Lezer for Dart #

A pure Dart port of Lezer - the incremental GLR parser system that powers CodeMirror 6.

Features #

• Incremental parsing - Only re-parses changed portions of the document
• Error recovery - Produces meaningful parse trees even for invalid input
• Efficient - Optimized for real-time editing scenarios
• Tree structure - Provides a concrete syntax tree for syntax highlighting and code analysis

Usage #

import 'package:lezer/lezer.dart';

// Parse source code using a language parser
final tree = parser.parse('const x = 42;');

// Traverse the tree
tree.iterate(
  enter: (node) {
    print('${node.name}: ${source.substring(node.from, node.to)}');
    return true;
  },
);

Language Support #

This package provides the core parsing infrastructure. Language-specific parsers are provided by the codemirror package which includes:

• JavaScript/TypeScript/JSX/TSX
• JSON
• Markdown
• HTML/CSS
• And more...

Related Packages #

• codemirror - Full code editor with syntax highlighting
• lezer-generator - Generate parsers from grammar files (JavaScript)

License #

MIT License - see LICENSE for details.

Based on Lezer by Marijn Haverbeke.