Unison Tree-sitter mode for Emacs

This project aims to provide a major mode for the Unison programming language in Emacs, leveraging the power of Tree Sitter to provide syntax highlighting, code folding, indentation and other advanced editor features.

Sample highlighting

Installation

1. Add unison-ts-mode using your preferred method.

• Example using straight

(straight-use-package
 '(unison-ts-mode :type git :host github :repo "fmguerreiro/unison-ts-mode" :files ("*.el")))

2. Ensure you have tree-sitter installed. You can find installation instructions here.

3. Upon loading a .u file, Emacs will complain about not finding the grammar. We're gonna install kylegoetz's grammar here.

• Option 1, through M-x treesit-install-language-grammar:

First eval (or temporarily add to your config) the following expression:

(setq treesit-language-source-alist '((unison "https://github.com/fmguerreiro/tree-sitter-unison-kylegoetz" "build/include-parser-in-src-control")))

Then run M-x treesit-install-language-grammar and choose unison.

• Option 2, build it manually:

git clone https://github.com/kylegoetz/tree-sitter-unison.git
cd tree-sitter-unison
npm install; npm run start

# figure out what kind of extension we need
if [ "$(uname)" = "Darwin" ]; then soext="dylib"; elif uname | grep -q "MINGW" > /dev/null; then soext="dll"; else soext="so"; fi

cd src
cc -fPIC -c -I. parser.c
cc -fPIC -c -I. scanner.c
cc -fPIC -shared *.o -o "unison.${soext}"

Now that the binary is built, we can just move it over to where the tree-sitter implementation is looking for them. In my case, I am using tree-sitter-langs package and Doom, so I can move the binary over with:

cp "unison.${soext}" ~/doom-emacs/.local/straight/build-30.0.50/tree-sitter-langs/bin

Your case might be different depending on your particular Emacs configuration.

NOTE: If you get an error about incompatible ABI versions, open up the package.json file and change the "start" script from "start": "tree-sitter generate, to "start": "tree-sitter generate --abi=13", and redo the build/copy steps.

Usage

Once the Unison mode is installed, it will automatically activate whenever you open a file with the .u extension.

The Unison mode provides the following features:

• Syntax highlighting for Unison code.
• Indentation and automatic formatting.

Contributing

Contributions to this project are welcome. Please follow the standard GitHub workflow for submitting pull requests.

License

This project is licensed under the MIT License. See the LICENSE file for more details.

Contributors

This mode depends on the Tree Sitter grammar work of @kylegoetz.