antlr4-tool

antlr4-tool

Overview

The purpose and intent of this project was to create and generate Typescript declaration files for the Antlr4 JavaScript target. Allowing for generated Antlr Parsers and Lexers that have full ES5 browser support. This tool also allows for pure JavaScript implementations, if needed.

Requirements

• Java Runtime Environment 1.6+ (1.8+ recommended)

Getting Stated

• Install antlr4-tool, adding it to your package.json

npm install --save-dev antlr4-tool

• Install the Antlr4 library

npm install -S antlr4

#
# (TypeScript Only)
#
npm install -S @types/antlr4

• Add a grammar to your project, e.g. path/to/Grammar.g4

"scripts": {
  "generate-parser": "antlr4-tool -o parser path/to/Grammar.g4"
}

• Run the NPM script command

npm run generate-parser

• Use your generated Parser

JavaScript

const antlr4 = require('antlr4')
const InputStream = antlr4.InputStream;
const CommonTokenStream = antlr4.CommonTokenStream;

const GrammarParser = require('./parser/GrammarParser').GrammarParser;
const GrammarLexer = require('./parser/GrammarLexer').GrammarLexer;

const inputStream = new InputStream('int x = 10;');
const lexer = new GrammarLexer(inputStream);
const tokenStream = new CommonTokenStream(lexer);
const parser = new GrammarParser(tokenStream);

// Parse the input, where `compilationUnit` is whatever entry point you defined
const tree = parser.compilationUnit();
console.log(tree);

TypeScript

import {InputStream, CommonTokenStream} from 'antlr4';
import {GrammarParser} from './parser/GrammarParser';
import {GrammarLexer} from './parser/GrammarLexer';

const inputStream = new InputStream('enter you grammar here');
const lexer = new GrammarLexer(inputStream);
const tokenStream = new CommonTokenStream(lexer);
const parser = new GrammarParser(tokenStream);

// Parse the input, where `compilationUnit` is whatever entry point you defined
const tree = parser.compilationUnit();
console.log(tree);

TypeScript Notes

Add to your tsconfig.json:

"typeRoots": ["types"],

For Command-Line Use

Installation For Command-Line Use

npm install -g antlr4-tool

Usage: antlr4-tool [options] <grammars...>

Options:

  -V, --version                 output the version number
  -o --output-dir [output_dir]  Output Directory (Default: Current Directory)
  -l --language [language]      Antlr Language Target: ts, typescript, js, javascript (Default: typescript)
  --listener                    Generate parse tree listener (Default)
  --no-listener                 Don't generate parse tree listener
  --visitor                     Generate parse tree visitor (Default)
  --no-visitor                  Don't generate parse tree visitor
  -h, --help                    output usage information

Finding the Version

antlr4-tool -V

Example Creating a C Parser for TypeScript

antlr4-tool -l ts -o c-parser samples/c/C.g4

Example Creating a C Parser for JavaScript

antlr4-tool -l js -o c-parser samples/c/C.g4

Using antlr4-tool as a Library

const tool = require('antlr4-tool');

const opts = {
   language: 'TypeScript', // Only support for JavaScript & TypeScript
   grammarFiles:  ['samples/c/C.g4'],
   outputDirectory: 'c-parser'
};

const compiledResults = tool.compile(opts);

console.log(compiledResults);