123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293 |
- "use strict";
- var __extends = (this && this.__extends) || function (d, b) {
- for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
- function __() { this.constructor = d; }
- d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
- };
- var Subscriber_1 = require('../Subscriber');
- var ArgumentOutOfRangeError_1 = require('../util/ArgumentOutOfRangeError');
- /**
- * Skip the last `count` values emitted by the source Observable.
- *
- * <img src="./img/skipLast.png" width="100%">
- *
- * `skipLast` returns an Observable that accumulates a queue with a length
- * enough to store the first `count` values. As more values are received,
- * values are taken from the front of the queue and produced on the result
- * sequence. This causes values to be delayed.
- *
- * @example <caption>Skip the last 2 values of an Observable with many values</caption>
- * var many = Rx.Observable.range(1, 5);
- * var skipLastTwo = many.skipLast(2);
- * skipLastTwo.subscribe(x => console.log(x));
- *
- * // Results in:
- * // 1 2 3
- *
- * @see {@link skip}
- * @see {@link skipUntil}
- * @see {@link skipWhile}
- * @see {@link take}
- *
- * @throws {ArgumentOutOfRangeError} When using `skipLast(i)`, it throws
- * ArgumentOutOrRangeError if `i < 0`.
- *
- * @param {number} count Number of elements to skip from the end of the source Observable.
- * @returns {Observable<T>} An Observable that skips the last count values
- * emitted by the source Observable.
- * @method skipLast
- * @owner Observable
- */
- function skipLast(count) {
- return function (source) { return source.lift(new SkipLastOperator(count)); };
- }
- exports.skipLast = skipLast;
- var SkipLastOperator = (function () {
- function SkipLastOperator(_skipCount) {
- this._skipCount = _skipCount;
- if (this._skipCount < 0) {
- throw new ArgumentOutOfRangeError_1.ArgumentOutOfRangeError;
- }
- }
- SkipLastOperator.prototype.call = function (subscriber, source) {
- if (this._skipCount === 0) {
- // If we don't want to skip any values then just subscribe
- // to Subscriber without any further logic.
- return source.subscribe(new Subscriber_1.Subscriber(subscriber));
- }
- else {
- return source.subscribe(new SkipLastSubscriber(subscriber, this._skipCount));
- }
- };
- return SkipLastOperator;
- }());
- /**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
- var SkipLastSubscriber = (function (_super) {
- __extends(SkipLastSubscriber, _super);
- function SkipLastSubscriber(destination, _skipCount) {
- _super.call(this, destination);
- this._skipCount = _skipCount;
- this._count = 0;
- this._ring = new Array(_skipCount);
- }
- SkipLastSubscriber.prototype._next = function (value) {
- var skipCount = this._skipCount;
- var count = this._count++;
- if (count < skipCount) {
- this._ring[count] = value;
- }
- else {
- var currentIndex = count % skipCount;
- var ring = this._ring;
- var oldValue = ring[currentIndex];
- ring[currentIndex] = value;
- this.destination.next(oldValue);
- }
- };
- return SkipLastSubscriber;
- }(Subscriber_1.Subscriber));
- //# sourceMappingURL=skipLast.js.map
|