feat(nix): add treesit support

modules/lang/nix/README.org

@@ -19,20 +19,18 @@ Includes:
 [[doom-contrib-maintainer:][Become a maintainer?]]
 
 ** Module flags
+- +lsp ::
+  Enable an LSP hook for ~nix-mode~. Requires [[doom-module::tools lsp]] and a
+  language server (one of either ~nil~ or ~rnix-lsp~).
 - +tree-sitter ::
   Leverages tree-sitter for better syntax highlighting and structural text
-  editing. Requires [[doom-module::tools tree-sitter]].
-- +lsp ::
-  Enable an LSP hook for ~nix-mode~. Requires [[doom-module::tools lsp]] and a language
-  server (one of either ~nil~ or ~rnix-lsp~).
-
-  You can still start a nix lsp manually without this flag, this just adds
-  a hook to always start the lsp when loading ~nix-mode~.
+  editing. Requires Emacs 29.1+ and [[doom-module::tools tree-sitter]].
 
 ** Packages
 - [[doom-package:company-nixos-options]] if [[doom-module::completion company]]
 - [[doom-package:helm-nixos-options]] if [[doom-module::completion helm]]
 - [[doom-package:nix-mode]]
+- [[doom-package:nix-ts-mode]] if [[doom-module:+tree-sitter]]
 - [[doom-package:nix-update]]
 
 ** Hacks

modules/lang/nix/config.el

@@ -7,33 +7,25 @@
 ;;
 ;;; Plugins
 
-(use-package! nix-mode
-  :interpreter ("\\(?:cached-\\)?nix-shell" . +nix-shell-init-mode)
-  :mode "\\.nix\\'"
-  :init
-  (add-to-list 'auto-mode-alist
-               (cons "/flake\\.lock\\'"
-                     (if (modulep! :lang json)
-                         'json-mode
-                       'js-mode)))
-  :config
-  (set-repl-handler! 'nix-mode #'+nix/open-repl)
-  (set-company-backend! 'nix-mode 'company-nixos-options)
-  (set-lookup-handlers! 'nix-mode
+(add-to-list 'auto-mode-alist
+             (cons "/flake\\.lock\\'"
+                   (if (modulep! :lang json)
+                       'json-mode
+                     'js-mode)))
+
+
+(defun +nix-common-config (mode)
+  (set-repl-handler! mode #'+nix/open-repl)
+  (set-company-backend! mode 'company-nixos-options)
+  (set-lookup-handlers! mode
     :documentation '(+nix/lookup-option :async t))
   (set-popup-rule! "^\\*nixos-options-doc\\*$" :ttl 0 :quit t)
 
-  ;; Fix #3927: disable idle completion because `company-nixos-options' is
-  ;; dreadfully slow. It can still be invoked manually..
-  (setq-hook! 'nix-mode-hook company-idle-delay nil)
-
   (when (modulep! +lsp)
-    (add-hook 'nix-mode-local-vars-hook #'lsp! 'append))
-  (when (modulep! +tree-sitter)
-    (add-hook 'nix-mode-local-vars-hook #'tree-sitter! 'append))
+    (add-hook (intern (format "%s-local-vars-hook" mode)) #'lsp! 'append))
 
   (map! :localleader
-        :map nix-mode-map
+        :map ,(symbol-value (intern (format "%s-map" mode)))
         "f" #'nix-update-fetch
         "p" #'nix-format-buffer
         "r" #'nix-repl-show
@@ -43,6 +35,32 @@
         "o" #'+nix/lookup-option))
 
 
+(use-package! nix-mode
+  :interpreter ("\\(?:cached-\\)?nix-shell" . +nix-shell-init-mode)
+  :mode "\\.nix\\'"
+  :config
+  (+nix-common-config 'nix-mode))
+
+
+(use-package! nix-ts-mode
+  :when (modulep! +tree-sitter)
+  :when (fboundp 'treesit-available-p)
+  :defer t
+  :init
+  (set-tree-sitter! 'nix-mode 'nix-ts-mode
+    '((nix :url "https://github.com/nix-community/tree-sitter-nix")))
+  :config
+  (+nix-common-config 'nix-ts-mode))
+
+
+(use-package! company-nixos-options
+  :defer t
+  :init
+  ;; Fix #3927: disable idle completion because `company-nixos-options' is
+  ;; dreadfully slow. It can still be invoked manually..
+  (setq-hook! '(nix-mode-hook nix-ts-mode-hook) company-idle-delay nil))
+
+
 (use-package! nix-update
   :commands nix-update-fetch)
 

modules/lang/nix/doctor.el

@@ -1,13 +1,13 @@
 ;; -*- lexical-binding: t; no-byte-compile: t; -*-
 ;;; lang/nix/doctor.el
 
+(assert! (or (modulep! -tree-sitter)
+             (modulep! :tools tree-sitter))
+         "This module requires (:tools tree-sitter)")
+
 (unless (executable-find "nix")
   (warn! "Couldn't find the nix package manager. nix-mode won't work."))
 
 (when (require 'nix-mode nil t)
   (unless (executable-find nix-nixfmt-bin)
     (warn! (concat "Couldn't find " nix-nixfmt-bin ". nix-format-buffer won't work."))))
-
-(assert! (or (modulep! -tree-sitter)
-             (modulep! :tools tree-sitter))
-         "This module requires (:tools tree-sitter)")

modules/lang/nix/packages.el

@@ -4,6 +4,10 @@
 (package! nix-mode :pin "719feb7868fb567ecfe5578f6119892c771ac5e5")
 (package! nix-update :pin "77022ccd918d665acbb519b243e7e3dc5eae1c47")
 
+(when (and (modulep! +tree-sitter)
+           (fboundp 'treesit-available-p))
+  (package! nix-ts-mode :pin "62ce3a2dc39529c5db3516427e84b2c96b8efcfd"))
+
 (when (modulep! :completion company)
   (package! company-nixos-options :pin "053a2d5110ce05b7f99bcc2ac4804b70cbe87916"))
 

modules/tools/tree-sitter/config.el

@@ -32,7 +32,6 @@
                  (javascript "https://github.com/tree-sitter/tree-sitter-javascript" "master" "src" nil nil)
                  (latex "https://github.com/latex-lsp/tree-sitter-latex" nil nil nil nil)
                  (make "https://github.com/tree-sitter-grammars/tree-sitter-make" nil nil nil nil)
-                 (nix "https://github.com/nix-community/tree-sitter-nix" nil nil nil nil)
                  (nu "https://github.com/nushell/tree-sitter-nu" nil nil nil nil)
                  (org "https://github.com/milisims/tree-sitter-org" nil nil nil nil)
                  (perl "https://github.com/ganezdragon/tree-sitter-perl" nil nil nil nil)