tree-sitter-indent.el

Use Tree-sitter as backend to source code indentation.

Provide an indent-line-function that resolves the indentation by looking at the syntax tree using the emacs-tree-sitter package.

Installation

First, install emacs-tree-sitter. I recommend using straight.el

(straight-use-package
 '(tree-sitter :host github
               :repo "ubolonton/emacs-tree-sitter"
               :files ("lisp/*.el")))

(straight-use-package
 '(tree-sitter-langs :host github
                     :repo "ubolonton/emacs-tree-sitter"
                     :files ("langs/*.el" "langs/queries")))

;; Load the language bundle

(require 'tree-sitter-langs)

Then, install tree-sitter-indent. Recommended way is using straight.el (no (M)ELPA package currently available).

(straight-use-package
 '(tree-sitter-indent :type git
                      :repo "https://codeberg.org/FelipeLema/tree-sitter-indent.el.git"
                      :branch "main"
                      :files ("tree-sitter-indent.el")))

Usage

So far, only rust language can be indented. Add the following to your init.el

;; install tree-sitter
;; …

;; install tree-sitter-indent
;; …

(tree-sitter-require 'rust)
(require 'tree-sitter-indent)

(add-hook 'rust-mode-hook #'tree-sitter-indent-mode)

Adding languages or fixing current

Currently, julia is work-in-progress as the Tree-sitter implementation is not done. Rust was actually the second language being worked on, which involved a more mature development, so you may want to check those commits.

The best way to work through a language is to add the targets you want to get ("I want this code to be indented like this") as a unit test. And then add code as needed.

PRs are welcome.

Running tests

To run tests, execute the following

make

This will byte-compile elisp files and run tests. Byte-compiler warnings will be treated as errors, so make sure to cover them.

Internally, make will fetch all dependencies using straight.el and run.

Code of Conduct