[!NOTE] This is one of 214 standalone projects, maintained as part of the @thi.ng/umbrella monorepo and anti-framework.

🚀 Please help me to work full-time on these projects by sponsoring me on GitHub. Thank you! ❤️

• About
  • TrieMap
  • MultiTrie
• Status
• Related packages
• Installation
• Dependencies
• API
• Authors
• License

About

Trie-based ES6-like Map data structures with prefix search/query support.

This package contains functionality which was previously part of and has been extracted from the @thi.ng/associative package.

TrieMap

Tries (also called Prefix maps) are useful data structures for search based use cases, auto-complete, text indexing etc. and provide partial key matching (prefixes), suffix iteration for a common prefix, longest matching prefix queries etc.

The implementations here too feature ES6 Map-like API, similar to other types in this package, with some further trie-specific additions.

import { defTrieMap } from "@thi.ng/trie";

// construct trie from given key-value pairs (optional)
const trie = defTrieMap([
  ["hey", "en"],
  ["hello", "en"],
  ["hallo", "de"],
  ["hallo", "de-at"],
  ["hola", "es"],
  ["hold", "en"],
  ["hej", "se"],
]);

// find longest known prefix given key
console.log(trie.knownPrefix("hole"));
// "hol"

// all known keys
console.log([...trie.keys()])
// [ "hold", "hola", "hallo", "hej", "hello", "hey" ]

// all keys starting with given prefix
console.log([...trie.keys("he")])
// [ "hej", "hello", "hey" ]

// suffixes of given key only
console.log([...trie.keys("he", false)])
// [ "j", "llo", "y" ]

// values of keys starting with prefix
console.log([...trie.values("hol")]);
// [ "en", "es" ]

MultiTrie

The MultiTrie is similar to TrieMap, but uses array-like keys and supports multiple values per key. Values are stored in sets whose implementation can be configured via ctor options (e.g. using custom ES6-like Sets with value-based equality semantics from the thi.ng/associative package).

import { defMultiTrie } from "@thi.ng/trie";
import { ArraySet } from "@thi.ng/associative";

// init w/ custom value set type (here purely for illustration)
const t = defMultiTrie<string, string>(null, { values: () => new ArraySet() });

t.add("to be or not to be".split(" "), 1);
t.add("to be or not to be".split(" "), 2);
t.add("to be and to live".split(" "), 3);

console.log(t.get("to be or not to be".split(" ")))
// Set(2) { 1, 2 }

console.log(t.knownPrefix(["to", "be", "not"]));
// [ "to", "be" ]

// suffixes for given prefix
console.log([...t.keys(["to", "be"], false)]);
// [["and", "to", "live"], ["or", "not", "to", "be"]]

Status

STABLE - used in production

Search or submit any issues for this package

Related packages

• @thi.ng/associative - ES Map/Set-compatible implementations with customizable equality semantics & supporting operations

Installation

yarn add @thi.ng/trie

ESM import:

import * as trie from "@thi.ng/trie";

Browser ESM import:

<script type="module" src="https://esm.run/@thi.ng/trie"></script>

JSDelivr documentation

For Node.js REPL:

const trie = await import("@thi.ng/trie");

Package sizes (brotli'd, pre-treeshake): ESM: 1.14 KB

Dependencies

• @thi.ng/api

Note: @thi.ng/api is in most cases a type-only import (not used at runtime)

API

Generated API docs

Authors

• Karsten Schmidt

If this project contributes to an academic publication, please cite it as:

@misc{thing-trie,
  title = "@thi.ng/trie",
  author = "Karsten Schmidt",
  note = "https://thi.ng/trie",
  year = 2020
}

License

© 2020 - 2026 Karsten Schmidt // Apache License 2.0