Kotlin Grammar for Tree-sitter

Kotlin language grammar for Tree-sitter. You can try it out directly on the web.

The grammar is based on the official language grammar.

Project Structure

Setup

npm install

Python Package

Install the Python package from PyPI:

pip install ts-kotlin

The package includes the highlight queries bundled with it. You can access the highlights.scm file using the command-line entry point:

ts-kotlin-highlights

This will print the contents of the queries/highlights.scm file to stdout. The queries directory is automatically included when installing the package via pip.

Usage

from tree_sitter import Parser, Language
from tree_sitter_kotlin import language

# Create parser
lang = Language(language())
parser = Parser(lang)

# Parse Kotlin code
code = b"""
fun greet(name: String): String {
    return "Hello, $name!"
}
"""

tree = parser.parse(code)
print(tree.root_node.sexp())  # Print syntax tree

Development

Compilation

To (re-)compile the grammar, run:

npm run generate

Note that the grammar is written completely in JavaScript (grammar.js), the other source files are generated by tree-sitter.

Testing

To run the unit tests, run:

npm run test

It is also helpful to run the parser on a real Kotlin project's source files.

./node_modules/.bin/tree-sitter parse "/path/to/some/project/**/*.kt"  --quiet --stat

WebAssembly

Compilation

First make sure to have Emscripten installed. If you use Homebrew, you can brew install emscripten. Then run:

npm run build-wasm

Playground

After compiling the grammar to WebAssembly, you can invoke

npm run playground

to launch an interactive editing environment that displays the parsed syntax tree on-the-fly in the browser. You can also view a deployed version of this playground on the web.

Documentation

More documentation on how to create Tree-sitter grammars can be found here.

See also

• Kotlin Language Server for code completion, diagnostics and more
• Kotlin Debug Adapter for JVM debugging support