46 lines
1.3 KiB
TypeScript
46 lines
1.3 KiB
TypeScript
/**
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* Ring buffer for Emacs-style kill/yank operations.
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*
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* Tracks killed (deleted) text entries. Consecutive kills can accumulate
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* into a single entry. Supports yank (paste most recent) and yank-pop
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* (cycle through older entries).
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*/
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export class KillRing {
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private ring: string[] = [];
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/**
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* Add text to the kill ring.
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*
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* @param text - The killed text to add
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* @param opts - Push options
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* @param opts.prepend - If accumulating, prepend (backward deletion) or append (forward deletion)
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* @param opts.accumulate - Merge with the most recent entry instead of creating a new one
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*/
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push(text: string, opts: { prepend: boolean; accumulate?: boolean }): void {
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if (!text) return;
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if (opts.accumulate && this.ring.length > 0) {
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const last = this.ring.pop()!;
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this.ring.push(opts.prepend ? text + last : last + text);
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} else {
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this.ring.push(text);
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}
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}
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/** Get most recent entry without modifying the ring. */
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peek(): string | undefined {
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return this.ring.length > 0 ? this.ring[this.ring.length - 1] : undefined;
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}
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/** Move last entry to front (for yank-pop cycling). */
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rotate(): void {
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if (this.ring.length > 1) {
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const last = this.ring.pop()!;
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this.ring.unshift(last);
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}
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}
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get length(): number {
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return this.ring.length;
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}
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}
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