Aho–Corasick multi‑pattern string matcher for Node and the browser. Typed, isomorphic, and overlap‑aware.

import { build } from 'tiny-aho-corasick';

const ac = build(['he', 'she', 'his', 'hers']);
const hits = ac.search('ushers');

console.log(hits);
/*
[
  { start: 1, end: 4, index: 1, pattern: 'she',  payload: 1 },
  { start: 2, end: 4, index: 0, pattern: 'he',   payload: 0 },
  { start: 2, end: 6, index: 3, pattern: 'hers', payload: 3 },
]
*/

// grab the matched substrings
console.log(hits.map(m => 'ushers'.slice(m.start, m.end))); // [ 'she', 'he', 'hers' ]

With payloads and ignoreCase:

import { build } from 'tiny-aho-corasick';

type Info = { kind: 'animal' | 'vehicle' };

const ac = build<Info>(
  [
    ['Cat', { kind: 'animal' }],
    ['car', { kind: 'vehicle' }],
  ],
  { ignoreCase: true }
);

for (const m of ac.matchAll('A CAT in a car')) {
  console.log(m.pattern, m.payload.kind, m.start, m.end);
}
// Cat animal 2 5
// car vehicle 11 14

build(patterns, options?): Matcher<number>

• patterns: readonly string[]
• Returns a matcher where payload is the pattern index (0‑based).

build<T>(patterns, options?): Matcher<T>

• patterns: readonly [string, T][]
• Returns a matcher where payload is your T.

AhoOptions

• ignoreCase?: boolean
  • If true, patterns and text are lower‑cased internally before building/searching.

Matcher

• matchAll(text: string): IterableIterator<Match<T>>
  • Lazily yields all matches, including overlaps.
• search(text: string): Match<T>[]
  • Collects all matches into an array.
• test(text: string): boolean
  • Returns true if there is at least one match.

Match

• start: number
• end: number
• index: number
  • Index of the pattern in the input list.
• pattern: string
  • Original (non‑normalized) pattern string you provided.
• payload: T

MIT