Expand description

This module provides a data structure for a space-efficient and time-efficient lookup of sequences of 16-bit units (commonly but not necessarily UTF-16 code units) which map to integer values.

It is an implementation of the existing ICU4C UCharsTrie / ICU4J CharsTrie API.


ICU4X Char16Trie is designed to provide a read-only view of UCharsTrie data that is exported from ICU4C.


Querying a Char16Trie

use icu_collections::char16trie::{Char16Trie, TrieResult};
use zerovec::ZeroVec;

// A Char16Trie containing the ASCII characters mapping 'a' to 1 and 'ab'
// to 100.
let trie_data = vec![48, 97, 176, 98, 32868];
let trie =

let mut iter = trie.iter();
let res = iter.next('a');
assert_eq!(res, TrieResult::Intermediate(1));
let res = iter.next('b');
assert_eq!(res, TrieResult::FinalValue(100));
let res = iter.next('c');
assert_eq!(res, TrieResult::NoMatch);


This struct represents a de-serialized Char16Trie that was exported from ICU binary data.

This struct represents an iterator over a Char16Trie.


An enum representing the return value from a lookup in Char16Trie.