🪴 Zero's Garden

tree-sitter

3 min read

Use existing *-ts-mode package

First, install packages in package.el.

(package! tree-sitter-langs
  :pin "3a3ad0527d5f8c7768678878eb5cfe399bedf703")
 
(package! typst-ts-mode
  :recipe (:host sourcehut :repo "l2dy/typst-ts-mode")
  :pin "39a9e63c019bd5498c8f0e5a7ee8cb9d6bb53fd0")

If package depends on treesit instead of tree-sitter, it’s required to copy and rename parser library files.

;; config.el
 
(defun treesit-copy-langs-lib-if-newer (lang)
  "Copy treesit libraries from tree-sitter-langs"
  (require 'tree-sitter-langs)
  (let* ((ts-lib-path (car (file-expand-wildcards (concat (tree-sitter-langs--bin-dir) lang ".*"))))
         (ts-lib-name (file-name-nondirectory ts-lib-path))
         (ts-lib-user-dir (concat user-emacs-directory (file-name-as-directory "tree-sitter")))
         (ts-lib-user-path (concat ts-lib-user-dir "libtree-sitter-" ts-lib-name)))
    (when (or (not (file-exists-p ts-lib-user-path))
              (time-less-p (file-attribute-modification-time (file-attributes ts-lib-user-path))
                           (file-attribute-modification-time (file-attributes ts-lib-path))))
      (make-directory ts-lib-user-dir t)
      (delete-file ts-lib-user-path)
      (copy-file ts-lib-path ts-lib-user-path nil t))))
 
(use-package! typst-ts-mode
  :mode "\\.typ\\'"
  :config
  (treesit-copy-langs-lib-if-newer "typst"))

Using pre-compiled language grammars

You can find them on his Github releases page. You can also download the tree-sitter-langs package from MELPA, but I recommend you just download the shared libs directly instead, as you’ll in any event have to rename them and place the grammar libraries somewhere else.

The names of the files are <LANGUAGE>.so (or with your platform’s equivalent extension) which is not in keeping with the expected naming style in Emacs. You must first rename them so they’re named libtree-sitter-<LANGUAGE>.so. This is as good a time as any to learn how to bulk rename them with Emacs’s M-x dired and the editable dired buffers feature.

Define your own new major mode for highlighting

Supported languages: https://github.com/emacs-tree-sitter/tree-sitter-langs/tree/master/queries

  1. Ensure (package! tree-sitter-langs ...) pins to the right commit (or a later commit) in packages.el and tree-sitter module is enabled in init.el.
  2. Run doom sync if pin is updated, and verify that updates are applied to local Straight directories.
  3. Define the major mode in config.el, or a custom Doom module with define-derived-mode split into autoload.el.
;;;###autoload
(define-derived-mode typst-mode text-mode "Typst"
  "Major mode for editing Typst documents."
  (set-tree-sitter-lang! 'typst-mode 'typst) ;; only required if not in tree-sitter-langs--init-major-mode-alist
  (add-hook 'typst-mode-local-vars-hook #'tree-sitter! 'append))
 
(add-to-list 'auto-mode-alist '("\\.typ\\'" . typst-mode))

To enable LSP instead, replace #'tree-sitter! with #'lsp!.

For Elisp gurus: Doom provides MAJOR-MODE-local-vars-hook, and we use it instead of MAJOR-MODE-hook because it runs later in the mode’s startup process (giving other functionality or packages — like direnv — time to configure the LSP client).

Lazy loading

Check if tsc-dyn-get-ensure is defined on start to verify lazy loading.

Linux AArch64 support

See also https://github.com/emacs-tree-sitter/elisp-tree-sitter/issues/166#issuecomment-1522766887.

Add the following to config.el, which is equivalent to use-package’s :init.

;; No binaries are provided for tree-sitter on AArch64 Linux
(setq tsc-dyn-get-from '(:compilation))

This does not fix missing binaries of tree-sitter-langs, so you need to build them yourself.

References

Graph View