# @lezer/lr

> Incremental parser

Latest version **1.4.10** (published 2026-04-18) · MIT license · 0 weekly downloads

## Install

```sh
npm install @lezer/lr
pnpm add @lezer/lr
yarn add @lezer/lr
bun add @lezer/lr
```

## Health

**Score 60/100 (C)** — status: active.

Positive: has types; esm support; no vulnerabilities; high quality score.

Warnings: low downloads.

## Facts

| | |
|---|---|
| Version | 1.4.10 |
| Published | 2026-04-18 |
| First published | 2021-08-11 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 1 |
| Unpacked size | 163.1 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Author | Marijn Haverbeke |
| Maintainers | marijn |

## Links

- npm: https://www.npmjs.com/package/@lezer/lr
- Repository: https://code.haverbeke.berlin/lezer/lr
- npm.io page: https://npm.io/package/@lezer/lr

## Dependencies (1)

- [@lezer/common](https://npm.io/package/@lezer/common.md) ^1.0.0

## Recent versions

- 1.4.10 (latest) — 2026-04-18
- 1.4.9 — 2026-04-16
- 1.4.8 — 2026-01-25
- 1.4.7 — 2026-01-06
- 1.4.6 — 2026-01-05
- 1.4.5 — 2025-12-09
- 1.4.4 — 2025-11-28
- 1.4.3 — 2025-11-03
- 1.4.2 — 2024-07-27
- 1.4.1 — 2024-05-30
- 1.4.0 — 2024-01-22
- 1.3.14 — 2023-11-02
- 1.3.13 — 2023-10-03
- 1.3.12 — 2023-09-22
- 1.3.11 — 2023-09-19
- … 32 more at https://npm.io/package/@lezer/lr/versions

## README

# @lezer/lr

[ [**WEBSITE**](http://lezer.codemirror.net) | [**ISSUES**](https://code.haverbeke.berlin/lezer/lezer/issues) | [**FORUM**](https://discuss.codemirror.net/c/lezer) | [**CHANGELOG**](https://code.haverbeke.berlin/lezer/lr/src/branch/main/CHANGELOG.md) ]

Lezer ("reader" in Dutch, pronounced pretty much as laser) is an
incremental GLR parser intended for use in an editor or similar
system, which needs to keep a representation of the program current
during changes and in the face of syntax errors.

It prioritizes speed and compactness (both of parser table files and
of syntax tree) over having a highly usable parse tree—trees nodes are
just blobs with a start, end, tag, and set of child nodes, with no
further labeling of child nodes or extra metadata.

This package contains the run-time LR parser library. It consumes
parsers generated by
[@lezer/generator](https://code.haverbeke.berlin/lezer/generator).

The parser programming interface is documented on [the
website](https://lezer.codemirror.net/docs/ref/#lr).

The code is licensed under an MIT license.

This project was hugely inspired by
[tree-sitter](http://tree-sitter.github.io/tree-sitter/).

---
_Source: https://npm.io/package/@lezer/lr · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._