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define(function(require,exports,module){
/** PURE_IMPORTS_START tslib,_OuterSubscriber,_util_subscribeToResult,_map,_observable_from PURE_IMPORTS_END */
import * as tslib_1 from "tslib";
import { OuterSubscriber } from '../OuterSubscriber';
import { subscribeToResult } from '../util/subscribeToResult';
import { map } from './map';
import { from } from '../observable/from';
/* tslint:enable:max-line-length */
/**
* Projects each source value to an Observable which is merged in the output
* Observable, emitting values only from the most recently projected Observable.
*
* <span class="informal">Maps each value to an Observable, then flattens all of
* these inner Observables using {@link switch}.</span>
*
* <img src="./img/switchMap.png" width="100%">
*
* Returns an Observable that emits items based on applying a function that you
* supply to each item emitted by the source Observable, where that function
* returns an (so-called "inner") Observable. Each time it observes one of these
* inner Observables, the output Observable begins emitting the items emitted by
* that inner Observable. When a new inner Observable is emitted, `switchMap`
* stops emitting items from the earlier-emitted inner Observable and begins
* emitting items from the new one. It continues to behave like this for
* subsequent inner Observables.
*
* @example <caption>Rerun an interval Observable on every click event</caption>
* var clicks = Rx.Observable.fromEvent(document, 'click');
* var result = clicks.switchMap((ev) => Rx.Observable.interval(1000));
* result.subscribe(x => console.log(x));
*
* @see {@link concatMap}
* @see {@link exhaustMap}
* @see {@link mergeMap}
* @see {@link switch}
* @see {@link switchMapTo}
*
* @param {function(value: T, ?index: number): ObservableInput} project A function
* that, when applied to an item emitted by the source Observable, returns an
* Observable.
* @return {Observable} An Observable that emits the result of applying the
* projection function (and the optional `resultSelector`) to each item emitted
* by the source Observable and taking only the values from the most recently
* projected inner Observable.
* @method switchMap
* @owner Observable
*/
export function switchMap(project, resultSelector) {
if (typeof resultSelector === 'function') {
return function (source) { return source.pipe(switchMap(function (a, i) { return from(project(a, i)).pipe(map(function (b, ii) { return resultSelector(a, b, i, ii); })); })); };
}
return function (source) { return source.lift(new SwitchMapOperator(project)); };
}
var SwitchMapOperator = /*@__PURE__*/ (function () {
function SwitchMapOperator(project) {
this.project = project;
}
SwitchMapOperator.prototype.call = function (subscriber, source) {
return source.subscribe(new SwitchMapSubscriber(subscriber, this.project));
};
return SwitchMapOperator;
}());
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
var SwitchMapSubscriber = /*@__PURE__*/ (function (_super) {
tslib_1.__extends(SwitchMapSubscriber, _super);
function SwitchMapSubscriber(destination, project) {
var _this = _super.call(this, destination) || this;
_this.project = project;
_this.index = 0;
return _this;
}
SwitchMapSubscriber.prototype._next = function (value) {
var result;
var index = this.index++;
try {
result = this.project(value, index);
}
catch (error) {
this.destination.error(error);
return;
}
this._innerSub(result, value, index);
};
SwitchMapSubscriber.prototype._innerSub = function (result, value, index) {
var innerSubscription = this.innerSubscription;
if (innerSubscription) {
innerSubscription.unsubscribe();
}
this.add(this.innerSubscription = subscribeToResult(this, result, value, index));
};
SwitchMapSubscriber.prototype._complete = function () {
var innerSubscription = this.innerSubscription;
if (!innerSubscription || innerSubscription.closed) {
_super.prototype._complete.call(this);
}
};
SwitchMapSubscriber.prototype._unsubscribe = function () {
this.innerSubscription = null;
};
SwitchMapSubscriber.prototype.notifyComplete = function (innerSub) {
this.remove(innerSub);
this.innerSubscription = null;
if (this.isStopped) {
_super.prototype._complete.call(this);
}
};
SwitchMapSubscriber.prototype.notifyNext = function (outerValue, innerValue, outerIndex, innerIndex, innerSub) {
this.destination.next(innerValue);
};
return SwitchMapSubscriber;
}(OuterSubscriber));
//# sourceMappingURL=switchMap.js.map
return module.exports;
});