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151 lines
6.2 KiB
151 lines
6.2 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 tryCatch_1 = require('../util/tryCatch'); |
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var errorObject_1 = require('../util/errorObject'); |
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var OuterSubscriber_1 = require('../OuterSubscriber'); |
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var subscribeToResult_1 = require('../util/subscribeToResult'); |
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/* tslint:enable:max-line-length */ |
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/** |
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* Recursively projects each source value to an Observable which is merged in |
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* the output Observable. |
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* |
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* <span class="informal">It's similar to {@link mergeMap}, but applies the |
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* projection function to every source value as well as every output value. |
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* It's recursive.</span> |
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* |
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* <img src="./img/expand.png" width="100%"> |
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* |
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* Returns an Observable that emits items based on applying a function that you |
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* supply to each item emitted by the source Observable, where that function |
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* returns an Observable, and then merging those resulting Observables and |
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* emitting the results of this merger. *Expand* will re-emit on the output |
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* Observable every source value. Then, each output value is given to the |
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* `project` function which returns an inner Observable to be merged on the |
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* output Observable. Those output values resulting from the projection are also |
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* given to the `project` function to produce new output values. This is how |
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* *expand* behaves recursively. |
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* |
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* @example <caption>Start emitting the powers of two on every click, at most 10 of them</caption> |
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* var clicks = Rx.Observable.fromEvent(document, 'click'); |
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* var powersOfTwo = clicks |
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* .mapTo(1) |
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* .expand(x => Rx.Observable.of(2 * x).delay(1000)) |
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* .take(10); |
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* powersOfTwo.subscribe(x => console.log(x)); |
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* |
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* @see {@link mergeMap} |
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* @see {@link mergeScan} |
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* |
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* @param {function(value: T, index: number) => Observable} project A function |
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* that, when applied to an item emitted by the source or the output Observable, |
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* returns an Observable. |
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* @param {number} [concurrent=Number.POSITIVE_INFINITY] Maximum number of input |
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* Observables being subscribed to concurrently. |
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* @param {Scheduler} [scheduler=null] The IScheduler to use for subscribing to |
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* each projected inner Observable. |
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* @return {Observable} An Observable that emits the source values and also |
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* result of applying the projection function to each value emitted on the |
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* output Observable and and merging the results of the Observables obtained |
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* from this transformation. |
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* @method expand |
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* @owner Observable |
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*/ |
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function expand(project, concurrent, scheduler) { |
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if (concurrent === void 0) { concurrent = Number.POSITIVE_INFINITY; } |
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if (scheduler === void 0) { scheduler = undefined; } |
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concurrent = (concurrent || 0) < 1 ? Number.POSITIVE_INFINITY : concurrent; |
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return function (source) { return source.lift(new ExpandOperator(project, concurrent, scheduler)); }; |
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} |
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exports.expand = expand; |
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var ExpandOperator = (function () { |
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function ExpandOperator(project, concurrent, scheduler) { |
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this.project = project; |
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this.concurrent = concurrent; |
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this.scheduler = scheduler; |
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} |
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ExpandOperator.prototype.call = function (subscriber, source) { |
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return source.subscribe(new ExpandSubscriber(subscriber, this.project, this.concurrent, this.scheduler)); |
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}; |
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return ExpandOperator; |
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}()); |
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exports.ExpandOperator = ExpandOperator; |
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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 ExpandSubscriber = (function (_super) { |
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__extends(ExpandSubscriber, _super); |
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function ExpandSubscriber(destination, project, concurrent, scheduler) { |
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_super.call(this, destination); |
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this.project = project; |
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this.concurrent = concurrent; |
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this.scheduler = scheduler; |
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this.index = 0; |
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this.active = 0; |
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this.hasCompleted = false; |
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if (concurrent < Number.POSITIVE_INFINITY) { |
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this.buffer = []; |
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} |
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} |
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ExpandSubscriber.dispatch = function (arg) { |
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var subscriber = arg.subscriber, result = arg.result, value = arg.value, index = arg.index; |
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subscriber.subscribeToProjection(result, value, index); |
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}; |
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ExpandSubscriber.prototype._next = function (value) { |
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var destination = this.destination; |
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if (destination.closed) { |
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this._complete(); |
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return; |
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} |
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var index = this.index++; |
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if (this.active < this.concurrent) { |
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destination.next(value); |
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var result = tryCatch_1.tryCatch(this.project)(value, index); |
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if (result === errorObject_1.errorObject) { |
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destination.error(errorObject_1.errorObject.e); |
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} |
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else if (!this.scheduler) { |
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this.subscribeToProjection(result, value, index); |
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} |
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else { |
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var state = { subscriber: this, result: result, value: value, index: index }; |
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this.add(this.scheduler.schedule(ExpandSubscriber.dispatch, 0, state)); |
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} |
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} |
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else { |
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this.buffer.push(value); |
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} |
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}; |
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ExpandSubscriber.prototype.subscribeToProjection = function (result, value, index) { |
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this.active++; |
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this.add(subscribeToResult_1.subscribeToResult(this, result, value, index)); |
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}; |
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ExpandSubscriber.prototype._complete = function () { |
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this.hasCompleted = true; |
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if (this.hasCompleted && this.active === 0) { |
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this.destination.complete(); |
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} |
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}; |
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ExpandSubscriber.prototype.notifyNext = function (outerValue, innerValue, outerIndex, innerIndex, innerSub) { |
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this._next(innerValue); |
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}; |
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ExpandSubscriber.prototype.notifyComplete = function (innerSub) { |
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var buffer = this.buffer; |
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this.remove(innerSub); |
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this.active--; |
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if (buffer && buffer.length > 0) { |
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this._next(buffer.shift()); |
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} |
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if (this.hasCompleted && this.active === 0) { |
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this.destination.complete(); |
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} |
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}; |
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return ExpandSubscriber; |
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}(OuterSubscriber_1.OuterSubscriber)); |
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exports.ExpandSubscriber = ExpandSubscriber; |
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//# sourceMappingURL=expand.js.map
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