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93 lines
3.2 KiB
93 lines
3.2 KiB
"use strict"; |
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var __extends = (this && this.__extends) || function (d, b) { |
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for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; |
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function __() { this.constructor = d; } |
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d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __()); |
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}; |
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var Subscriber_1 = require('../Subscriber'); |
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var ArgumentOutOfRangeError_1 = require('../util/ArgumentOutOfRangeError'); |
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/** |
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* Skip the last `count` values emitted by the source Observable. |
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* |
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* <img src="./img/skipLast.png" width="100%"> |
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* |
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* `skipLast` returns an Observable that accumulates a queue with a length |
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* enough to store the first `count` values. As more values are received, |
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* values are taken from the front of the queue and produced on the result |
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* sequence. This causes values to be delayed. |
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* |
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* @example <caption>Skip the last 2 values of an Observable with many values</caption> |
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* var many = Rx.Observable.range(1, 5); |
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* var skipLastTwo = many.skipLast(2); |
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* skipLastTwo.subscribe(x => console.log(x)); |
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* |
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* // Results in: |
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* // 1 2 3 |
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* |
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* @see {@link skip} |
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* @see {@link skipUntil} |
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* @see {@link skipWhile} |
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* @see {@link take} |
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* |
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* @throws {ArgumentOutOfRangeError} When using `skipLast(i)`, it throws |
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* ArgumentOutOrRangeError if `i < 0`. |
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* |
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* @param {number} count Number of elements to skip from the end of the source Observable. |
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* @returns {Observable<T>} An Observable that skips the last count values |
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* emitted by the source Observable. |
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* @method skipLast |
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* @owner Observable |
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*/ |
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function skipLast(count) { |
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return function (source) { return source.lift(new SkipLastOperator(count)); }; |
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} |
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exports.skipLast = skipLast; |
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var SkipLastOperator = (function () { |
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function SkipLastOperator(_skipCount) { |
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this._skipCount = _skipCount; |
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if (this._skipCount < 0) { |
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throw new ArgumentOutOfRangeError_1.ArgumentOutOfRangeError; |
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} |
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} |
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SkipLastOperator.prototype.call = function (subscriber, source) { |
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if (this._skipCount === 0) { |
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// If we don't want to skip any values then just subscribe |
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// to Subscriber without any further logic. |
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return source.subscribe(new Subscriber_1.Subscriber(subscriber)); |
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} |
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else { |
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return source.subscribe(new SkipLastSubscriber(subscriber, this._skipCount)); |
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} |
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}; |
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return SkipLastOperator; |
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}()); |
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/** |
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* We need this JSDoc comment for affecting ESDoc. |
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* @ignore |
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* @extends {Ignored} |
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*/ |
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var SkipLastSubscriber = (function (_super) { |
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__extends(SkipLastSubscriber, _super); |
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function SkipLastSubscriber(destination, _skipCount) { |
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_super.call(this, destination); |
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this._skipCount = _skipCount; |
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this._count = 0; |
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this._ring = new Array(_skipCount); |
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} |
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SkipLastSubscriber.prototype._next = function (value) { |
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var skipCount = this._skipCount; |
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var count = this._count++; |
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if (count < skipCount) { |
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this._ring[count] = value; |
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} |
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else { |
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var currentIndex = count % skipCount; |
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var ring = this._ring; |
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var oldValue = ring[currentIndex]; |
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ring[currentIndex] = value; |
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this.destination.next(oldValue); |
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} |
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}; |
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return SkipLastSubscriber; |
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}(Subscriber_1.Subscriber)); |
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//# sourceMappingURL=skipLast.js.map
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