Chevrotain

Chevrotain is a very fast and feature rich JavaScript LL(k) Parsing DSL. It can be used to build parsers/compilers/interperters for various use cases ranging from simple configuration files, to full fledged programing languages.

It is important to note that Chevrotain is NOT a parser generator. It solves the same kind of problems as a parser generator, just without any code generation. Chevrotain Grammars are pure JavaScript code which can be created/debugged/edited as any other JavaScript code without requiring any new tools or processes.

---> Try it online <---

Features

Parsing DSL.
- LL(k) grammars support.
- Separation of grammar and semantics.
- 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
Lexer Engine
- Based on Regular Expressions.
- Full position information tracking (lines/columns/offsets).
- Token skipping (whitespace/comments/...).
- Prioritise longest match (Keywords vs Identifiers).
- Multiple Lexer Modes depending on the context.
- Tokens Grouping.
- Custom Token patterns(none RegExp) support
- No code generation The Lexer does not require any code generation phase.
High Performance.
Railroad Diagrams Generation.
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.
Well tested with ~100% code coverage, Unit & Integration tests

Installation

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/chevrotain@0.28.3/lib/chevrotain.js
  - https://unpkg.com/chevrotain@0.28.3/lib/chevrotain.min.js

Documentation & Resources

Dependencies

None.

Compatibility

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

Contributions are greatly appreciated. See CONTRIBUTING.md for details

ibdknox/chevrotain