signal-desktop/ts/util/grapheme.ts
2023-01-03 11:55:46 -08:00

41 lines
1 KiB
TypeScript

// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import { map, size, take, join } from './iterables';
export function getGraphemes(str: string): Iterable<string> {
const segments = new Intl.Segmenter().segment(str);
return map(segments, s => s.segment);
}
export function count(str: string): number {
const segments = new Intl.Segmenter().segment(str);
return size(segments);
}
/** @return truncated string and size (after any truncation) */
export function truncateAndSize(
str: string,
toSize?: number
): [string, number] {
const segments = new Intl.Segmenter().segment(str);
const originalSize = size(segments);
if (toSize === undefined || originalSize <= toSize) {
return [str, originalSize];
}
return [
join(
map(take(segments, toSize), s => s.segment),
''
),
toSize,
];
}
export function isSingleGrapheme(str: string): boolean {
if (str === '') {
return false;
}
const segments = new Intl.Segmenter().segment(str);
return segments.containing(0).segment === str;
}