eploko/pegjs-loader

PEG.js loader for webpack

PEG.js loader for webpack

Install

npm install --save-dev pegjs-loader pegjs webpack

The pegjs-loader requires PEG.js and webpack as peerDependency. Thus you are able to specify the required versions accurately.

Usage

Documentation: Using loaders

var parser = require("!pegjs!./parser.pegjs");
// => returns compiled PEG.js parser

Apply via webpack config

It's recommended to adjust your webpack.config so pegjs! is applied automatically on all files ending with .pegjs:

module.exports = {
  ...
  module: {
    loaders: [
      {
        test: /\.pegjs$/,
        loader: 'pegjs-loader'
      }
    ]
  }
};

Then you only need to write: require("./parser.pegjs").

PEG.js options

You can pass options to PEG.js as query parameters. The following options are supported:

• allowedStartRules - The rules the built parser will be allowed to start parsing from (default: the first rule in the grammar).

• cache — If true, makes the parser cache results, avoiding exponential parsing time in pathological cases but making the parser slower (default: false).

• dependencies - Parser dependencies, the value is an object which maps variables used to access the dependencies in the parser to module IDs used to load them (default: {}).

• optimize - Whether to optimize the built parser either for speed or size (default: speed).

• trace - If true, the tracing support in the built parser is enabled (default: false).

module.exports = {
  ...
  module: {
    loaders: [
      {
        test: /\.pegjs$/,
        loader: 'pegjs-loader?cache=true&optimize=size&allowedStartRules[]=RuleA,allowedStartRules[]=RuleB&trace=true'
      }
    ]
  }
};

Change Log

This project adheres to Semantic Versioning.
Every release, along with the migration instructions, if any, is documented on the Github Releases page.

Thanks

• Victor Homyakov for the propagation of the cache option.
• VladimirTechMan for the propagation of the optimize option and updating things to be compatible with PEG.js 0.10.0.
• ragtime for the propagation of the allowedStartRules and trace options.
• Jan Varwig for the Webpack 2 compatibility fix.
• retorquere for the propagation of the dependencies option.

License

MIT (http://www.opensource.org/licenses/mit-license.php)

pegjs-loader's Issues

boilerplate starter template?

Would love if there was a generator or quick start boilerplate project using this for getting started with PEG.js

Webpack 2 support?

Will the loader be updated for webpack 2?

switch to `loaderUtils.getOptions`

webpack/loader-utils#56

Prototype pollution in loader-utils dependency

GHSA-76p3-8jx3-jpfq

The earliest fixed version is 1.4.1.

#21

Webpack peer dependency: remove?

I implemented this project in my webpack config with the latest webpack (3.1.0) only to find the peer dependency warning crop up. This normally wouldn't be an issue, but I do run my project through Travis, where it seems like these issues can't be ignored.

Webpack@3 is fairly new, but there was a previous PR to get webpack@2 included in the peer dependencies, and if I open one for 3, there's nothing stopping 4 from not working in the future.

Is it a justifiable solution to just remove the peer dependency, or make it more future-proof at least? Just make it like > 1 or something like that.

Feature request - support for plugins

In particular, this one would be useful.
https://github.com/metadevpro/ts-pegjs

SQLite grammar not parsing

https://github.com/codeschool/sqlite-parser/blob/master/src/grammar.pegjs

I cant' figure out why this file raises the error.

pegjs 0.10.0 breaks pegjs-loader

The API changed:

The peg.buildParser function was renamed to peg.generate.