'),
-      hl('BinaryPlus', '+'),
-      hl('Number', '2'),
-      hl('Multiplication', '*'),
-      hl('Number', '2'),
-    })
-
-    check_parsing('2+2*', {
-      --           0123
-      ast = {
-        {
-          'BinaryPlus:0:1:+',
-          children = {
-            'Integer(val=2):0:0:2',
-            {
-              'Multiplication:0:3:*',
-              children = {
-                'Integer(val=2):0:2:2',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('Number', '2'),
-      hl('BinaryPlus', '+'),
-      hl('Number', '2'),
-      hl('Multiplication', '*'),
-    })
-
-    check_parsing('2+*2', {
-      --           0123
-      ast = {
-        {
-          'BinaryPlus:0:1:+',
-          children = {
-            'Integer(val=2):0:0:2',
-            {
-              'Multiplication:0:2:*',
-              children = {
-                'Missing:0:2:',
-                'Integer(val=2):0:3:2',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '*2',
-        msg = 'E15: Unexpected multiplication-like operator: %.*s',
-      },
-    }, {
-      hl('Number', '2'),
-      hl('BinaryPlus', '+'),
-      hl('InvalidMultiplication', '*'),
-      hl('Number', '2'),
-    })
-
-    check_parsing('2+2/2', {
-      --           01234
-      ast = {
-        {
-          'BinaryPlus:0:1:+',
-          children = {
-            'Integer(val=2):0:0:2',
-            {
-              'Division:0:3:/',
-              children = {
-                'Integer(val=2):0:2:2',
-                'Integer(val=2):0:4:2',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Number', '2'),
-      hl('BinaryPlus', '+'),
-      hl('Number', '2'),
-      hl('Division', '/'),
-      hl('Number', '2'),
-    })
-
-    check_parsing('2+2/', {
-      --           0123
-      ast = {
-        {
-          'BinaryPlus:0:1:+',
-          children = {
-            'Integer(val=2):0:0:2',
-            {
-              'Division:0:3:/',
-              children = {
-                'Integer(val=2):0:2:2',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('Number', '2'),
-      hl('BinaryPlus', '+'),
-      hl('Number', '2'),
-      hl('Division', '/'),
-    })
-
-    check_parsing('2+/2', {
-      --           0123
-      ast = {
-        {
-          'BinaryPlus:0:1:+',
-          children = {
-            'Integer(val=2):0:0:2',
-            {
-              'Division:0:2:/',
-              children = {
-                'Missing:0:2:',
-                'Integer(val=2):0:3:2',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '/2',
-        msg = 'E15: Unexpected multiplication-like operator: %.*s',
-      },
-    }, {
-      hl('Number', '2'),
-      hl('BinaryPlus', '+'),
-      hl('InvalidDivision', '/'),
-      hl('Number', '2'),
-    })
-
-    check_parsing('2+2%2', {
-      --           01234
-      ast = {
-        {
-          'BinaryPlus:0:1:+',
-          children = {
-            'Integer(val=2):0:0:2',
-            {
-              'Mod:0:3:%',
-              children = {
-                'Integer(val=2):0:2:2',
-                'Integer(val=2):0:4:2',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Number', '2'),
-      hl('BinaryPlus', '+'),
-      hl('Number', '2'),
-      hl('Mod', '%'),
-      hl('Number', '2'),
-    })
-
-    check_parsing('2+2%', {
-      --           0123
-      ast = {
-        {
-          'BinaryPlus:0:1:+',
-          children = {
-            'Integer(val=2):0:0:2',
-            {
-              'Mod:0:3:%',
-              children = {
-                'Integer(val=2):0:2:2',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('Number', '2'),
-      hl('BinaryPlus', '+'),
-      hl('Number', '2'),
-      hl('Mod', '%'),
-    })
-
-    check_parsing('2+%2', {
-      --           0123
-      ast = {
-        {
-          'BinaryPlus:0:1:+',
-          children = {
-            'Integer(val=2):0:0:2',
-            {
-              'Mod:0:2:%',
-              children = {
-                'Missing:0:2:',
-                'Integer(val=2):0:3:2',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '%2',
-        msg = 'E15: Unexpected multiplication-like operator: %.*s',
-      },
-    }, {
-      hl('Number', '2'),
-      hl('BinaryPlus', '+'),
-      hl('InvalidMod', '%'),
-      hl('Number', '2'),
-    })
-  end)
-  itp('works with -', function()
-    check_parsing('@a', {
-      ast = {
-        'Register(name=a):0:0:@a',
-      },
-    }, {
-      hl('Register', '@a'),
-    })
-    check_parsing('-@a', {
-      ast = {
-        {
-          'UnaryMinus:0:0:-',
-          children = {
-            'Register(name=a):0:1:@a',
-          },
-        },
-      },
-    }, {
-      hl('UnaryMinus', '-'),
-      hl('Register', '@a'),
-    })
-    check_parsing('@a-@b', {
-      ast = {
-        {
-          'BinaryMinus:0:2:-',
-          children = {
-            'Register(name=a):0:0:@a',
-            'Register(name=b):0:3:@b',
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryMinus', '-'),
-      hl('Register', '@b'),
-    })
-    check_parsing('@a-@b-@c', {
-      ast = {
-        {
-          'BinaryMinus:0:5:-',
-          children = {
-            {
-              'BinaryMinus:0:2:-',
-              children = {
-                'Register(name=a):0:0:@a',
-                'Register(name=b):0:3:@b',
-              },
-            },
-            'Register(name=c):0:6:@c',
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryMinus', '-'),
-      hl('Register', '@b'),
-      hl('BinaryMinus', '-'),
-      hl('Register', '@c'),
-    })
-    check_parsing('-@a-@b', {
-      ast = {
-        {
-          'BinaryMinus:0:3:-',
-          children = {
-            {
-              'UnaryMinus:0:0:-',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-            'Register(name=b):0:4:@b',
-          },
-        },
-      },
-    }, {
-      hl('UnaryMinus', '-'),
-      hl('Register', '@a'),
-      hl('BinaryMinus', '-'),
-      hl('Register', '@b'),
-    })
-    check_parsing('-@a--@b', {
-      ast = {
-        {
-          'BinaryMinus:0:3:-',
-          children = {
-            {
-              'UnaryMinus:0:0:-',
-              children = {
-                'Register(name=a):0:1:@a',
-              },
-            },
-            {
-              'UnaryMinus:0:4:-',
-              children = {
-                'Register(name=b):0:5:@b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('UnaryMinus', '-'),
-      hl('Register', '@a'),
-      hl('BinaryMinus', '-'),
-      hl('UnaryMinus', '-'),
-      hl('Register', '@b'),
-    })
-    check_parsing('-', {
-      ast = {
-        'UnaryMinus:0:0:-',
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('UnaryMinus', '-'),
-    })
-    check_parsing(' -', {
-      ast = {
-        'UnaryMinus:0:0: -',
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('UnaryMinus', '-', 1),
-    })
-    check_parsing('@a-  ', {
-      ast = {
-        {
-          'BinaryMinus:0:2:-',
-          children = {
-            'Register(name=a):0:0:@a',
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('BinaryMinus', '-'),
-    })
-  end)
-  itp('works with logical operators', function()
-    check_parsing('a && b || c && d', {
-      --           0123456789012345
-      --           0         1
-      ast = {
-        {
-          'Or:0:6: ||',
-          children = {
-            {
-              'And:0:1: &&',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                'PlainIdentifier(scope=0,ident=b):0:4: b',
-              },
-            },
-            {
-              'And:0:11: &&',
-              children = {
-                'PlainIdentifier(scope=0,ident=c):0:9: c',
-                'PlainIdentifier(scope=0,ident=d):0:14: d',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('And', '&&', 1),
-      hl('IdentifierName', 'b', 1),
-      hl('Or', '||', 1),
-      hl('IdentifierName', 'c', 1),
-      hl('And', '&&', 1),
-      hl('IdentifierName', 'd', 1),
-    })
-
-    check_parsing('&& a', {
-      --           0123
-      ast = {
-        {
-          'And:0:0:&&',
-          children = {
-            'Missing:0:0:',
-            'PlainIdentifier(scope=0,ident=a):0:2: a',
-          },
-        },
-      },
-      err = {
-        arg = '&& a',
-        msg = 'E15: Unexpected and operator: %.*s',
-      },
-    }, {
-      hl('InvalidAnd', '&&'),
-      hl('IdentifierName', 'a', 1),
-    })
-
-    check_parsing('|| a', {
-      --           0123
-      ast = {
-        {
-          'Or:0:0:||',
-          children = {
-            'Missing:0:0:',
-            'PlainIdentifier(scope=0,ident=a):0:2: a',
-          },
-        },
-      },
-      err = {
-        arg = '|| a',
-        msg = 'E15: Unexpected or operator: %.*s',
-      },
-    }, {
-      hl('InvalidOr', '||'),
-      hl('IdentifierName', 'a', 1),
-    })
-
-    check_parsing('a||', {
-      --           012
-      ast = {
-        {
-          'Or:0:1:||',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Or', '||'),
-    })
-
-    check_parsing('a&&', {
-      --           012
-      ast = {
-        {
-          'And:0:1:&&',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('And', '&&'),
-    })
-
-    check_parsing('(&&)', {
-      --           0123
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'And:0:1:&&',
-              children = {
-                'Missing:0:1:',
-                'Missing:0:3:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '&&)',
-        msg = 'E15: Unexpected and operator: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('InvalidAnd', '&&'),
-      hl('InvalidNestingParenthesis', ')'),
-    })
-
-    check_parsing('(||)', {
-      --           0123
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'Or:0:1:||',
-              children = {
-                'Missing:0:1:',
-                'Missing:0:3:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '||)',
-        msg = 'E15: Unexpected or operator: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('InvalidOr', '||'),
-      hl('InvalidNestingParenthesis', ')'),
-    })
-
-    check_parsing('(a||)', {
-      --           01234
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'Or:0:2:||',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'Missing:0:4:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ')',
-        msg = 'E15: Expected value, got parenthesis: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('IdentifierName', 'a'),
-      hl('Or', '||'),
-      hl('InvalidNestingParenthesis', ')'),
-    })
-
-    check_parsing('(a&&)', {
-      --           01234
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'And:0:2:&&',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'Missing:0:4:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ')',
-        msg = 'E15: Expected value, got parenthesis: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('IdentifierName', 'a'),
-      hl('And', '&&'),
-      hl('InvalidNestingParenthesis', ')'),
-    })
-
-    check_parsing('(&&a)', {
-      --           01234
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'And:0:1:&&',
-              children = {
-                'Missing:0:1:',
-                'PlainIdentifier(scope=0,ident=a):0:3:a',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '&&a)',
-        msg = 'E15: Unexpected and operator: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('InvalidAnd', '&&'),
-      hl('IdentifierName', 'a'),
-      hl('NestingParenthesis', ')'),
-    })
-
-    check_parsing('(||a)', {
-      --           01234
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'Or:0:1:||',
-              children = {
-                'Missing:0:1:',
-                'PlainIdentifier(scope=0,ident=a):0:3:a',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '||a)',
-        msg = 'E15: Unexpected or operator: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('InvalidOr', '||'),
-      hl('IdentifierName', 'a'),
-      hl('NestingParenthesis', ')'),
-    })
-  end)
-  itp('works with &opt', function()
-    check_parsing('&', {
-      --           0
-      ast = {
-        'Option(scope=0,ident=):0:0:&',
-      },
-      err = {
-        arg = '&',
-        msg = 'E112: Option name missing: %.*s',
-      },
-    }, {
-      hl('InvalidOptionSigil', '&'),
-    })
-
-    check_parsing('&opt', {
-      --           0123
-      ast = {
-        'Option(scope=0,ident=opt):0:0:&opt',
-      },
-    }, {
-      hl('OptionSigil', '&'),
-      hl('OptionName', 'opt'),
-    })
-
-    check_parsing('&l:opt', {
-      --           012345
-      ast = {
-        'Option(scope=l,ident=opt):0:0:&l:opt',
-      },
-    }, {
-      hl('OptionSigil', '&'),
-      hl('OptionScope', 'l'),
-      hl('OptionScopeDelimiter', ':'),
-      hl('OptionName', 'opt'),
-    })
-
-    check_parsing('&g:opt', {
-      --           012345
-      ast = {
-        'Option(scope=g,ident=opt):0:0:&g:opt',
-      },
-    }, {
-      hl('OptionSigil', '&'),
-      hl('OptionScope', 'g'),
-      hl('OptionScopeDelimiter', ':'),
-      hl('OptionName', 'opt'),
-    })
-
-    check_parsing('&s:opt', {
-      --           012345
-      ast = {
-        {
-          'Colon:0:2::',
-          children = {
-            'Option(scope=0,ident=s):0:0:&s',
-            'PlainIdentifier(scope=0,ident=opt):0:3:opt',
-          },
-        },
-      },
-      err = {
-        arg = ':opt',
-        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-      },
-    }, {
-      hl('OptionSigil', '&'),
-      hl('OptionName', 's'),
-      hl('InvalidColon', ':'),
-      hl('IdentifierName', 'opt'),
-    })
-
-    check_parsing('& ', {
-      --           01
-      ast = {
-        'Option(scope=0,ident=):0:0:&',
-      },
-      err = {
-        arg = '& ',
-        msg = 'E112: Option name missing: %.*s',
-      },
-    }, {
-      hl('InvalidOptionSigil', '&'),
-    })
-
-    check_parsing('&-', {
-      --           01
-      ast = {
-        {
-          'BinaryMinus:0:1:-',
-          children = {
-            'Option(scope=0,ident=):0:0:&',
-          },
-        },
-      },
-      err = {
-        arg = '&-',
-        msg = 'E112: Option name missing: %.*s',
-      },
-    }, {
-      hl('InvalidOptionSigil', '&'),
-      hl('BinaryMinus', '-'),
-    })
-
-    check_parsing('&A', {
-      --           01
-      ast = {
-        'Option(scope=0,ident=A):0:0:&A',
-      },
-    }, {
-      hl('OptionSigil', '&'),
-      hl('OptionName', 'A'),
-    })
-
-    check_parsing('&xxx_yyy', {
-      --           01234567
-      ast = {
-        {
-          'OpMissing:0:4:',
-          children = {
-            'Option(scope=0,ident=xxx):0:0:&xxx',
-            'PlainIdentifier(scope=0,ident=_yyy):0:4:_yyy',
-          },
-        },
-      },
-      err = {
-        arg = '_yyy',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('OptionSigil', '&'),
-      hl('OptionName', 'xxx'),
-      hl('InvalidIdentifierName', '_yyy'),
-    }, {
-      [1] = {
-        ast = {
-          err = REMOVE_THIS,
-          ast = {
-            'Option(scope=0,ident=xxx):0:0:&xxx',
-          },
-        },
-        hl_fs = {
-          [3] = REMOVE_THIS,
-        },
-      },
-    })
-
-    check_parsing('(1+&)', {
-      --           01234
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'BinaryPlus:0:2:+',
-              children = {
-                'Integer(val=1):0:1:1',
-                'Option(scope=0,ident=):0:3:&',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '&)',
-        msg = 'E112: Option name missing: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Number', '1'),
-      hl('BinaryPlus', '+'),
-      hl('InvalidOptionSigil', '&'),
-      hl('NestingParenthesis', ')'),
-    })
-
-    check_parsing('(&+1)', {
-      --           01234
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'BinaryPlus:0:2:+',
-              children = {
-                'Option(scope=0,ident=):0:1:&',
-                'Integer(val=1):0:3:1',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '&+1)',
-        msg = 'E112: Option name missing: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('InvalidOptionSigil', '&'),
-      hl('BinaryPlus', '+'),
-      hl('Number', '1'),
-      hl('NestingParenthesis', ')'),
-    })
-  end)
-  itp('works with $ENV', function()
-    check_parsing('$', {
-      --           0
-      ast = {
-        'Environment(ident=):0:0:$',
-      },
-      err = {
-        arg = '$',
-        msg = 'E15: Environment variable name missing',
-      },
-    }, {
-      hl('InvalidEnvironmentSigil', '$'),
-    })
-
-    check_parsing('$g:A', {
-      --           0123
-      ast = {
-        {
-          'Colon:0:2::',
-          children = {
-            'Environment(ident=g):0:0:$g',
-            'PlainIdentifier(scope=0,ident=A):0:3:A',
-          },
-        },
-      },
-      err = {
-        arg = ':A',
-        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-      },
-    }, {
-      hl('EnvironmentSigil', '$'),
-      hl('EnvironmentName', 'g'),
-      hl('InvalidColon', ':'),
-      hl('IdentifierName', 'A'),
-    })
-
-    check_parsing('$A', {
-      --           01
-      ast = {
-        'Environment(ident=A):0:0:$A',
-      },
-    }, {
-      hl('EnvironmentSigil', '$'),
-      hl('EnvironmentName', 'A'),
-    })
-
-    check_parsing('$ABC', {
-      --           0123
-      ast = {
-        'Environment(ident=ABC):0:0:$ABC',
-      },
-    }, {
-      hl('EnvironmentSigil', '$'),
-      hl('EnvironmentName', 'ABC'),
-    })
-
-    check_parsing('(1+$)', {
-      --           01234
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'BinaryPlus:0:2:+',
-              children = {
-                'Integer(val=1):0:1:1',
-                'Environment(ident=):0:3:$',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '$)',
-        msg = 'E15: Environment variable name missing',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Number', '1'),
-      hl('BinaryPlus', '+'),
-      hl('InvalidEnvironmentSigil', '$'),
-      hl('NestingParenthesis', ')'),
-    })
-
-    check_parsing('($+1)', {
-      --           01234
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'BinaryPlus:0:2:+',
-              children = {
-                'Environment(ident=):0:1:$',
-                'Integer(val=1):0:3:1',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '$+1)',
-        msg = 'E15: Environment variable name missing',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('InvalidEnvironmentSigil', '$'),
-      hl('BinaryPlus', '+'),
-      hl('Number', '1'),
-      hl('NestingParenthesis', ')'),
-    })
-
-    check_parsing('$_ABC', {
-      --           01234
-      ast = {
-        'Environment(ident=_ABC):0:0:$_ABC',
-      },
-    }, {
-      hl('EnvironmentSigil', '$'),
-      hl('EnvironmentName', '_ABC'),
-    })
-
-    check_parsing('$_', {
-      --           01
-      ast = {
-        'Environment(ident=_):0:0:$_',
-      },
-    }, {
-      hl('EnvironmentSigil', '$'),
-      hl('EnvironmentName', '_'),
-    })
-
-    check_parsing('$ABC_DEF', {
-      --           01234567
-      ast = {
-        'Environment(ident=ABC_DEF):0:0:$ABC_DEF',
-      },
-    }, {
-      hl('EnvironmentSigil', '$'),
-      hl('EnvironmentName', 'ABC_DEF'),
-    })
-  end)
-  itp('works with unary !', function()
-    check_parsing('!', {
-      --           0
-      ast = {
-        'Not:0:0:!',
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('Not', '!'),
-    })
-
-    check_parsing('!!', {
-      --           01
-      ast = {
-        {
-          'Not:0:0:!',
-          children = {
-            'Not:0:1:!',
-          },
-        },
-      },
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-      hl('Not', '!'),
-      hl('Not', '!'),
-    })
-
-    check_parsing('!!1', {
-      --           012
-      ast = {
-        {
-          'Not:0:0:!',
-          children = {
-            {
-              'Not:0:1:!',
-              children = {
-                'Integer(val=1):0:2:1',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('Not', '!'),
-      hl('Not', '!'),
-      hl('Number', '1'),
-    })
-
-    check_parsing('!1', {
-      --           01
-      ast = {
-        {
-          'Not:0:0:!',
-          children = {
-            'Integer(val=1):0:1:1',
-          },
-        },
-      },
-    }, {
-      hl('Not', '!'),
-      hl('Number', '1'),
-    })
-
-    check_parsing('(!1)', {
-      --           0123
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'Not:0:1:!',
-              children = {
-                'Integer(val=1):0:2:1',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Not', '!'),
-      hl('Number', '1'),
-      hl('NestingParenthesis', ')'),
-    })
-
-    check_parsing('(!)', {
-      --           012
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'Not:0:1:!',
-              children = {
-                'Missing:0:2:',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ')',
-        msg = 'E15: Expected value, got parenthesis: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Not', '!'),
-      hl('InvalidNestingParenthesis', ')'),
-    })
-
-    check_parsing('(1!2)', {
-      --           01234
-      ast = {
-        {
-          'Nested:0:0:(',
-          children = {
-            {
-              'OpMissing:0:2:',
-              children = {
-                'Integer(val=1):0:1:1',
-                {
-                  'Not:0:2:!',
-                  children = {
-                    'Integer(val=2):0:3:2',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '!2)',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('NestingParenthesis', '('),
-      hl('Number', '1'),
-      hl('InvalidNot', '!'),
-      hl('Number', '2'),
-      hl('NestingParenthesis', ')'),
-    })
-
-    check_parsing('1!2', {
-      --           012
-      ast = {
-        {
-          'OpMissing:0:1:',
-          children = {
-            'Integer(val=1):0:0:1',
-            {
-              'Not:0:1:!',
-              children = {
-                'Integer(val=2):0:2:2',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '!2',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('Number', '1'),
-      hl('InvalidNot', '!'),
-      hl('Number', '2'),
-    }, {
-      [1] = {
-        ast = {
-          err = REMOVE_THIS,
-          ast = {
-            'Integer(val=1):0:0:1',
-          },
-        },
-        hl_fs = {
-          [2] = REMOVE_THIS,
-          [3] = REMOVE_THIS,
-        },
-      },
-    })
-  end)
-  itp('highlights numbers with prefix', function()
-    check_parsing('0xABCDEF', {
-      --           01234567
-      ast = {
-        'Integer(val=11259375):0:0:0xABCDEF',
-      },
-    }, {
-      hl('NumberPrefix', '0x'),
-      hl('Number', 'ABCDEF'),
-    })
-
-    check_parsing('0Xabcdef', {
-      --           01234567
-      ast = {
-        'Integer(val=11259375):0:0:0Xabcdef',
-      },
-    }, {
-      hl('NumberPrefix', '0X'),
-      hl('Number', 'abcdef'),
-    })
-
-    check_parsing('0XABCDEF', {
-      --           01234567
-      ast = {
-        'Integer(val=11259375):0:0:0XABCDEF',
-      },
-    }, {
-      hl('NumberPrefix', '0X'),
-      hl('Number', 'ABCDEF'),
-    })
-
-    check_parsing('0xabcdef', {
-      --           01234567
-      ast = {
-        'Integer(val=11259375):0:0:0xabcdef',
-      },
-    }, {
-      hl('NumberPrefix', '0x'),
-      hl('Number', 'abcdef'),
-    })
-
-    check_parsing('0b001', {
-      --           01234
-      ast = {
-        'Integer(val=1):0:0:0b001',
-      },
-    }, {
-      hl('NumberPrefix', '0b'),
-      hl('Number', '001'),
-    })
-
-    check_parsing('0B001', {
-      --           01234
-      ast = {
-        'Integer(val=1):0:0:0B001',
-      },
-    }, {
-      hl('NumberPrefix', '0B'),
-      hl('Number', '001'),
-    })
-
-    check_parsing('0B00', {
-      --           0123
-      ast = {
-        'Integer(val=0):0:0:0B00',
-      },
-    }, {
-      hl('NumberPrefix', '0B'),
-      hl('Number', '00'),
-    })
-
-    check_parsing('00', {
-      --           01
-      ast = {
-        'Integer(val=0):0:0:00',
-      },
-    }, {
-      hl('NumberPrefix', '0'),
-      hl('Number', '0'),
-    })
-
-    check_parsing('001', {
-      --           012
-      ast = {
-        'Integer(val=1):0:0:001',
-      },
-    }, {
-      hl('NumberPrefix', '0'),
-      hl('Number', '01'),
-    })
-
-    check_parsing('01', {
-      --           01
-      ast = {
-        'Integer(val=1):0:0:01',
-      },
-    }, {
-      hl('NumberPrefix', '0'),
-      hl('Number', '1'),
-    })
-
-    check_parsing('1', {
-      --           0
-      ast = {
-        'Integer(val=1):0:0:1',
-      },
-    }, {
-      hl('Number', '1'),
-    })
-  end)
-  itp('works (KLEE tests)', function()
-    check_parsing('\0002&A:\000', {
-      ast = nil,
-      err = {
-        arg = '',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-    }, {
-      [2] = {
-        ast = {
-          ast = {
-            {
-              'Colon:0:4::',
-              children = {
-                {
-                  'OpMissing:0:2:',
-                  children = {
-                    'Integer(val=2):0:1:2',
-                    'Option(scope=0,ident=A):0:2:&A',
-                  },
-                },
-              },
-            },
-          },
-          err = {
-            msg = 'E15: Unexpected EOC character: %.*s',
-          },
-        },
-        hl_fs = {
-          hl('InvalidSpacing', '\0'),
-          hl('Number', '2'),
-          hl('InvalidOptionSigil', '&'),
-          hl('InvalidOptionName', 'A'),
-          hl('InvalidColon', ':'),
-          hl('InvalidSpacing', '\0'),
-        },
-      },
-      [3] = {
-        ast = {
-          ast = {
-            'Integer(val=2):0:1:2',
-          },
-          err = {
-            msg = 'E15: Unexpected EOC character: %.*s',
-          },
-        },
-        hl_fs = {
-          hl('InvalidSpacing', '\0'),
-          hl('Number', '2'),
-        },
-      },
-    })
-    check_parsing({data='01', size=1}, {
-      ast = {
-        'Integer(val=0):0:0:0',
-      },
-    }, {
-      hl('Number', '0'),
-    })
-    check_parsing({data='001', size=2}, {
-      ast = {
-        'Integer(val=0):0:0:00',
-      },
-    }, {
-      hl('NumberPrefix', '0'),
-      hl('Number', '0'),
-    })
-    check_parsing('"\\U\\', {
-      --           0123
-      ast = {
-        [[DoubleQuotedString(val="U\\"):0:0:"\U\]],
-      },
-      err = {
-        arg = '"\\U\\',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
-      hl('InvalidDoubleQuotedBody', '\\'),
-    })
-    check_parsing('"\\U', {
-      --           012
-      ast = {
-        'DoubleQuotedString(val="U"):0:0:"\\U',
-      },
-      err = {
-        arg = '"\\U',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
-    })
-    check_parsing('|"\\U\\', {
-      --           01234
-      err = {
-        arg = '|"\\U\\',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-    }, {
-      [2] = {
-        ast = {
-          ast = {
-            {
-              'Or:0:0:|',
-              children = {
-                'Missing:0:0:',
-                'DoubleQuotedString(val="U\\\\"):0:1:"\\U\\',
-              },
-            },
-          },
-          err = {
-            msg = 'E15: Unexpected EOC character: %.*s',
-          },
-        },
-        hl_fs = {
-          hl('InvalidOr', '|'),
-          hl('InvalidDoubleQuote', '"'),
-          hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
-          hl('InvalidDoubleQuotedBody', '\\'),
-        },
-      },
-    })
-    check_parsing('|"\\e"', {
-      --           01234
-      err = {
-        arg = '|"\\e"',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-    }, {
-      [2] = {
-        ast = {
-          ast = {
-            {
-              'Or:0:0:|',
-              children = {
-                'Missing:0:0:',
-                'DoubleQuotedString(val="\\27"):0:1:"\\e"',
-              },
-            },
-          },
-          err = {
-            msg = 'E15: Unexpected EOC character: %.*s',
-          },
-        },
-        hl_fs = {
-          hl('InvalidOr', '|'),
-          hl('DoubleQuote', '"'),
-          hl('DoubleQuotedEscape', '\\e'),
-          hl('DoubleQuote', '"'),
-        },
-      },
-    })
-    check_parsing('|\029', {
-      --           01
-      err = {
-        arg = '|\029',
-        msg = 'E15: Expected value, got EOC: %.*s',
-      },
-    }, {
-    }, {
-      [2] = {
-        ast = {
-          ast = {
-            {
-              'Or:0:0:|',
-              children = {
-                'Missing:0:0:',
-                'PlainIdentifier(scope=0,ident=\029):0:1:\029',
-              },
-            },
-          },
-          err = {
-            msg = 'E15: Unexpected EOC character: %.*s',
-          },
-        },
-        hl_fs = {
-          hl('InvalidOr', '|'),
-          hl('InvalidIdentifierName', '\029'),
-        },
-      },
-    })
-    check_parsing('"\\<', {
-      --           012
-      ast = {
-        'DoubleQuotedString(val="<"):0:0:"\\<',
-      },
-      err = {
-        arg = '"\\<',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedUnknownEscape', '\\<'),
-    })
-    check_parsing('"\\1', {
-      --           012
-      ast = {
-        'DoubleQuotedString(val="\\1"):0:0:"\\1',
-      },
-      err = {
-        arg = '"\\1',
-        msg = 'E114: Missing double quote: %.*s',
-      },
-    }, {
-      hl('InvalidDoubleQuote', '"'),
-      hl('InvalidDoubleQuotedEscape', '\\1'),
-    })
-    check_parsing('}l', {
-      --           01
-      ast = {
-        {
-          'OpMissing:0:1:',
-          children = {
-            'UnknownFigure(---):0:0:',
-            'PlainIdentifier(scope=0,ident=l):0:1:l',
-          },
-        },
-      },
-      err = {
-        arg = '}l',
-        msg = 'E15: Unexpected closing figure brace: %.*s',
-      },
-    }, {
-      hl('InvalidFigureBrace', '}'),
-      hl('InvalidIdentifierName', 'l'),
-    }, {
-      [1] = {
-        ast = {
-          ast = {
-            'UnknownFigure(---):0:0:',
-          },
-        },
-        hl_fs = {
-          [2] = REMOVE_THIS,
-        },
-      },
-    })
-    check_parsing(':?\000\000\000\000\000\000\000', {
-      ast = {
-        {
-          'Colon:0:0::',
-          children = {
-            'Missing:0:0:',
-            {
-              'Ternary:0:1:?',
-              children = {
-                'Missing:0:1:',
-                'TernaryValue:0:1:?',
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = ':?',
-        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
-      },
-    }, {
-      hl('InvalidColon', ':'),
-      hl('InvalidTernary', '?'),
-    }, {
-      [2] = {
-        hl_fs = {
-          [3] = hl('InvalidSpacing', '\0'),
-          [4] = hl('InvalidSpacing', '\0'),
-          [5] = hl('InvalidSpacing', '\0'),
-          [6] = hl('InvalidSpacing', '\0'),
-          [7] = hl('InvalidSpacing', '\0'),
-          [8] = hl('InvalidSpacing', '\0'),
-          [9] = hl('InvalidSpacing', '\0'),
-        },
-      },
-    })
-  end)
-  itp('works with assignments', function()
-    check_asgn_parsing('a=b', {
-      --                012
-      ast = {
-        {
-          'Assignment(Plain):0:1:=',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:2:b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('PlainAssignment', '='),
-      hl('IdentifierName', 'b'),
-    })
-
-    check_asgn_parsing('a+=b', {
-      --                0123
-      ast = {
-        {
-          'Assignment(Add):0:1:+=',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:3:b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('AssignmentWithAddition', '+='),
-      hl('IdentifierName', 'b'),
-    })
-
-    check_asgn_parsing('a-=b', {
-      --                0123
-      ast = {
-        {
-          'Assignment(Subtract):0:1:-=',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:3:b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('AssignmentWithSubtraction', '-='),
-      hl('IdentifierName', 'b'),
-    })
-
-    check_asgn_parsing('a.=b', {
-      --                0123
-      ast = {
-        {
-          'Assignment(Concat):0:1:.=',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:3:b',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('AssignmentWithConcatenation', '.='),
-      hl('IdentifierName', 'b'),
-    })
-
-    check_asgn_parsing('a', {
-      --                0
-      ast = {
-        'PlainIdentifier(scope=0,ident=a):0:0:a',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-    })
-
-    check_asgn_parsing('a b', {
-      --                012
-      ast = {
-        {
-          'OpMissing:0:1:',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            'PlainIdentifier(scope=0,ident=b):0:1: b',
-          },
-        },
-      },
-      err = {
-        arg = 'b',
-        msg = 'E15: Expected assignment operator or subscript: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('InvalidSpacing', ' '),
-      hl('IdentifierName', 'b'),
-    }, {
-      [5] = {
-        ast = {
-          ast = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-          },
-          err = REMOVE_THIS,
-        },
-        hl_fs = {
-          [2] = REMOVE_THIS,
-          [3] = REMOVE_THIS,
-        }
-      },
-    })
-
-    check_asgn_parsing('[a, b, c]', {
-      --                012345678
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                {
-                  'Comma:0:5:,',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:3: b',
-                    'PlainIdentifier(scope=0,ident=c):0:6: c',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b', 1),
-      hl('Comma', ','),
-      hl('IdentifierName', 'c', 1),
-      hl('List', ']'),
-    })
-
-    check_asgn_parsing('[a, b]', {
-      --                012345
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            {
-              'Comma:0:2:,',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-                'PlainIdentifier(scope=0,ident=b):0:3: b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('Comma', ','),
-      hl('IdentifierName', 'b', 1),
-      hl('List', ']'),
-    })
-
-    check_asgn_parsing('[a]', {
-      --                012
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:1:a',
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('List', ']'),
-    })
-
-    check_asgn_parsing('[]', {
-      --                01
-      ast = {
-        'ListLiteral:0:0:[',
-      },
-      err = {
-        arg = ']',
-        msg = 'E475: Unable to assign to empty list: %.*s',
-      },
-    }, {
-      hl('List', '['),
-      hl('InvalidList', ']'),
-    })
-
-    check_asgn_parsing('a[1] += 3', {
-      --                012345678
-      ast = {
-        {
-          'Assignment(Add):0:4: +=',
-          children = {
-            {
-              'Subscript:0:1:[',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                'Integer(val=1):0:2:1',
-              },
-            },
-            'Integer(val=3):0:7: 3',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('Number', '1'),
-      hl('SubscriptBracket', ']'),
-      hl('AssignmentWithAddition', '+=', 1),
-      hl('Number', '3', 1),
-    })
-
-    check_asgn_parsing('a[1 + 2] += 3', {
-      --                0123456789012
-      --                0         1
-      ast = {
-        {
-          'Assignment(Add):0:8: +=',
-          children = {
-            {
-              'Subscript:0:1:[',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                {
-                  'BinaryPlus:0:3: +',
-                  children = {
-                    'Integer(val=1):0:2:1',
-                    'Integer(val=2):0:5: 2',
-                  },
-                },
-              },
-            },
-            'Integer(val=3):0:11: 3',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('Number', '1'),
-      hl('BinaryPlus', '+', 1),
-      hl('Number', '2', 1),
-      hl('SubscriptBracket', ']'),
-      hl('AssignmentWithAddition', '+=', 1),
-      hl('Number', '3', 1),
-    })
-
-    check_asgn_parsing('a[{-> {b{3}: 4}[5]}()] += 6', {
-      --                012345678901234567890123456
-      --                0         1         2
-      ast = {
-        {
-          'Assignment(Add):0:22: +=',
-          children = {
-            {
-              'Subscript:0:1:[',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                {
-                  'Call:0:19:(',
-                  children = {
-                    {
-                      'Lambda(\\di):0:2:{',
-                      children = {
-                        {
-                          'Arrow:0:3:->',
-                          children = {
-                            {
-                              'Subscript:0:15:[',
-                              children = {
-                                {
-                                  'DictLiteral(-di):0:5: {',
-                                  children = {
-                                    {
-                                      'Colon:0:11::',
-                                      children = {
-                                        {
-                                          'ComplexIdentifier:0:8:',
-                                          children = {
-                                            'PlainIdentifier(scope=0,ident=b):0:7:b',
-                                            {
-                                              'CurlyBracesIdentifier(--i):0:8:{',
-                                              children = {
-                                                'Integer(val=3):0:9:3',
-                                              },
-                                            },
-                                          },
-                                        },
-                                        'Integer(val=4):0:12: 4',
-                                      },
-                                    },
-                                  },
-                                },
-                                'Integer(val=5):0:16:5',
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-            'Integer(val=6):0:25: 6',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('Lambda', '{'),
-      hl('Arrow', '->'),
-      hl('Dict', '{', 1),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '{'),
-      hl('Number', '3'),
-      hl('Curly', '}'),
-      hl('Colon', ':'),
-      hl('Number', '4', 1),
-      hl('Dict', '}'),
-      hl('SubscriptBracket', '['),
-      hl('Number', '5'),
-      hl('SubscriptBracket', ']'),
-      hl('Lambda', '}'),
-      hl('CallingParenthesis', '('),
-      hl('CallingParenthesis', ')'),
-      hl('SubscriptBracket', ']'),
-      hl('AssignmentWithAddition', '+=', 1),
-      hl('Number', '6', 1),
-    })
-
-    check_asgn_parsing('a{1}.2[{-> {b{3}: 4}[5]}()]', {
-      --                012345678901234567890123456
-      --                0         1         2
-      ast = {
-        {
-          'Subscript:0:6:[',
-          children = {
-            {
-              'ConcatOrSubscript:0:4:.',
-              children = {
-                {
-                  'ComplexIdentifier:0:1:',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=a):0:0:a',
-                    {
-                      'CurlyBracesIdentifier(--i):0:1:{',
-                      children = {
-                        'Integer(val=1):0:2:1',
-                      },
-                    },
-                  },
-                },
-                'PlainKey(key=2):0:5:2',
-              },
-            },
-            {
-              'Call:0:24:(',
-              children = {
-                {
-                  'Lambda(\\di):0:7:{',
-                  children = {
-                    {
-                      'Arrow:0:8:->',
-                      children = {
-                        {
-                          'Subscript:0:20:[',
-                          children = {
-                            {
-                              'DictLiteral(-di):0:10: {',
-                              children = {
-                                {
-                                  'Colon:0:16::',
-                                  children = {
-                                    {
-                                      'ComplexIdentifier:0:13:',
-                                      children = {
-                                        'PlainIdentifier(scope=0,ident=b):0:12:b',
-                                        {
-                                          'CurlyBracesIdentifier(--i):0:13:{',
-                                          children = {
-                                            'Integer(val=3):0:14:3',
-                                          },
-                                        },
-                                      },
-                                    },
-                                    'Integer(val=4):0:17: 4',
-                                  },
-                                },
-                              },
-                            },
-                            'Integer(val=5):0:21:5',
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Curly', '{'),
-      hl('Number', '1'),
-      hl('Curly', '}'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '2'),
-      hl('SubscriptBracket', '['),
-      hl('Lambda', '{'),
-      hl('Arrow', '->'),
-      hl('Dict', '{', 1),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '{'),
-      hl('Number', '3'),
-      hl('Curly', '}'),
-      hl('Colon', ':'),
-      hl('Number', '4', 1),
-      hl('Dict', '}'),
-      hl('SubscriptBracket', '['),
-      hl('Number', '5'),
-      hl('SubscriptBracket', ']'),
-      hl('Lambda', '}'),
-      hl('CallingParenthesis', '('),
-      hl('CallingParenthesis', ')'),
-      hl('SubscriptBracket', ']'),
-    })
-
-    check_asgn_parsing('a', {
-      --                0
-      ast = {
-        'PlainIdentifier(scope=0,ident=a):0:0:a',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-    })
-
-    check_asgn_parsing('{a}', {
-      --                012
-      ast = {
-        {
-          'CurlyBracesIdentifier(--i):0:0:{',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:1:a',
-          },
-        },
-      },
-    }, {
-      hl('FigureBrace', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Curly', '}'),
-    })
-
-    check_asgn_parsing('{a}b', {
-      --                0123
-      ast = {
-        {
-          'ComplexIdentifier:0:3:',
-          children = {
-            {
-              'CurlyBracesIdentifier(--i):0:0:{',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-              },
-            },
-            'PlainIdentifier(scope=0,ident=b):0:3:b',
-          },
-        },
-      },
-    }, {
-      hl('FigureBrace', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Curly', '}'),
-      hl('IdentifierName', 'b'),
-    })
-
-    check_asgn_parsing('a{b}c', {
-      --                01234
-      ast = {
-        {
-          'ComplexIdentifier:0:1:',
-          children = {
-            'PlainIdentifier(scope=0,ident=a):0:0:a',
-            {
-              'ComplexIdentifier:0:4:',
-              children = {
-                {
-                  'CurlyBracesIdentifier(--i):0:1:{',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=b):0:2:b',
-                  },
-                },
-                'PlainIdentifier(scope=0,ident=c):0:4:c',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '}'),
-      hl('IdentifierName', 'c'),
-    })
-
-    check_asgn_parsing('a{b}c[0]', {
-      --                01234567
-      ast = {
-        {
-          'Subscript:0:5:[',
-          children = {
-            {
-              'ComplexIdentifier:0:1:',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                {
-                  'ComplexIdentifier:0:4:',
-                  children = {
-                    {
-                      'CurlyBracesIdentifier(--i):0:1:{',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=b):0:2:b',
-                      },
-                    },
-                    'PlainIdentifier(scope=0,ident=c):0:4:c',
-                  },
-                },
-              },
-            },
-            'Integer(val=0):0:6:0',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '}'),
-      hl('IdentifierName', 'c'),
-      hl('SubscriptBracket', '['),
-      hl('Number', '0'),
-      hl('SubscriptBracket', ']'),
-    })
-
-    check_asgn_parsing('a{b}c.0', {
-      --                0123456
-      ast = {
-        {
-          'ConcatOrSubscript:0:5:.',
-          children = {
-            {
-              'ComplexIdentifier:0:1:',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                {
-                  'ComplexIdentifier:0:4:',
-                  children = {
-                    {
-                      'CurlyBracesIdentifier(--i):0:1:{',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=b):0:2:b',
-                      },
-                    },
-                    'PlainIdentifier(scope=0,ident=c):0:4:c',
-                  },
-                },
-              },
-            },
-            'PlainKey(key=0):0:6:0',
-          },
-        },
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '}'),
-      hl('IdentifierName', 'c'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '0'),
-    })
-
-    check_asgn_parsing('[a{b}c[0].0]', {
-      --                012345678901
-      --                0         1
-      ast = {
-        {
-          'ListLiteral:0:0:[',
-          children = {
-            {
-              'ConcatOrSubscript:0:9:.',
-              children = {
-                {
-                  'Subscript:0:6:[',
-                  children = {
-                    {
-                      'ComplexIdentifier:0:2:',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=a):0:1:a',
-                        {
-                          'ComplexIdentifier:0:5:',
-                          children = {
-                            {
-                              'CurlyBracesIdentifier(--i):0:2:{',
-                              children = {
-                                'PlainIdentifier(scope=0,ident=b):0:3:b',
-                              },
-                            },
-                            'PlainIdentifier(scope=0,ident=c):0:5:c',
-                          },
-                        },
-                      },
-                    },
-                    'Integer(val=0):0:7:0',
-                  },
-                },
-                'PlainKey(key=0):0:10:0',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '}'),
-      hl('IdentifierName', 'c'),
-      hl('SubscriptBracket', '['),
-      hl('Number', '0'),
-      hl('SubscriptBracket', ']'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', '0'),
-      hl('List', ']'),
-    })
-
-    check_asgn_parsing('{a}{b}', {
-      --                012345
-      ast = {
-        {
-          'ComplexIdentifier:0:3:',
-          children = {
-            {
-              'CurlyBracesIdentifier(--i):0:0:{',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-              },
-            },
-            {
-              'CurlyBracesIdentifier(--i):0:3:{',
-              children = {
-                'PlainIdentifier(scope=0,ident=b):0:4:b',
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('FigureBrace', '{'),
-      hl('IdentifierName', 'a'),
-      hl('Curly', '}'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'b'),
-      hl('Curly', '}'),
-    })
-
-    check_asgn_parsing('a.b{c}{d}', {
-      --                012345678
-      ast = {
-        {
-          'OpMissing:0:3:',
-          children = {
-            {
-              'ConcatOrSubscript:0:1:.',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:0:a',
-                'PlainKey(key=b):0:2:b',
-              },
-            },
-            {
-              'ComplexIdentifier:0:6:',
-              children = {
-                {
-                  'CurlyBracesIdentifier(--i):0:3:{',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=c):0:4:c',
-                  },
-                },
-                {
-                  'CurlyBracesIdentifier(--i):0:6:{',
-                  children = {
-                    'PlainIdentifier(scope=0,ident=d):0:7:d',
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-      err = {
-        arg = '{c}{d}',
-        msg = 'E15: Missing operator: %.*s',
-      },
-    }, {
-      hl('IdentifierName', 'a'),
-      hl('ConcatOrSubscript', '.'),
-      hl('IdentifierKey', 'b'),
-      hl('InvalidFigureBrace', '{'),
-      hl('IdentifierName', 'c'),
-      hl('Curly', '}'),
-      hl('Curly', '{'),
-      hl('IdentifierName', 'd'),
-      hl('Curly', '}'),
-    })
-
-    check_asgn_parsing('[a] = 1', {
-      --                0123456
-      ast = {
-        {
-          'Assignment(Plain):0:3: =',
-          children = {
-            {
-              'ListLiteral:0:0:[',
-              children = {
-                'PlainIdentifier(scope=0,ident=a):0:1:a',
-              },
-            },
-            'Integer(val=1):0:5: 1',
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('List', ']'),
-      hl('PlainAssignment', '=', 1),
-      hl('Number', '1', 1),
-    })
-
-    check_asgn_parsing('[a[b], [c, [d, [e]]]] = 1', {
-      --                0123456789012345678901234
-      --                0         1         2
-      ast = {
-        {
-          'Assignment(Plain):0:21: =',
-          children = {
-            {
-              'ListLiteral:0:0:[',
-              children = {
-                {
-                  'Comma:0:5:,',
-                  children = {
-                    {
-                      'Subscript:0:2:[',
-                      children = {
-                        'PlainIdentifier(scope=0,ident=a):0:1:a',
-                        'PlainIdentifier(scope=0,ident=b):0:3:b',
-                      },
-                    },
-                    {
-                      'ListLiteral:0:6: [',
-                      children = {
-                        {
-                          'Comma:0:9:,',
-                          children = {
-                            'PlainIdentifier(scope=0,ident=c):0:8:c',
-                            {
-                              'ListLiteral:0:10: [',
-                              children = {
-                                {
-                                  'Comma:0:13:,',
-                                  children = {
-                                    'PlainIdentifier(scope=0,ident=d):0:12:d',
-                                    {
-                                      'ListLiteral:0:14: [',
-                                      children = {
-                                        'PlainIdentifier(scope=0,ident=e):0:16:e',
-                                      },
-                                    },
-                                  },
-                                },
-                              },
-                            },
-                          },
-                        },
-                      },
-                    },
-                  },
-                },
-              },
-            },
-            'Integer(val=1):0:23: 1',
-          },
-        },
-      },
-      err = {
-        arg = '[c, [d, [e]]]] = 1',
-        msg = 'E475: Nested lists not allowed when assigning: %.*s',
-      },
-    }, {
-      hl('List', '['),
-      hl('IdentifierName', 'a'),
-      hl('SubscriptBracket', '['),
-      hl('IdentifierName', 'b'),
-      hl('SubscriptBracket', ']'),
-      hl('Comma', ','),
-      hl('InvalidList', '[', 1),
-      hl('IdentifierName', 'c'),
-      hl('Comma', ','),
-      hl('InvalidList', '[', 1),
-      hl('IdentifierName', 'd'),
-      hl('Comma', ','),
-      hl('InvalidList', '[', 1),
-      hl('IdentifierName', 'e'),
-      hl('List', ']'),
-      hl('List', ']'),
-      hl('List', ']'),
-      hl('List', ']'),
-      hl('PlainAssignment', '=', 1),
-      hl('Number', '1', 1),
-    })
-
-    check_asgn_parsing('$X += 1', {
-      --                0123456
-      ast = {
-        {
-          'Assignment(Add):0:2: +=',
-          children = {
-            'Environment(ident=X):0:0:$X',
-            'Integer(val=1):0:5: 1',
-          },
-        },
-      },
-    }, {
-      hl('EnvironmentSigil', '$'),
-      hl('EnvironmentName', 'X'),
-      hl('AssignmentWithAddition', '+=', 1),
-      hl('Number', '1', 1),
-    })
-
-    check_asgn_parsing('@a .= 1', {
-      --                0123456
-      ast = {
-        {
-          'Assignment(Concat):0:2: .=',
-          children = {
-            'Register(name=a):0:0:@a',
-            'Integer(val=1):0:5: 1',
-          },
-        },
-      },
-    }, {
-      hl('Register', '@a'),
-      hl('AssignmentWithConcatenation', '.=', 1),
-      hl('Number', '1', 1),
-    })
-
-    check_asgn_parsing('&option -= 1', {
-      --                012345678901
-      --                0         1
-      ast = {
-        {
-          'Assignment(Subtract):0:7: -=',
-          children = {
-            'Option(scope=0,ident=option):0:0:&option',
-            'Integer(val=1):0:10: 1',
-          },
-        },
-      },
-    }, {
-      hl('OptionSigil', '&'),
-      hl('OptionName', 'option'),
-      hl('AssignmentWithSubtraction', '-=', 1),
-      hl('Number', '1', 1),
-    })
-
-    check_asgn_parsing('[$X, @a, &l:option] = [1, 2, 3]', {
-      --                0123456789012345678901234567890
-      --                0         1         2         3
-      ast = {
-        {
-          'Assignment(Plain):0:19: =',
-          children = {
-            {
-              'ListLiteral:0:0:[',
-              children = {
-                {
-                  'Comma:0:3:,',
-                  children = {
-                    'Environment(ident=X):0:1:$X',
-                    {
-                      'Comma:0:7:,',
-                      children = {
-                        'Register(name=a):0:4: @a',
-                        'Option(scope=l,ident=option):0:8: &l:option',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-            {
-              'ListLiteral:0:21: [',
-              children = {
-                {
-                  'Comma:0:24:,',
-                  children = {
-                    'Integer(val=1):0:23:1',
-                    {
-                      'Comma:0:27:,',
-                      children = {
-                        'Integer(val=2):0:25: 2',
-                        'Integer(val=3):0:28: 3',
-                      },
-                    },
-                  },
-                },
-              },
-            },
-          },
-        },
-      },
-    }, {
-      hl('List', '['),
-      hl('EnvironmentSigil', '$'),
-      hl('EnvironmentName', 'X'),
-      hl('Comma', ','),
-      hl('Register', '@a', 1),
-      hl('Comma', ','),
-      hl('OptionSigil', '&', 1),
-      hl('OptionScope', 'l'),
-      hl('OptionScopeDelimiter', ':'),
-      hl('OptionName', 'option'),
-      hl('List', ']'),
-      hl('PlainAssignment', '=', 1),
-      hl('List', '[', 1),
-      hl('Number', '1'),
-      hl('Comma', ','),
-      hl('Number', '2', 1),
-      hl('Comma', ','),
-      hl('Number', '3', 1),
-      hl('List', ']'),
-    })
-  end)
-  -- FIXME: Somehow make functional tests use the same code. Or, at least,
-  --        create an automated script which will do the import.
+  local function fmtn(typ, args, rest)
+    return ('%s(%s)%s'):format(typ, args, rest)
+  end
+  require('test.unit.viml.expressions.parser_tests')(
+      itp, _check_parsing, hl, fmtn)
 end)
diff --git a/test/unit/viml/expressions/parser_tests.lua b/test/unit/viml/expressions/parser_tests.lua
new file mode 100644
index 0000000000..f0c2723a38
--- /dev/null
+++ b/test/unit/viml/expressions/parser_tests.lua
@@ -0,0 +1,8185 @@
+local global_helpers = require('test.helpers')
+
+local REMOVE_THIS = global_helpers.REMOVE_THIS
+
+return function(itp, _check_parsing, hl, fmtn)
+  local function check_parsing(...)
+    return _check_parsing({flags={0, 1, 2, 3}, funcname='check_parsing'}, ...)
+  end
+  local function check_asgn_parsing(...)
+    return _check_parsing({
+      flags={4, 5, 6, 7},
+      funcname='check_asgn_parsing',
+    }, ...)
+  end
+  itp('works with + and @a', function()
+    check_parsing('@a', {
+      ast = {
+        'Register(name=a):0:0:@a',
+      },
+    }, {
+      hl('Register', '@a'),
+    })
+    check_parsing('+@a', {
+      ast = {
+        {
+          'UnaryPlus:0:0:+',
+          children = {
+            'Register(name=a):0:1:@a',
+          },
+        },
+      },
+    }, {
+      hl('UnaryPlus', '+'),
+      hl('Register', '@a'),
+    })
+    check_parsing('@a+@b', {
+      ast = {
+        {
+          'BinaryPlus:0:2:+',
+          children = {
+            'Register(name=a):0:0:@a',
+            'Register(name=b):0:3:@b',
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+      hl('Register', '@b'),
+    })
+    check_parsing('@a+@b+@c', {
+      ast = {
+        {
+          'BinaryPlus:0:5:+',
+          children = {
+            {
+              'BinaryPlus:0:2:+',
+              children = {
+                'Register(name=a):0:0:@a',
+                'Register(name=b):0:3:@b',
+              },
+            },
+            'Register(name=c):0:6:@c',
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+      hl('Register', '@b'),
+      hl('BinaryPlus', '+'),
+      hl('Register', '@c'),
+    })
+    check_parsing('+@a+@b', {
+      ast = {
+        {
+          'BinaryPlus:0:3:+',
+          children = {
+            {
+              'UnaryPlus:0:0:+',
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+            'Register(name=b):0:4:@b',
+          },
+        },
+      },
+    }, {
+      hl('UnaryPlus', '+'),
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+      hl('Register', '@b'),
+    })
+    check_parsing('+@a++@b', {
+      ast = {
+        {
+          'BinaryPlus:0:3:+',
+          children = {
+            {
+              'UnaryPlus:0:0:+',
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+            {
+              'UnaryPlus:0:4:+',
+              children = {
+                'Register(name=b):0:5:@b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('UnaryPlus', '+'),
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+      hl('UnaryPlus', '+'),
+      hl('Register', '@b'),
+    })
+    check_parsing('@a@b', {
+      ast = {
+        {
+          'OpMissing:0:2:',
+          children = {
+            'Register(name=a):0:0:@a',
+            'Register(name=b):0:2:@b',
+          },
+        },
+      },
+      err = {
+        arg = '@b',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('InvalidRegister', '@b'),
+    }, {
+      [1] = {
+        ast = {
+          len = 2,
+          err = REMOVE_THIS,
+          ast = {
+            'Register(name=a):0:0:@a'
+          },
+        },
+        hl_fs = {
+          [2] = REMOVE_THIS,
+        },
+      },
+    })
+    check_parsing(' @a \t @b', {
+      ast = {
+        {
+          'OpMissing:0:3:',
+          children = {
+            'Register(name=a):0:0: @a',
+            'Register(name=b):0:3: \t @b',
+          },
+        },
+      },
+      err = {
+        arg = '@b',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('Register', '@a', 1),
+      hl('InvalidSpacing', ' \t '),
+      hl('Register', '@b'),
+    }, {
+      [1] = {
+        ast = {
+          len = 6,
+          err = REMOVE_THIS,
+          ast = {
+            'Register(name=a):0:0: @a'
+          },
+        },
+        hl_fs = {
+          [2] = REMOVE_THIS,
+          [3] = REMOVE_THIS,
+        },
+      },
+    })
+    check_parsing('+', {
+      ast = {
+        'UnaryPlus:0:0:+',
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('UnaryPlus', '+'),
+    })
+    check_parsing(' +', {
+      ast = {
+        'UnaryPlus:0:0: +',
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('UnaryPlus', '+', 1),
+    })
+    check_parsing('@a+  ', {
+      ast = {
+        {
+          'BinaryPlus:0:2:+',
+          children = {
+            'Register(name=a):0:0:@a',
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+    })
+  end)
+  itp('works with @a, + and parenthesis', function()
+    check_parsing('(@a)', {
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            'Register(name=a):0:1:@a',
+          },
+        },
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Register', '@a'),
+      hl('NestingParenthesis', ')'),
+    })
+    check_parsing('()', {
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            'Missing:0:1:',
+          },
+        },
+      },
+      err = {
+        arg = ')',
+        msg = 'E15: Expected value, got parenthesis: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('InvalidNestingParenthesis', ')'),
+    })
+    check_parsing(')', {
+      ast = {
+        {
+          'Nested:0:0:',
+          children = {
+            'Missing:0:0:',
+          },
+        },
+      },
+      err = {
+        arg = ')',
+        msg = 'E15: Expected value, got parenthesis: %.*s',
+      },
+    }, {
+      hl('InvalidNestingParenthesis', ')'),
+    })
+    check_parsing('+)', {
+      ast = {
+        {
+          'Nested:0:1:',
+          children = {
+            {
+              'UnaryPlus:0:0:+',
+              children = {
+                'Missing:0:1:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ')',
+        msg = 'E15: Expected value, got parenthesis: %.*s',
+      },
+    }, {
+      hl('UnaryPlus', '+'),
+      hl('InvalidNestingParenthesis', ')'),
+    })
+    check_parsing('+@a(@b)', {
+      ast = {
+        {
+          'UnaryPlus:0:0:+',
+          children = {
+            {
+              'Call:0:3:(',
+              children = {
+                'Register(name=a):0:1:@a',
+                'Register(name=b):0:4:@b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('UnaryPlus', '+'),
+      hl('Register', '@a'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@b'),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('@a+@b(@c)', {
+      ast = {
+        {
+          'BinaryPlus:0:2:+',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Call:0:5:(',
+              children = {
+                'Register(name=b):0:3:@b',
+                'Register(name=c):0:6:@c',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+      hl('Register', '@b'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@c'),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('@a()', {
+      ast = {
+        {
+          'Call:0:2:(',
+          children = {
+            'Register(name=a):0:0:@a',
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('CallingParenthesis', '('),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('@a ()', {
+      ast = {
+        {
+          'OpMissing:0:2:',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Nested:0:2: (',
+              children = {
+                'Missing:0:4:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '()',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('InvalidSpacing', ' '),
+      hl('NestingParenthesis', '('),
+      hl('InvalidNestingParenthesis', ')'),
+    }, {
+      [1] = {
+        ast = {
+          len = 3,
+          err = REMOVE_THIS,
+          ast = {
+            'Register(name=a):0:0:@a',
+          },
+        },
+        hl_fs = {
+          [2] = REMOVE_THIS,
+          [3] = REMOVE_THIS,
+          [4] = REMOVE_THIS,
+        },
+      },
+    })
+    check_parsing('@a + (@b)', {
+      ast = {
+        {
+          'BinaryPlus:0:2: +',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Nested:0:4: (',
+              children = {
+                'Register(name=b):0:6:@b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+', 1),
+      hl('NestingParenthesis', '(', 1),
+      hl('Register', '@b'),
+      hl('NestingParenthesis', ')'),
+    })
+    check_parsing('@a + (+@b)', {
+      ast = {
+        {
+          'BinaryPlus:0:2: +',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Nested:0:4: (',
+              children = {
+                {
+                  'UnaryPlus:0:6:+',
+                  children = {
+                    'Register(name=b):0:7:@b',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+', 1),
+      hl('NestingParenthesis', '(', 1),
+      hl('UnaryPlus', '+'),
+      hl('Register', '@b'),
+      hl('NestingParenthesis', ')'),
+    })
+    check_parsing('@a + (@b + @c)', {
+      ast = {
+        {
+          'BinaryPlus:0:2: +',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Nested:0:4: (',
+              children = {
+                {
+                  'BinaryPlus:0:8: +',
+                  children = {
+                    'Register(name=b):0:6:@b',
+                    'Register(name=c):0:10: @c',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+', 1),
+      hl('NestingParenthesis', '(', 1),
+      hl('Register', '@b'),
+      hl('BinaryPlus', '+', 1),
+      hl('Register', '@c', 1),
+      hl('NestingParenthesis', ')'),
+    })
+    check_parsing('(@a)+@b', {
+      ast = {
+        {
+          'BinaryPlus:0:4:+',
+          children = {
+            {
+              'Nested:0:0:(',
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+            'Register(name=b):0:5:@b',
+          },
+        },
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Register', '@a'),
+      hl('NestingParenthesis', ')'),
+      hl('BinaryPlus', '+'),
+      hl('Register', '@b'),
+    })
+    check_parsing('@a+(@b)(@c)', {
+      --           01234567890
+      ast = {
+        {
+          'BinaryPlus:0:2:+',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Call:0:7:(',
+              children = {
+                {
+                  'Nested:0:3:(',
+                  children = { 'Register(name=b):0:4:@b' },
+                },
+                'Register(name=c):0:8:@c',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+      hl('NestingParenthesis', '('),
+      hl('Register', '@b'),
+      hl('NestingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@c'),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('@a+((@b))(@c)', {
+      --           01234567890123456890123456789
+      --           0         1        2
+      ast = {
+        {
+          'BinaryPlus:0:2:+',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Call:0:9:(',
+              children = {
+                {
+                  'Nested:0:3:(',
+                  children = {
+                    {
+                      'Nested:0:4:(',
+                      children = { 'Register(name=b):0:5:@b' }
+                    },
+                  },
+                },
+                'Register(name=c):0:10:@c',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+      hl('NestingParenthesis', '('),
+      hl('NestingParenthesis', '('),
+      hl('Register', '@b'),
+      hl('NestingParenthesis', ')'),
+      hl('NestingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@c'),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('@a+((@b))+@c', {
+      --           01234567890123456890123456789
+      --           0         1        2
+      ast = {
+        {
+          'BinaryPlus:0:9:+',
+          children = {
+            {
+              'BinaryPlus:0:2:+',
+              children = {
+                'Register(name=a):0:0:@a',
+                {
+                  'Nested:0:3:(',
+                  children = {
+                    {
+                      'Nested:0:4:(',
+                      children = { 'Register(name=b):0:5:@b' }
+                    },
+                  },
+                },
+              },
+            },
+            'Register(name=c):0:10:@c',
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+      hl('NestingParenthesis', '('),
+      hl('NestingParenthesis', '('),
+      hl('Register', '@b'),
+      hl('NestingParenthesis', ')'),
+      hl('NestingParenthesis', ')'),
+      hl('BinaryPlus', '+'),
+      hl('Register', '@c'),
+    })
+    check_parsing(
+      '@a + (@b + @c) + @d(@e) + (+@f) + ((+@g(@h))(@j)(@k))(@l)', {--[[
+       | | | | | |   | |  ||  | | ||  | | ||| ||   ||  ||   ||
+       000000000011111111112222222222333333333344444444445555555
+       012345678901234567890123456789012345678901234567890123456
+      ]]
+        ast = {{
+          'BinaryPlus:0:31: +',
+          children = {
+            {
+              'BinaryPlus:0:23: +',
+              children = {
+                {
+                  'BinaryPlus:0:14: +',
+                  children = {
+                    {
+                      'BinaryPlus:0:2: +',
+                      children = {
+                        'Register(name=a):0:0:@a',
+                        {
+                          'Nested:0:4: (',
+                          children = {
+                            {
+                              'BinaryPlus:0:8: +',
+                              children = {
+                                'Register(name=b):0:6:@b',
+                                'Register(name=c):0:10: @c',
+                              },
+                            },
+                          },
+                        },
+                      },
+                    },
+                    {
+                      'Call:0:19:(',
+                      children = {
+                        'Register(name=d):0:16: @d',
+                        'Register(name=e):0:20:@e',
+                      },
+                    },
+                  },
+                },
+                {
+                  'Nested:0:25: (',
+                  children = {
+                    {
+                      'UnaryPlus:0:27:+',
+                      children = {
+                        'Register(name=f):0:28:@f',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+            {
+              'Call:0:53:(',
+              children = {
+                {
+                  'Nested:0:33: (',
+                  children = {
+                    {
+                      'Call:0:48:(',
+                      children = {
+                        {
+                          'Call:0:44:(',
+                          children = {
+                            {
+                              'Nested:0:35:(',
+                              children = {
+                                {
+                                  'UnaryPlus:0:36:+',
+                                  children = {
+                                    {
+                                      'Call:0:39:(',
+                                      children = {
+                                        'Register(name=g):0:37:@g',
+                                        'Register(name=h):0:40:@h',
+                                      },
+                                    },
+                                  },
+                                },
+                              },
+                            },
+                            'Register(name=j):0:45:@j',
+                          },
+                        },
+                        'Register(name=k):0:49:@k',
+                      },
+                    },
+                  },
+                },
+                'Register(name=l):0:54:@l',
+              },
+            },
+          },
+        }},
+      }, {
+        hl('Register', '@a'),
+        hl('BinaryPlus', '+', 1),
+        hl('NestingParenthesis', '(', 1),
+        hl('Register', '@b'),
+        hl('BinaryPlus', '+', 1),
+        hl('Register', '@c', 1),
+        hl('NestingParenthesis', ')'),
+        hl('BinaryPlus', '+', 1),
+        hl('Register', '@d', 1),
+        hl('CallingParenthesis', '('),
+        hl('Register', '@e'),
+        hl('CallingParenthesis', ')'),
+        hl('BinaryPlus', '+', 1),
+        hl('NestingParenthesis', '(', 1),
+        hl('UnaryPlus', '+'),
+        hl('Register', '@f'),
+        hl('NestingParenthesis', ')'),
+        hl('BinaryPlus', '+', 1),
+        hl('NestingParenthesis', '(', 1),
+        hl('NestingParenthesis', '('),
+        hl('UnaryPlus', '+'),
+        hl('Register', '@g'),
+        hl('CallingParenthesis', '('),
+        hl('Register', '@h'),
+        hl('CallingParenthesis', ')'),
+        hl('NestingParenthesis', ')'),
+        hl('CallingParenthesis', '('),
+        hl('Register', '@j'),
+        hl('CallingParenthesis', ')'),
+        hl('CallingParenthesis', '('),
+        hl('Register', '@k'),
+        hl('CallingParenthesis', ')'),
+        hl('NestingParenthesis', ')'),
+        hl('CallingParenthesis', '('),
+        hl('Register', '@l'),
+        hl('CallingParenthesis', ')'),
+      })
+    check_parsing('@a)', {
+      --           012
+      ast = {
+        {
+          'Nested:0:2:',
+          children = {
+            'Register(name=a):0:0:@a',
+          },
+        },
+      },
+      err = {
+        arg = ')',
+        msg = 'E15: Unexpected closing parenthesis: %.*s',
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('InvalidNestingParenthesis', ')'),
+    })
+    check_parsing('(@a', {
+      --           012
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            'Register(name=a):0:1:@a',
+          },
+        },
+      },
+      err = {
+        arg = '(@a',
+        msg = 'E110: Missing closing parenthesis for nested expression: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Register', '@a'),
+    })
+    check_parsing('@a(@b', {
+      --           01234
+      ast = {
+        {
+          'Call:0:2:(',
+          children = {
+            'Register(name=a):0:0:@a',
+            'Register(name=b):0:3:@b',
+          },
+        },
+      },
+      err = {
+        arg = '(@b',
+        msg = 'E116: Missing closing parenthesis for function call: %.*s',
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@b'),
+    })
+    check_parsing('@a(@b, @c, @d, @e)', {
+      --           012345678901234567
+      --           0         1
+      ast = {
+        {
+          'Call:0:2:(',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Comma:0:5:,',
+              children = {
+                'Register(name=b):0:3:@b',
+                {
+                  'Comma:0:9:,',
+                  children = {
+                    'Register(name=c):0:6: @c',
+                    {
+                      'Comma:0:13:,',
+                      children = {
+                        'Register(name=d):0:10: @d',
+                        'Register(name=e):0:14: @e',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@b'),
+      hl('Comma', ','),
+      hl('Register', '@c', 1),
+      hl('Comma', ','),
+      hl('Register', '@d', 1),
+      hl('Comma', ','),
+      hl('Register', '@e', 1),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('@a(@b(@c))', {
+      --           01234567890123456789012345678901234567
+      --           0         1         2         3
+      ast = {
+        {
+          'Call:0:2:(',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Call:0:5:(',
+              children = {
+                'Register(name=b):0:3:@b',
+                'Register(name=c):0:6:@c',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@b'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@c'),
+      hl('CallingParenthesis', ')'),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('@a(@b(@c(@d(@e), @f(@g(@h), @i(@j)))))', {
+      --           01234567890123456789012345678901234567
+      --           0         1         2         3
+      ast = {
+        {
+          'Call:0:2:(',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'Call:0:5:(',
+              children = {
+                'Register(name=b):0:3:@b',
+                {
+                  'Call:0:8:(',
+                  children = {
+                    'Register(name=c):0:6:@c',
+                    {
+                      'Comma:0:15:,',
+                      children = {
+                        {
+                          'Call:0:11:(',
+                          children = {
+                            'Register(name=d):0:9:@d',
+                            'Register(name=e):0:12:@e',
+                          },
+                        },
+                        {
+                          'Call:0:19:(',
+                          children = {
+                            'Register(name=f):0:16: @f',
+                            {
+                              'Comma:0:26:,',
+                              children = {
+                                {
+                                  'Call:0:22:(',
+                                  children = {
+                                    'Register(name=g):0:20:@g',
+                                    'Register(name=h):0:23:@h',
+                                  },
+                                },
+                                {
+                                  'Call:0:30:(',
+                                  children = {
+                                    'Register(name=i):0:27: @i',
+                                    'Register(name=j):0:31:@j',
+                                  },
+                                },
+                              },
+                            },
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@b'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@c'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@d'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@e'),
+      hl('CallingParenthesis', ')'),
+      hl('Comma', ','),
+      hl('Register', '@f', 1),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@g'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@h'),
+      hl('CallingParenthesis', ')'),
+      hl('Comma', ','),
+      hl('Register', '@i', 1),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@j'),
+      hl('CallingParenthesis', ')'),
+      hl('CallingParenthesis', ')'),
+      hl('CallingParenthesis', ')'),
+      hl('CallingParenthesis', ')'),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('()()', {
+      --           0123
+      ast = {
+        {
+          'Call:0:2:(',
+          children = {
+            {
+              'Nested:0:0:(',
+              children = {
+                'Missing:0:1:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ')()',
+        msg = 'E15: Expected value, got parenthesis: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('InvalidNestingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('(@a)()', {
+      --           012345
+      ast = {
+        {
+          'Call:0:4:(',
+          children = {
+            {
+              'Nested:0:0:(',
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Register', '@a'),
+      hl('NestingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('(@a)(@b)', {
+      --           01234567
+      ast = {
+        {
+          'Call:0:4:(',
+          children = {
+            {
+              'Nested:0:0:(',
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+            'Register(name=b):0:5:@b',
+          },
+        },
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Register', '@a'),
+      hl('NestingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@b'),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('(@a) (@b)', {
+      --           012345678
+      ast = {
+        {
+          'OpMissing:0:4:',
+          children = {
+            {
+              'Nested:0:0:(',
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+            {
+              'Nested:0:4: (',
+              children = {
+                'Register(name=b):0:6:@b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '(@b)',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Register', '@a'),
+      hl('NestingParenthesis', ')'),
+      hl('InvalidSpacing', ' '),
+      hl('NestingParenthesis', '('),
+      hl('Register', '@b'),
+      hl('NestingParenthesis', ')'),
+    }, {
+      [1] = {
+        ast = {
+          len = 5,
+          ast = {
+            {
+              'Nested:0:0:(',
+              children = {
+                'Register(name=a):0:1:@a',
+                REMOVE_THIS,
+              },
+            },
+          },
+          err = REMOVE_THIS,
+        },
+        hl_fs = {
+          [4] = REMOVE_THIS,
+          [5] = REMOVE_THIS,
+          [6] = REMOVE_THIS,
+          [7] = REMOVE_THIS,
+        },
+      },
+    })
+  end)
+  itp('works with variable names, including curly braces ones', function()
+    check_parsing('var', {
+        ast = {
+          'PlainIdentifier(scope=0,ident=var):0:0:var',
+        },
+    }, {
+      hl('IdentifierName', 'var'),
+    })
+    check_parsing('g:var', {
+        ast = {
+          'PlainIdentifier(scope=g,ident=var):0:0:g:var',
+        },
+    }, {
+      hl('IdentifierScope', 'g'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('IdentifierName', 'var'),
+    })
+    check_parsing('g:', {
+        ast = {
+          'PlainIdentifier(scope=g,ident=):0:0:g:',
+        },
+    }, {
+      hl('IdentifierScope', 'g'),
+      hl('IdentifierScopeDelimiter', ':'),
+    })
+    check_parsing('{a}', {
+      --           012
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:1:a',
+          },
+        },
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Curly', '}'),
+    })
+    check_parsing('{a:b}', {
+      --           012
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+          children = {
+            'PlainIdentifier(scope=a,ident=b):0:1:a:b',
+          },
+        },
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('IdentifierScope', 'a'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '}'),
+    })
+    check_parsing('{a:@b}', {
+      --           012345
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+          children = {
+            {
+              'OpMissing:0:3:',
+              children={
+                'PlainIdentifier(scope=a,ident=):0:1:a:',
+                'Register(name=b):0:3:@b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '@b}',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('IdentifierScope', 'a'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('InvalidRegister', '@b'),
+      hl('Curly', '}'),
+    })
+    check_parsing('{@a}', {
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+          children = {
+            'Register(name=a):0:1:@a',
+          },
+        },
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('Register', '@a'),
+      hl('Curly', '}'),
+    })
+    check_parsing('{@a}{@b}', {
+      --           01234567
+      ast = {
+        {
+          'ComplexIdentifier:0:4:',
+          children = {
+            {
+              fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+            {
+              fmtn('CurlyBracesIdentifier', '--i', ':0:4:{'),
+              children = {
+                'Register(name=b):0:5:@b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('Register', '@a'),
+      hl('Curly', '}'),
+      hl('Curly', '{'),
+      hl('Register', '@b'),
+      hl('Curly', '}'),
+    })
+    check_parsing('g:{@a}', {
+      --           01234567
+      ast = {
+        {
+          'ComplexIdentifier:0:2:',
+          children = {
+            'PlainIdentifier(scope=g,ident=):0:0:g:',
+            {
+              fmtn('CurlyBracesIdentifier', '--i', ':0:2:{'),
+              children = {
+                'Register(name=a):0:3:@a',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierScope', 'g'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('Curly', '{'),
+      hl('Register', '@a'),
+      hl('Curly', '}'),
+    })
+    check_parsing('{@a}_test', {
+      --           012345678
+      ast = {
+        {
+          'ComplexIdentifier:0:4:',
+          children = {
+            {
+              fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+            'PlainIdentifier(scope=0,ident=_test):0:4:_test',
+          },
+        },
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('Register', '@a'),
+      hl('Curly', '}'),
+      hl('IdentifierName', '_test'),
+    })
+    check_parsing('g:{@a}_test', {
+      --           01234567890
+      ast = {
+        {
+          'ComplexIdentifier:0:2:',
+          children = {
+            'PlainIdentifier(scope=g,ident=):0:0:g:',
+            {
+              'ComplexIdentifier:0:6:',
+              children = {
+                {
+                  fmtn('CurlyBracesIdentifier', '--i', ':0:2:{'),
+                  children = {
+                    'Register(name=a):0:3:@a',
+                  },
+                },
+                'PlainIdentifier(scope=0,ident=_test):0:6:_test',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierScope', 'g'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('Curly', '{'),
+      hl('Register', '@a'),
+      hl('Curly', '}'),
+      hl('IdentifierName', '_test'),
+    })
+    check_parsing('g:{@a}_test()', {
+      --           0123456789012
+      ast = {
+        {
+          'Call:0:11:(',
+          children = {
+            {
+              'ComplexIdentifier:0:2:',
+              children = {
+                'PlainIdentifier(scope=g,ident=):0:0:g:',
+                {
+                  'ComplexIdentifier:0:6:',
+                  children = {
+                    {
+                      fmtn('CurlyBracesIdentifier', '--i', ':0:2:{'),
+                      children = {
+                        'Register(name=a):0:3:@a',
+                      },
+                    },
+                    'PlainIdentifier(scope=0,ident=_test):0:6:_test',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierScope', 'g'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('Curly', '{'),
+      hl('Register', '@a'),
+      hl('Curly', '}'),
+      hl('IdentifierName', '_test'),
+      hl('CallingParenthesis', '('),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('{@a} ()', {
+      --           0123456789012
+      ast = {
+        {
+          'Call:0:4: (',
+          children = {
+            {
+              fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('Register', '@a'),
+      hl('Curly', '}'),
+      hl('CallingParenthesis', '(', 1),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('g:{@a} ()', {
+      --           0123456789012
+      ast = {
+        {
+          'Call:0:6: (',
+          children = {
+            {
+              'ComplexIdentifier:0:2:',
+              children = {
+                'PlainIdentifier(scope=g,ident=):0:0:g:',
+                {
+                  fmtn('CurlyBracesIdentifier', '--i', ':0:2:{'),
+                  children = {
+                    'Register(name=a):0:3:@a',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierScope', 'g'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('Curly', '{'),
+      hl('Register', '@a'),
+      hl('Curly', '}'),
+      hl('CallingParenthesis', '(', 1),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('{@a', {
+      --           012
+      ast = {
+        {
+          fmtn('UnknownFigure', '-di', ':0:0:{'),
+          children = {
+            'Register(name=a):0:1:@a',
+          },
+        },
+      },
+      err = {
+        arg = '{@a',
+        msg = 'E15: Missing closing figure brace: %.*s',
+      },
+    }, {
+      hl('FigureBrace', '{'),
+      hl('Register', '@a'),
+    })
+    check_parsing('a ()', {
+      --           0123
+      ast = {
+        {
+          'Call:0:1: (',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('CallingParenthesis', '(', 1),
+      hl('CallingParenthesis', ')'),
+    })
+  end)
+  itp('works with lambdas and dictionaries', function()
+    check_parsing('{}', {
+      ast = {
+        fmtn('DictLiteral', '-di', ':0:0:{'),
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('Dict', '}'),
+    })
+    check_parsing('{->@a}', {
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Arrow:0:1:->',
+              children = {
+                'Register(name=a):0:3:@a',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('Arrow', '->'),
+      hl('Register', '@a'),
+      hl('Lambda', '}'),
+    })
+    check_parsing('{->@a+@b}', {
+      --           012345678
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Arrow:0:1:->',
+              children = {
+                {
+                  'BinaryPlus:0:5:+',
+                  children = {
+                    'Register(name=a):0:3:@a',
+                    'Register(name=b):0:6:@b',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('Arrow', '->'),
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+'),
+      hl('Register', '@b'),
+      hl('Lambda', '}'),
+    })
+    check_parsing('{a->@a}', {
+      --           012345678
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:1:a',
+            {
+              'Arrow:0:2:->',
+              children = {
+                'Register(name=a):0:4:@a',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Arrow', '->'),
+      hl('Register', '@a'),
+      hl('Lambda', '}'),
+    })
+    check_parsing('{a,b->@a}', {
+      --           012345678
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:3:b',
+              },
+            },
+            {
+              'Arrow:0:4:->',
+              children = {
+                'Register(name=a):0:6:@a',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+      hl('Arrow', '->'),
+      hl('Register', '@a'),
+      hl('Lambda', '}'),
+    })
+    check_parsing('{a,b,c->@a}', {
+      --           01234567890
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                {
+                  'Comma:0:4:,',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:3:b',
+                    'PlainIdentifier(scope=0,ident=c):0:5:c',
+                  },
+                },
+              },
+            },
+            {
+              'Arrow:0:6:->',
+              children = {
+                'Register(name=a):0:8:@a',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'c'),
+      hl('Arrow', '->'),
+      hl('Register', '@a'),
+      hl('Lambda', '}'),
+    })
+    check_parsing('{a,b,c,d->@a}', {
+      --           0123456789012
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                {
+                  'Comma:0:4:,',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:3:b',
+                    {
+                      'Comma:0:6:,',
+                      children = {
+                        'PlainIdentifier(scope=0,ident=c):0:5:c',
+                        'PlainIdentifier(scope=0,ident=d):0:7:d',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+            {
+              'Arrow:0:8:->',
+              children = {
+                'Register(name=a):0:10:@a',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'c'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'd'),
+      hl('Arrow', '->'),
+      hl('Register', '@a'),
+      hl('Lambda', '}'),
+    })
+    check_parsing('{a,b,c,d,->@a}', {
+      --           01234567890123
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                {
+                  'Comma:0:4:,',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:3:b',
+                    {
+                      'Comma:0:6:,',
+                      children = {
+                        'PlainIdentifier(scope=0,ident=c):0:5:c',
+                        {
+                          'Comma:0:8:,',
+                          children = {
+                            'PlainIdentifier(scope=0,ident=d):0:7:d',
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+            {
+              'Arrow:0:9:->',
+              children = {
+                'Register(name=a):0:11:@a',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'c'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'd'),
+      hl('Comma', ','),
+      hl('Arrow', '->'),
+      hl('Register', '@a'),
+      hl('Lambda', '}'),
+    })
+    check_parsing('{a,b->{c,d->{e,f->@a}}}', {
+      --           01234567890123456789012
+      --           0         1         2
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:3:b',
+              },
+            },
+            {
+              'Arrow:0:4:->',
+              children = {
+                {
+                  fmtn('Lambda', '\\di', ':0:6:{'),
+                  children = {
+                    {
+                      'Comma:0:8:,',
+                      children = {
+                        'PlainIdentifier(scope=0,ident=c):0:7:c',
+                        'PlainIdentifier(scope=0,ident=d):0:9:d',
+                      },
+                    },
+                    {
+                      'Arrow:0:10:->',
+                      children = {
+                        {
+                          fmtn('Lambda', '\\di', ':0:12:{'),
+                          children = {
+                            {
+                              'Comma:0:14:,',
+                              children = {
+                                'PlainIdentifier(scope=0,ident=e):0:13:e',
+                                'PlainIdentifier(scope=0,ident=f):0:15:f',
+                              },
+                            },
+                            {
+                              'Arrow:0:16:->',
+                              children = {
+                                'Register(name=a):0:18:@a',
+                              },
+                            },
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+      hl('Arrow', '->'),
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'c'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'd'),
+      hl('Arrow', '->'),
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'e'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'f'),
+      hl('Arrow', '->'),
+      hl('Register', '@a'),
+      hl('Lambda', '}'),
+      hl('Lambda', '}'),
+      hl('Lambda', '}'),
+    })
+    check_parsing('{a,b->c,d}', {
+      --           0123456789
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:3:b',
+              },
+            },
+            {
+              'Arrow:0:4:->',
+              children = {
+                {
+                  'Comma:0:7:,',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=c):0:6:c',
+                    'PlainIdentifier(scope=0,ident=d):0:8:d',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ',d}',
+        msg = 'E15: Comma outside of call, lambda or literal: %.*s',
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+      hl('Arrow', '->'),
+      hl('IdentifierName', 'c'),
+      hl('InvalidComma', ','),
+      hl('IdentifierName', 'd'),
+      hl('Lambda', '}'),
+    })
+    check_parsing('a,b,c,d', {
+      --           0123456789
+      ast = {
+        {
+          'Comma:0:1:,',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'Comma:0:3:,',
+              children = {
+              'PlainIdentifier(scope=0,ident=b):0:2:b',
+                {
+                  'Comma:0:5:,',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=c):0:4:c',
+                    'PlainIdentifier(scope=0,ident=d):0:6:d',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ',b,c,d',
+        msg = 'E15: Comma outside of call, lambda or literal: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('InvalidComma', ','),
+      hl('IdentifierName', 'b'),
+      hl('InvalidComma', ','),
+      hl('IdentifierName', 'c'),
+      hl('InvalidComma', ','),
+      hl('IdentifierName', 'd'),
+    })
+    check_parsing('a,b,c,d,', {
+      --           0123456789
+      ast = {
+        {
+          'Comma:0:1:,',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'Comma:0:3:,',
+              children = {
+              'PlainIdentifier(scope=0,ident=b):0:2:b',
+                {
+                  'Comma:0:5:,',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=c):0:4:c',
+                    {
+                      'Comma:0:7:,',
+                      children = {
+                        'PlainIdentifier(scope=0,ident=d):0:6:d',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ',b,c,d,',
+        msg = 'E15: Comma outside of call, lambda or literal: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('InvalidComma', ','),
+      hl('IdentifierName', 'b'),
+      hl('InvalidComma', ','),
+      hl('IdentifierName', 'c'),
+      hl('InvalidComma', ','),
+      hl('IdentifierName', 'd'),
+      hl('InvalidComma', ','),
+    })
+    check_parsing(',', {
+      --           0123456789
+      ast = {
+        {
+          'Comma:0:0:,',
+          children = {
+            'Missing:0:0:',
+          },
+        },
+      },
+      err = {
+        arg = ',',
+        msg = 'E15: Expected value, got comma: %.*s',
+      },
+    }, {
+      hl('InvalidComma', ','),
+    })
+    check_parsing('{,a->@a}', {
+      --           0123456789
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+          children = {
+            {
+              'Arrow:0:3:->',
+              children = {
+                {
+                  'Comma:0:1:,',
+                  children = {
+                    'Missing:0:1:',
+                    'PlainIdentifier(scope=0,ident=a):0:2:a',
+                  },
+                },
+                'Register(name=a):0:5:@a',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ',a->@a}',
+        msg = 'E15: Expected value, got comma: %.*s',
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('InvalidComma', ','),
+      hl('IdentifierName', 'a'),
+      hl('InvalidArrow', '->'),
+      hl('Register', '@a'),
+      hl('Curly', '}'),
+    })
+    check_parsing('}', {
+      --           0123456789
+      ast = {
+        fmtn('UnknownFigure', '---', ':0:0:'),
+      },
+      err = {
+        arg = '}',
+        msg = 'E15: Unexpected closing figure brace: %.*s',
+      },
+    }, {
+      hl('InvalidFigureBrace', '}'),
+    })
+    check_parsing('{->}', {
+      --           0123456789
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            'Arrow:0:1:->',
+          },
+        },
+      },
+      err = {
+        arg = '}',
+        msg = 'E15: Expected value, got closing figure brace: %.*s',
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('Arrow', '->'),
+      hl('InvalidLambda', '}'),
+    })
+    check_parsing('{a,b}', {
+      --           0123456789
+      ast = {
+        {
+          fmtn('Lambda', '-di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:3:b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '}',
+        msg = 'E15: Expected lambda arguments list or arrow: %.*s',
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+      hl('InvalidLambda', '}'),
+    })
+    check_parsing('{a,}', {
+      --           0123456789
+      ast = {
+        {
+          fmtn('Lambda', '-di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '}',
+        msg = 'E15: Expected lambda arguments list or arrow: %.*s',
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('InvalidLambda', '}'),
+    })
+    check_parsing('{@a:@b}', {
+      --           0123456789
+      ast = {
+        {
+          fmtn('DictLiteral', '-di', ':0:0:{'),
+          children = {
+            {
+              'Colon:0:3::',
+              children = {
+                'Register(name=a):0:1:@a',
+                'Register(name=b):0:4:@b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('Register', '@a'),
+      hl('Colon', ':'),
+      hl('Register', '@b'),
+      hl('Dict', '}'),
+    })
+    check_parsing('{@a:@b,@c:@d}', {
+      --           0123456789012
+      --           0         1
+      ast = {
+        {
+          fmtn('DictLiteral', '-di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:6:,',
+              children = {
+                {
+                  'Colon:0:3::',
+                  children = {
+                    'Register(name=a):0:1:@a',
+                    'Register(name=b):0:4:@b',
+                  },
+                },
+                {
+                  'Colon:0:9::',
+                  children = {
+                    'Register(name=c):0:7:@c',
+                    'Register(name=d):0:10:@d',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('Register', '@a'),
+      hl('Colon', ':'),
+      hl('Register', '@b'),
+      hl('Comma', ','),
+      hl('Register', '@c'),
+      hl('Colon', ':'),
+      hl('Register', '@d'),
+      hl('Dict', '}'),
+    })
+    check_parsing('{@a:@b,@c:@d,@e:@f,}', {
+      --           01234567890123456789
+      --           0         1
+      ast = {
+        {
+          fmtn('DictLiteral', '-di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:6:,',
+              children = {
+                {
+                  'Colon:0:3::',
+                  children = {
+                    'Register(name=a):0:1:@a',
+                    'Register(name=b):0:4:@b',
+                  },
+                },
+                {
+                  'Comma:0:12:,',
+                  children = {
+                    {
+                      'Colon:0:9::',
+                      children = {
+                        'Register(name=c):0:7:@c',
+                        'Register(name=d):0:10:@d',
+                      },
+                    },
+                    {
+                      'Comma:0:18:,',
+                      children = {
+                        {
+                          'Colon:0:15::',
+                          children = {
+                            'Register(name=e):0:13:@e',
+                            'Register(name=f):0:16:@f',
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('Register', '@a'),
+      hl('Colon', ':'),
+      hl('Register', '@b'),
+      hl('Comma', ','),
+      hl('Register', '@c'),
+      hl('Colon', ':'),
+      hl('Register', '@d'),
+      hl('Comma', ','),
+      hl('Register', '@e'),
+      hl('Colon', ':'),
+      hl('Register', '@f'),
+      hl('Comma', ','),
+      hl('Dict', '}'),
+    })
+    check_parsing('{@a:@b,@c:@d,@e:@f,@g:}', {
+      --           01234567890123456789012
+      --           0         1         2
+      ast = {
+        {
+          fmtn('DictLiteral', '-di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:6:,',
+              children = {
+                {
+                  'Colon:0:3::',
+                  children = {
+                    'Register(name=a):0:1:@a',
+                    'Register(name=b):0:4:@b',
+                  },
+                },
+                {
+                  'Comma:0:12:,',
+                  children = {
+                    {
+                      'Colon:0:9::',
+                      children = {
+                        'Register(name=c):0:7:@c',
+                        'Register(name=d):0:10:@d',
+                      },
+                    },
+                    {
+                      'Comma:0:18:,',
+                      children = {
+                        {
+                          'Colon:0:15::',
+                          children = {
+                            'Register(name=e):0:13:@e',
+                            'Register(name=f):0:16:@f',
+                          },
+                        },
+                        {
+                          'Colon:0:21::',
+                          children = {
+                            'Register(name=g):0:19:@g',
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '}',
+        msg = 'E15: Expected value, got closing figure brace: %.*s',
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('Register', '@a'),
+      hl('Colon', ':'),
+      hl('Register', '@b'),
+      hl('Comma', ','),
+      hl('Register', '@c'),
+      hl('Colon', ':'),
+      hl('Register', '@d'),
+      hl('Comma', ','),
+      hl('Register', '@e'),
+      hl('Colon', ':'),
+      hl('Register', '@f'),
+      hl('Comma', ','),
+      hl('Register', '@g'),
+      hl('Colon', ':'),
+      hl('InvalidDict', '}'),
+    })
+    check_parsing('{@a:@b,}', {
+      --           01234567890123
+      --           0         1
+      ast = {
+        {
+          fmtn('DictLiteral', '-di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:6:,',
+              children = {
+                {
+                  'Colon:0:3::',
+                  children = {
+                    'Register(name=a):0:1:@a',
+                    'Register(name=b):0:4:@b',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('Register', '@a'),
+      hl('Colon', ':'),
+      hl('Register', '@b'),
+      hl('Comma', ','),
+      hl('Dict', '}'),
+    })
+    check_parsing('{({f -> g})(@h)(@i)}', {
+      --           01234567890123456789
+      --           0         1
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+          children = {
+            {
+              'Call:0:15:(',
+              children = {
+                {
+                  'Call:0:11:(',
+                  children = {
+                    {
+                      'Nested:0:1:(',
+                      children = {
+                        {
+                          fmtn('Lambda', '\\di', ':0:2:{'),
+                          children = {
+                            'PlainIdentifier(scope=0,ident=f):0:3:f',
+                            {
+                              'Arrow:0:4: ->',
+                              children = {
+                                'PlainIdentifier(scope=0,ident=g):0:7: g',
+                              },
+                            },
+                          },
+                        },
+                      },
+                    },
+                    'Register(name=h):0:12:@h',
+                  },
+                },
+                'Register(name=i):0:16:@i',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('NestingParenthesis', '('),
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'f'),
+      hl('Arrow', '->', 1),
+      hl('IdentifierName', 'g', 1),
+      hl('Lambda', '}'),
+      hl('NestingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@h'),
+      hl('CallingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@i'),
+      hl('CallingParenthesis', ')'),
+      hl('Curly', '}'),
+    })
+    check_parsing('a:{b()}c', {
+      --           01234567
+      ast = {
+        {
+          'ComplexIdentifier:0:2:',
+          children = {
+            'PlainIdentifier(scope=a,ident=):0:0:a:',
+            {
+              'ComplexIdentifier:0:7:',
+              children = {
+                {
+                  fmtn('CurlyBracesIdentifier', '--i', ':0:2:{'),
+                  children = {
+                    {
+                      'Call:0:4:(',
+                      children = {
+                        'PlainIdentifier(scope=0,ident=b):0:3:b',
+                      },
+                    },
+                  },
+                },
+                'PlainIdentifier(scope=0,ident=c):0:7:c',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierScope', 'a'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'b'),
+      hl('CallingParenthesis', '('),
+      hl('CallingParenthesis', ')'),
+      hl('Curly', '}'),
+      hl('IdentifierName', 'c'),
+    })
+    check_parsing('a:{{b, c -> @d + @e + ({f -> g})(@h)}(@i)}j', {
+      --           01234567890123456789012345678901234567890123456
+      --           0         1         2         3         4
+      ast = {
+        {
+          'ComplexIdentifier:0:2:',
+          children = {
+            'PlainIdentifier(scope=a,ident=):0:0:a:',
+            {
+              'ComplexIdentifier:0:42:',
+              children = {
+                {
+                  fmtn('CurlyBracesIdentifier', '--i', ':0:2:{'),
+                  children = {
+                    {
+                      'Call:0:37:(',
+                      children = {
+                        {
+                          fmtn('Lambda', '\\di', ':0:3:{'),
+                          children = {
+                            {
+                              'Comma:0:5:,',
+                              children = {
+                                'PlainIdentifier(scope=0,ident=b):0:4:b',
+                                'PlainIdentifier(scope=0,ident=c):0:6: c',
+                              },
+                            },
+                            {
+                              'Arrow:0:8: ->',
+                              children = {
+                                {
+                                  'BinaryPlus:0:19: +',
+                                  children = {
+                                    {
+                                      'BinaryPlus:0:14: +',
+                                      children = {
+                                        'Register(name=d):0:11: @d',
+                                        'Register(name=e):0:16: @e',
+                                      },
+                                    },
+                                    {
+                                      'Call:0:32:(',
+                                      children = {
+                                        {
+                                          'Nested:0:21: (',
+                                          children = {
+                                            {
+                                              fmtn('Lambda', '\\di', ':0:23:{'),
+                                              children = {
+                                                'PlainIdentifier(scope=0,ident=f):0:24:f',
+                                                {
+                                                  'Arrow:0:25: ->',
+                                                  children = {
+                                                    'PlainIdentifier(scope=0,ident=g):0:28: g',
+                                                  },
+                                                },
+                                              },
+                                            },
+                                          },
+                                        },
+                                        'Register(name=h):0:33:@h',
+                                      },
+                                    },
+                                  },
+                                },
+                              },
+                            },
+                          },
+                        },
+                        'Register(name=i):0:38:@i',
+                      },
+                    },
+                  },
+                },
+                'PlainIdentifier(scope=0,ident=j):0:42:j',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierScope', 'a'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('Curly', '{'),
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'b'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'c', 1),
+      hl('Arrow', '->', 1),
+      hl('Register', '@d', 1),
+      hl('BinaryPlus', '+', 1),
+      hl('Register', '@e', 1),
+      hl('BinaryPlus', '+', 1),
+      hl('NestingParenthesis', '(', 1),
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'f'),
+      hl('Arrow', '->', 1),
+      hl('IdentifierName', 'g', 1),
+      hl('Lambda', '}'),
+      hl('NestingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@h'),
+      hl('CallingParenthesis', ')'),
+      hl('Lambda', '}'),
+      hl('CallingParenthesis', '('),
+      hl('Register', '@i'),
+      hl('CallingParenthesis', ')'),
+      hl('Curly', '}'),
+      hl('IdentifierName', 'j'),
+    })
+    check_parsing('{@a + @b : @c + @d, @e + @f : @g + @i}', {
+      --           01234567890123456789012345678901234567
+      --           0         1         2         3
+      ast = {
+        {
+          fmtn('DictLiteral', '-di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:18:,',
+              children = {
+                {
+                  'Colon:0:8: :',
+                  children = {
+                    {
+                      'BinaryPlus:0:3: +',
+                      children = {
+                        'Register(name=a):0:1:@a',
+                        'Register(name=b):0:5: @b',
+                      },
+                    },
+                    {
+                      'BinaryPlus:0:13: +',
+                      children = {
+                        'Register(name=c):0:10: @c',
+                        'Register(name=d):0:15: @d',
+                      },
+                    },
+                  },
+                },
+                {
+                  'Colon:0:27: :',
+                  children = {
+                    {
+                      'BinaryPlus:0:22: +',
+                      children = {
+                        'Register(name=e):0:19: @e',
+                        'Register(name=f):0:24: @f',
+                      },
+                    },
+                    {
+                      'BinaryPlus:0:32: +',
+                      children = {
+                        'Register(name=g):0:29: @g',
+                        'Register(name=i):0:34: @i',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('Register', '@a'),
+      hl('BinaryPlus', '+', 1),
+      hl('Register', '@b', 1),
+      hl('Colon', ':', 1),
+      hl('Register', '@c', 1),
+      hl('BinaryPlus', '+', 1),
+      hl('Register', '@d', 1),
+      hl('Comma', ','),
+      hl('Register', '@e', 1),
+      hl('BinaryPlus', '+', 1),
+      hl('Register', '@f', 1),
+      hl('Colon', ':', 1),
+      hl('Register', '@g', 1),
+      hl('BinaryPlus', '+', 1),
+      hl('Register', '@i', 1),
+      hl('Dict', '}'),
+    })
+    check_parsing('-> -> ->', {
+      --           01234567
+      ast = {
+        {
+          'Arrow:0:0:->',
+          children = {
+            'Missing:0:0:',
+            {
+              'Arrow:0:2: ->',
+              children = {
+                'Missing:0:2:',
+                {
+                  'Arrow:0:5: ->',
+                  children = {
+                    'Missing:0:5:',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '-> -> ->',
+        msg = 'E15: Unexpected arrow: %.*s',
+      },
+    }, {
+      hl('InvalidArrow', '->'),
+      hl('InvalidArrow', '->', 1),
+      hl('InvalidArrow', '->', 1),
+    })
+    check_parsing('a -> b -> c -> d', {
+      --           0123456789012345
+      --           0         1
+      ast = {
+        {
+          'Arrow:0:1: ->',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'Arrow:0:6: ->',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:4: b',
+                {
+                  'Arrow:0:11: ->',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=c):0:9: c',
+                    'PlainIdentifier(scope=0,ident=d):0:14: d',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '-> b -> c -> d',
+        msg = 'E15: Arrow outside of lambda: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('InvalidArrow', '->', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('InvalidArrow', '->', 1),
+      hl('IdentifierName', 'c', 1),
+      hl('InvalidArrow', '->', 1),
+      hl('IdentifierName', 'd', 1),
+    })
+    check_parsing('{a -> b -> c}', {
+      --           0123456789012
+      --           0         1
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:1:a',
+            {
+              'Arrow:0:2: ->',
+              children = {
+                {
+                  'Arrow:0:7: ->',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:5: b',
+                    'PlainIdentifier(scope=0,ident=c):0:10: c',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '-> c}',
+        msg = 'E15: Arrow outside of lambda: %.*s',
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Arrow', '->', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('InvalidArrow', '->', 1),
+      hl('IdentifierName', 'c', 1),
+      hl('Lambda', '}'),
+    })
+    check_parsing('{a: -> b}', {
+      --           012345678
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+          children = {
+            {
+              'Arrow:0:3: ->',
+              children = {
+                'PlainIdentifier(scope=a,ident=):0:1:a:',
+                'PlainIdentifier(scope=0,ident=b):0:6: b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '-> b}',
+        msg = 'E15: Arrow outside of lambda: %.*s',
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('IdentifierScope', 'a'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('InvalidArrow', '->', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('Curly', '}'),
+    })
+
+    check_parsing('{a:b -> b}', {
+      --           0123456789
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+          children = {
+            {
+              'Arrow:0:4: ->',
+              children = {
+                'PlainIdentifier(scope=a,ident=b):0:1:a:b',
+                'PlainIdentifier(scope=0,ident=b):0:7: b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '-> b}',
+        msg = 'E15: Arrow outside of lambda: %.*s',
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('IdentifierScope', 'a'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('IdentifierName', 'b'),
+      hl('InvalidArrow', '->', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('Curly', '}'),
+    })
+
+    check_parsing('{a#b -> b}', {
+      --           0123456789
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+          children = {
+            {
+              'Arrow:0:4: ->',
+              children = {
+                'PlainIdentifier(scope=0,ident=a#b):0:1:a#b',
+                'PlainIdentifier(scope=0,ident=b):0:7: b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '-> b}',
+        msg = 'E15: Arrow outside of lambda: %.*s',
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('IdentifierName', 'a#b'),
+      hl('InvalidArrow', '->', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('Curly', '}'),
+    })
+    check_parsing('{a : b : c}', {
+      --           01234567890
+      --           0         1
+      ast = {
+        {
+          fmtn('DictLiteral', '-di', ':0:0:{'),
+          children = {
+            {
+              'Colon:0:2: :',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                {
+                  'Colon:0:6: :',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:4: b',
+                    'PlainIdentifier(scope=0,ident=c):0:8: c',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ': c}',
+        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Colon', ':', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('InvalidColon', ':', 1),
+      hl('IdentifierName', 'c', 1),
+      hl('Dict', '}'),
+    })
+    check_parsing('{', {
+      --           0
+      ast = {
+        fmtn('UnknownFigure', '\\di', ':0:0:{'),
+      },
+      err = {
+        arg = '{',
+        msg = 'E15: Missing closing figure brace: %.*s',
+      },
+    }, {
+      hl('FigureBrace', '{'),
+    })
+    check_parsing('{a', {
+      --           01
+      ast = {
+        {
+          fmtn('UnknownFigure', '\\di', ':0:0:{'),
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:1:a',
+          },
+        },
+      },
+      err = {
+        arg = '{a',
+        msg = 'E15: Missing closing figure brace: %.*s',
+      },
+    }, {
+      hl('FigureBrace', '{'),
+      hl('IdentifierName', 'a'),
+    })
+    check_parsing('{a,b', {
+      --           0123
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:3:b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '{a,b',
+        msg = 'E15: Missing closing figure brace for lambda: %.*s',
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+    })
+    check_parsing('{a,b->', {
+      --           012345
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:3:b',
+              },
+            },
+            'Arrow:0:4:->',
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+      hl('Arrow', '->'),
+    })
+    check_parsing('{a,b->c', {
+      --           0123456
+      ast = {
+        {
+          fmtn('Lambda', '\\di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:3:b',
+              },
+            },
+            {
+              'Arrow:0:4:->',
+              children = {
+                'PlainIdentifier(scope=0,ident=c):0:6:c',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '{a,b->c',
+        msg = 'E15: Missing closing figure brace for lambda: %.*s',
+      },
+    }, {
+      hl('Lambda', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b'),
+      hl('Arrow', '->'),
+      hl('IdentifierName', 'c'),
+    })
+    check_parsing('{a : b', {
+      --           012345
+      ast = {
+        {
+          fmtn('DictLiteral', '-di', ':0:0:{'),
+          children = {
+            {
+              'Colon:0:2: :',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:4: b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '{a : b',
+        msg = 'E723: Missing end of Dictionary \'}\': %.*s',
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Colon', ':', 1),
+      hl('IdentifierName', 'b', 1),
+    })
+    check_parsing('{a : b,', {
+      --           0123456
+      ast = {
+        {
+          fmtn('DictLiteral', '-di', ':0:0:{'),
+          children = {
+            {
+              'Comma:0:6:,',
+              children = {
+                {
+                  'Colon:0:2: :',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=a):0:1:a',
+                    'PlainIdentifier(scope=0,ident=b):0:4: b',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('Dict', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Colon', ':', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('Comma', ','),
+    })
+  end)
+  itp('works with ternary operator', function()
+    check_parsing('a ? b : c', {
+      --           012345678
+      ast = {
+        {
+          'Ternary:0:1: ?',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'TernaryValue:0:5: :',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:3: b',
+                'PlainIdentifier(scope=0,ident=c):0:7: c',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Ternary', '?', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('TernaryColon', ':', 1),
+      hl('IdentifierName', 'c', 1),
+    })
+    check_parsing('@a?@b?@c:@d:@e', {
+      --           01234567890123
+      --           0         1
+      ast = {
+        {
+          'Ternary:0:2:?',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'TernaryValue:0:11::',
+              children = {
+                {
+                  'Ternary:0:5:?',
+                  children = {
+                    'Register(name=b):0:3:@b',
+                    {
+                      'TernaryValue:0:8::',
+                      children = {
+                        'Register(name=c):0:6:@c',
+                        'Register(name=d):0:9:@d',
+                      },
+                    },
+                  },
+                },
+                'Register(name=e):0:12:@e',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('Ternary', '?'),
+      hl('Register', '@b'),
+      hl('Ternary', '?'),
+      hl('Register', '@c'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@d'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@e'),
+    })
+    check_parsing('@a?@b:@c?@d:@e', {
+      --           01234567890123
+      --           0         1
+      ast = {
+        {
+          'Ternary:0:2:?',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'TernaryValue:0:5::',
+              children = {
+                'Register(name=b):0:3:@b',
+                {
+                  'Ternary:0:8:?',
+                  children = {
+                    'Register(name=c):0:6:@c',
+                    {
+                      'TernaryValue:0:11::',
+                      children = {
+                        'Register(name=d):0:9:@d',
+                        'Register(name=e):0:12:@e',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('Ternary', '?'),
+      hl('Register', '@b'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@c'),
+      hl('Ternary', '?'),
+      hl('Register', '@d'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@e'),
+    })
+    check_parsing('@a?@b?@c?@d:@e?@f:@g:@h?@i:@j:@k', {
+      --           01234567890123456789012345678901
+      --           0         1         2         3
+      ast = {
+        {
+          'Ternary:0:2:?',
+          children = {
+            'Register(name=a):0:0:@a',
+            {
+              'TernaryValue:0:29::',
+              children = {
+                {
+                  'Ternary:0:5:?',
+                  children = {
+                    'Register(name=b):0:3:@b',
+                    {
+                      'TernaryValue:0:20::',
+                      children = {
+                        {
+                          'Ternary:0:8:?',
+                          children = {
+                            'Register(name=c):0:6:@c',
+                            {
+                              'TernaryValue:0:11::',
+                              children = {
+                                'Register(name=d):0:9:@d',
+                                {
+                                  'Ternary:0:14:?',
+                                  children = {
+                                    'Register(name=e):0:12:@e',
+                                    {
+                                      'TernaryValue:0:17::',
+                                      children = {
+                                        'Register(name=f):0:15:@f',
+                                        'Register(name=g):0:18:@g',
+                                      },
+                                    },
+                                  },
+                                },
+                              },
+                            },
+                          },
+                        },
+                        {
+                          'Ternary:0:23:?',
+                          children = {
+                            'Register(name=h):0:21:@h',
+                            {
+                              'TernaryValue:0:26::',
+                              children = {
+                                'Register(name=i):0:24:@i',
+                                'Register(name=j):0:27:@j',
+                              },
+                            },
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+                'Register(name=k):0:30:@k',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('Ternary', '?'),
+      hl('Register', '@b'),
+      hl('Ternary', '?'),
+      hl('Register', '@c'),
+      hl('Ternary', '?'),
+      hl('Register', '@d'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@e'),
+      hl('Ternary', '?'),
+      hl('Register', '@f'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@g'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@h'),
+      hl('Ternary', '?'),
+      hl('Register', '@i'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@j'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@k'),
+    })
+    check_parsing('?', {
+      --           0
+      ast = {
+        {
+          'Ternary:0:0:?',
+          children = {
+            'Missing:0:0:',
+            'TernaryValue:0:0:?',
+          },
+        },
+      },
+      err = {
+        arg = '?',
+        msg = 'E15: Expected value, got question mark: %.*s',
+      },
+    }, {
+      hl('InvalidTernary', '?'),
+    })
+
+    check_parsing('?:', {
+      --           01
+      ast = {
+        {
+          'Ternary:0:0:?',
+          children = {
+            'Missing:0:0:',
+            {
+              'TernaryValue:0:1::',
+              children = {
+                'Missing:0:1:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '?:',
+        msg = 'E15: Expected value, got question mark: %.*s',
+      },
+    }, {
+      hl('InvalidTernary', '?'),
+      hl('InvalidTernaryColon', ':'),
+    })
+
+    check_parsing('?::', {
+      --           012
+      ast = {
+        {
+          'Colon:0:2::',
+          children = {
+            {
+              'Ternary:0:0:?',
+              children = {
+                'Missing:0:0:',
+                {
+                  'TernaryValue:0:1::',
+                  children = {
+                    'Missing:0:1:',
+                    'Missing:0:2:',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '?::',
+        msg = 'E15: Expected value, got question mark: %.*s',
+      },
+    }, {
+      hl('InvalidTernary', '?'),
+      hl('InvalidTernaryColon', ':'),
+      hl('InvalidColon', ':'),
+    })
+
+    check_parsing('a?b', {
+      --           012
+      ast = {
+        {
+          'Ternary:0:1:?',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'TernaryValue:0:1:?',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:2:b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '?b',
+        msg = 'E109: Missing \':\' after \'?\': %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Ternary', '?'),
+      hl('IdentifierName', 'b'),
+    })
+    check_parsing('a?b:', {
+      --           0123
+      ast = {
+        {
+          'Ternary:0:1:?',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'TernaryValue:0:1:?',
+              children = {
+                'PlainIdentifier(scope=b,ident=):0:2:b:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '?b:',
+        msg = 'E109: Missing \':\' after \'?\': %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Ternary', '?'),
+      hl('IdentifierScope', 'b'),
+      hl('IdentifierScopeDelimiter', ':'),
+    })
+
+    check_parsing('a?b::c', {
+      --           012345
+      ast = {
+        {
+          'Ternary:0:1:?',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'TernaryValue:0:4::',
+              children = {
+                'PlainIdentifier(scope=b,ident=):0:2:b:',
+                'PlainIdentifier(scope=0,ident=c):0:5:c',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Ternary', '?'),
+      hl('IdentifierScope', 'b'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('TernaryColon', ':'),
+      hl('IdentifierName', 'c'),
+    })
+
+    check_parsing('a?b :', {
+      --           01234
+      ast = {
+        {
+          'Ternary:0:1:?',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'TernaryValue:0:3: :',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:2:b',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Ternary', '?'),
+      hl('IdentifierName', 'b'),
+      hl('TernaryColon', ':', 1),
+    })
+
+    check_parsing('(@a?@b:@c)?@d:@e', {
+      --           0123456789012345
+      --           0         1
+      ast = {
+        {
+          'Ternary:0:10:?',
+          children = {
+            {
+              'Nested:0:0:(',
+              children = {
+                {
+                  'Ternary:0:3:?',
+                  children = {
+                    'Register(name=a):0:1:@a',
+                    {
+                      'TernaryValue:0:6::',
+                      children = {
+                        'Register(name=b):0:4:@b',
+                        'Register(name=c):0:7:@c',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+            {
+              'TernaryValue:0:13::',
+              children = {
+                'Register(name=d):0:11:@d',
+                'Register(name=e):0:14:@e',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Register', '@a'),
+      hl('Ternary', '?'),
+      hl('Register', '@b'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@c'),
+      hl('NestingParenthesis', ')'),
+      hl('Ternary', '?'),
+      hl('Register', '@d'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@e'),
+    })
+
+    check_parsing('(@a?@b:@c)?(@d?@e:@f):(@g?@h:@i)', {
+      --           01234567890123456789012345678901
+      --           0         1         2         3
+      ast = {
+        {
+          'Ternary:0:10:?',
+          children = {
+            {
+              'Nested:0:0:(',
+              children = {
+                {
+                  'Ternary:0:3:?',
+                  children = {
+                    'Register(name=a):0:1:@a',
+                    {
+                      'TernaryValue:0:6::',
+                      children = {
+                        'Register(name=b):0:4:@b',
+                        'Register(name=c):0:7:@c',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+            {
+              'TernaryValue:0:21::',
+              children = {
+                {
+                  'Nested:0:11:(',
+                  children = {
+                    {
+                      'Ternary:0:14:?',
+                      children = {
+                        'Register(name=d):0:12:@d',
+                        {
+                          'TernaryValue:0:17::',
+                          children = {
+                            'Register(name=e):0:15:@e',
+                            'Register(name=f):0:18:@f',
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+                {
+                  'Nested:0:22:(',
+                  children = {
+                    {
+                      'Ternary:0:25:?',
+                      children = {
+                        'Register(name=g):0:23:@g',
+                        {
+                          'TernaryValue:0:28::',
+                          children = {
+                            'Register(name=h):0:26:@h',
+                            'Register(name=i):0:29:@i',
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Register', '@a'),
+      hl('Ternary', '?'),
+      hl('Register', '@b'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@c'),
+      hl('NestingParenthesis', ')'),
+      hl('Ternary', '?'),
+      hl('NestingParenthesis', '('),
+      hl('Register', '@d'),
+      hl('Ternary', '?'),
+      hl('Register', '@e'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@f'),
+      hl('NestingParenthesis', ')'),
+      hl('TernaryColon', ':'),
+      hl('NestingParenthesis', '('),
+      hl('Register', '@g'),
+      hl('Ternary', '?'),
+      hl('Register', '@h'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@i'),
+      hl('NestingParenthesis', ')'),
+    })
+
+    check_parsing('(@a?@b:@c)?@d?@e:@f:@g?@h:@i', {
+      --           0123456789012345678901234567
+      --           0         1         2
+      ast = {
+        {
+          'Ternary:0:10:?',
+          children = {
+            {
+              'Nested:0:0:(',
+              children = {
+                {
+                  'Ternary:0:3:?',
+                  children = {
+                    'Register(name=a):0:1:@a',
+                    {
+                      'TernaryValue:0:6::',
+                      children = {
+                        'Register(name=b):0:4:@b',
+                        'Register(name=c):0:7:@c',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+            {
+              'TernaryValue:0:19::',
+              children = {
+                {
+                  'Ternary:0:13:?',
+                  children = {
+                    'Register(name=d):0:11:@d',
+                    {
+                      'TernaryValue:0:16::',
+                      children = {
+                        'Register(name=e):0:14:@e',
+                        'Register(name=f):0:17:@f',
+                      },
+                    },
+                  },
+                },
+                {
+                  'Ternary:0:22:?',
+                  children = {
+                    'Register(name=g):0:20:@g',
+                    {
+                      'TernaryValue:0:25::',
+                      children = {
+                        'Register(name=h):0:23:@h',
+                        'Register(name=i):0:26:@i',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Register', '@a'),
+      hl('Ternary', '?'),
+      hl('Register', '@b'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@c'),
+      hl('NestingParenthesis', ')'),
+      hl('Ternary', '?'),
+      hl('Register', '@d'),
+      hl('Ternary', '?'),
+      hl('Register', '@e'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@f'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@g'),
+      hl('Ternary', '?'),
+      hl('Register', '@h'),
+      hl('TernaryColon', ':'),
+      hl('Register', '@i'),
+    })
+    check_parsing('a?b{cdef}g:h', {
+      --           012345678901
+      --           0         1
+      ast = {
+        {
+          'Ternary:0:1:?',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'TernaryValue:0:10::',
+              children = {
+                {
+                  'ComplexIdentifier:0:3:',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:2:b',
+                    {
+                      'ComplexIdentifier:0:9:',
+                      children = {
+                        {
+                          fmtn('CurlyBracesIdentifier', '--i', ':0:3:{'),
+                          children = {
+                            'PlainIdentifier(scope=0,ident=cdef):0:4:cdef',
+                          },
+                        },
+                        'PlainIdentifier(scope=0,ident=g):0:9:g',
+                      },
+                    },
+                  },
+                },
+                'PlainIdentifier(scope=0,ident=h):0:11:h',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Ternary', '?'),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'cdef'),
+      hl('Curly', '}'),
+      hl('IdentifierName', 'g'),
+      hl('TernaryColon', ':'),
+      hl('IdentifierName', 'h'),
+    })
+    check_parsing('a ? b : c : d', {
+      --           0123456789012
+      --           0         1
+      ast = {
+        {
+          'Colon:0:9: :',
+          children = {
+            {
+              'Ternary:0:1: ?',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                {
+                  'TernaryValue:0:5: :',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:3: b',
+                    'PlainIdentifier(scope=0,ident=c):0:7: c',
+                  },
+                },
+              },
+            },
+            'PlainIdentifier(scope=0,ident=d):0:11: d',
+          },
+        },
+      },
+      err = {
+        arg = ': d',
+        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Ternary', '?', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('TernaryColon', ':', 1),
+      hl('IdentifierName', 'c', 1),
+      hl('InvalidColon', ':', 1),
+      hl('IdentifierName', 'd', 1),
+    })
+  end)
+  itp('works with comparison operators', function()
+    check_parsing('a == b', {
+      --           012345
+      ast = {
+        {
+          'Comparison(type=Equal,inv=0,ccs=UseOption):0:1: ==',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:4: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '==', 1),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a ==? b', {
+      --           0123456
+      ast = {
+        {
+          'Comparison(type=Equal,inv=0,ccs=IgnoreCase):0:1: ==?',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:5: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '==', 1),
+      hl('ComparisonModifier', '?'),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a ==# b', {
+      --           0123456
+      ast = {
+        {
+          'Comparison(type=Equal,inv=0,ccs=MatchCase):0:1: ==#',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:5: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '==', 1),
+      hl('ComparisonModifier', '#'),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a !=# b', {
+      --           0123456
+      ast = {
+        {
+          'Comparison(type=Equal,inv=1,ccs=MatchCase):0:1: !=#',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:5: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '!=', 1),
+      hl('ComparisonModifier', '#'),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a <=# b', {
+      --           0123456
+      ast = {
+        {
+          'Comparison(type=Greater,inv=1,ccs=MatchCase):0:1: <=#',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:5: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '<=', 1),
+      hl('ComparisonModifier', '#'),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a >=# b', {
+      --           0123456
+      ast = {
+        {
+          'Comparison(type=GreaterOrEqual,inv=0,ccs=MatchCase):0:1: >=#',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:5: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '>=', 1),
+      hl('ComparisonModifier', '#'),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a ># b', {
+      --           012345
+      ast = {
+        {
+          'Comparison(type=Greater,inv=0,ccs=MatchCase):0:1: >#',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:4: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '>', 1),
+      hl('ComparisonModifier', '#'),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a <# b', {
+      --           012345
+      ast = {
+        {
+          'Comparison(type=GreaterOrEqual,inv=1,ccs=MatchCase):0:1: <#',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:4: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '<', 1),
+      hl('ComparisonModifier', '#'),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a is#b', {
+      --           012345
+      ast = {
+        {
+          'Comparison(type=Identical,inv=0,ccs=MatchCase):0:1: is#',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:5:b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', 'is', 1),
+      hl('ComparisonModifier', '#'),
+      hl('IdentifierName', 'b'),
+    })
+
+    check_parsing('a is?b', {
+      --           012345
+      ast = {
+        {
+          'Comparison(type=Identical,inv=0,ccs=IgnoreCase):0:1: is?',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:5:b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', 'is', 1),
+      hl('ComparisonModifier', '?'),
+      hl('IdentifierName', 'b'),
+    })
+
+    check_parsing('a isnot b', {
+      --           012345678
+      ast = {
+        {
+          'Comparison(type=Identical,inv=1,ccs=UseOption):0:1: isnot',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:7: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', 'isnot', 1),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a < b < c', {
+      --           012345678
+      ast = {
+        {
+          'Comparison(type=GreaterOrEqual,inv=1,ccs=UseOption):0:1: <',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'Comparison(type=GreaterOrEqual,inv=1,ccs=UseOption):0:5: <',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:3: b',
+                'PlainIdentifier(scope=0,ident=c):0:7: c',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ' < c',
+        msg = 'E15: Operator is not associative: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '<', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('InvalidComparison', '<', 1),
+      hl('IdentifierName', 'c', 1),
+    })
+
+    check_parsing('a < b <# c', {
+      --           012345678
+      ast = {
+        {
+          'Comparison(type=GreaterOrEqual,inv=1,ccs=UseOption):0:1: <',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'Comparison(type=GreaterOrEqual,inv=1,ccs=MatchCase):0:5: <#',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:3: b',
+                'PlainIdentifier(scope=0,ident=c):0:8: c',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ' <# c',
+        msg = 'E15: Operator is not associative: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Comparison', '<', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('InvalidComparison', '<', 1),
+      hl('InvalidComparisonModifier', '#'),
+      hl('IdentifierName', 'c', 1),
+    })
+
+    check_parsing('a += b', {
+      --           012345
+      ast = {
+        {
+          'Assignment(Add):0:1: +=',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:4: b',
+          },
+        },
+      },
+      err = {
+        arg = '+= b',
+        msg = 'E15: Misplaced assignment: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('InvalidAssignmentWithAddition', '+=', 1),
+      hl('IdentifierName', 'b', 1),
+    })
+    check_parsing('a + b == c + d', {
+      --           01234567890123
+      --           0         1
+      ast = {
+        {
+          'Comparison(type=Equal,inv=0,ccs=UseOption):0:5: ==',
+          children = {
+            {
+              'BinaryPlus:0:1: +',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                'PlainIdentifier(scope=0,ident=b):0:3: b',
+              },
+            },
+            {
+              'BinaryPlus:0:10: +',
+              children = {
+                'PlainIdentifier(scope=0,ident=c):0:8: c',
+                'PlainIdentifier(scope=0,ident=d):0:12: d',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('BinaryPlus', '+', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('Comparison', '==', 1),
+      hl('IdentifierName', 'c', 1),
+      hl('BinaryPlus', '+', 1),
+      hl('IdentifierName', 'd', 1),
+    })
+    check_parsing('+ a == + b', {
+      --           0123456789
+      ast = {
+        {
+          'Comparison(type=Equal,inv=0,ccs=UseOption):0:3: ==',
+          children = {
+            {
+              'UnaryPlus:0:0:+',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1: a',
+              },
+            },
+            {
+              'UnaryPlus:0:6: +',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:8: b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('UnaryPlus', '+'),
+      hl('IdentifierName', 'a', 1),
+      hl('Comparison', '==', 1),
+      hl('UnaryPlus', '+', 1),
+      hl('IdentifierName', 'b', 1),
+    })
+  end)
+  itp('works with concat/subscript', function()
+    check_parsing('.', {
+      --           0
+      ast = {
+        {
+          'ConcatOrSubscript:0:0:.',
+          children = {
+            'Missing:0:0:',
+          },
+        },
+      },
+      err = {
+        arg = '.',
+        msg = 'E15: Unexpected dot: %.*s',
+      },
+    }, {
+      hl('InvalidConcatOrSubscript', '.'),
+    })
+
+    check_parsing('a.', {
+      --           01
+      ast = {
+        {
+          'ConcatOrSubscript:0:1:.',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('ConcatOrSubscript', '.'),
+    })
+
+    check_parsing('a.b', {
+      --           012
+      ast = {
+        {
+          'ConcatOrSubscript:0:1:.',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainKey(key=b):0:2:b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', 'b'),
+    })
+
+    check_parsing('1.2', {
+      --           012
+      ast = {
+        'Float(val=1.200000e+00):0:0:1.2',
+      },
+    }, {
+      hl('Float', '1.2'),
+    })
+
+    check_parsing('1.2 + 1.3e-5', {
+      --           012345678901
+      --           0         1
+      ast = {
+        {
+          'BinaryPlus:0:3: +',
+          children = {
+            'Float(val=1.200000e+00):0:0:1.2',
+            'Float(val=1.300000e-05):0:5: 1.3e-5',
+          },
+        },
+      },
+    }, {
+      hl('Float', '1.2'),
+      hl('BinaryPlus', '+', 1),
+      hl('Float', '1.3e-5', 1),
+    })
+
+    check_parsing('a . 1.2 + 1.3e-5', {
+      --           0123456789012345
+      --           0         1
+      ast = {
+        {
+          'BinaryPlus:0:7: +',
+          children = {
+            {
+              'Concat:0:1: .',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                {
+                  'ConcatOrSubscript:0:5:.',
+                  children = {
+                    'Integer(val=1):0:3: 1',
+                    'PlainKey(key=2):0:6:2',
+                  },
+                },
+              },
+            },
+            'Float(val=1.300000e-05):0:9: 1.3e-5',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Concat', '.', 1),
+      hl('Number', '1', 1),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '2'),
+      hl('BinaryPlus', '+', 1),
+      hl('Float', '1.3e-5', 1),
+    })
+
+    check_parsing('1.3e-5 + 1.2 . a', {
+      --           0123456789012345
+      --           0         1
+      ast = {
+        {
+          'Concat:0:12: .',
+          children = {
+            {
+              'BinaryPlus:0:6: +',
+              children = {
+                'Float(val=1.300000e-05):0:0:1.3e-5',
+                'Float(val=1.200000e+00):0:8: 1.2',
+              },
+            },
+            'PlainIdentifier(scope=0,ident=a):0:14: a',
+          },
+        },
+      },
+    }, {
+      hl('Float', '1.3e-5'),
+      hl('BinaryPlus', '+', 1),
+      hl('Float', '1.2', 1),
+      hl('Concat', '.', 1),
+      hl('IdentifierName', 'a', 1),
+    })
+
+    check_parsing('1.3e-5 + a . 1.2', {
+      --           0123456789012345
+      --           0         1
+      ast = {
+        {
+          'Concat:0:10: .',
+          children = {
+            {
+              'BinaryPlus:0:6: +',
+              children = {
+                'Float(val=1.300000e-05):0:0:1.3e-5',
+                'PlainIdentifier(scope=0,ident=a):0:8: a',
+              },
+            },
+            {
+              'ConcatOrSubscript:0:14:.',
+              children = {
+                'Integer(val=1):0:12: 1',
+                'PlainKey(key=2):0:15:2',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Float', '1.3e-5'),
+      hl('BinaryPlus', '+', 1),
+      hl('IdentifierName', 'a', 1),
+      hl('Concat', '.', 1),
+      hl('Number', '1', 1),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '2'),
+    })
+
+    check_parsing('1.2.3', {
+      --           01234
+      ast = {
+        {
+          'ConcatOrSubscript:0:3:.',
+          children = {
+            {
+              'ConcatOrSubscript:0:1:.',
+              children = {
+                'Integer(val=1):0:0:1',
+                'PlainKey(key=2):0:2:2',
+              },
+            },
+            'PlainKey(key=3):0:4:3',
+          },
+        },
+      },
+    }, {
+      hl('Number', '1'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '2'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '3'),
+    })
+
+    check_parsing('a.1.2', {
+      --           01234
+      ast = {
+        {
+          'ConcatOrSubscript:0:3:.',
+          children = {
+            {
+              'ConcatOrSubscript:0:1:.',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                'PlainKey(key=1):0:2:1',
+              },
+            },
+            'PlainKey(key=2):0:4:2',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '1'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '2'),
+    })
+
+    check_parsing('a . 1.2', {
+      --           0123456
+      ast = {
+        {
+          'Concat:0:1: .',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'ConcatOrSubscript:0:5:.',
+              children = {
+                'Integer(val=1):0:3: 1',
+                'PlainKey(key=2):0:6:2',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Concat', '.', 1),
+      hl('Number', '1', 1),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '2'),
+    })
+
+    check_parsing('+a . +b', {
+      --           0123456
+      ast = {
+        {
+          'Concat:0:2: .',
+          children = {
+            {
+              'UnaryPlus:0:0:+',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+              },
+            },
+            {
+              'UnaryPlus:0:4: +',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:6:b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('UnaryPlus', '+'),
+      hl('IdentifierName', 'a'),
+      hl('Concat', '.', 1),
+      hl('UnaryPlus', '+', 1),
+      hl('IdentifierName', 'b'),
+    })
+
+    check_parsing('a. b', {
+      --           0123
+      ast = {
+        {
+          'Concat:0:1:.',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:2: b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierName', 'b', 1),
+    })
+
+    check_parsing('a. 1', {
+      --           0123
+      ast = {
+        {
+          'Concat:0:1:.',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'Integer(val=1):0:2: 1',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('ConcatOrSubscript', '.'),
+      hl('Number', '1', 1),
+    })
+  end)
+  itp('works with bracket subscripts', function()
+    check_parsing(':', {
+      --           0
+      ast = {
+        {
+          'Colon:0:0::',
+          children = {
+            'Missing:0:0:',
+          },
+        },
+      },
+      err = {
+        arg = ':',
+        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
+      },
+    }, {
+      hl('InvalidColon', ':'),
+    })
+    check_parsing('a[]', {
+      --           012
+      ast = {
+        {
+          'Subscript:0:1:[',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+          },
+        },
+      },
+      err = {
+        arg = ']',
+        msg = 'E15: Expected value, got closing bracket: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('InvalidSubscriptBracket', ']'),
+    })
+    check_parsing('a[b:]', {
+      --           01234
+      ast = {
+        {
+          'Subscript:0:1:[',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=b,ident=):0:2:b:',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierScope', 'b'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('SubscriptBracket', ']'),
+    })
+
+    check_parsing('a[b:c]', {
+      --           012345
+      ast = {
+        {
+          'Subscript:0:1:[',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=b,ident=c):0:2:b:c',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierScope', 'b'),
+      hl('IdentifierScopeDelimiter', ':'),
+      hl('IdentifierName', 'c'),
+      hl('SubscriptBracket', ']'),
+    })
+    check_parsing('a[b : c]', {
+      --           01234567
+      ast = {
+        {
+          'Subscript:0:1:[',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'Colon:0:3: :',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:2:b',
+                'PlainIdentifier(scope=0,ident=c):0:5: c',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierName', 'b'),
+      hl('SubscriptColon', ':', 1),
+      hl('IdentifierName', 'c', 1),
+      hl('SubscriptBracket', ']'),
+    })
+
+    check_parsing('a[: b]', {
+      --           012345
+      ast = {
+        {
+          'Subscript:0:1:[',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'Colon:0:2::',
+              children = {
+                'Missing:0:2:',
+                'PlainIdentifier(scope=0,ident=b):0:3: b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('SubscriptColon', ':'),
+      hl('IdentifierName', 'b', 1),
+      hl('SubscriptBracket', ']'),
+    })
+
+    check_parsing('a[b :]', {
+      --           012345
+      ast = {
+        {
+          'Subscript:0:1:[',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'Colon:0:3: :',
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:2:b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierName', 'b'),
+      hl('SubscriptColon', ':', 1),
+      hl('SubscriptBracket', ']'),
+    })
+    check_parsing('a[b][c][d](e)(f)(g)', {
+      --           0123456789012345678
+      --           0         1
+      ast = {
+        {
+          'Call:0:16:(',
+          children = {
+            {
+              'Call:0:13:(',
+              children = {
+                {
+                  'Call:0:10:(',
+                  children = {
+                    {
+                      'Subscript:0:7:[',
+                      children = {
+                        {
+                          'Subscript:0:4:[',
+                          children = {
+                            {
+                              'Subscript:0:1:[',
+                              children = {
+                                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                                'PlainIdentifier(scope=0,ident=b):0:2:b',
+                              },
+                            },
+                            'PlainIdentifier(scope=0,ident=c):0:5:c',
+                          },
+                        },
+                        'PlainIdentifier(scope=0,ident=d):0:8:d',
+                      },
+                    },
+                    'PlainIdentifier(scope=0,ident=e):0:11:e',
+                  },
+                },
+                'PlainIdentifier(scope=0,ident=f):0:14:f',
+              },
+            },
+            'PlainIdentifier(scope=0,ident=g):0:17:g',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierName', 'b'),
+      hl('SubscriptBracket', ']'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierName', 'c'),
+      hl('SubscriptBracket', ']'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierName', 'd'),
+      hl('SubscriptBracket', ']'),
+      hl('CallingParenthesis', '('),
+      hl('IdentifierName', 'e'),
+      hl('CallingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('IdentifierName', 'f'),
+      hl('CallingParenthesis', ')'),
+      hl('CallingParenthesis', '('),
+      hl('IdentifierName', 'g'),
+      hl('CallingParenthesis', ')'),
+    })
+    check_parsing('{a}{b}{c}[d][e][f]', {
+      --           012345678901234567
+      --           0         1
+      ast = {
+        {
+          'Subscript:0:15:[',
+          children = {
+            {
+              'Subscript:0:12:[',
+              children = {
+                {
+                  'Subscript:0:9:[',
+                  children = {
+                    {
+                      'ComplexIdentifier:0:3:',
+                      children = {
+                        {
+                          fmtn('CurlyBracesIdentifier', '-di', ':0:0:{'),
+                          children = {
+                            'PlainIdentifier(scope=0,ident=a):0:1:a',
+                          },
+                        },
+                        {
+                          'ComplexIdentifier:0:6:',
+                          children = {
+                            {
+                              fmtn('CurlyBracesIdentifier', '--i', ':0:3:{'),
+                              children = {
+                                'PlainIdentifier(scope=0,ident=b):0:4:b',
+                              },
+                            },
+                            {
+                              fmtn('CurlyBracesIdentifier', '--i', ':0:6:{'),
+                              children = {
+                                'PlainIdentifier(scope=0,ident=c):0:7:c',
+                              },
+                            },
+                          },
+                        },
+                      },
+                    },
+                    'PlainIdentifier(scope=0,ident=d):0:10:d',
+                  },
+                },
+                'PlainIdentifier(scope=0,ident=e):0:13:e',
+              },
+            },
+            'PlainIdentifier(scope=0,ident=f):0:16:f',
+          },
+        },
+      },
+    }, {
+      hl('Curly', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Curly', '}'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '}'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'c'),
+      hl('Curly', '}'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierName', 'd'),
+      hl('SubscriptBracket', ']'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierName', 'e'),
+      hl('SubscriptBracket', ']'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierName', 'f'),
+      hl('SubscriptBracket', ']'),
+    })
+  end)
+  itp('supports list literals', function()
+    check_parsing('[]', {
+      --           01
+      ast = {
+        'ListLiteral:0:0:[',
+      },
+    }, {
+      hl('List', '['),
+      hl('List', ']'),
+    })
+
+    check_parsing('[a]', {
+      --           012
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:1:a',
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('List', ']'),
+    })
+
+    check_parsing('[a, b]', {
+      --           012345
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:3: b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b', 1),
+      hl('List', ']'),
+    })
+
+    check_parsing('[a, b, c]', {
+      --           012345678
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                {
+                  'Comma:0:5:,',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:3: b',
+                    'PlainIdentifier(scope=0,ident=c):0:6: c',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b', 1),
+      hl('Comma', ','),
+      hl('IdentifierName', 'c', 1),
+      hl('List', ']'),
+    })
+
+    check_parsing('[a, b, c, ]', {
+      --           01234567890
+      --           0         1
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                {
+                  'Comma:0:5:,',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:3: b',
+                    {
+                      'Comma:0:8:,',
+                      children = {
+                        'PlainIdentifier(scope=0,ident=c):0:6: c',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b', 1),
+      hl('Comma', ','),
+      hl('IdentifierName', 'c', 1),
+      hl('Comma', ','),
+      hl('List', ']', 1),
+    })
+
+    check_parsing('[a : b, c : d]', {
+      --           01234567890123
+      --           0         1
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            {
+              'Comma:0:6:,',
+              children = {
+                {
+                  'Colon:0:2: :',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=a):0:1:a',
+                    'PlainIdentifier(scope=0,ident=b):0:4: b',
+                  },
+                },
+                {
+                  'Colon:0:9: :',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=c):0:7: c',
+                    'PlainIdentifier(scope=0,ident=d):0:11: d',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ': b, c : d]',
+        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('InvalidColon', ':', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('Comma', ','),
+      hl('IdentifierName', 'c', 1),
+      hl('InvalidColon', ':', 1),
+      hl('IdentifierName', 'd', 1),
+      hl('List', ']'),
+    })
+
+    check_parsing(']', {
+      --           0
+      ast = {
+        'ListLiteral:0:0:',
+      },
+      err = {
+        arg = ']',
+        msg = 'E15: Unexpected closing figure brace: %.*s',
+      },
+    }, {
+      hl('InvalidList', ']'),
+    })
+
+    check_parsing('a]', {
+      --           01
+      ast = {
+        {
+          'ListLiteral:0:1:',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+          },
+        },
+      },
+      err = {
+        arg = ']',
+        msg = 'E15: Unexpected closing figure brace: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('InvalidList', ']'),
+    })
+
+    check_parsing('[] []', {
+      --           01234
+      ast = {
+        {
+          'OpMissing:0:2:',
+          children = {
+            'ListLiteral:0:0:[',
+            'ListLiteral:0:2: [',
+          },
+        },
+      },
+      err = {
+        arg = '[]',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('List', '['),
+      hl('List', ']'),
+      hl('InvalidSpacing', ' '),
+      hl('List', '['),
+      hl('List', ']'),
+    }, {
+      [1] = {
+        ast = {
+          len = 3,
+          err = REMOVE_THIS,
+          ast = {
+            'ListLiteral:0:0:[',
+          },
+        },
+        hl_fs = {
+          [3] = REMOVE_THIS,
+          [4] = REMOVE_THIS,
+          [5] = REMOVE_THIS,
+        },
+      },
+    })
+
+    check_parsing('[][]', {
+      --           0123
+      ast = {
+        {
+          'Subscript:0:2:[',
+          children = {
+            'ListLiteral:0:0:[',
+          },
+        },
+      },
+      err = {
+        arg = ']',
+        msg = 'E15: Expected value, got closing bracket: %.*s',
+      },
+    }, {
+      hl('List', '['),
+      hl('List', ']'),
+      hl('SubscriptBracket', '['),
+      hl('InvalidSubscriptBracket', ']'),
+    })
+
+    check_parsing('[', {
+      --           0
+      ast = {
+        'ListLiteral:0:0:[',
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('List', '['),
+    })
+
+    check_parsing('[1', {
+      --           01
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            'Integer(val=1):0:1:1',
+          },
+        },
+      },
+      err = {
+        arg = '[1',
+        msg = 'E697: Missing end of List \']\': %.*s',
+      },
+    }, {
+      hl('List', '['),
+      hl('Number', '1'),
+    })
+  end)
+  itp('works with strings', function()
+    check_parsing('\'abc\'', {
+      --           01234
+      ast = {
+        fmtn('SingleQuotedString', 'val="abc"', ':0:0:\'abc\''),
+      },
+    }, {
+      hl('SingleQuote', '\''),
+      hl('SingleQuotedBody', 'abc'),
+      hl('SingleQuote', '\''),
+    })
+    check_parsing('"abc"', {
+      --           01234
+      ast = {
+        fmtn('DoubleQuotedString', 'val="abc"', ':0:0:"abc"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedBody', 'abc'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('\'\'', {
+      --           01
+      ast = {
+        fmtn('SingleQuotedString', 'val=NULL', ':0:0:\'\''),
+      },
+    }, {
+      hl('SingleQuote', '\''),
+      hl('SingleQuote', '\''),
+    })
+    check_parsing('""', {
+      --           01
+      ast = {
+        fmtn('DoubleQuotedString', 'val=NULL', ':0:0:""'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"', {
+      --           0
+      ast = {
+        fmtn('DoubleQuotedString', 'val=NULL', ':0:0:"'),
+      },
+      err = {
+        arg = '"',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+    })
+    check_parsing('\'', {
+      --           0
+      ast = {
+        fmtn('SingleQuotedString', 'val=NULL', ':0:0:\''),
+      },
+      err = {
+        arg = '\'',
+        msg = 'E115: Missing single quote: %.*s',
+      },
+    }, {
+      hl('InvalidSingleQuote', '\''),
+    })
+    check_parsing('"a', {
+      --           01
+      ast = {
+        fmtn('DoubleQuotedString', 'val="a"', ':0:0:"a'),
+      },
+      err = {
+        arg = '"a',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedBody', 'a'),
+    })
+    check_parsing('\'a', {
+      --           01
+      ast = {
+        fmtn('SingleQuotedString', 'val="a"', ':0:0:\'a'),
+      },
+      err = {
+        arg = '\'a',
+        msg = 'E115: Missing single quote: %.*s',
+      },
+    }, {
+      hl('InvalidSingleQuote', '\''),
+      hl('InvalidSingleQuotedBody', 'a'),
+    })
+    check_parsing('\'abc\'\'def\'', {
+      --           0123456789
+      ast = {
+        fmtn('SingleQuotedString', 'val="abc\'def"', ':0:0:\'abc\'\'def\''),
+      },
+    }, {
+      hl('SingleQuote', '\''),
+      hl('SingleQuotedBody', 'abc'),
+      hl('SingleQuotedQuote', '\'\''),
+      hl('SingleQuotedBody', 'def'),
+      hl('SingleQuote', '\''),
+    })
+    check_parsing('\'abc\'\'', {
+      --           012345
+      ast = {
+        fmtn('SingleQuotedString', 'val="abc\'"', ':0:0:\'abc\'\''),
+      },
+      err = {
+        arg = '\'abc\'\'',
+        msg = 'E115: Missing single quote: %.*s',
+      },
+    }, {
+      hl('InvalidSingleQuote', '\''),
+      hl('InvalidSingleQuotedBody', 'abc'),
+      hl('InvalidSingleQuotedQuote', '\'\''),
+    })
+    check_parsing('\'\'\'\'\'\'\'\'', {
+      --           01234567
+      ast = {
+        fmtn('SingleQuotedString', 'val="\'\'\'"', ':0:0:\'\'\'\'\'\'\'\''),
+      },
+    }, {
+      hl('SingleQuote', '\''),
+      hl('SingleQuotedQuote', '\'\''),
+      hl('SingleQuotedQuote', '\'\''),
+      hl('SingleQuotedQuote', '\'\''),
+      hl('SingleQuote', '\''),
+    })
+    check_parsing('\'\'\'a\'\'\'\'bc\'', {
+      --           01234567890
+      --           0         1
+      ast = {
+        fmtn('SingleQuotedString', 'val="\'a\'\'bc"', ':0:0:\'\'\'a\'\'\'\'bc\''),
+      },
+    }, {
+      hl('SingleQuote', '\''),
+      hl('SingleQuotedQuote', '\'\''),
+      hl('SingleQuotedBody', 'a'),
+      hl('SingleQuotedQuote', '\'\''),
+      hl('SingleQuotedQuote', '\'\''),
+      hl('SingleQuotedBody', 'bc'),
+      hl('SingleQuote', '\''),
+    })
+    check_parsing('"\\"\\"\\"\\""', {
+      --           0123456789
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\"\\"\\"\\""', ':0:0:"\\"\\"\\"\\""'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\"'),
+      hl('DoubleQuotedEscape', '\\"'),
+      hl('DoubleQuotedEscape', '\\"'),
+      hl('DoubleQuotedEscape', '\\"'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"abc\\"def\\"ghi\\"jkl\\"mno"', {
+      --           0123456789012345678901234
+      --           0         1         2
+      ast = {
+        fmtn('DoubleQuotedString', 'val="abc\\"def\\"ghi\\"jkl\\"mno"', ':0:0:"abc\\"def\\"ghi\\"jkl\\"mno"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedBody', 'abc'),
+      hl('DoubleQuotedEscape', '\\"'),
+      hl('DoubleQuotedBody', 'def'),
+      hl('DoubleQuotedEscape', '\\"'),
+      hl('DoubleQuotedBody', 'ghi'),
+      hl('DoubleQuotedEscape', '\\"'),
+      hl('DoubleQuotedBody', 'jkl'),
+      hl('DoubleQuotedEscape', '\\"'),
+      hl('DoubleQuotedBody', 'mno'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"\\b\\e\\f\\r\\t\\\\"', {
+      --           0123456789012345
+      --           0         1
+      ast = {
+        [[DoubleQuotedString(val="\8\27\12\13\9\\"):0:0:"\b\e\f\r\t\\"]],
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\b'),
+      hl('DoubleQuotedEscape', '\\e'),
+      hl('DoubleQuotedEscape', '\\f'),
+      hl('DoubleQuotedEscape', '\\r'),
+      hl('DoubleQuotedEscape', '\\t'),
+      hl('DoubleQuotedEscape', '\\\\'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"\\n\n"', {
+      --           01234
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\\n\\\n"', ':0:0:"\\n\n"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\n'),
+      hl('DoubleQuotedBody', '\n'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"\\x00"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0"', ':0:0:"\\x00"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\x00'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"\\xFF"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\255"', ':0:0:"\\xFF"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\xFF'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"\\xF"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\15"', ':0:0:"\\xF"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\xF'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"\\u00AB"', {
+      --           01234567
+      ast = {
+        fmtn('DoubleQuotedString', 'val="«"', ':0:0:"\\u00AB"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\u00AB'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"\\U000000AB"', {
+      --           01234567
+      ast = {
+        fmtn('DoubleQuotedString', 'val="«"', ':0:0:"\\U000000AB"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U000000AB'),
+      hl('DoubleQuote', '"'),
+    })
+    check_parsing('"\\x"', {
+      --           0123
+      ast = {
+        fmtn('DoubleQuotedString', 'val="x"', ':0:0:"\\x"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\x'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\x', {
+      --           012
+      ast = {
+        fmtn('DoubleQuotedString', 'val="x"', ':0:0:"\\x'),
+      },
+      err = {
+        arg = '"\\x',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedUnknownEscape', '\\x'),
+    })
+
+    check_parsing('"\\xF', {
+      --           0123
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\15"', ':0:0:"\\xF'),
+      },
+      err = {
+        arg = '"\\xF',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedEscape', '\\xF'),
+    })
+
+    check_parsing('"\\u"', {
+      --           0123
+      ast = {
+        fmtn('DoubleQuotedString', 'val="u"', ':0:0:"\\u"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\u'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\u', {
+      --           012
+      ast = {
+        fmtn('DoubleQuotedString', 'val="u"', ':0:0:"\\u'),
+      },
+      err = {
+        arg = '"\\u',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedUnknownEscape', '\\u'),
+    })
+
+    check_parsing('"\\U', {
+      --           012
+      ast = {
+        fmtn('DoubleQuotedString', 'val="U"', ':0:0:"\\U'),
+      },
+      err = {
+        arg = '"\\U',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
+    })
+
+    check_parsing('"\\U"', {
+      --           0123
+      ast = {
+        fmtn('DoubleQuotedString', 'val="U"', ':0:0:"\\U"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\U'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\xFX"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\15X"', ':0:0:"\\xFX"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\xF'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\XFX"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\15X"', ':0:0:"\\XFX"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\XF'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\xX"', {
+      --           01234
+      ast = {
+        fmtn('DoubleQuotedString', 'val="xX"', ':0:0:"\\xX"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\x'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\XX"', {
+      --           01234
+      ast = {
+        fmtn('DoubleQuotedString', 'val="XX"', ':0:0:"\\XX"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\X'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\uX"', {
+      --           01234
+      ast = {
+        fmtn('DoubleQuotedString', 'val="uX"', ':0:0:"\\uX"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\u'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\UX"', {
+      --           01234
+      ast = {
+        fmtn('DoubleQuotedString', 'val="UX"', ':0:0:"\\UX"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\U'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\x0X"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\x0X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\x0'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\X0X"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\X0X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\X0'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\u0X"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\u0X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\u0'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\U0X"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\U0X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U0'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\x00X"', {
+      --           0123456
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\x00X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\x00'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\X00X"', {
+      --           0123456
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\X00X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\X00'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\u00X"', {
+      --           0123456
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\u00X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\u00'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\U00X"', {
+      --           0123456
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\U00X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U00'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\u000X"', {
+      --           01234567
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\u000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\u000'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\U000X"', {
+      --           01234567
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\U000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U000'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\u0000X"', {
+      --           012345678
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\u0000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\u0000'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\U0000X"', {
+      --           012345678
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\U0000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U0000'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\U00000X"', {
+      --           0123456789
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\U00000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U00000'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\U000000X"', {
+      --           01234567890
+      --           0         1
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\U000000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U000000'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\U0000000X"', {
+      --           012345678901
+      --           0         1
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\U0000000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U0000000'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\U00000000X"', {
+      --           0123456789012
+      --           0         1
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0X"', ':0:0:"\\U00000000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U00000000'),
+      hl('DoubleQuotedBody', 'X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\x000X"', {
+      --           01234567
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0000X"', ':0:0:"\\x000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\x00'),
+      hl('DoubleQuotedBody', '0X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\X000X"', {
+      --           01234567
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0000X"', ':0:0:"\\X000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\X00'),
+      hl('DoubleQuotedBody', '0X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\u00000X"', {
+      --           0123456789
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0000X"', ':0:0:"\\u00000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\u0000'),
+      hl('DoubleQuotedBody', '0X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\U000000000X"', {
+      --           01234567890123
+      --           0         1
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0000X"', ':0:0:"\\U000000000X"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\U00000000'),
+      hl('DoubleQuotedBody', '0X'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\0"', {
+      --           0123
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0"', ':0:0:"\\0"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\0'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\00"', {
+      --           01234
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0"', ':0:0:"\\00"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\00'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\000"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0"', ':0:0:"\\000"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\000'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\0000"', {
+      --           0123456
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0000"', ':0:0:"\\0000"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\000'),
+      hl('DoubleQuotedBody', '0'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\8"', {
+      --           0123
+      ast = {
+        fmtn('DoubleQuotedString', 'val="8"', ':0:0:"\\8"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\8'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\08"', {
+      --           01234
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0008"', ':0:0:"\\08"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\0'),
+      hl('DoubleQuotedBody', '8'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\008"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0008"', ':0:0:"\\008"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\00'),
+      hl('DoubleQuotedBody', '8'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\0008"', {
+      --           0123456
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\0008"', ':0:0:"\\0008"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\000'),
+      hl('DoubleQuotedBody', '8'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\777"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\255"', ':0:0:"\\777"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\777'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\050"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\40"', ':0:0:"\\050"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\050'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\<C-u>"', {
+      --           012345
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\21"', ':0:0:"\\<C-u>"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedEscape', '\\<C-u>'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\<', {
+      --           012
+      ast = {
+        fmtn('DoubleQuotedString', 'val="<"', ':0:0:"\\<'),
+      },
+      err = {
+        arg = '"\\<',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedUnknownEscape', '\\<'),
+    })
+
+    check_parsing('"\\<"', {
+      --           0123
+      ast = {
+        fmtn('DoubleQuotedString', 'val="<"', ':0:0:"\\<"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\<'),
+      hl('DoubleQuote', '"'),
+    })
+
+    check_parsing('"\\<C-u"', {
+      --           0123456
+      ast = {
+        fmtn('DoubleQuotedString', 'val="<C-u"', ':0:0:"\\<C-u"'),
+      },
+    }, {
+      hl('DoubleQuote', '"'),
+      hl('DoubleQuotedUnknownEscape', '\\<'),
+      hl('DoubleQuotedBody', 'C-u'),
+      hl('DoubleQuote', '"'),
+    })
+  end)
+  itp('works with multiplication-like operators', function()
+    check_parsing('2+2*2', {
+      --           01234
+      ast = {
+        {
+          'BinaryPlus:0:1:+',
+          children = {
+            'Integer(val=2):0:0:2',
+            {
+              'Multiplication:0:3:*',
+              children = {
+                'Integer(val=2):0:2:2',
+                'Integer(val=2):0:4:2',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Number', '2'),
+      hl('BinaryPlus', '+'),
+      hl('Number', '2'),
+      hl('Multiplication', '*'),
+      hl('Number', '2'),
+    })
+
+    check_parsing('2+2*', {
+      --           0123
+      ast = {
+        {
+          'BinaryPlus:0:1:+',
+          children = {
+            'Integer(val=2):0:0:2',
+            {
+              'Multiplication:0:3:*',
+              children = {
+                'Integer(val=2):0:2:2',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('Number', '2'),
+      hl('BinaryPlus', '+'),
+      hl('Number', '2'),
+      hl('Multiplication', '*'),
+    })
+
+    check_parsing('2+*2', {
+      --           0123
+      ast = {
+        {
+          'BinaryPlus:0:1:+',
+          children = {
+            'Integer(val=2):0:0:2',
+            {
+              'Multiplication:0:2:*',
+              children = {
+                'Missing:0:2:',
+                'Integer(val=2):0:3:2',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '*2',
+        msg = 'E15: Unexpected multiplication-like operator: %.*s',
+      },
+    }, {
+      hl('Number', '2'),
+      hl('BinaryPlus', '+'),
+      hl('InvalidMultiplication', '*'),
+      hl('Number', '2'),
+    })
+
+    check_parsing('2+2/2', {
+      --           01234
+      ast = {
+        {
+          'BinaryPlus:0:1:+',
+          children = {
+            'Integer(val=2):0:0:2',
+            {
+              'Division:0:3:/',
+              children = {
+                'Integer(val=2):0:2:2',
+                'Integer(val=2):0:4:2',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Number', '2'),
+      hl('BinaryPlus', '+'),
+      hl('Number', '2'),
+      hl('Division', '/'),
+      hl('Number', '2'),
+    })
+
+    check_parsing('2+2/', {
+      --           0123
+      ast = {
+        {
+          'BinaryPlus:0:1:+',
+          children = {
+            'Integer(val=2):0:0:2',
+            {
+              'Division:0:3:/',
+              children = {
+                'Integer(val=2):0:2:2',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('Number', '2'),
+      hl('BinaryPlus', '+'),
+      hl('Number', '2'),
+      hl('Division', '/'),
+    })
+
+    check_parsing('2+/2', {
+      --           0123
+      ast = {
+        {
+          'BinaryPlus:0:1:+',
+          children = {
+            'Integer(val=2):0:0:2',
+            {
+              'Division:0:2:/',
+              children = {
+                'Missing:0:2:',
+                'Integer(val=2):0:3:2',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '/2',
+        msg = 'E15: Unexpected multiplication-like operator: %.*s',
+      },
+    }, {
+      hl('Number', '2'),
+      hl('BinaryPlus', '+'),
+      hl('InvalidDivision', '/'),
+      hl('Number', '2'),
+    })
+
+    check_parsing('2+2%2', {
+      --           01234
+      ast = {
+        {
+          'BinaryPlus:0:1:+',
+          children = {
+            'Integer(val=2):0:0:2',
+            {
+              'Mod:0:3:%',
+              children = {
+                'Integer(val=2):0:2:2',
+                'Integer(val=2):0:4:2',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Number', '2'),
+      hl('BinaryPlus', '+'),
+      hl('Number', '2'),
+      hl('Mod', '%'),
+      hl('Number', '2'),
+    })
+
+    check_parsing('2+2%', {
+      --           0123
+      ast = {
+        {
+          'BinaryPlus:0:1:+',
+          children = {
+            'Integer(val=2):0:0:2',
+            {
+              'Mod:0:3:%',
+              children = {
+                'Integer(val=2):0:2:2',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('Number', '2'),
+      hl('BinaryPlus', '+'),
+      hl('Number', '2'),
+      hl('Mod', '%'),
+    })
+
+    check_parsing('2+%2', {
+      --           0123
+      ast = {
+        {
+          'BinaryPlus:0:1:+',
+          children = {
+            'Integer(val=2):0:0:2',
+            {
+              'Mod:0:2:%',
+              children = {
+                'Missing:0:2:',
+                'Integer(val=2):0:3:2',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '%2',
+        msg = 'E15: Unexpected multiplication-like operator: %.*s',
+      },
+    }, {
+      hl('Number', '2'),
+      hl('BinaryPlus', '+'),
+      hl('InvalidMod', '%'),
+      hl('Number', '2'),
+    })
+  end)
+  itp('works with -', function()
+    check_parsing('@a', {
+      ast = {
+        'Register(name=a):0:0:@a',
+      },
+    }, {
+      hl('Register', '@a'),
+    })
+    check_parsing('-@a', {
+      ast = {
+        {
+          'UnaryMinus:0:0:-',
+          children = {
+            'Register(name=a):0:1:@a',
+          },
+        },
+      },
+    }, {
+      hl('UnaryMinus', '-'),
+      hl('Register', '@a'),
+    })
+    check_parsing('@a-@b', {
+      ast = {
+        {
+          'BinaryMinus:0:2:-',
+          children = {
+            'Register(name=a):0:0:@a',
+            'Register(name=b):0:3:@b',
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryMinus', '-'),
+      hl('Register', '@b'),
+    })
+    check_parsing('@a-@b-@c', {
+      ast = {
+        {
+          'BinaryMinus:0:5:-',
+          children = {
+            {
+              'BinaryMinus:0:2:-',
+              children = {
+                'Register(name=a):0:0:@a',
+                'Register(name=b):0:3:@b',
+              },
+            },
+            'Register(name=c):0:6:@c',
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryMinus', '-'),
+      hl('Register', '@b'),
+      hl('BinaryMinus', '-'),
+      hl('Register', '@c'),
+    })
+    check_parsing('-@a-@b', {
+      ast = {
+        {
+          'BinaryMinus:0:3:-',
+          children = {
+            {
+              'UnaryMinus:0:0:-',
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+            'Register(name=b):0:4:@b',
+          },
+        },
+      },
+    }, {
+      hl('UnaryMinus', '-'),
+      hl('Register', '@a'),
+      hl('BinaryMinus', '-'),
+      hl('Register', '@b'),
+    })
+    check_parsing('-@a--@b', {
+      ast = {
+        {
+          'BinaryMinus:0:3:-',
+          children = {
+            {
+              'UnaryMinus:0:0:-',
+              children = {
+                'Register(name=a):0:1:@a',
+              },
+            },
+            {
+              'UnaryMinus:0:4:-',
+              children = {
+                'Register(name=b):0:5:@b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('UnaryMinus', '-'),
+      hl('Register', '@a'),
+      hl('BinaryMinus', '-'),
+      hl('UnaryMinus', '-'),
+      hl('Register', '@b'),
+    })
+    check_parsing('-', {
+      ast = {
+        'UnaryMinus:0:0:-',
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('UnaryMinus', '-'),
+    })
+    check_parsing(' -', {
+      ast = {
+        'UnaryMinus:0:0: -',
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('UnaryMinus', '-', 1),
+    })
+    check_parsing('@a-  ', {
+      ast = {
+        {
+          'BinaryMinus:0:2:-',
+          children = {
+            'Register(name=a):0:0:@a',
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('BinaryMinus', '-'),
+    })
+  end)
+  itp('works with logical operators', function()
+    check_parsing('a && b || c && d', {
+      --           0123456789012345
+      --           0         1
+      ast = {
+        {
+          'Or:0:6: ||',
+          children = {
+            {
+              'And:0:1: &&',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                'PlainIdentifier(scope=0,ident=b):0:4: b',
+              },
+            },
+            {
+              'And:0:11: &&',
+              children = {
+                'PlainIdentifier(scope=0,ident=c):0:9: c',
+                'PlainIdentifier(scope=0,ident=d):0:14: d',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('And', '&&', 1),
+      hl('IdentifierName', 'b', 1),
+      hl('Or', '||', 1),
+      hl('IdentifierName', 'c', 1),
+      hl('And', '&&', 1),
+      hl('IdentifierName', 'd', 1),
+    })
+
+    check_parsing('&& a', {
+      --           0123
+      ast = {
+        {
+          'And:0:0:&&',
+          children = {
+            'Missing:0:0:',
+            'PlainIdentifier(scope=0,ident=a):0:2: a',
+          },
+        },
+      },
+      err = {
+        arg = '&& a',
+        msg = 'E15: Unexpected and operator: %.*s',
+      },
+    }, {
+      hl('InvalidAnd', '&&'),
+      hl('IdentifierName', 'a', 1),
+    })
+
+    check_parsing('|| a', {
+      --           0123
+      ast = {
+        {
+          'Or:0:0:||',
+          children = {
+            'Missing:0:0:',
+            'PlainIdentifier(scope=0,ident=a):0:2: a',
+          },
+        },
+      },
+      err = {
+        arg = '|| a',
+        msg = 'E15: Unexpected or operator: %.*s',
+      },
+    }, {
+      hl('InvalidOr', '||'),
+      hl('IdentifierName', 'a', 1),
+    })
+
+    check_parsing('a||', {
+      --           012
+      ast = {
+        {
+          'Or:0:1:||',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Or', '||'),
+    })
+
+    check_parsing('a&&', {
+      --           012
+      ast = {
+        {
+          'And:0:1:&&',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('And', '&&'),
+    })
+
+    check_parsing('(&&)', {
+      --           0123
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'And:0:1:&&',
+              children = {
+                'Missing:0:1:',
+                'Missing:0:3:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '&&)',
+        msg = 'E15: Unexpected and operator: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('InvalidAnd', '&&'),
+      hl('InvalidNestingParenthesis', ')'),
+    })
+
+    check_parsing('(||)', {
+      --           0123
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'Or:0:1:||',
+              children = {
+                'Missing:0:1:',
+                'Missing:0:3:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '||)',
+        msg = 'E15: Unexpected or operator: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('InvalidOr', '||'),
+      hl('InvalidNestingParenthesis', ')'),
+    })
+
+    check_parsing('(a||)', {
+      --           01234
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'Or:0:2:||',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'Missing:0:4:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ')',
+        msg = 'E15: Expected value, got parenthesis: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('IdentifierName', 'a'),
+      hl('Or', '||'),
+      hl('InvalidNestingParenthesis', ')'),
+    })
+
+    check_parsing('(a&&)', {
+      --           01234
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'And:0:2:&&',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'Missing:0:4:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ')',
+        msg = 'E15: Expected value, got parenthesis: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('IdentifierName', 'a'),
+      hl('And', '&&'),
+      hl('InvalidNestingParenthesis', ')'),
+    })
+
+    check_parsing('(&&a)', {
+      --           01234
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'And:0:1:&&',
+              children = {
+                'Missing:0:1:',
+                'PlainIdentifier(scope=0,ident=a):0:3:a',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '&&a)',
+        msg = 'E15: Unexpected and operator: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('InvalidAnd', '&&'),
+      hl('IdentifierName', 'a'),
+      hl('NestingParenthesis', ')'),
+    })
+
+    check_parsing('(||a)', {
+      --           01234
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'Or:0:1:||',
+              children = {
+                'Missing:0:1:',
+                'PlainIdentifier(scope=0,ident=a):0:3:a',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '||a)',
+        msg = 'E15: Unexpected or operator: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('InvalidOr', '||'),
+      hl('IdentifierName', 'a'),
+      hl('NestingParenthesis', ')'),
+    })
+  end)
+  itp('works with &opt', function()
+    check_parsing('&', {
+      --           0
+      ast = {
+        'Option(scope=0,ident=):0:0:&',
+      },
+      err = {
+        arg = '&',
+        msg = 'E112: Option name missing: %.*s',
+      },
+    }, {
+      hl('InvalidOptionSigil', '&'),
+    })
+
+    check_parsing('&opt', {
+      --           0123
+      ast = {
+        'Option(scope=0,ident=opt):0:0:&opt',
+      },
+    }, {
+      hl('OptionSigil', '&'),
+      hl('OptionName', 'opt'),
+    })
+
+    check_parsing('&l:opt', {
+      --           012345
+      ast = {
+        'Option(scope=l,ident=opt):0:0:&l:opt',
+      },
+    }, {
+      hl('OptionSigil', '&'),
+      hl('OptionScope', 'l'),
+      hl('OptionScopeDelimiter', ':'),
+      hl('OptionName', 'opt'),
+    })
+
+    check_parsing('&g:opt', {
+      --           012345
+      ast = {
+        'Option(scope=g,ident=opt):0:0:&g:opt',
+      },
+    }, {
+      hl('OptionSigil', '&'),
+      hl('OptionScope', 'g'),
+      hl('OptionScopeDelimiter', ':'),
+      hl('OptionName', 'opt'),
+    })
+
+    check_parsing('&s:opt', {
+      --           012345
+      ast = {
+        {
+          'Colon:0:2::',
+          children = {
+            'Option(scope=0,ident=s):0:0:&s',
+            'PlainIdentifier(scope=0,ident=opt):0:3:opt',
+          },
+        },
+      },
+      err = {
+        arg = ':opt',
+        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
+      },
+    }, {
+      hl('OptionSigil', '&'),
+      hl('OptionName', 's'),
+      hl('InvalidColon', ':'),
+      hl('IdentifierName', 'opt'),
+    })
+
+    check_parsing('& ', {
+      --           01
+      ast = {
+        'Option(scope=0,ident=):0:0:&',
+      },
+      err = {
+        arg = '& ',
+        msg = 'E112: Option name missing: %.*s',
+      },
+    }, {
+      hl('InvalidOptionSigil', '&'),
+    })
+
+    check_parsing('&-', {
+      --           01
+      ast = {
+        {
+          'BinaryMinus:0:1:-',
+          children = {
+            'Option(scope=0,ident=):0:0:&',
+          },
+        },
+      },
+      err = {
+        arg = '&-',
+        msg = 'E112: Option name missing: %.*s',
+      },
+    }, {
+      hl('InvalidOptionSigil', '&'),
+      hl('BinaryMinus', '-'),
+    })
+
+    check_parsing('&A', {
+      --           01
+      ast = {
+        'Option(scope=0,ident=A):0:0:&A',
+      },
+    }, {
+      hl('OptionSigil', '&'),
+      hl('OptionName', 'A'),
+    })
+
+    check_parsing('&xxx_yyy', {
+      --           01234567
+      ast = {
+        {
+          'OpMissing:0:4:',
+          children = {
+            'Option(scope=0,ident=xxx):0:0:&xxx',
+            'PlainIdentifier(scope=0,ident=_yyy):0:4:_yyy',
+          },
+        },
+      },
+      err = {
+        arg = '_yyy',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('OptionSigil', '&'),
+      hl('OptionName', 'xxx'),
+      hl('InvalidIdentifierName', '_yyy'),
+    }, {
+      [1] = {
+        ast = {
+          len = 4,
+          err = REMOVE_THIS,
+          ast = {
+            'Option(scope=0,ident=xxx):0:0:&xxx',
+          },
+        },
+        hl_fs = {
+          [3] = REMOVE_THIS,
+        },
+      },
+    })
+
+    check_parsing('(1+&)', {
+      --           01234
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'BinaryPlus:0:2:+',
+              children = {
+                'Integer(val=1):0:1:1',
+                'Option(scope=0,ident=):0:3:&',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '&)',
+        msg = 'E112: Option name missing: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Number', '1'),
+      hl('BinaryPlus', '+'),
+      hl('InvalidOptionSigil', '&'),
+      hl('NestingParenthesis', ')'),
+    })
+
+    check_parsing('(&+1)', {
+      --           01234
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'BinaryPlus:0:2:+',
+              children = {
+                'Option(scope=0,ident=):0:1:&',
+                'Integer(val=1):0:3:1',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '&+1)',
+        msg = 'E112: Option name missing: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('InvalidOptionSigil', '&'),
+      hl('BinaryPlus', '+'),
+      hl('Number', '1'),
+      hl('NestingParenthesis', ')'),
+    })
+  end)
+  itp('works with $ENV', function()
+    check_parsing('$', {
+      --           0
+      ast = {
+        'Environment(ident=):0:0:$',
+      },
+      err = {
+        arg = '$',
+        msg = 'E15: Environment variable name missing',
+      },
+    }, {
+      hl('InvalidEnvironmentSigil', '$'),
+    })
+
+    check_parsing('$g:A', {
+      --           0123
+      ast = {
+        {
+          'Colon:0:2::',
+          children = {
+            'Environment(ident=g):0:0:$g',
+            'PlainIdentifier(scope=0,ident=A):0:3:A',
+          },
+        },
+      },
+      err = {
+        arg = ':A',
+        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
+      },
+    }, {
+      hl('EnvironmentSigil', '$'),
+      hl('EnvironmentName', 'g'),
+      hl('InvalidColon', ':'),
+      hl('IdentifierName', 'A'),
+    })
+
+    check_parsing('$A', {
+      --           01
+      ast = {
+        'Environment(ident=A):0:0:$A',
+      },
+    }, {
+      hl('EnvironmentSigil', '$'),
+      hl('EnvironmentName', 'A'),
+    })
+
+    check_parsing('$ABC', {
+      --           0123
+      ast = {
+        'Environment(ident=ABC):0:0:$ABC',
+      },
+    }, {
+      hl('EnvironmentSigil', '$'),
+      hl('EnvironmentName', 'ABC'),
+    })
+
+    check_parsing('(1+$)', {
+      --           01234
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'BinaryPlus:0:2:+',
+              children = {
+                'Integer(val=1):0:1:1',
+                'Environment(ident=):0:3:$',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '$)',
+        msg = 'E15: Environment variable name missing',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Number', '1'),
+      hl('BinaryPlus', '+'),
+      hl('InvalidEnvironmentSigil', '$'),
+      hl('NestingParenthesis', ')'),
+    })
+
+    check_parsing('($+1)', {
+      --           01234
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'BinaryPlus:0:2:+',
+              children = {
+                'Environment(ident=):0:1:$',
+                'Integer(val=1):0:3:1',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '$+1)',
+        msg = 'E15: Environment variable name missing',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('InvalidEnvironmentSigil', '$'),
+      hl('BinaryPlus', '+'),
+      hl('Number', '1'),
+      hl('NestingParenthesis', ')'),
+    })
+
+    check_parsing('$_ABC', {
+      --           01234
+      ast = {
+        'Environment(ident=_ABC):0:0:$_ABC',
+      },
+    }, {
+      hl('EnvironmentSigil', '$'),
+      hl('EnvironmentName', '_ABC'),
+    })
+
+    check_parsing('$_', {
+      --           01
+      ast = {
+        'Environment(ident=_):0:0:$_',
+      },
+    }, {
+      hl('EnvironmentSigil', '$'),
+      hl('EnvironmentName', '_'),
+    })
+
+    check_parsing('$ABC_DEF', {
+      --           01234567
+      ast = {
+        'Environment(ident=ABC_DEF):0:0:$ABC_DEF',
+      },
+    }, {
+      hl('EnvironmentSigil', '$'),
+      hl('EnvironmentName', 'ABC_DEF'),
+    })
+  end)
+  itp('works with unary !', function()
+    check_parsing('!', {
+      --           0
+      ast = {
+        'Not:0:0:!',
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('Not', '!'),
+    })
+
+    check_parsing('!!', {
+      --           01
+      ast = {
+        {
+          'Not:0:0:!',
+          children = {
+            'Not:0:1:!',
+          },
+        },
+      },
+      err = {
+        arg = '',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+      hl('Not', '!'),
+      hl('Not', '!'),
+    })
+
+    check_parsing('!!1', {
+      --           012
+      ast = {
+        {
+          'Not:0:0:!',
+          children = {
+            {
+              'Not:0:1:!',
+              children = {
+                'Integer(val=1):0:2:1',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('Not', '!'),
+      hl('Not', '!'),
+      hl('Number', '1'),
+    })
+
+    check_parsing('!1', {
+      --           01
+      ast = {
+        {
+          'Not:0:0:!',
+          children = {
+            'Integer(val=1):0:1:1',
+          },
+        },
+      },
+    }, {
+      hl('Not', '!'),
+      hl('Number', '1'),
+    })
+
+    check_parsing('(!1)', {
+      --           0123
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'Not:0:1:!',
+              children = {
+                'Integer(val=1):0:2:1',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Not', '!'),
+      hl('Number', '1'),
+      hl('NestingParenthesis', ')'),
+    })
+
+    check_parsing('(!)', {
+      --           012
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'Not:0:1:!',
+              children = {
+                'Missing:0:2:',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ')',
+        msg = 'E15: Expected value, got parenthesis: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Not', '!'),
+      hl('InvalidNestingParenthesis', ')'),
+    })
+
+    check_parsing('(1!2)', {
+      --           01234
+      ast = {
+        {
+          'Nested:0:0:(',
+          children = {
+            {
+              'OpMissing:0:2:',
+              children = {
+                'Integer(val=1):0:1:1',
+                {
+                  'Not:0:2:!',
+                  children = {
+                    'Integer(val=2):0:3:2',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '!2)',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('NestingParenthesis', '('),
+      hl('Number', '1'),
+      hl('InvalidNot', '!'),
+      hl('Number', '2'),
+      hl('NestingParenthesis', ')'),
+    })
+
+    check_parsing('1!2', {
+      --           012
+      ast = {
+        {
+          'OpMissing:0:1:',
+          children = {
+            'Integer(val=1):0:0:1',
+            {
+              'Not:0:1:!',
+              children = {
+                'Integer(val=2):0:2:2',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '!2',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('Number', '1'),
+      hl('InvalidNot', '!'),
+      hl('Number', '2'),
+    }, {
+      [1] = {
+        ast = {
+          len = 1,
+          err = REMOVE_THIS,
+          ast = {
+            'Integer(val=1):0:0:1',
+          },
+        },
+        hl_fs = {
+          [2] = REMOVE_THIS,
+          [3] = REMOVE_THIS,
+        },
+      },
+    })
+  end)
+  itp('highlights numbers with prefix', function()
+    check_parsing('0xABCDEF', {
+      --           01234567
+      ast = {
+        'Integer(val=11259375):0:0:0xABCDEF',
+      },
+    }, {
+      hl('NumberPrefix', '0x'),
+      hl('Number', 'ABCDEF'),
+    })
+
+    check_parsing('0Xabcdef', {
+      --           01234567
+      ast = {
+        'Integer(val=11259375):0:0:0Xabcdef',
+      },
+    }, {
+      hl('NumberPrefix', '0X'),
+      hl('Number', 'abcdef'),
+    })
+
+    check_parsing('0XABCDEF', {
+      --           01234567
+      ast = {
+        'Integer(val=11259375):0:0:0XABCDEF',
+      },
+    }, {
+      hl('NumberPrefix', '0X'),
+      hl('Number', 'ABCDEF'),
+    })
+
+    check_parsing('0xabcdef', {
+      --           01234567
+      ast = {
+        'Integer(val=11259375):0:0:0xabcdef',
+      },
+    }, {
+      hl('NumberPrefix', '0x'),
+      hl('Number', 'abcdef'),
+    })
+
+    check_parsing('0b001', {
+      --           01234
+      ast = {
+        'Integer(val=1):0:0:0b001',
+      },
+    }, {
+      hl('NumberPrefix', '0b'),
+      hl('Number', '001'),
+    })
+
+    check_parsing('0B001', {
+      --           01234
+      ast = {
+        'Integer(val=1):0:0:0B001',
+      },
+    }, {
+      hl('NumberPrefix', '0B'),
+      hl('Number', '001'),
+    })
+
+    check_parsing('0B00', {
+      --           0123
+      ast = {
+        'Integer(val=0):0:0:0B00',
+      },
+    }, {
+      hl('NumberPrefix', '0B'),
+      hl('Number', '00'),
+    })
+
+    check_parsing('00', {
+      --           01
+      ast = {
+        'Integer(val=0):0:0:00',
+      },
+    }, {
+      hl('NumberPrefix', '0'),
+      hl('Number', '0'),
+    })
+
+    check_parsing('001', {
+      --           012
+      ast = {
+        'Integer(val=1):0:0:001',
+      },
+    }, {
+      hl('NumberPrefix', '0'),
+      hl('Number', '01'),
+    })
+
+    check_parsing('01', {
+      --           01
+      ast = {
+        'Integer(val=1):0:0:01',
+      },
+    }, {
+      hl('NumberPrefix', '0'),
+      hl('Number', '1'),
+    })
+
+    check_parsing('1', {
+      --           0
+      ast = {
+        'Integer(val=1):0:0:1',
+      },
+    }, {
+      hl('Number', '1'),
+    })
+  end)
+  itp('works (KLEE tests)', function()
+    check_parsing('\0002&A:\000', {
+      len = 0,
+      ast = nil,
+      err = {
+        arg = '\0002&A:\000',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+    }, {
+      [2] = {
+        ast = {
+          len = REMOVE_THIS,
+          ast = {
+            {
+              'Colon:0:4::',
+              children = {
+                {
+                  'OpMissing:0:2:',
+                  children = {
+                    'Integer(val=2):0:1:2',
+                    'Option(scope=0,ident=A):0:2:&A',
+                  },
+                },
+              },
+            },
+          },
+          err = {
+            msg = 'E15: Unexpected EOC character: %.*s',
+          },
+        },
+        hl_fs = {
+          hl('InvalidSpacing', '\0'),
+          hl('Number', '2'),
+          hl('InvalidOptionSigil', '&'),
+          hl('InvalidOptionName', 'A'),
+          hl('InvalidColon', ':'),
+          hl('InvalidSpacing', '\0'),
+        },
+      },
+      [3] = {
+        ast = {
+          len = 2,
+          ast = {
+            'Integer(val=2):0:1:2',
+          },
+          err = {
+            msg = 'E15: Unexpected EOC character: %.*s',
+          },
+        },
+        hl_fs = {
+          hl('InvalidSpacing', '\0'),
+          hl('Number', '2'),
+        },
+      },
+    })
+    check_parsing({data='01', size=1}, {
+      len = 1,
+      ast = {
+        'Integer(val=0):0:0:0',
+      },
+    }, {
+      hl('Number', '0'),
+    })
+    check_parsing({data='001', size=2}, {
+      len = 2,
+      ast = {
+        'Integer(val=0):0:0:00',
+      },
+    }, {
+      hl('NumberPrefix', '0'),
+      hl('Number', '0'),
+    })
+    check_parsing('"\\U\\', {
+      --           0123
+      ast = {
+        [[DoubleQuotedString(val="U\\"):0:0:"\U\]],
+      },
+      err = {
+        arg = '"\\U\\',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
+      hl('InvalidDoubleQuotedBody', '\\'),
+    })
+    check_parsing('"\\U', {
+      --           012
+      ast = {
+        fmtn('DoubleQuotedString', 'val="U"', ':0:0:"\\U'),
+      },
+      err = {
+        arg = '"\\U',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
+    })
+    check_parsing('|"\\U\\', {
+      --           01234
+      len = 0,
+      err = {
+        arg = '|"\\U\\',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+    }, {
+      [2] = {
+        ast = {
+          len = REMOVE_THIS,
+          ast = {
+            {
+              'Or:0:0:|',
+              children = {
+                'Missing:0:0:',
+                fmtn('DoubleQuotedString', 'val="U\\\\"', ':0:1:"\\U\\'),
+              },
+            },
+          },
+          err = {
+            msg = 'E15: Unexpected EOC character: %.*s',
+          },
+        },
+        hl_fs = {
+          hl('InvalidOr', '|'),
+          hl('InvalidDoubleQuote', '"'),
+          hl('InvalidDoubleQuotedUnknownEscape', '\\U'),
+          hl('InvalidDoubleQuotedBody', '\\'),
+        },
+      },
+    })
+    check_parsing('|"\\e"', {
+      --           01234
+      len = 0,
+      err = {
+        arg = '|"\\e"',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+    }, {
+      [2] = {
+        ast = {
+          len = REMOVE_THIS,
+          ast = {
+            {
+              'Or:0:0:|',
+              children = {
+                'Missing:0:0:',
+                fmtn('DoubleQuotedString', 'val="\\27"', ':0:1:"\\e"'),
+              },
+            },
+          },
+          err = {
+            msg = 'E15: Unexpected EOC character: %.*s',
+          },
+        },
+        hl_fs = {
+          hl('InvalidOr', '|'),
+          hl('DoubleQuote', '"'),
+          hl('DoubleQuotedEscape', '\\e'),
+          hl('DoubleQuote', '"'),
+        },
+      },
+    })
+    check_parsing('|\029', {
+      --           01
+      len = 0,
+      err = {
+        arg = '|\029',
+        msg = 'E15: Expected value, got EOC: %.*s',
+      },
+    }, {
+    }, {
+      [2] = {
+        ast = {
+          len = REMOVE_THIS,
+          ast = {
+            {
+              'Or:0:0:|',
+              children = {
+                'Missing:0:0:',
+                'PlainIdentifier(scope=0,ident=\029):0:1:\029',
+              },
+            },
+          },
+          err = {
+            msg = 'E15: Unexpected EOC character: %.*s',
+          },
+        },
+        hl_fs = {
+          hl('InvalidOr', '|'),
+          hl('InvalidIdentifierName', '\029'),
+        },
+      },
+    })
+    check_parsing('"\\<', {
+      --           012
+      ast = {
+        fmtn('DoubleQuotedString', 'val="<"', ':0:0:"\\<'),
+      },
+      err = {
+        arg = '"\\<',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedUnknownEscape', '\\<'),
+    })
+    check_parsing('"\\1', {
+      --           012
+      ast = {
+        fmtn('DoubleQuotedString', 'val="\\1"', ':0:0:"\\1'),
+      },
+      err = {
+        arg = '"\\1',
+        msg = 'E114: Missing double quote: %.*s',
+      },
+    }, {
+      hl('InvalidDoubleQuote', '"'),
+      hl('InvalidDoubleQuotedEscape', '\\1'),
+    })
+    check_parsing('}l', {
+      --           01
+      ast = {
+        {
+          'OpMissing:0:1:',
+          children = {
+            fmtn('UnknownFigure', '---', ':0:0:'),
+            'PlainIdentifier(scope=0,ident=l):0:1:l',
+          },
+        },
+      },
+      err = {
+        arg = '}l',
+        msg = 'E15: Unexpected closing figure brace: %.*s',
+      },
+    }, {
+      hl('InvalidFigureBrace', '}'),
+      hl('InvalidIdentifierName', 'l'),
+    }, {
+      [1] = {
+        ast = {
+          len = 1,
+          ast = {
+            fmtn('UnknownFigure', '---', ':0:0:'),
+          },
+        },
+        hl_fs = {
+          [2] = REMOVE_THIS,
+        },
+      },
+    })
+    check_parsing(':?\000\000\000\000\000\000\000', {
+      len = 2,
+      ast = {
+        {
+          'Colon:0:0::',
+          children = {
+            'Missing:0:0:',
+            {
+              'Ternary:0:1:?',
+              children = {
+                'Missing:0:1:',
+                'TernaryValue:0:1:?',
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = ':?\000\000\000\000\000\000\000',
+        msg = 'E15: Colon outside of dictionary or ternary operator: %.*s',
+      },
+    }, {
+      hl('InvalidColon', ':'),
+      hl('InvalidTernary', '?'),
+    }, {
+      [2] = {
+        ast = {
+          len = REMOVE_THIS,
+        },
+        hl_fs = {
+          [3] = hl('InvalidSpacing', '\0'),
+          [4] = hl('InvalidSpacing', '\0'),
+          [5] = hl('InvalidSpacing', '\0'),
+          [6] = hl('InvalidSpacing', '\0'),
+          [7] = hl('InvalidSpacing', '\0'),
+          [8] = hl('InvalidSpacing', '\0'),
+          [9] = hl('InvalidSpacing', '\0'),
+        },
+      },
+    })
+  end)
+  itp('works with assignments', function()
+    check_asgn_parsing('a=b', {
+      --                012
+      ast = {
+        {
+          'Assignment(Plain):0:1:=',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:2:b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('PlainAssignment', '='),
+      hl('IdentifierName', 'b'),
+    })
+
+    check_asgn_parsing('a+=b', {
+      --                0123
+      ast = {
+        {
+          'Assignment(Add):0:1:+=',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:3:b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('AssignmentWithAddition', '+='),
+      hl('IdentifierName', 'b'),
+    })
+
+    check_asgn_parsing('a-=b', {
+      --                0123
+      ast = {
+        {
+          'Assignment(Subtract):0:1:-=',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:3:b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('AssignmentWithSubtraction', '-='),
+      hl('IdentifierName', 'b'),
+    })
+
+    check_asgn_parsing('a.=b', {
+      --                0123
+      ast = {
+        {
+          'Assignment(Concat):0:1:.=',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:3:b',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('AssignmentWithConcatenation', '.='),
+      hl('IdentifierName', 'b'),
+    })
+
+    check_asgn_parsing('a', {
+      --                0
+      ast = {
+        'PlainIdentifier(scope=0,ident=a):0:0:a',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+    })
+
+    check_asgn_parsing('a b', {
+      --                012
+      ast = {
+        {
+          'OpMissing:0:1:',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            'PlainIdentifier(scope=0,ident=b):0:1: b',
+          },
+        },
+      },
+      err = {
+        arg = 'b',
+        msg = 'E15: Expected assignment operator or subscript: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('InvalidSpacing', ' '),
+      hl('IdentifierName', 'b'),
+    }, {
+      [5] = {
+        ast = {
+          len = 2,
+          ast = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+          },
+          err = REMOVE_THIS,
+        },
+        hl_fs = {
+          [2] = REMOVE_THIS,
+          [3] = REMOVE_THIS,
+        }
+      },
+    })
+
+    check_asgn_parsing('[a, b, c]', {
+      --                012345678
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                {
+                  'Comma:0:5:,',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:3: b',
+                    'PlainIdentifier(scope=0,ident=c):0:6: c',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b', 1),
+      hl('Comma', ','),
+      hl('IdentifierName', 'c', 1),
+      hl('List', ']'),
+    })
+
+    check_asgn_parsing('[a, b]', {
+      --                012345
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            {
+              'Comma:0:2:,',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+                'PlainIdentifier(scope=0,ident=b):0:3: b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('Comma', ','),
+      hl('IdentifierName', 'b', 1),
+      hl('List', ']'),
+    })
+
+    check_asgn_parsing('[a]', {
+      --                012
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:1:a',
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('List', ']'),
+    })
+
+    check_asgn_parsing('[]', {
+      --                01
+      ast = {
+        'ListLiteral:0:0:[',
+      },
+      err = {
+        arg = ']',
+        msg = 'E475: Unable to assign to empty list: %.*s',
+      },
+    }, {
+      hl('List', '['),
+      hl('InvalidList', ']'),
+    })
+
+    check_asgn_parsing('a[1] += 3', {
+      --                012345678
+      ast = {
+        {
+          'Assignment(Add):0:4: +=',
+          children = {
+            {
+              'Subscript:0:1:[',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                'Integer(val=1):0:2:1',
+              },
+            },
+            'Integer(val=3):0:7: 3',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('Number', '1'),
+      hl('SubscriptBracket', ']'),
+      hl('AssignmentWithAddition', '+=', 1),
+      hl('Number', '3', 1),
+    })
+
+    check_asgn_parsing('a[1 + 2] += 3', {
+      --                0123456789012
+      --                0         1
+      ast = {
+        {
+          'Assignment(Add):0:8: +=',
+          children = {
+            {
+              'Subscript:0:1:[',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                {
+                  'BinaryPlus:0:3: +',
+                  children = {
+                    'Integer(val=1):0:2:1',
+                    'Integer(val=2):0:5: 2',
+                  },
+                },
+              },
+            },
+            'Integer(val=3):0:11: 3',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('Number', '1'),
+      hl('BinaryPlus', '+', 1),
+      hl('Number', '2', 1),
+      hl('SubscriptBracket', ']'),
+      hl('AssignmentWithAddition', '+=', 1),
+      hl('Number', '3', 1),
+    })
+
+    check_asgn_parsing('a[{-> {b{3}: 4}[5]}()] += 6', {
+      --                012345678901234567890123456
+      --                0         1         2
+      ast = {
+        {
+          'Assignment(Add):0:22: +=',
+          children = {
+            {
+              'Subscript:0:1:[',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                {
+                  'Call:0:19:(',
+                  children = {
+                    {
+                      fmtn('Lambda', '\\di', ':0:2:{'),
+                      children = {
+                        {
+                          'Arrow:0:3:->',
+                          children = {
+                            {
+                              'Subscript:0:15:[',
+                              children = {
+                                {
+                                  fmtn('DictLiteral', '-di', ':0:5: {'),
+                                  children = {
+                                    {
+                                      'Colon:0:11::',
+                                      children = {
+                                        {
+                                          'ComplexIdentifier:0:8:',
+                                          children = {
+                                            'PlainIdentifier(scope=0,ident=b):0:7:b',
+                                            {
+                                              fmtn('CurlyBracesIdentifier', '--i', ':0:8:{'),
+                                              children = {
+                                                'Integer(val=3):0:9:3',
+                                              },
+                                            },
+                                          },
+                                        },
+                                        'Integer(val=4):0:12: 4',
+                                      },
+                                    },
+                                  },
+                                },
+                                'Integer(val=5):0:16:5',
+                              },
+                            },
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+            'Integer(val=6):0:25: 6',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('Lambda', '{'),
+      hl('Arrow', '->'),
+      hl('Dict', '{', 1),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '{'),
+      hl('Number', '3'),
+      hl('Curly', '}'),
+      hl('Colon', ':'),
+      hl('Number', '4', 1),
+      hl('Dict', '}'),
+      hl('SubscriptBracket', '['),
+      hl('Number', '5'),
+      hl('SubscriptBracket', ']'),
+      hl('Lambda', '}'),
+      hl('CallingParenthesis', '('),
+      hl('CallingParenthesis', ')'),
+      hl('SubscriptBracket', ']'),
+      hl('AssignmentWithAddition', '+=', 1),
+      hl('Number', '6', 1),
+    })
+
+    check_asgn_parsing('a{1}.2[{-> {b{3}: 4}[5]}()]', {
+      --                012345678901234567890123456
+      --                0         1         2
+      ast = {
+        {
+          'Subscript:0:6:[',
+          children = {
+            {
+              'ConcatOrSubscript:0:4:.',
+              children = {
+                {
+                  'ComplexIdentifier:0:1:',
+                  children = {
+                    'PlainIdentifier(scope=0,ident=a):0:0:a',
+                    {
+                      fmtn('CurlyBracesIdentifier', '--i', ':0:1:{'),
+                      children = {
+                        'Integer(val=1):0:2:1',
+                      },
+                    },
+                  },
+                },
+                'PlainKey(key=2):0:5:2',
+              },
+            },
+            {
+              'Call:0:24:(',
+              children = {
+                {
+                  fmtn('Lambda', '\\di', ':0:7:{'),
+                  children = {
+                    {
+                      'Arrow:0:8:->',
+                      children = {
+                        {
+                          'Subscript:0:20:[',
+                          children = {
+                            {
+                              fmtn('DictLiteral', '-di', ':0:10: {'),
+                              children = {
+                                {
+                                  'Colon:0:16::',
+                                  children = {
+                                    {
+                                      'ComplexIdentifier:0:13:',
+                                      children = {
+                                        'PlainIdentifier(scope=0,ident=b):0:12:b',
+                                        {
+                                          fmtn('CurlyBracesIdentifier', '--i', ':0:13:{'),
+                                          children = {
+                                            'Integer(val=3):0:14:3',
+                                          },
+                                        },
+                                      },
+                                    },
+                                    'Integer(val=4):0:17: 4',
+                                  },
+                                },
+                              },
+                            },
+                            'Integer(val=5):0:21:5',
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Curly', '{'),
+      hl('Number', '1'),
+      hl('Curly', '}'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '2'),
+      hl('SubscriptBracket', '['),
+      hl('Lambda', '{'),
+      hl('Arrow', '->'),
+      hl('Dict', '{', 1),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '{'),
+      hl('Number', '3'),
+      hl('Curly', '}'),
+      hl('Colon', ':'),
+      hl('Number', '4', 1),
+      hl('Dict', '}'),
+      hl('SubscriptBracket', '['),
+      hl('Number', '5'),
+      hl('SubscriptBracket', ']'),
+      hl('Lambda', '}'),
+      hl('CallingParenthesis', '('),
+      hl('CallingParenthesis', ')'),
+      hl('SubscriptBracket', ']'),
+    })
+
+    check_asgn_parsing('a', {
+      --                0
+      ast = {
+        'PlainIdentifier(scope=0,ident=a):0:0:a',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+    })
+
+    check_asgn_parsing('{a}', {
+      --                012
+      ast = {
+        {
+          fmtn('CurlyBracesIdentifier', '--i', ':0:0:{'),
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:1:a',
+          },
+        },
+      },
+    }, {
+      hl('FigureBrace', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Curly', '}'),
+    })
+
+    check_asgn_parsing('{a}b', {
+      --                0123
+      ast = {
+        {
+          'ComplexIdentifier:0:3:',
+          children = {
+            {
+              fmtn('CurlyBracesIdentifier', '--i', ':0:0:{'),
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+              },
+            },
+            'PlainIdentifier(scope=0,ident=b):0:3:b',
+          },
+        },
+      },
+    }, {
+      hl('FigureBrace', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Curly', '}'),
+      hl('IdentifierName', 'b'),
+    })
+
+    check_asgn_parsing('a{b}c', {
+      --                01234
+      ast = {
+        {
+          'ComplexIdentifier:0:1:',
+          children = {
+            'PlainIdentifier(scope=0,ident=a):0:0:a',
+            {
+              'ComplexIdentifier:0:4:',
+              children = {
+                {
+                  fmtn('CurlyBracesIdentifier', '--i', ':0:1:{'),
+                  children = {
+                    'PlainIdentifier(scope=0,ident=b):0:2:b',
+                  },
+                },
+                'PlainIdentifier(scope=0,ident=c):0:4:c',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '}'),
+      hl('IdentifierName', 'c'),
+    })
+
+    check_asgn_parsing('a{b}c[0]', {
+      --                01234567
+      ast = {
+        {
+          'Subscript:0:5:[',
+          children = {
+            {
+              'ComplexIdentifier:0:1:',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                {
+                  'ComplexIdentifier:0:4:',
+                  children = {
+                    {
+                      fmtn('CurlyBracesIdentifier', '--i', ':0:1:{'),
+                      children = {
+                        'PlainIdentifier(scope=0,ident=b):0:2:b',
+                      },
+                    },
+                    'PlainIdentifier(scope=0,ident=c):0:4:c',
+                  },
+                },
+              },
+            },
+            'Integer(val=0):0:6:0',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '}'),
+      hl('IdentifierName', 'c'),
+      hl('SubscriptBracket', '['),
+      hl('Number', '0'),
+      hl('SubscriptBracket', ']'),
+    })
+
+    check_asgn_parsing('a{b}c.0', {
+      --                0123456
+      ast = {
+        {
+          'ConcatOrSubscript:0:5:.',
+          children = {
+            {
+              'ComplexIdentifier:0:1:',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                {
+                  'ComplexIdentifier:0:4:',
+                  children = {
+                    {
+                      fmtn('CurlyBracesIdentifier', '--i', ':0:1:{'),
+                      children = {
+                        'PlainIdentifier(scope=0,ident=b):0:2:b',
+                      },
+                    },
+                    'PlainIdentifier(scope=0,ident=c):0:4:c',
+                  },
+                },
+              },
+            },
+            'PlainKey(key=0):0:6:0',
+          },
+        },
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '}'),
+      hl('IdentifierName', 'c'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '0'),
+    })
+
+    check_asgn_parsing('[a{b}c[0].0]', {
+      --                012345678901
+      --                0         1
+      ast = {
+        {
+          'ListLiteral:0:0:[',
+          children = {
+            {
+              'ConcatOrSubscript:0:9:.',
+              children = {
+                {
+                  'Subscript:0:6:[',
+                  children = {
+                    {
+                      'ComplexIdentifier:0:2:',
+                      children = {
+                        'PlainIdentifier(scope=0,ident=a):0:1:a',
+                        {
+                          'ComplexIdentifier:0:5:',
+                          children = {
+                            {
+                              fmtn('CurlyBracesIdentifier', '--i', ':0:2:{'),
+                              children = {
+                                'PlainIdentifier(scope=0,ident=b):0:3:b',
+                              },
+                            },
+                            'PlainIdentifier(scope=0,ident=c):0:5:c',
+                          },
+                        },
+                      },
+                    },
+                    'Integer(val=0):0:7:0',
+                  },
+                },
+                'PlainKey(key=0):0:10:0',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '}'),
+      hl('IdentifierName', 'c'),
+      hl('SubscriptBracket', '['),
+      hl('Number', '0'),
+      hl('SubscriptBracket', ']'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', '0'),
+      hl('List', ']'),
+    })
+
+    check_asgn_parsing('{a}{b}', {
+      --                012345
+      ast = {
+        {
+          'ComplexIdentifier:0:3:',
+          children = {
+            {
+              fmtn('CurlyBracesIdentifier', '--i', ':0:0:{'),
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+              },
+            },
+            {
+              fmtn('CurlyBracesIdentifier', '--i', ':0:3:{'),
+              children = {
+                'PlainIdentifier(scope=0,ident=b):0:4:b',
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('FigureBrace', '{'),
+      hl('IdentifierName', 'a'),
+      hl('Curly', '}'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'b'),
+      hl('Curly', '}'),
+    })
+
+    check_asgn_parsing('a.b{c}{d}', {
+      --                012345678
+      ast = {
+        {
+          'OpMissing:0:3:',
+          children = {
+            {
+              'ConcatOrSubscript:0:1:.',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:0:a',
+                'PlainKey(key=b):0:2:b',
+              },
+            },
+            {
+              'ComplexIdentifier:0:6:',
+              children = {
+                {
+                  fmtn('CurlyBracesIdentifier', '--i', ':0:3:{'),
+                  children = {
+                    'PlainIdentifier(scope=0,ident=c):0:4:c',
+                  },
+                },
+                {
+                  fmtn('CurlyBracesIdentifier', '--i', ':0:6:{'),
+                  children = {
+                    'PlainIdentifier(scope=0,ident=d):0:7:d',
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+      err = {
+        arg = '{c}{d}',
+        msg = 'E15: Missing operator: %.*s',
+      },
+    }, {
+      hl('IdentifierName', 'a'),
+      hl('ConcatOrSubscript', '.'),
+      hl('IdentifierKey', 'b'),
+      hl('InvalidFigureBrace', '{'),
+      hl('IdentifierName', 'c'),
+      hl('Curly', '}'),
+      hl('Curly', '{'),
+      hl('IdentifierName', 'd'),
+      hl('Curly', '}'),
+    })
+
+    check_asgn_parsing('[a] = 1', {
+      --                0123456
+      ast = {
+        {
+          'Assignment(Plain):0:3: =',
+          children = {
+            {
+              'ListLiteral:0:0:[',
+              children = {
+                'PlainIdentifier(scope=0,ident=a):0:1:a',
+              },
+            },
+            'Integer(val=1):0:5: 1',
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('List', ']'),
+      hl('PlainAssignment', '=', 1),
+      hl('Number', '1', 1),
+    })
+
+    check_asgn_parsing('[a[b], [c, [d, [e]]]] = 1', {
+      --                0123456789012345678901234
+      --                0         1         2
+      ast = {
+        {
+          'Assignment(Plain):0:21: =',
+          children = {
+            {
+              'ListLiteral:0:0:[',
+              children = {
+                {
+                  'Comma:0:5:,',
+                  children = {
+                    {
+                      'Subscript:0:2:[',
+                      children = {
+                        'PlainIdentifier(scope=0,ident=a):0:1:a',
+                        'PlainIdentifier(scope=0,ident=b):0:3:b',
+                      },
+                    },
+                    {
+                      'ListLiteral:0:6: [',
+                      children = {
+                        {
+                          'Comma:0:9:,',
+                          children = {
+                            'PlainIdentifier(scope=0,ident=c):0:8:c',
+                            {
+                              'ListLiteral:0:10: [',
+                              children = {
+                                {
+                                  'Comma:0:13:,',
+                                  children = {
+                                    'PlainIdentifier(scope=0,ident=d):0:12:d',
+                                    {
+                                      'ListLiteral:0:14: [',
+                                      children = {
+                                        'PlainIdentifier(scope=0,ident=e):0:16:e',
+                                      },
+                                    },
+                                  },
+                                },
+                              },
+                            },
+                          },
+                        },
+                      },
+                    },
+                  },
+                },
+              },
+            },
+            'Integer(val=1):0:23: 1',
+          },
+        },
+      },
+      err = {
+        arg = '[c, [d, [e]]]] = 1',
+        msg = 'E475: Nested lists not allowed when assigning: %.*s',
+      },
+    }, {
+      hl('List', '['),
+      hl('IdentifierName', 'a'),
+      hl('SubscriptBracket', '['),
+      hl('IdentifierName', 'b'),
+      hl('SubscriptBracket', ']'),
+      hl('Comma', ','),
+      hl('InvalidList', '[', 1),
+      hl('IdentifierName', 'c'),
+      hl('Comma', ','),
+      hl('InvalidList', '[', 1),
+      hl('IdentifierName', 'd'),
+      hl('Comma', ','),
+      hl('InvalidList', '[', 1),
+      hl('IdentifierName', 'e'),
+      hl('List', ']'),
+      hl('List', ']'),
+      hl('List', ']'),
+      hl('List', ']'),
+      hl('PlainAssignment', '=', 1),
+      hl('Number', '1', 1),
+    })
+
+    check_asgn_parsing('$X += 1', {
+      --                0123456
+      ast = {
+        {
+          'Assignment(Add):0:2: +=',
+          children = {
+            'Environment(ident=X):0:0:$X',
+            'Integer(val=1):0:5: 1',
+          },
+        },
+      },
+    }, {
+      hl('EnvironmentSigil', '$'),
+      hl('EnvironmentName', 'X'),
+      hl('AssignmentWithAddition', '+=', 1),
+      hl('Number', '1', 1),
+    })
+
+    check_asgn_parsing('@a .= 1', {
+      --                0123456
+      ast = {
+        {
+          'Assignment(Concat):0:2: .=',
+          children = {
+            'Register(name=a):0:0:@a',
+            'Integer(val=1):0:5: 1',
+          },
+        },
+      },
+    }, {
+      hl('Register', '@a'),
+      hl('AssignmentWithConcatenation', '.=', 1),
+      hl('Number', '1', 1),
+    })
+
+    check_asgn_parsing('&option -= 1', {
+      --                012345678901
+      --                0         1
+      ast = {
+        {
+          'Assignment(Subtract):0:7: -=',
+          children = {
+            'Option(scope=0,ident=option):0:0:&option',
+            'Integer(val=1):0:10: 1',
+          },
+        },
+      },
+    }, {
+      hl('OptionSigil', '&'),
+      hl('OptionName', 'option'),
+      hl('AssignmentWithSubtraction', '-=', 1),
+      hl('Number', '1', 1),
+    })
+
+    check_asgn_parsing('[$X, @a, &l:option] = [1, 2, 3]', {
+      --                0123456789012345678901234567890
+      --                0         1         2         3
+      ast = {
+        {
+          'Assignment(Plain):0:19: =',
+          children = {
+            {
+              'ListLiteral:0:0:[',
+              children = {
+                {
+                  'Comma:0:3:,',
+                  children = {
+                    'Environment(ident=X):0:1:$X',
+                    {
+                      'Comma:0:7:,',
+                      children = {
+                        'Register(name=a):0:4: @a',
+                        'Option(scope=l,ident=option):0:8: &l:option',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+            {
+              'ListLiteral:0:21: [',
+              children = {
+                {
+                  'Comma:0:24:,',
+                  children = {
+                    'Integer(val=1):0:23:1',
+                    {
+                      'Comma:0:27:,',
+                      children = {
+                        'Integer(val=2):0:25: 2',
+                        'Integer(val=3):0:28: 3',
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    }, {
+      hl('List', '['),
+      hl('EnvironmentSigil', '$'),
+      hl('EnvironmentName', 'X'),
+      hl('Comma', ','),
+      hl('Register', '@a', 1),
+      hl('Comma', ','),
+      hl('OptionSigil', '&', 1),
+      hl('OptionScope', 'l'),
+      hl('OptionScopeDelimiter', ':'),
+      hl('OptionName', 'option'),
+      hl('List', ']'),
+      hl('PlainAssignment', '=', 1),
+      hl('List', '[', 1),
+      hl('Number', '1'),
+      hl('Comma', ','),
+      hl('Number', '2', 1),
+      hl('Comma', ','),
+      hl('Number', '3', 1),
+      hl('List', ']'),
+    })
+  end)
+end