feat(treesitter): add filetype -> lang API

Problem:

  vim.treesitter does not know how to map a specific filetype to a parser.

  This creates problems since in a few places (including in vim.treesitter itself), the filetype is incorrectly used in place of lang.

Solution:

  Add an API to enable this:

  - Add vim.treesitter.language.add() as a replacement for vim.treesitter.language.require_language().
    - Optional arguments are now passed via an opts table.
    - Also takes a filetype (or list of filetypes) so we can keep track of what filetypes are associated with which langs.
    - Deprecated vim.treesitter.language.require_language().
  - Add vim.treesitter.language.get_lang() which returns the associated lang for a given filetype.
  - Add vim.treesitter.language.register() to associate filetypes to a lang without loading the parser.

1 files changed, 6 insertions, 5 deletions

diff --git a/test/functional/treesitter/language_spec.lua b/test/functional/treesitter/language_spec.lua
index 51d8eb62f3..a8831b9a9b 100644
--- a/test/functional/treesitter/language_spec.lua
+++ b/test/functional/treesitter/language_spec.lua
@@ -18,22 +18,23 @@ describe('treesitter language API', function()
 
     -- actual message depends on platform
     matches("Failed to load parser for language 'borklang': uv_dlopen: .+",
-       pcall_err(exec_lua, "parser = vim.treesitter.require_language('borklang', 'borkbork.so')"))
+       pcall_err(exec_lua, "parser = vim.treesitter.add('borklang', { path = 'borkbork.so' })"))
 
     -- Should not throw an error when silent
-    eq(false, exec_lua("return vim.treesitter.require_language('borklang', nil, true)"))
-    eq(false, exec_lua("return vim.treesitter.require_language('borklang', 'borkbork.so', true)"))
+    eq(false, exec_lua("return vim.treesitter.add('borklang', { silent = true })"))
+
+    eq(false, exec_lua("return vim.treesitter.add('borklang', { path = 'borkbork.so', silent = true })"))
 
     eq(".../language.lua:0: no parser for 'borklang' language, see :help treesitter-parsers",
        pcall_err(exec_lua, "parser = vim.treesitter.inspect_language('borklang')"))
 
     matches("Failed to load parser: uv_dlsym: .+",
-       pcall_err(exec_lua, 'vim.treesitter.require_language("c", nil, false, "borklang")'))
+       pcall_err(exec_lua, 'vim.treesitter.add("c", { symbol_name = "borklang" })'))
   end)
 
   it('shows error for invalid language name', function()
     eq(".../language.lua:0: '/foo/' is not a valid language name",
-      pcall_err(exec_lua, 'vim.treesitter.require_language("/foo/", nil, false)'))
+      pcall_err(exec_lua, 'vim.treesitter.add("/foo/", nil, false)'))
   end)
 
   it('inspects language', function()