Replacement helpers

Reuse literal replacement policies in whole-text queries and stream operations (v3.2.0+).

Mask, map or replace once

import AhoCorasick from 'modern-ahocorasick'
import { fromMap, mask, once } from 'modern-ahocorasick/replace'

const matcher = new AhoCorasick(['cat', 'dog'])
matcher.replace('cat dog', mask()) // '*** ***'
matcher.replace('cat dog', fromMap({ cat: '猫' })) // '猫 dog'
const first = once('X')
matcher.replace('cat cat', first) // 'X cat'
matcher.replace('cat cat', first) // 'X cat'

Helper contracts

/replace supplies keep(), remove(), mask(character = '*'), fromMap(mapOrRecord) and once(replacement). Masks repeat once per original grapheme. Maps are snapshotted, keyed by the original dictionary pattern, and keep unmapped matches unchanged. once() has independent state for each library replacement operation, even when the same helper is reused by simultaneous streams. Replacement strings remain literal.

Selection and safety

Helpers receive only selected matches. They do not evaluate replacement strings or generate HTML. Use keep() to retain the original substring and remove() to replace it with an empty string.

See Replacement and tokenization.