Tree Sitter NG

Next generation Tree Sitter Java binding.

Getting started

Add dependencies to your build.gradle or pom.xml.

// Gradle
dependencies {
    // add tree sitter
    implementation 'io.github.bonede:tree-sitter:$VERSION'
    // add json parser
    implementation 'io.github.bonede:tree-sitter-json:$VERSION'
}

<!-- Maven -->
<dpendencies>
    <!-- add tree sitter -->
    <dependency>
        <groupId>io.github.bonede</groupId>
        <artifactId>tree-sitter</artifactId>
        <version>$VERSION</version>
    </dependency>
    <!-- add json parser -->
    <dependency>
        <groupId>io.github.bonede</groupId>
        <artifactId>tree-sitter-json</artifactId>
        <version>$VERSION</version>
    </dependency>
</dpendencies>

Start hacking!

// imports are omitted
class Main {
    public static void main(String[] args) {
        TSParser parser = new TSParser();
        // Use `TSLanguage.load` instead if you would like to load parsers as shared object(.so, .dylib, or .dll).
        // TSLanguage.load("path/to/languane/shared/object", "tree_sitter_some_lang");
        TSLanguage json = new TreeSitterJson();
        parser.setLanguage(json);
        TSTree tree = parser.parseString(null, "[1, null]");
        TSNode rootNode = tree.getRootNode();
        TSNode arrayNode = rootNode.getNamedChild(0);
        TSNode numberNode = arrayNode.getNamedChild(0);
    }
}

Features

• 100% Tree Sitter API coverage.
• Easy to bootstrap cross compiling environments powered by Zig.
• Built-in official parsers.
• Load parsers as shared object from disk.

Supported CPUs and OSes

• x86_64-windows
• x86_64-macos
• aarch64-macos
• x86_64-linux
• aarch64-linux

Developers: How to Add a Parser

To add a new language parser to this project, we provide a code generation task that handles most of the boilerplate. This is also how you can add an "unofficial" or community parser.

1. Generate the subproject: Run the gen task, providing the language name (in this example, Kotlin), its version, and the URL to its source code zip file.

   ./gradlew gen --parser-name=kotlin --parser-version=0.3.8 --parser-zip=https://github.com/fwcd/tree-sitter-kotlin/archive/refs/tags/0.3.8.zip

   This will create a new directory tree-sitter-kotlin with the correct build.gradle, gradle.properties, JNI bindings, and Java class extending TSLanguage. Finally, an entry of include 'tree-sitter-kotlin' will be inserted into settings.gradle.

2. Build native modules and test: Our build system automatically uses Zig to cross-compile the native shared libraries for the new parser. You can trigger the download, native compilation, and tests:

   ./gradlew :tree-sitter-kotlin:buildNative
   ./gradlew :tree-sitter-kotlin:test

Built-in official parsers

Name	Version
tree-sitter-agda
tree-sitter-bash
tree-sitter-c
tree-sitter-c-sharp
tree-sitter-cpp
tree-sitter-css
tree-sitter-embedded-template
tree-sitter-go
tree-sitter-haskell
tree-sitter-html
tree-sitter-java
tree-sitter-javascript
tree-sitter-json
tree-sitter-julia
tree-sitter-ocaml
tree-sitter-php
tree-sitter-python
tree-sitter-regex
tree-sitter-ruby
tree-sitter-rust
tree-sitter-scala
tree-sitter-tsx
tree-sitter-typescript
tree-sitter-verilog

API Tour

class Main {
    public static void main(String[] args) {
        String jsonSource = "[1, null]";
        TSParser parser = new TSParser();
        TSLanguage json = new TreeSitterJson();
        // set language parser
        parser.setLanguage(json);
        // parser with string input
        parser.parseString(null, jsonSource);
        parser.reset();
        // or parser with encoding
        parser.parseStringEncoding(null, JSON_SRC, TSInputEncoding.TSInputEncodingUTF8);
        parser.reset();
        // or parser with custom reader
        byte[] buffer = new byte[1024];
        TSReader reader = (buf, offset, position) -> {
            if(offset >= jsonSource.length()){
                return 0;
            }
            ByteBuffer charBuffer = ByteBuffer.wrap(buf);
            charBuffer.put(jsonSource.getBytes());
            return jsonSource.length();
        };
        TSTree tree = parser.parse(buffer, null, reader, TSInputEncoding.TSInputEncodingUTF8);
        // traverse the AST tree with DOM like APIs
        TSNode rootNode = tree.getRootNode();
        TSNode arrayNode = rootNode.getNamedChild(0);
        // or travers the AST with cursor
        TSTreeCursor rootCursor = new TSTreeCursor(rootNode);
        rootCursor.gotoFirstChild();
        // or query the AST with S-expression
        TreeSitterQuery query = new TSQuery(json, "((document) @root)");
        TSQueryCursor cursor = new TSQueryCursor();
        cursor.exec(query, rootNode);
        SQueryMatch match = new TSQueryMatch();
        while(cursor.nextMatch(match)){
            // do something with the match
        }
        // debug the parser with a logger
        TSLogger logger = (type, message) -> {
            System.out.println(message);
        };
        parser.setLogger(logger);
        // or output the AST tree as DOT graph
        File dotFile = File.createTempFile("json", ".dot");
        parser.printDotGraphs(dotFile);
    }
}