Chevrotain is a JavaScript parsing DSL for building High Performance LL(k) Parsers with optional fault-tolerant capabilities.

Chevrotain is NOT a parser generator. It solves the same kind of problems as a parser generator, just without any code generation phase.

1. Parsing DSL. * LL(k) grammars support.
   * Error Reporting with full location information. * Strong Error Recovery/Fault-Tolerance capabilities based on Antlr3's algorithms. * Supports gates/predicates. * Backtracking support. * Grammar Inheritance. * Multiple starting rules. * Parametrized Rules. * Syntactic Content Assist * No code generation.

   • The DSL is just JavaScript, not an external language.
   • The grammar is directly debuggable as plain JavaScript source.
   • Short feedback loops.
   • Allows great flexibility for inserting custom Parser actions

2. Lexer Engine based on Regular Expressions. * Full Token position information. * Token skipping (whitespace/comments/...). * Prioritise shorter matches (Keywords vs Identifiers). * Multiple Lexer Modes depending on the context. * Tokens Grouping. * Different Token types for balancing performance, memory usage and ease of use. * Custom Token patterns(none RegExp) support * No code generation The Lexer does not require any code generation phase.

3. High Performance.

4. Railroad Diagrams Generation.

5. Grammar Reflection/Introspection. * The Grammar's structure is known and exposed at runtime. * Can be used to implement advanced features such as dynamically generated syntax diagrams or Syntactic error recovery.

6. Well tested with ~100% code coverage, Unit & Integration tests

• npm: npm install chevrotain
• Browser: The npm package contains Chevrotain as concatenated and minified files ready for use in a browser. These can also be accessed directly via UNPKG in a script tag.
  • Latest:
    • https://unpkg.com/chevrotain/lib/chevrotain.js
    • https://unpkg.com/chevrotain/lib/chevrotain.min.js
  • Explicit version number:
    • https://unpkg.com/[email protected]/lib/chevrotain.js
    • https://unpkg.com/[email protected]/lib/chevrotain.min.js

• FAQ.

• Getting Started Tutorial.

• Sample Grammars.

• Other Examples.

• Chevrotain Google Group for questions and discussions.

• HTML docs.

  • The Parsing DSL Docs.

• Token Types Docs.

None.

Chevrotain should run on any modern JavaScript ES5.1 runtime.

• The CI build runs the tests under:

  • Node.js (4 / 6 / 7).
  • Latest stable: Chrome, FireFox, IE Edge, IE 11 and Safari 9.

• Uses UMD to work with common module loaders (browser global / amd / commonjs).

Contributions are greatly appreciated. See CONTRIBUTING.md for details