# zaach/jison

Bison in JavaScript.

Repository: https://github.com/zaach/jison
Canonical: https://ross.abutalabs.com/products/jison
Homepage: http://jison.org
Language: JavaScript
License Family: other
Last push: 2022-10-14T08:26:50+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 6119, "days_push": 1419, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4382, forks 451 (observed 2026-08-28T04:08:46.978998+00:00)

## What it is
Jison is a parser generator for JavaScript with an API similar to Bison, taking JSON or Bison-style grammar definitions and generating bottom-up (LR/LALR) parsers. It can be used from the command line or programmatically in Node.js to produce standalone parser scripts.

## Use cases
- generate a parser for a custom DSL in JavaScript
- build a calculator or expression evaluator from a grammar
- convert a Bison grammar into a JavaScript parser
- write a lexer and tokenizer for a custom language
- parse structured input files in a Node.js application

## When to choose
- you know Bison/Yacc and want a similar workflow in JavaScript
- you need to generate a standalone parser file from a grammar
- you're building a DSL, config format, or expression language in Node.js

## When to avoid
- you need a modern, actively maintained parser generator with recent JavaScript ecosystem support
- you want PEG-style or parser-combinator parsing rather than LR grammars
- you need parsers for languages outside JavaScript runtimes

## Facets
- artifact type: library
- maturity: maintenance
- function: parser, compiler, developer-tools
- domain: parsers, programming-languages, developer-tools, compilers
- platform: cli, cross-platform
- tags: parser-generator, bison, yacc, lexer, grammar, lalr, tokenizer, nodejs, javascript

## Member repositories
- zaach/jison (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:46.978998+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:21:17.538144+00:00, confidence not recorded.
  - readme: https://github.com/zaach/jison (fetched 2026-08-28T04:08:46.978998+00:00, sha 268950998293)
  - registry_npm: https://registry.npmjs.org/jison (fetched 2026-08-29T09:09:43.423019+00:00, sha ed0090183a59)
- Data as of 2026-08-30T08:39:29.467469+00:00.