Dynamic dictionaries

Batch dictionary edits and compile an immutable snapshot for queries (v3.2.0+).

Edit and compile

import DynamicDictionary from 'modern-ahocorasick/dynamic'

const dictionary = new DynamicDictionary(['cat'])
const old = dictionary.compile()
const dogID = dictionary.add('dog')
const current = dictionary.compile()
old.matcher.match('dog') // false
current.matcher.match('dog') // true
dictionary.delete(dogID)

Stable IDs and snapshots

add returns a stable non-negative ID; duplicate strings get separate IDs. delete(id) returns whether the ID existed. clear() never reuses IDs. compile() returns the same cached { matcher, ids } snapshot until an effective edit. The frozen ids array maps each snapshot's dense patternIndex to the stable ID. Metadata references remain caller-owned. Existing iterators and streams keep their original snapshot.

Async compilation and persistence

compileAsync({ signal? }) yields once before compiling, so a cancelled request does not start a synchronous build. Edits made while a build is pending do not enter that snapshot. serialize() preserves active entries and stable IDs; DynamicDictionary.deserialize() restores the next ID frontier and accepts the same metadata codec options as the core matcher.

Choose a compiler

Pass a third constructor argument (patterns, options) => new UnicodeAhoCorasick(patterns, options) to choose another built-in matcher. Compilation rebuilds an immutable snapshot and does not promise constant-time online index updates. The async method still runs the compiler on the calling thread, so use a Worker for very large builds.