feat(api): expose list of available and installed languages

doc/nvim-treesitter.txt

@@ -102,7 +102,7 @@ setup({opts})                                          *nvim-treesitter.setup()*
                 directory to install parsers and queries to. Note: will be
                 prepended to |runtimepath|.
 
-install({languages} [, {opts}])                    *nvim-treesitter.install()*
+install({languages} [, {opts}])                      *nvim-treesitter.install()*
 
     Download, compile, and install the specified treesitter parsers and copy
     the corresponding queries to a directory on |runtimepath|, enabling their
@@ -126,7 +126,7 @@ install({languages} [, {opts}])                    *nvim-treesitter.install()*
                    • {max_jobs} (`integer?`) limit parallel tasks (useful in
                      combination with {generate} on memory-limited systems).
 
-uninstall({languages})                              *nvim-treesitter.uninstall()*
+uninstall({languages})                             *nvim-treesitter.uninstall()*
 
     Remove the parser and queries for the specified language(s).
 
@@ -134,7 +134,7 @@ uninstall({languages})                              *nvim-treesitter.uninstall()
     • {languages}  `(string[]|string)` (List of) languages or tiers (`stable`,
                    `unstable`) to update.
 
-update([{languages}])                                  *nvim-treesitter.update()*
+update([{languages}])                                 *nvim-treesitter.update()*
 
     Update the parsers and queries if older than the revision specified in the
     manifest.
@@ -153,5 +153,20 @@ indentexpr()                                      *nvim-treesitter.indentexpr()*
     Used to enable treesitter indentation for a language via >lua
         vim.bo.indentexpr = "v:lua.require'nvim-treesitter'.indentexpr()"
 <
+get_available([{tier}])                        *nvim-treesitter.get_available()*
+
+    Return list of languages available for installation.
+
+    Parameters: ~
+    • {tier}  `(integer?)` Only return languages of specified {tier} (`1`:
+              stable, `2`: unstable, `3`: unmaintained, `4`: unsupported)
+
+get_installed([{type}])                        *nvim-treesitter.get_installed()*
+
+    Return list of languages installed via `nvim-treesitter`.
+
+    Parameters: ~
+    • {type}  `('queries'|parsers'?)` If specified, only show languages with
+              installed queries or parsers, respectively.
 
 vim:tw=78:ts=8:expandtab:noet:ft=help:norl:

lua/nvim-treesitter/config.lua

@@ -41,7 +41,7 @@ end
 
 ---@param type 'queries'|'parsers'?
 ---@return string[]
-function M.installed_languages(type)
+function M.get_installed(type)
   local installed = {} --- @type table<string, boolean>
   if not (type and type == 'parsers') then
     for f in vim.fs.dir(M.get_install_dir('queries')) do
@@ -107,7 +107,7 @@ function M.norm_languages(languages, skip)
 
   if vim.list_contains(languages, 'all') then
     if skip and skip.missing then
-      return M.installed_languages()
+      return M.get_installed()
     end
     languages = M.get_available()
   end
@@ -115,7 +115,7 @@ function M.norm_languages(languages, skip)
   languages = expand_tiers(languages)
 
   if skip and skip.installed then
-    local installed = M.installed_languages()
+    local installed = M.get_installed()
     languages = vim.tbl_filter(
       --- @param v string
       function(v)
@@ -126,7 +126,7 @@ function M.norm_languages(languages, skip)
   end
 
   if skip and skip.missing then
-    local installed = M.installed_languages()
+    local installed = M.get_installed()
     languages = vim.tbl_filter(
       --- @param v string
       function(v)

lua/nvim-treesitter/health.lua

@@ -136,7 +136,7 @@ function M.check()
 
   -- Parser installation checks
   health.start('Installed languages' .. string.rep(' ', 5) .. 'H L F I J')
-  local languages = config.installed_languages()
+  local languages = config.get_installed()
   for _, lang in pairs(languages) do
     local parser = parsers[lang]
     local out = lang .. string.rep(' ', 22 - #lang)

lua/nvim-treesitter/init.lua

@@ -4,6 +4,14 @@ function M.setup(...)
   require('nvim-treesitter.config').setup(...)
 end
 
+function M.get_available(...)
+  return require('nvim-treesitter.config').get_available(...)
+end
+
+function M.get_installed(...)
+  return require('nvim-treesitter.config').get_installed(...)
+end
+
 function M.install(...)
   return require('nvim-treesitter.install').install(...)
 end

lua/nvim-treesitter/install.lua

@@ -402,7 +402,7 @@ local install_status = {} ---@type table<string,InstallStatus?>
 ---@param generate? boolean
 ---@return InstallStatus status
 local function install_lang(lang, cache_dir, install_dir, force, generate)
-  if not force and vim.list_contains(config.installed_languages(), lang) then
+  if not force and vim.list_contains(config.get_installed(), lang) then
     install_status[lang] = 'installed'
     return 'installed'
   end
@@ -537,7 +537,7 @@ M.uninstall = a.async(function(languages)
 
   local parser_dir = config.get_install_dir('parser')
   local query_dir = config.get_install_dir('queries')
-  local installed = config.installed_languages()
+  local installed = config.get_installed()
 
   local task_funs = {} ---@type async.TaskFun[]
   local done = 0

plugin/nvim-treesitter.lua

@@ -21,7 +21,7 @@ local function complete_installed_parsers(arglead)
     function(v)
       return v:find(arglead) ~= nil
     end,
-    require('nvim-treesitter.config').installed_languages()
+    require('nvim-treesitter.config').get_installed()
   )
 end
 

scripts/check-parsers.lua

@@ -3,7 +3,7 @@ vim.opt.runtimepath:append('.')
 
 local configs = require('nvim-treesitter.parsers')
 local parsers = #_G.arg > 0 and { unpack(_G.arg) }
-  or require('nvim-treesitter.config').installed_languages('parsers')
+  or require('nvim-treesitter.config').get_installed('parsers')
 
 local data = {} ---@type table[]
 local errors = {} ---@type string[]

scripts/check-queries.lua

@@ -4,7 +4,7 @@ vim.opt.runtimepath:append('.')
 local query_types = require('nvim-treesitter.health').bundled_queries
 local configs = require('nvim-treesitter.parsers')
 local parsers = #_G.arg > 0 and { unpack(_G.arg) }
-  or require('nvim-treesitter.config').installed_languages('queries')
+  or require('nvim-treesitter.config').get_installed('queries')
 
 -- Check queries for each installed parser in parsers
 local errors = {} ---@type string[]