Zed Cirru

Cirru language support for Zed.

This first implementation focuses on syntax highlighting and bracket matching. It maps the lexical categories from parser.rs into a lightweight Tree-sitter grammar that highlights:

• line comments starting with ; or ;;
• string literals and escape sequences
• special Cirru operators $ and ,
• parentheses
• common keyword, boolean, number, and keyword-like token patterns

Local Development

1. Generate the parser in grammars/tree-sitter-cirru/.
2. Install this repository as a Zed dev extension.
3. Open a .cirru file and confirm highlighting.

The grammar is currently loaded from a local file:// URL in extension.toml so it can be tested immediately on this machine. Before publishing, switch that to the real Git repository URL and a fixed commit hash.

Current Limitations

• This grammar is intentionally lexical-first. It does not yet model Cirru's indentation tree like parser.rs does.
• Highlighting is already useful, but structural features such as indentation, outline, and exact top-level form detection still need a second iteration.
• Once the basic grammar settles, the next step is likely an external scanner for indentation-sensitive parsing.

Installation Notes

If you clone this repo to a new machine and install it as a dev extension, there are a few things to watch out for:

1. grammars/tree-sitter-cirru must be a standalone Git repository

extension.toml uses a file:// URL to point Zed at the grammar source. Zed treats this as a Git remote and tries to git clone it at the specified rev. If grammars/tree-sitter-cirru/ is not itself a Git repo (e.g. after a fresh clone of the parent project), Zed will fail with a checkout error.

Fix: initialise it as a Git repo and create a commit:

cd grammars/tree-sitter-cirru
git init && git add -A && git commit -m "tree-sitter grammar for cirru"

Then update the rev in extension.toml to the new commit hash:

git rev-parse HEAD   # copy this hash into extension.toml

2. Update the file:// path in extension.toml

The repository field under [grammars.cirru] contains an absolute local path (e.g. file:///Users/<username>/repo/cirru/zed-cirru/grammars/tree-sitter-cirru). Make sure this matches the actual path on your machine.

3. Delete the grammars/cirru/ directory before installing

Zed expects to clone the grammar into grammars/cirru/ itself. If that directory already exists (even if empty), Zed will refuse to proceed with:

grammar directory '…/grammars/cirru' already exists, but is not a git clone of '…'

Fix: remove the directory and let Zed recreate it:

rm -rf grammars/cirru

4. Files excluded by .gitignore

The top-level .gitignore excludes many generated files under grammars/tree-sitter-cirru/ (bindings, Cargo.toml, node_modules, etc.). These are not needed for Zed to compile the grammar — Zed only requires src/parser.c and the header files in src/tree_sitter/. As long as those exist (they are tracked in Git), the extension will build correctly.