text: import { concatMap as higherOrderConcatMap } from '../../operators/concatMap';
  /**
   * Projects each source value to an Observable which is merged in the output
   * Observable, in a serialized fashion waiting for each one to complete before
   * merging the next.
   *
   * <span class="informal">Maps each value to an Observable, then flattens all of
   * these inner Observables using {@link concatAll}.</span>
   *
   * <img src="./img/concatMap.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 new inner Observable is
   * concatenated with the previous inner Observable.
   *
   * __Warning:__ if source values arrive endlessly and faster than their
   * corresponding inner Observables can complete, it will result in memory issues
   * as inner Observables amass in an unbounded buffer waiting for their turn to
   * be subscribed to.
   *
   * Note: `concatMap` is equivalent to `mergeMap` with concurrency parameter set
   * to `1`.
   *
   * @example <caption>For each click event, tick every second from 0 to 3, with no concurrency</caption>
   * var clicks = Rx.Observable.fromEvent(document, 'click');
   * var result = clicks.concatMap(ev => Rx.Observable.interval(1000).take(4));
   * result.subscribe(x => console.log(x));
   *
   * // Results in the following:
   * // (results are not concurrent)
   * // For every click on the "document" it will emit values 0 to 3 spaced
   * // on a 1000ms interval
   * // one click = 1000ms-> 0 -1000ms-> 1 -1000ms-> 2 -1000ms-> 3
   *
   * @see {@link concat}
   * @see {@link concatAll}
   * @see {@link concatMapTo}
   * @see {@link exhaustMap}
   * @see {@link mergeMap}
   * @see {@link switchMap}
   *
   * @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 values from each projected inner
   * Observable sequentially.
   * @method concatMap
   * @owner Observable
   */
  export function concatMap(project) {
      return higherOrderConcatMap(project)(this);
  }
  //# sourceMappingURL=concatMap.js.map