treesitter: add filetype mappings

docs/manual/release-notes/rl-0.9.md

@@ -283,6 +283,10 @@
 - Added {option}`vim.languages.tera.treesitter.injection` to configure, what
   language the content is.
 
+- Added {option}`vim.treesitter.filetypeMappings` to support mappings similar to
+  <https://github.com/nvim-treesitter/nvim-treesitter/blob/main/plugin/filetypes.lua>.
+  This is mostly use full for Markdown code block injections.
+
 - Added `vim.lsp.presets.<name>` to contain LSP configurations. This allows for
   more flexibility in nvf and reuse of LSPs across languages. Dropped
   `deprecatedSingleOrListOf` in favor of `listOf` for the affected LSP options.

modules/plugins/treesitter/config.nix

@@ -24,7 +24,8 @@ in {
 
       treesitter.grammars = optionals cfg.addDefaultGrammars cfg.defaultGrammars;
 
-      pluginRC.treesitter-autocommands = entryAfter ["basic"] ''
+      pluginRC = {
+        treesitter-autocommands = entryAfter ["basic"] ''
           vim.api.nvim_create_augroup("nvf_treesitter", { clear = true })
 
           ${lib.optionalString cfg.highlight.enable ''
@@ -67,6 +68,12 @@ in {
             })
           ''}
         '';
+        treesitter-filetype-mappings = entryAfter ["basic"] ''
+          for lang, ft in pairs(${toLuaObject cfg.filetypeMappings}) do
+            vim.treesitter.language.register(lang, ft)
+          end
+        '';
+      };
 
       additionalRuntimePaths = mkIf (cfg.queries != []) [
         (let

modules/plugins/treesitter/treesitter.nix

@@ -4,7 +4,7 @@
   ...
 }: let
   inherit (lib.options) mkOption mkEnableOption literalExpression;
-  inherit (lib.types) listOf nullOr package bool str lines enum submodule oneOf;
+  inherit (lib.types) listOf nullOr package bool str lines enum submodule oneOf attrsOf;
 
   queriesType = submodule {
     options = {
@@ -111,5 +111,18 @@ in {
       default = [];
       description = "A list of Neovim treesitter queries to be registered.";
     };
+
+    filetypeMappings = mkOption {
+      type = attrsOf (listOf str);
+      default = {};
+      example = {
+        "sh" = ["ash" "dash"];
+      };
+      description = ''
+        Register alternative parser names for a filetype.
+        For more information see `:h vim.treesitter.language.register()`.
+        See treesitter builtin mappings here: <https://github.com/nvim-treesitter/nvim-treesitter/blob/main/plugin/filetypes.lua>
+      '';
+    };
   };
 }