Parse tree

Exposes an api function that can be used to get a parse tree node for a given file location.

Usage

Can be used as follows:

const parseTreeExtension = vscode.extensions.getExtension("pokey.parse-tree");

if (parseTreeExtension == null) {
  throw new Error("Depends on pokey.parse-tree extension");
}

const { getNodeAtLocation } = await parseTreeExtension.activate();

Don't forget to add an extensionDependencies-entry to package.json as described in https://code.visualstudio.com/api/references/vscode-api#extensions.

Parsing a custom language

If you'd like to add support for a new language, see the Adding a new language section below. Alternatively, your extension can register a custom language with this extension. Although this is not the preferred way to add a new language, it can be convenient when you have a parser that you don't believe belongs in the main extension.

Parsing your own language is as simple as registering your languageId with an absolute path to your .wasm file:

const { registerLanguage } = await parseTreeExtension.activate();

registerLanguage(languageId, wasmPath);

Contributing

Setup

1. yarn
2. Install emscripten for generating parser wasm files

Adding a new language

It's straightforward to add any language with a tree-sitter grammar.

1. Add a dependency on the npm package for that language: yarn add -D tree-sitter-yourlang.
2. Add a language to the dictionary at the top of ./src/extension.ts
3. Add a reference to onLanguage:yourlang to the activationEvents section of package.json. yourlang must be a VSCode language identifier.
4. Add your language to the top of the Makefile
5. Run yarn compile, then hit F5 in VSCode, with this project open, to test your changes.
6. Submit a PR!

Developing on WSL2

When working with WSL, the host vscode instance connects to a vscode server on the WSL vm. This happens automatically when you run "code" in WSL, as long as you have the "Remote - WSL" extension installed on the host. From there you need to:

• Install the pokey.command-server extension on the host vscode
• Clone the extension in the WSL side.
• If you're adding language support to vscode-parse-tree, you need to clone that as well, build it, and link it into the vscode-server extension folder: ln -s ~/your/code/vscode-parse-tree ~/.vscode-server/extensions/parse-tree for instance.
• If you get errors about needing to install the Remote-WSL extension, you might need to manually delete the extension from the host side and try again.

Updating web-tree-sitter

We build a custom version of web-tree-sitter to ensure that we can always use the latest version and fix any problems as they come up. To update web-tree-sitter update the contents of ./tree-sitter-version to the latest commit sha of tree-sitter.

The script which builds our custom version is at the end of our Makefile.

Change Log

See CHANGELOG.md.

Credits

Forked from https://github.com/georgewfraser/vscode-tree-sitter.