feat(install): add "maintained" option to only install maintained parsers

Unmaintained parsers only give users little benefit but take sometimes a
a long time to install (e.g. Markdown, Julia, Haskell parser). We could
recommend to only install maintained parsers by default.

2 files changed, 12 insertions, 1 deletions

diff --git a/lua/nvim-treesitter/install.lua b/lua/nvim-treesitter/install.lua
index 38abfc9c7..f7fb1d47a 100644
--- a/lua/nvim-treesitter/install.lua
+++ b/lua/nvim-treesitter/install.lua
@@ -188,6 +188,9 @@ local function install(with_sync, ask_reinstall)
     if ... == 'all' then
       languages = parsers.available_parsers()
       ask = false
+    elseif ... == 'maintained' then
+      languages = parsers.maintained_parsers()
+      ask = false
     else
       languages = vim.tbl_flatten({...})
       ask = ask_reinstall
@@ -221,9 +224,13 @@ function M.uninstall(lang)
     path_sep = '\\'
   end
 
-  if lang == 'all' then
+  if vim.tbl_contains({'all', 'maintained'}, lang) then
     reset_progress_counter()
     local installed = info.installed_parsers()
+    if lang == "maintained" then
+      local maintained = parsers.maintained_parsers()
+      installed = vim.tbl_filter(function(l) return vim.tbl_contains(maintained, l) end, installed)
+    end
     for _, lang in pairs(installed) do
       M.uninstall(lang)
     end
diff --git a/lua/nvim-treesitter/parsers.lua b/lua/nvim-treesitter/parsers.lua
index 864907d6b..293186c59 100644
--- a/lua/nvim-treesitter/parsers.lua
+++ b/lua/nvim-treesitter/parsers.lua
@@ -357,6 +357,10 @@ function M.available_parsers()
   return vim.tbl_keys(M.list)
 end
 
+function M.maintained_parsers()
+  return vim.tbl_filter(function(lang) return M.list[lang].maintainers end, M.available_parsers())
+end
+
 function M.get_parser_configs()
   return M.list
 end