46 lines
1.5 KiB
JavaScript
46 lines
1.5 KiB
JavaScript
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"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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/**
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* Returns a new observable that triggers on the second and following inputs.
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* An input that triggers an event will return an pair of [(N - 1)th, Nth].
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* The (N-1)th is stored in the internal state until Nth input occurs.
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*
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* <img src="./img/pairwise.png" width="100%">
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*
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* @returns {Observable<R>} an observable of pairs of values.
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*/
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function pairwise() {
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return this.lift(new PairwiseOperator());
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}
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exports.pairwise = pairwise;
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var PairwiseOperator = (function () {
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function PairwiseOperator() {
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}
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PairwiseOperator.prototype.call = function (subscriber) {
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return new PairwiseSubscriber(subscriber);
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};
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return PairwiseOperator;
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}());
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var PairwiseSubscriber = (function (_super) {
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__extends(PairwiseSubscriber, _super);
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function PairwiseSubscriber(destination) {
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_super.call(this, destination);
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this.hasPrev = false;
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}
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PairwiseSubscriber.prototype._next = function (value) {
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if (this.hasPrev) {
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this.destination.next([this.prev, value]);
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}
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else {
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this.hasPrev = true;
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}
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this.prev = value;
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};
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return PairwiseSubscriber;
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}(Subscriber_1.Subscriber));
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//# sourceMappingURL=pairwise.js.map
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