1 | import { MonoTypeOperatorFunction } from '../types';
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2 | /**
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3 | * Emits only the last `count` values emitted by the source Observable.
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4 | *
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5 | * <span class="informal">Remembers the latest `count` values, then emits those
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6 | * only when the source completes.</span>
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7 | *
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8 | * ![](takeLast.png)
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9 | *
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10 | * `takeLast` returns an Observable that emits at most the last `count` values
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11 | * emitted by the source Observable. If the source emits fewer than `count`
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12 | * values then all of its values are emitted. This operator must wait until the
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13 | * `complete` notification emission from the source in order to emit the `next`
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14 | * values on the output Observable, because otherwise it is impossible to know
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15 | * whether or not more values will be emitted on the source. For this reason,
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16 | * all values are emitted synchronously, followed by the complete notification.
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17 | *
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18 | * ## Example
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19 | * Take the last 3 values of an Observable with many values
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20 | * ```ts
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21 | * import { range } from 'rxjs';
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22 | * import { takeLast } from 'rxjs/operators';
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23 | *
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24 | * const many = range(1, 100);
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25 | * const lastThree = many.pipe(takeLast(3));
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26 | * lastThree.subscribe(x => console.log(x));
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27 | * ```
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28 | *
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29 | * @see {@link take}
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30 | * @see {@link takeUntil}
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31 | * @see {@link takeWhile}
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32 | * @see {@link skip}
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33 | *
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34 | * @throws {ArgumentOutOfRangeError} When using `takeLast(i)`, it delivers an
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35 | * ArgumentOutOrRangeError to the Observer's `error` callback if `i < 0`.
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36 | *
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37 | * @param {number} count The maximum number of values to emit from the end of
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38 | * the sequence of values emitted by the source Observable.
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39 | * @return {Observable<T>} An Observable that emits at most the last count
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40 | * values emitted by the source Observable.
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41 | * @method takeLast
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42 | * @owner Observable
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43 | */
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44 | export declare function takeLast<T>(count: number): MonoTypeOperatorFunction<T>;
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