| import { SimpleOuterSubscriber, innerSubscribe, SimpleInnerSubscriber } from '../innerSubscribe'; | 
| export function expand(project, concurrent = Number.POSITIVE_INFINITY, scheduler) { | 
|     concurrent = (concurrent || 0) < 1 ? Number.POSITIVE_INFINITY : concurrent; | 
|     return (source) => source.lift(new ExpandOperator(project, concurrent, scheduler)); | 
| } | 
| export class ExpandOperator { | 
|     constructor(project, concurrent, scheduler) { | 
|         this.project = project; | 
|         this.concurrent = concurrent; | 
|         this.scheduler = scheduler; | 
|     } | 
|     call(subscriber, source) { | 
|         return source.subscribe(new ExpandSubscriber(subscriber, this.project, this.concurrent, this.scheduler)); | 
|     } | 
| } | 
| export class ExpandSubscriber extends SimpleOuterSubscriber { | 
|     constructor(destination, project, concurrent, scheduler) { | 
|         super(destination); | 
|         this.project = project; | 
|         this.concurrent = concurrent; | 
|         this.scheduler = scheduler; | 
|         this.index = 0; | 
|         this.active = 0; | 
|         this.hasCompleted = false; | 
|         if (concurrent < Number.POSITIVE_INFINITY) { | 
|             this.buffer = []; | 
|         } | 
|     } | 
|     static dispatch(arg) { | 
|         const { subscriber, result, value, index } = arg; | 
|         subscriber.subscribeToProjection(result, value, index); | 
|     } | 
|     _next(value) { | 
|         const destination = this.destination; | 
|         if (destination.closed) { | 
|             this._complete(); | 
|             return; | 
|         } | 
|         const index = this.index++; | 
|         if (this.active < this.concurrent) { | 
|             destination.next(value); | 
|             try { | 
|                 const { project } = this; | 
|                 const result = project(value, index); | 
|                 if (!this.scheduler) { | 
|                     this.subscribeToProjection(result, value, index); | 
|                 } | 
|                 else { | 
|                     const state = { subscriber: this, result, value, index }; | 
|                     const destination = this.destination; | 
|                     destination.add(this.scheduler.schedule(ExpandSubscriber.dispatch, 0, state)); | 
|                 } | 
|             } | 
|             catch (e) { | 
|                 destination.error(e); | 
|             } | 
|         } | 
|         else { | 
|             this.buffer.push(value); | 
|         } | 
|     } | 
|     subscribeToProjection(result, value, index) { | 
|         this.active++; | 
|         const destination = this.destination; | 
|         destination.add(innerSubscribe(result, new SimpleInnerSubscriber(this))); | 
|     } | 
|     _complete() { | 
|         this.hasCompleted = true; | 
|         if (this.hasCompleted && this.active === 0) { | 
|             this.destination.complete(); | 
|         } | 
|         this.unsubscribe(); | 
|     } | 
|     notifyNext(innerValue) { | 
|         this._next(innerValue); | 
|     } | 
|     notifyComplete() { | 
|         const buffer = this.buffer; | 
|         this.active--; | 
|         if (buffer && buffer.length > 0) { | 
|             this._next(buffer.shift()); | 
|         } | 
|         if (this.hasCompleted && this.active === 0) { | 
|             this.destination.complete(); | 
|         } | 
|     } | 
| } | 
| //# sourceMappingURL=expand.js.map |