@esdmr/nearley
v3.0.3
Published
Simple, fast, powerful parser toolkit for JavaScript.
Downloads
8
Maintainers
Readme
This fork: esdmr/nearley
Modernized version of nearley with slightly better support for TypeScript,
mostly for personal use. It is available as @esdmr/nearley
on npm.
Original README: nearley ↗️
nearley is a simple, fast and powerful parsing toolkit. It consists of:
- A powerful, modular DSL for describing languages
- An efficient, lightweight Earley parser
- Loads of tools, editor plug-ins, and other goodies!
nearley is a streaming parser with support for catching errors gracefully and providing all parsings for ambiguous grammars. It is compatible with a variety of lexers (we recommend moo). It comes with tools for creating tests, railroad diagrams and fuzzers from your grammars, and has support for a variety of editors and platforms. It works in both node and the browser.
Unlike most other parser generators, nearley can handle any grammar you can define in BNF (and more!). In particular, while most existing JS parsers such as PEG.js and Jison choke on certain grammars (e.g., left recursive ones), nearley handles them easily and efficiently by using the Earley parsing algorithm.
nearley is used by a wide variety of projects:
- Artificial intelligence and
- computational linguistics classes at universities;
- file format parsers;
- data-driven markup languages;
- compilers for real-world programming languages;
- and nearley itself! The nearley compiler is bootstrapped.
nearley is an npm staff pick.
Documentation
Please visit our website https://nearley.js.org to get started! You will find a tutorial, detailed reference documents, and links to several real-world examples to get inspired.
Contributing
Please read this document before working on
nearley. If you are interested in contributing but unsure where to start, take a
look at the issues labeled “up for grabs” on the issue tracker, or message a
maintainer (@kach
or @tjvr
on GitHub).
nearley is MIT licensed.
A big thanks to Nathan Dinsmore for teaching me how to Earley, Aria Stewart for helping structure nearley into a mature module, and Robin Windels for bootstrapping the grammar. Additionally, Jacob Edelman wrote an experimental JavaScript parser with nearley and contributed ideas for EBNF support. Joshua T. Corbin refactored the compiler to be much, much prettier. Bojidar Marinov implemented postprocessors-in-other-languages. Shachar Itzhaky fixed a subtle bug with nullables.
Citing nearley
If you are citing nearley in academic work, please use the following BibTeX entry.
@misc{nearley,
author = "Kartik Chandra and Tim Radvan",
title = "{nearley}: a parsing toolkit for {JavaScript}",
year = {2014},
doi = {10.5281/zenodo.3897993},
url = {https://github.com/kach/nearley}
}