81 lines
3.3 KiB
Markdown
81 lines
3.3 KiB
Markdown
|
# [nearley](http://nearley.js.org) ↗️
|
||
|
|
[](http://js.org)
|
||
|
|
[](https://badge.fury.io/js/nearley)
|
||
|
|
|
||
|
|
nearley is a simple, fast and powerful parsing toolkit. It consists of:
|
||
|
|
1. [A powerful, modular DSL for describing
|
||
|
|
languages](https://nearley.js.org/docs/grammar)
|
||
|
|
2. [An efficient, lightweight Earley
|
||
|
|
parser](https://nearley.js.org/docs/parser)
|
||
|
|
3. [Loads of tools, editor plug-ins, and other
|
||
|
|
goodies!](https://nearley.js.org/docs/tooling)
|
||
|
|
|
||
|
|
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](http://github.com/tjvr/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 PEGjs and Jison choke on certain grammars (e.g. [left recursive
|
||
|
|
ones](http://en.wikipedia.org/wiki/Left_recursion)), nearley handles them
|
||
|
|
easily and efficiently by using the [Earley parsing
|
||
|
|
algorithm](https://en.wikipedia.org/wiki/Earley_parser).
|
||
|
|
|
||
|
|
nearley is used by a wide variety of projects:
|
||
|
|
|
||
|
|
- [artificial
|
||
|
|
intelligence](https://github.com/ChalmersGU-AI-course/shrdlite-course-project)
|
||
|
|
and
|
||
|
|
- [computational
|
||
|
|
linguistics](https://wiki.eecs.yorku.ca/course_archive/2014-15/W/6339/useful_handouts)
|
||
|
|
classes at universities;
|
||
|
|
- [file format parsers](https://github.com/raymond-h/node-dmi);
|
||
|
|
- [data-driven markup languages](https://github.com/idyll-lang/idyll-compiler);
|
||
|
|
- [compilers for real-world programming
|
||
|
|
languages](https://github.com/sizigi/lp5562);
|
||
|
|
- and nearley itself! The nearley compiler is bootstrapped.
|
||
|
|
|
||
|
|
nearley is an npm [staff
|
||
|
|
pick](https://www.npmjs.com/package/npm-collection-staff-picks).
|
||
|
|
|
||
|
|
## 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](.github/CONTRIBUTING.md) *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.
|
||
|
|
|
||
|
|
```bibtex
|
||
|
|
@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}
|
||
|
|
}
|
||
|
|
```
|