CT — C with Traits for VS Code

Syntax highlighting, snippets and language configuration for CT, the trait-flavoured C compiled by ctc.

trait Greeter {
    void greet();
}

struct Person {
    char *name;
} use Greeter;

impl Greeter for Person {
    void greet() {
        printf("Hello, %s\n", self->name);
    }
}

What it gives you

Everything else — strings, comments, preprocessor lines, types, function bodies — is VS Code's own C grammar, pulled in with include: source.c. No duplicated C grammar to maintain and nothing to drift.

Strings, chars and comments are tokenised before the CT rules, so the compiler's core guarantee ("never touch anything inside a string, char or comment") holds for the highlighter too: printf("use self here") stays a plain string.

Also included: comment and bracket configuration, auto-closing and surrounding pairs, brace-based indentation, block-comment continuation on Enter, and the snippets trait, structuse, impl, method, call.

The extension is declarative JSON — no build step, no dependencies. The .ct sources are not compiled by this extension; use ctc for that.

Install

From a local checkout (development):

cd editors/vscode
code --extensionDevelopmentPath="$PWD"   # open VS Code with the extension loaded

Or symlink it into your extensions folder and reload VS Code:

ln -s "$PWD" ~/.vscode/extensions/ct-vscode

To get an F5 workflow, add a launch configuration at the repository root as .vscode/launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Run Extension",
      "type": "extensionHost",
      "request": "launch",
      "args": ["--extensionDevelopmentPath=${workspaceFolder}/editors/vscode"]
    }
  ]
}

Checks

python3 test/check-grammar.py    # 13 assertions; exit code 0 means it passed

The script replays the grammar's patterns with Python's re over the demos in examples/ and the cases in test/cases/, asserting both directions: the CT rules fire on trait / use / impl / self, and they stay silent inside comments, strings and look-alike identifiers (use_it, selfish).

It is a smoke test, not a substitute for a human pass: Python's re is not Oniguruma, and the real engine also runs VS Code's built-in source.c grammar, which the script deliberately does not emulate. Open a .ct file in VS Code once before publishing.

Package and publish

cd editors/vscode
npx @vscode/vsce package        # produces ct-vscode-0.0.1.vsix
npx @vscode/vsce publish        # needs a Marketplace publisher + PAT

Two things are needed before publishing:

• publisher in package.json must match your Marketplace publisher id (currently set to samxxu, which does not exist yet).
• icon.png — a 128×128 PNG referenced as "icon": "icon.png". It is intentionally absent from the repo; add your own before publishing (vsce still packages without it, but the listing looks bare).

License

MIT — see LICENSE. The compiler itself is GPL-3.0-or-later with an output exception; see the repository for details.

中文说明

给 CT（C with Traits） 用的 VS Code 扩展：语法高亮 + 代码片段 + 编辑器配置。

• CT 独有构造（trait 定义、use 子句含逗号列表、impl … for …、隐式 self）由本扩展高亮； 其余全部交给 VS Code 内置的 C 语法，不需要维护一份 C 语法副本。
• 字符串、字符、注释先于 CT 规则被整体吃掉，因此编译器"字符串/注释内绝不改写"的保证在高亮层面同样成立。
• 纯 JSON，无构建、无依赖，可直接 npx @vscode/vsce package 打包。
• 发布前需要补两样：package.json 里的 publisher 改成你真实的 Marketplace 发布者 ID，以及自备一张 128×128 的 icon.png。