| const SURROGATE_PAIR_AT_START = /^[\uD800-\uDBFF][\uDC00-\uDFFF]/; |
| const SURROGATE_PAIR_EXACT = /^[\uD800-\uDBFF][\uDC00-\uDFFF]$/; |
|
|
| export interface MentionMatchSpan { |
| text: string; |
| hit: boolean; |
| } |
|
|
| |
| |
| |
| |
| export function mentionMatchSpans( |
| text: string, |
| positions: readonly number[] | undefined, |
| start: number, |
| ): MentionMatchSpan[] { |
| if (positions === undefined || positions.length === 0 || text.length === 0) { |
| return [{ text, hit: false }]; |
| } |
| const hits = new Set<number>(); |
| for (const pos of positions) { |
| const i = pos - start; |
| if (i >= 0 && i < text.length) hits.add(i); |
| } |
| if (hits.size === 0) return [{ text, hit: false }]; |
| for (const i of Array.from(hits)) { |
| if (SURROGATE_PAIR_AT_START.test(text.slice(i, i + 2))) { |
| hits.add(i + 1); |
| } else if (SURROGATE_PAIR_EXACT.test(text.slice(i - 1, i + 1))) { |
| hits.add(i - 1); |
| } |
| } |
| const spans: MentionMatchSpan[] = []; |
| let runStart = 0; |
| let runHit = hits.has(0); |
| for (let i = 1; i < text.length; i++) { |
| const hit = hits.has(i); |
| if (hit !== runHit) { |
| spans.push({ text: text.slice(runStart, i), hit: runHit }); |
| runStart = i; |
| runHit = hit; |
| } |
| } |
| spans.push({ text: text.slice(runStart), hit: runHit }); |
| return spans; |
| } |
|
|
