porter2  

Fast JavaScript implementation of the porter2 English stemming algorithm.

$ npm install porter2

Usage

The package is simple: it has no dependencies and exports a single function named stem.

Import using CommonJS:

const { stem } = require('porter2')

Or, import using EcmaScript Modules (through interopability with CommonJS):

import { stem } from 'porter2'

Use the stemmer:

const word = stem('animadversion')
console.log(word) //=> animadvers

This stemmer expects lowercase text.

The code is compatible with ES5. TypeScript type declarations are included.

Benchmarks

On my machine, the 29.4k test suite executes in ~9.5ms (~3M/s throughput) in a hot loop (~70ms for the first run).

Here is a comparison with some other libraries (you probably should take it with a little grain of salt):

library	throughput (node)	throughput (bun)
porter2.js	3118 kops/s	3283 kops/s
stemr	342 kops/s	367 kops/s
wink-porter2-stemmer 1	162 kops/s	174 kops/s

Here are libraries that implement older porter 1 (note the behavior is not identical):

library	throughput (node)	throughput (bun)
porter-stemmer-js 2	1422 kops/s	1484 kops/s
stemmer 3	1064 kops/s	623 kops/s
@stdlib/nlp-porter-stemmer	842 kops/s	685 kops/s
porter-stemmer	497 kops/s	520 kops/s

The benchmark code is in bench/run.mjs.

This is tested with Node.js v20.12.2 and bun v1.1.4. The library versions are latest as of 2024-04-29.

Footnotes

1. wink-porter2-stemmer is 99.97% porter2 compliant (fails on ' cases only) ↩

2. That one has similar goals and, surprisingly, was published just 3 days before this package was released! (And after I started working on porter2.js.) ↩

3. ESM only ↩