Jac

Jac Zed Extension

Jac language support for Zed.

• Tree-sitter: tree-sitter-jac
• Language Server: jaclang (jac lsp)

Installation

Install the jac CLI and ensure it is on your PATH:

pip install jaclang

Zed will automatically start jac lsp for .jac files.

Configuration

You can override the language server binary or arguments in your Zed settings:

{
  "lsp": {
    "jac-lsp": {
      "binary": {
        "path": "/path/to/jac",
        "arguments": ["lsp"]
      }
    }
  }
}

Any settings placed under lsp.jac-lsp.settings are forwarded to the language server as workspace configuration.

Development

Build the extension as a WebAssembly module:

rustup target add wasm32-wasip2
cargo build --target wasm32-wasip2

Then open Zed, run the "zed: extensions" command, click Install Dev Extension, and select this directory.

Project Structure

• extension.toml — extension manifest and language/grammar declarations
• Cargo.toml / src/jac.rs — Rust extension entry point that launches jac lsp
• languages/jac/ — language configuration and Tree-sitter highlights