2 files changed, 138 insertions, 0 deletions
diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index 53ff761b16..8e52542446 100644
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -925,6 +925,8 @@ add_custom_command(
     ${API_SOURCES}
     ${LUA_SOURCES}
     ${VIMDOC_FILES}
+    ${PROJECT_SOURCE_DIR}/scripts/gen_vimdoc.py
+    ${PROJECT_SOURCE_DIR}/scripts/lua2dox.lua
   WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
 )
 
diff --git a/src/nvim/generators/luacats_grammar.lua b/src/nvim/generators/luacats_grammar.lua
new file mode 100644
index 0000000000..dcccd028ce
--- /dev/null
+++ b/src/nvim/generators/luacats_grammar.lua
@@ -0,0 +1,136 @@
+--[[!
+LPEG grammar for LuaCATS
+
+Currently only partially supports:
+- @param
+- @return
+]]
+
+local lpeg = vim.lpeg
+local P, R, S = lpeg.P, lpeg.R, lpeg.S
+local Ct, Cg = lpeg.Ct, lpeg.Cg
+
+--- @param x vim.lpeg.Pattern
+local function rep(x)
+  return x ^ 0
+end
+
+--- @param x vim.lpeg.Pattern
+local function rep1(x)
+  return x ^ 1
+end
+
+--- @param x vim.lpeg.Pattern
+local function opt(x)
+  return x ^ -1
+end
+
+local nl = P('\r\n') + P('\n')
+local ws = rep1(S(' \t') + nl)
+local fill = opt(ws)
+
+local any = P(1) -- (consume one character)
+local letter = R('az', 'AZ') + S('_$')
+local num = R('09')
+local ident = letter * rep(letter + num + S '-.')
+local string_single = P "'" * rep(any - P "'") * P "'"
+local string_double = P '"' * rep(any - P '"') * P '"'
+
+local literal = (string_single + string_double + (opt(P '-') * num) + P 'false' + P 'true')
+
+local lname = (ident + P '...') * opt(P '?')
+
+--- @param x string
+local function Pf(x)
+  return fill * P(x) * fill
+end
+
+--- @param x string
+local function Sf(x)
+  return fill * S(x) * fill
+end
+
+--- @param x vim.lpeg.Pattern
+local function comma(x)
+  return x * rep(Pf ',' * x)
+end
+
+--- @param x vim.lpeg.Pattern
+local function parenOpt(x)
+  return (Pf('(') * x ^ -1 * fill * P(')')) + x ^ -1
+end
+
+--- @type table<string,vim.lpeg.Pattern>
+local v = setmetatable({}, {
+  __index = function(_, k)
+    return lpeg.V(k)
+  end,
+})
+
+local desc_delim = Sf '#:' + ws
+
+--- @class luacats.Param
+--- @field kind 'param'
+--- @field name string
+--- @field type string
+--- @field desc? string
+
+--- @class luacats.Return
+--- @field kind 'return'
+--- @field [integer] { type: string, name?: string}
+--- @field desc? string
+
+--- @class luacats.Generic
+--- @field kind 'generic'
+--- @field name string
+--- @field type? string
+
+--- @alias luacats.grammar.result
+--- | luacats.Param
+--- | luacats.Return
+--- | luacats.Generic
+
+--- @class luacats.grammar
+--- @field match fun(self, input: string): luacats.grammar.result?
+
+local grammar = P {
+  rep1(P('@') * v.ats),
+
+  ats = (v.at_param + v.at_return + v.at_generic),
+
+  at_param = Ct(
+    Cg(P('param'), 'kind')
+      * ws
+      * Cg(lname, 'name')
+      * ws
+      * Cg(v.ltype, 'type')
+      * opt(desc_delim * Cg(rep(any), 'desc'))
+  ),
+
+  at_return = Ct(
+    Cg(P('return'), 'kind')
+      * ws
+      * parenOpt(comma(Ct(Cg(v.ltype, 'type') * opt(ws * Cg(ident, 'name')))))
+      * opt(desc_delim * Cg(rep(any), 'desc'))
+  ),
+
+  at_generic = Ct(
+    Cg(P('generic'), 'kind') * ws * Cg(ident, 'name') * opt(Pf ':' * Cg(v.ltype, 'type'))
+  ),
+
+  ltype = v.ty_union + Pf '(' * v.ty_union * fill * P ')',
+
+  ty_union = v.ty_opt * rep(Pf '|' * v.ty_opt),
+  ty = v.ty_fun + ident + v.ty_table + literal,
+  ty_param = Pf '<' * comma(v.ltype) * fill * P '>',
+  ty_opt = v.ty * opt(v.ty_param) * opt(P '[]') * opt(P '?'),
+
+  table_key = (Pf '[' * literal * Pf ']') + lname,
+  table_elem = v.table_key * Pf ':' * v.ltype,
+  ty_table = Pf '{' * comma(v.table_elem) * Pf '}',
+
+  fun_param = lname * opt(Pf ':' * v.ltype),
+  ty_fun = Pf 'fun(' * rep(comma(v.fun_param)) * fill * P ')' * opt(Pf ':' * v.ltype),
+}
+
+return grammar --[[@as luacats.grammar]]