You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 

74 lines
2.7 KiB

import { Operator } from '../Operator';
import { Subscriber } from '../Subscriber';
import { Subscription } from '../Subscription';
import { OuterSubscriber } from '../OuterSubscriber';
import { InnerSubscriber } from '../InnerSubscriber';
import { ObservableInput, OperatorFunction } from '../types';
/**
* Applies an accumulator function over the source Observable where the
* accumulator function itself returns an Observable, then each intermediate
* Observable returned is merged into the output Observable.
*
* <span class="informal">It's like {@link scan}, but the Observables returned
* by the accumulator are merged into the outer Observable.</span>
*
* ## Example
* Count the number of click events
* ```ts
* import { fromEvent, of } from 'rxjs';
* import { mapTo, mergeScan } from 'rxjs/operators';
*
* const click$ = fromEvent(document, 'click');
* const one$ = click$.pipe(mapTo(1));
* const seed = 0;
* const count$ = one$.pipe(
* mergeScan((acc, one) => of(acc + one), seed),
* );
* count$.subscribe(x => console.log(x));
*
* // Results:
* // 1
* // 2
* // 3
* // 4
* // ...and so on for each click
* ```
*
* @param {function(acc: R, value: T): Observable<R>} accumulator
* The accumulator function called on each source value.
* @param seed The initial accumulation value.
* @param {number} [concurrent=Number.POSITIVE_INFINITY] Maximum number of
* input Observables being subscribed to concurrently.
* @return {Observable<R>} An observable of the accumulated values.
* @method mergeScan
* @owner Observable
*/
export declare function mergeScan<T, R>(accumulator: (acc: R, value: T, index: number) => ObservableInput<R>, seed: R, concurrent?: number): OperatorFunction<T, R>;
export declare class MergeScanOperator<T, R> implements Operator<T, R> {
private accumulator;
private seed;
private concurrent;
constructor(accumulator: (acc: R, value: T, index: number) => ObservableInput<R>, seed: R, concurrent: number);
call(subscriber: Subscriber<R>, source: any): any;
}
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
export declare class MergeScanSubscriber<T, R> extends OuterSubscriber<T, R> {
private accumulator;
private acc;
private concurrent;
private hasValue;
private hasCompleted;
private buffer;
private active;
protected index: number;
constructor(destination: Subscriber<R>, accumulator: (acc: R, value: T, index: number) => ObservableInput<R>, acc: R, concurrent: number);
protected _next(value: any): void;
private _innerSub;
protected _complete(): void;
notifyNext(outerValue: T, innerValue: R, outerIndex: number, innerIndex: number, innerSub: InnerSubscriber<T, R>): void;
notifyComplete(innerSub: Subscription): void;
}