porter2 v1.0.2
porter2 
Fast JavaScript implementation of the porter2 English stemming algorithm.
$ npm install porter2Usage
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) //=> animadversThis 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.
^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