| 1 | import { AsyncIterableX } from './asynciterablex';
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| 2 | export class SliceAsyncIterable extends AsyncIterableX {
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| 3 | constructor(source, begin, end) {
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| 4 | super();
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| 5 | this._source = source;
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| 6 | this._begin = begin;
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| 7 | this._end = end;
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| 8 | }
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| 9 | async *[Symbol.asyncIterator]() {
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| 10 | let it = this._source[Symbol.asyncIterator](), begin = this._begin, next;
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| 11 | while (begin > 0 && !(next = await it.next()).done) {
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| 12 | begin--;
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| 13 | }
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| 14 | let end = this._end;
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| 15 | if (end > 0) {
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| 16 | while (!(next = await it.next()).done) {
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| 17 | yield next.value;
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| 18 | if (--end === 0) {
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| 19 | break;
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| 20 | }
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| 21 | }
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| 22 | }
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| 23 | }
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| 24 | }
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| 25 | export function slice(source, begin, end = Infinity) {
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| 26 | return new SliceAsyncIterable(source, begin, end);
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| 27 | }
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| 28 |
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| 29 |
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