# antlr4ts > ANTLR 4 runtime for JavaScript written in Typescript Latest version **0.5.0-alpha.4** (published 2021-01-01) · BSD-3-Clause license · 0 weekly downloads ## Install ```sh npm install antlr4ts pnpm add antlr4ts yarn add antlr4ts bun add antlr4ts ``` ## Health **Score 15/100 (F)** — status: abandoned. Positive: no vulnerabilities. Warnings: low downloads; no types; no esm support; pre 1.0. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 0.5.0-alpha.4 | | Published | 2021-01-01 | | First published | 2016-11-22 | | Weekly downloads | 0 | | License | BSD-3-Clause | | TypeScript types | none | | Module format | CommonJS | | Dependencies | 0 | | Unpacked size | 2.9 MB | | Known vulnerabilities | 0 | | Install scripts | no | | GitHub stars | 676 | | Author | Terence Parr, Sam Harwell, and Burt Harris | | Maintainers | burt_harris, sharwell | | Keywords | ANTLR4, typescript | ## Links - npm: https://www.npmjs.com/package/antlr4ts - Repository: https://github.com/tunnelvisionlabs/antlr4ts - Homepage: https://github.com/tunnelvisionlabs/antlr4ts#readme - Issues: https://github.com/tunnelvisionlabs/antlr4ts/issues - npm.io page: https://npm.io/package/antlr4ts ## Alternatives - [@openai/codex-sdk](https://npm.io/package/@openai/codex-sdk.md) — 731.4K weekly downloads - [babel-plugin-transform-react-jsx](https://npm.io/package/babel-plugin-transform-react-jsx.md) — 565.0K weekly downloads - [babel-helper-remove-or-void](https://npm.io/package/babel-helper-remove-or-void.md) — 508.5K weekly downloads - [@pnpm/store-controller-types](https://npm.io/package/@pnpm/store-controller-types.md) — 186.9K weekly downloads - [react-native-signature-canvas](https://npm.io/package/react-native-signature-canvas.md) — 155.6K weekly downloads ## Recent versions - 0.5.0-alpha.4 (latest) — 2021-01-01 - 0.5.0-dev (burt) — 2020-04-15 - 0.5.0-alpha.8565fd2b (canary) — 2017-12-16 - 0.4.1-alpha.0 (alpha) — 2017-05-22 - 0.4.0-burt.2 (experiment) — 2017-05-22 - 0.5.0-alpha.3 — 2019-03-02 - 0.5.0-alpha.2 — 2019-02-04 - 0.5.0-alpha.1 — 2018-11-30 - 0.1.0-alpha.771c7c6a — 2017-12-16 - 0.5.0-alpha.771c7c6a — 2017-12-16 - 0.0.0-alpha.49892a05 — 2017-06-30 - 0.4.0-burt.1 — 2017-05-22 - 0.4.0-burt — 2017-05-22 - 0.4.0-alpha.4 — 2017-01-08 - 0.4.0-alpha.3 — 2017-01-08 - … 2 more at https://npm.io/package/antlr4ts/versions ## README # antlr4ts - TypeScript/JavaScript target for ANTLR 4 [![Join the chat at https://gitter.im/tunnelvisionlabs/antlr4ts](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/tunnelvisionlabs/antlr4ts?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [![Build status](https://ci.appveyor.com/api/projects/status/d4gpmnrkfo3tb2t1/branch/master?svg=true)](https://ci.appveyor.com/project/sharwell/antlr4ts/branch/master) [![License](https://img.shields.io/badge/License-BSD%203--Clause-blue.svg)](./LICENSE) ## Overview * **Releases:** See the [GitHub Releases](https://github.com/tunnelvisionlabs/antlr4ts/releases) page for release notes and links to the distribution * **Feedback:** Use [GitHub Issues](https://github.com/tunnelvisionlabs/antlr4ts/issues) for issues (bugs, enhancements, features, and questions) ## Requirements This project has separate requirements for developers and end users. > :bulb: The requirements listed on this page only cover user scenarios - that is, scenarios where developers wish to > use ANTLR 4 for parsing tasks inside of a TypeScript application. If you are interested in contributing to ANTLR 4 > itself, see [CONTRIBUTING.md](CONTRIBUTING.md) for contributor documentation. ### End user requirements Parsers generated by the ANTLR 4 TypeScript target have a runtime dependency on the [antlr4ts](https://www.npmjs.com/package/antlr4ts) package. The package is tested and known to work with Node.js 6.7. ### Development requirements The tool used to generate TypeScript code from an ANTLR 4 grammar is written in Java. To fully utilize the ANTLR 4 TypeScript target (including the ability to regenerate code from a grammar file after changes are made), a Java Runtime Environment (JRE) needs to be installed on the developer machine. The generated code itself uses several features new to TypeScript 2.0. * Java Runtime Environment 1.6+ (1.8+ recommended) * TypeScript 2.0+ ## Getting started 1. Install `antlr4ts` as a runtime dependency using your preferred package manager. ```bash npm install antlr4ts --save ``` ```bash yarn add antlr4ts ``` 2. Install `antlr4ts-cli` as a development dependency using your preferred package manager. ```bash npm install antlr4ts-cli --save-dev ``` ```bash yarn add -D antlr4ts-cli ``` 3. Add a grammar to your project, e.g. **path/to/MyGrammar.g4** 4. Add a script to **package.json** for compiling your grammar to TypeScript ``` "scripts": { // ... "antlr4ts": "antlr4ts -visitor path/to/MyGrammar.g4" } ``` 5. Use your grammar in TypeScript ```typescript import { ANTLRInputStream, CommonTokenStream } from 'antlr4ts'; // Create the lexer and parser let inputStream = new ANTLRInputStream("text"); let lexer = new MyGrammarLexer(inputStream); let tokenStream = new CommonTokenStream(lexer); let parser = new MyGrammarParser(tokenStream); // Parse the input, where `compilationUnit` is whatever entry point you defined let tree = parser.compilationUnit(); ``` The two main ways to inspect the tree are by using a listener or a visitor, you can read about the differences between the two [here](https://github.com/antlr/antlr4/blob/master/doc/listeners.md). ###### Listener Approach ```typescript // ... import { MyGrammarParserListener } from './MyGrammarParserListener' import { FunctionDeclarationContext } from './MyGrammarParser' import { ParseTreeWalker } from 'antlr4ts/tree/ParseTreeWalker' class EnterFunctionListener implements MyGrammarParserListener { // Assuming a parser rule with name: `functionDeclaration` enterFunctionDeclaration(context: FunctionDeclarationContext) { console.log(`Function start line number ${context._start.line}`) // ... } // other enterX functions... } // Create the listener const listener: MyGrammarParserListener = new EnterFunctionListener(); // Use the entry point for listeners ParseTreeWalker.DEFAULT.walk(listener, tree) ``` ###### Visitor Approach Note you must pass the `-visitor` flag to antlr4ts to get the generated visitor file. ```typescript // ... import { MyGrammarParserVisitor } from './MyGrammarParserVisitor' import { AbstractParseTreeVisitor } from 'antlr4ts/tree/AbstractParseTreeVisitor' // Extend the AbstractParseTreeVisitor to get default visitor behaviour class CountFunctionsVisitor extends AbstractParseTreeVisitor implements MyGrammarParserVisitor { defaultResult() { return 0 } aggregateResult(aggregate: number, nextResult: number) { return aggregate + nextResult } visitFunctionDeclaration(context: FunctionDeclarationContext): number { return 1 + super.visitChildren(context) } } // Create the visitor const countFunctionsVisitor = new CountFunctionsVisitor() // Use the visitor entry point countFunctionsVisitor.visit(tree) ``` --- _Source: https://npm.io/package/antlr4ts · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._