text: import { subscribeToResult } from '../util/subscribeToResult';
  import { OuterSubscriber } from '../OuterSubscriber';
  import { map } from './map';
  import { from } from '../observable/from';
  export function mergeMap(project, resultSelector, concurrent = Number.POSITIVE_INFINITY) {
      if (typeof resultSelector === 'function') {
          return (source) => source.pipe(mergeMap((a, i) => from(project(a, i)).pipe(map((b, ii) => resultSelector(a, b, i, ii))), concurrent));
      }
      else if (typeof resultSelector === 'number') {
          concurrent = resultSelector;
      }
      return (source) => source.lift(new MergeMapOperator(project, concurrent));
  }
  export class MergeMapOperator {
      constructor(project, concurrent = Number.POSITIVE_INFINITY) {
          this.project = project;
          this.concurrent = concurrent;
      }
      call(observer, source) {
          return source.subscribe(new MergeMapSubscriber(observer, this.project, this.concurrent));
      }
  }
  export class MergeMapSubscriber extends OuterSubscriber {
      constructor(destination, project, concurrent = Number.POSITIVE_INFINITY) {
          super(destination);
          this.project = project;
          this.concurrent = concurrent;
          this.hasCompleted = false;
          this.buffer = [];
          this.active = 0;
          this.index = 0;
      }
      _next(value) {
          if (this.active < this.concurrent) {
              this._tryNext(value);
          }
          else {
              this.buffer.push(value);
          }
      }
      _tryNext(value) {
          let result;
          const index = this.index++;
          try {
              result = this.project(value, index);
          }
          catch (err) {
              this.destination.error(err);
              return;
          }
          this.active++;
          this._innerSub(result, value, index);
      }
      _innerSub(ish, value, index) {
          this.add(subscribeToResult(this, ish, value, index));
      }
      _complete() {
          this.hasCompleted = true;
          if (this.active === 0 && this.buffer.length === 0) {
              this.destination.complete();
          }
      }
      notifyNext(outerValue, innerValue, outerIndex, innerIndex, innerSub) {
          this.destination.next(innerValue);
      }
      notifyComplete(innerSub) {
          const buffer = this.buffer;
          this.remove(innerSub);
          this.active--;
          if (buffer.length > 0) {
              this._next(buffer.shift());
          }
          else if (this.active === 0 && this.hasCompleted) {
              this.destination.complete();
          }
      }
  }
  //# sourceMappingURL=mergeMap.js.map