lezer-webpack-loader

Webpack loader for Lezer grammar files.

Getting Started

To begin, you'll need to install lezer-webpack-loader:

npm install --save-dev lezer-webpack-loader

Then add the plugin to your webpack config. For example:

file.js

import { parser } from "example.grammar";

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.grammar$/i,
        use: "lezer-webpack-loader",
      },
    ],
  },
};

And run webpack via your preferred method.

This way you can import the parser and the tokens directly from the grammar file.

Options

• warn
• includeNames
• moduleStyle
• typeScript
• exportName
• externalTokenizer
• externalPropSource
• externalSpecializer
• externalProp
• contextTracker

warn

Type:

type warn = (message: string) => void;

Default: console.warn

A function that should be called with warnings.

includeNames

Type:

type includeNames = boolean;

Default: false

Whether to include term names in the output file.

moduleStyle

Type:

type moduleStyle = string;

Default: "es"

Determines the module system used by the output file. Can be either "cjs" (CommonJS) or "es" (ES2015 module).

typeScript

Type:

type typeScript = boolean;

Default: false

Set this to true to output TypeScript code instead of plain JavaScript.

exportName

Type:

type exportName = string;

Default: "parser"

The name of the export that holds the parser in the output file.

externalTokenizer

Type:

import { ExternalTokenizer } from "@lezer/lr";

type externalTokenizer = (
  name: string,
  terms: Object<number>
) => ExternalTokenizer;

Default: undefined

When calling buildParser, this can be used to provide placeholders for external tokenizers.

externalPropSource

Type:

import { NodePropSource } from "@lezer/common";

type externalPropSource = (name: string) => NodePropSource;

Default: undefined

Used by buildParser to resolve external prop sources.

externalSpecializer

Type:

import { Stack } from "@lezer/lr";

type externalPropSource = (
  name: string,
  terms: Object<number>
) => (value: string, stack: Stack) => number;

Default: undefined

Provide placeholders for external specializers when using buildParser.

externalProp

Type:

import { NodeProp } from "@lezer/common";

type externalProp = (name: string) => NodeProp<any>;

Default: undefined

If given, will be used to initialize external props in the parser returned by buildParser.

contextTracker

Type:

import { ContextTracker } from "@lezer/lr";

type contextTracker = ContextTracker<any> | ((terms: Object<number>) => ContextTracker<any>);

Default: undefined

If given, will be used as context tracker in a parser built with buildParser.

License

This project is licensed under the GPLv3 License - see the LICENSE file for details.