vscode-just

VSCode syntax highlighting extension for the just language.

Contents:

• Features
• Known Issues
• Release Notes
• Roadmap
• Contributing
• References

Features

Basic syntax highlighting for just files:

• Comments
• Variable assignment and settings
• Strings & interpolation blocks
• Recipes: recipe attributes, names, params and dependencies
• Keywords, constants and operators
• Some embedded languages

Note: Unlike previous iterations of VSCode just extensions, this extension does not provide command running capabilities from VSCode.

Known Issues

This extension does simple and/or best effort syntax highlighting. It is not intended to be 100% comprehensive, but rather provide a good enough experience for most users. That being said, if you find a bug or missing feature, please open an issue or a pull request.

Nesting and scoping

Since expressions can have deep nesting and we cannot tell the scope based on indentation or other markers, we run into the following issues. These are limitations of TextMate grammars and is not easily fixable.

• Expression and recipe specific rules pollute the global repository scopes, meaning we apply just highlighting within recipe bodies. This means just keywords/operators/etc, like if, will highlight everywhere. This is necessary to highlight expressions correctly elsewhere.

• Some nested expressions will break due to lack of awareness of depth and preemptively match a closing character. Ex.

  echo {{ '{{ string }}' }}
  

  will echo {{ string }} since braces within the string are escaped and part of the string's scope. Textmate can't handle this without a full parser, so will match on the first closing brace it finds.

• Line breaking and expressions that span multiple lines may not highlight correctly. As a simple example

  foo param1 \
      param2='foo':
  echo {{param1}} {{param2}}
  

Publishing

This extension is not available on open source marketplaces (for now). If you are using an open source build of VSCode, you might need to install the extension manually. To do so:

1. Navigate to the latest release and download the .vsix file.
2. Copy the file to your .vscode/extensions directory.
3. Install via the command line: code --install-extension .vscode/extensions/vscode-just-X.Y.Z.vsix

Release Notes

See CHANGELOG.md.

Roadmap

Outstanding:

• [ ] Update to match just grammar more accurately
• [ ] Improve escaping within strings

Completed:

• [x] Initial release
• [x] Update with new just releases
• [x] Migrate to yaml grammar for composability and readability
• [x] Add snapshot testing
• [x] Publish to open source marketplaces
• [x] Format on save
• [x] Run recipe

Beyond

• Semantic highlighting / LSP

  To avoid implementing a parser for files, it would be ideal for just to expose the AST or other APIs for editor extensions to leverage. This would allow for more advanced features like semantic highlighting, code folding, and more.

  If VSCode works to support tree-sitter, that would be a possible alternative.

Contributing

See CONTRIBUTING.md.

References

• TextMate Language Grammars

• Previous iterations on just syntax grammars

  • shellock/vscode-just
  • sclu1034/vscode-just

• Example language grammars

• Just manual

• Packaging and publishing extensions