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89 lines
3.3 KiB
89 lines
3.3 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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/** |
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* Applies a given `project` function to each value emitted by the source |
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* Observable, and emits the resulting values as an Observable. |
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* |
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* <span class="informal">Like [Array.prototype.map()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map), |
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* it passes each source value through a transformation function to get |
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* corresponding output values.</span> |
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* |
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* <img src="./img/map.png" width="100%"> |
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* |
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* Similar to the well known `Array.prototype.map` function, this operator |
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* applies a projection to each value and emits that projection in the output |
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* Observable. |
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* |
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* @example <caption>Map every click to the clientX position of that click</caption> |
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* var clicks = Rx.Observable.fromEvent(document, 'click'); |
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* var positions = clicks.map(ev => ev.clientX); |
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* positions.subscribe(x => console.log(x)); |
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* |
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* @see {@link mapTo} |
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* @see {@link pluck} |
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* |
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* @param {function(value: T, index: number): R} project The function to apply |
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* to each `value` emitted by the source Observable. The `index` parameter is |
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* the number `i` for the i-th emission that has happened since the |
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* subscription, starting from the number `0`. |
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* @param {any} [thisArg] An optional argument to define what `this` is in the |
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* `project` function. |
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* @return {Observable<R>} An Observable that emits the values from the source |
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* Observable transformed by the given `project` function. |
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* @method map |
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* @owner Observable |
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*/ |
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function map(project, thisArg) { |
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return function mapOperation(source) { |
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if (typeof project !== 'function') { |
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throw new TypeError('argument is not a function. Are you looking for `mapTo()`?'); |
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} |
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return source.lift(new MapOperator(project, thisArg)); |
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}; |
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} |
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exports.map = map; |
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var MapOperator = (function () { |
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function MapOperator(project, thisArg) { |
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this.project = project; |
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this.thisArg = thisArg; |
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} |
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MapOperator.prototype.call = function (subscriber, source) { |
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return source.subscribe(new MapSubscriber(subscriber, this.project, this.thisArg)); |
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}; |
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return MapOperator; |
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}()); |
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exports.MapOperator = MapOperator; |
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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 MapSubscriber = (function (_super) { |
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__extends(MapSubscriber, _super); |
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function MapSubscriber(destination, project, thisArg) { |
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_super.call(this, destination); |
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this.project = project; |
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this.count = 0; |
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this.thisArg = thisArg || this; |
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} |
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// NOTE: This looks unoptimized, but it's actually purposefully NOT |
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// using try/catch optimizations. |
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MapSubscriber.prototype._next = function (value) { |
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var result; |
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try { |
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result = this.project.call(this.thisArg, value, this.count++); |
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} |
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catch (err) { |
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this.destination.error(err); |
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return; |
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} |
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this.destination.next(result); |
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}; |
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return MapSubscriber; |
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}(Subscriber_1.Subscriber)); |
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//# sourceMappingURL=map.js.map
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