Treesitter¶

See also

How To Get Started with Tree Sitter: Article on Matering Emacs
Combobulate: Structured Movement and Editing with Tree-Sitter: Another introducing the combobulate package

As of version 29.1 Emacs comes with support out of the box (assuming it has been compiled with the --with-tree-sitter flag)

init.el

(use-package alc-treesitter
  :load-path "lisp"
  :if (treesit-available-p))

Installing Grammars¶

While Emacs supports the tree-sitter library itself, it does not come with any grammars which need to be installed separately. Thankfully, Emacs does provide a few utilities to help with this

lisp/alc-treesitter.el

(setq treesit-language-source-alist
      '((python "https://github.com/tree-sitter/tree-sitter-python" "v0.20.4")
        (typescript "https://github.com/tree-sitter/tree-sitter-typescript" "v0.20.3" "typescript/src")))

The treesit-language-source-alist variable tells Emacs where it can find a given grammar and what language it is for. Once defined (and assuming you have the necessary dependencies) you can use M-x treesit-install-language-grammar command to install one of the grammars you defined. Alternatively this snippet will install them all in one go

(mapc #'treesit-install-language-grammar (mapcar #'car treesit-language-source-alist))

Major Modes¶

Switching to tree-sitter powered major modes by default would not be backwards compatible, so if we actually want to make use of the tree-sitter support we need to opt into it.

lisp/alc-treesitter.el

(if (treesit-language-available-p 'python)
  (add-to-list 'major-mode-remap-alist '(python-mode . python-ts-mode)))

Combobulate¶

mickeynp/combobulate provides a nice set of movement and editing commands that leverage the parse tree generated by tree sitter.

lisp/alc-treesitter.el

 (use-package combobulate
  :vc (:url "https://github.com/mickeynp/combobulate" :rev "master")
  :hook ((python-ts-mode . combobulate-mode)
         (typescript-ts-mode . combobulate-mode)))