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import { Observable } from '../Observable';
import { Subject } from '../Subject';
import { multicast } from './multicast';
import { ConnectableObservable } from '../observable/ConnectableObservable';
import { MonoTypeOperatorFunction, OperatorFunction, UnaryFunction, ObservableInput, ObservedValueOf } from '../types';
/* tslint:disable:max-line-length */
export function publish<T>(): UnaryFunction<Observable<T>, ConnectableObservable<T>>;
export function publish<T, O extends ObservableInput<any>>(selector: (shared: Observable<T>) => O): OperatorFunction<T, ObservedValueOf<O>>;
export function publish<T>(selector: MonoTypeOperatorFunction<T>): MonoTypeOperatorFunction<T>;
/* tslint:enable:max-line-length */
/**
* Returns a ConnectableObservable, which is a variety of Observable that waits until its connect method is called
* before it begins emitting items to those Observers that have subscribed to it.
*
* <span class="informal">Makes a cold Observable hot</span>
*
* ![](publish.png)
*
* ## Examples
* Make source$ hot by applying publish operator, then merge each inner observable into a single one
* and subscribe.
* ```ts
* import { of, zip, interval, merge } from "rxjs";
* import { map, publish } from "rxjs/operators";
*
* const source$ = zip(
* interval(2000),
* of(1, 2, 3, 4, 5, 6, 7, 8, 9),
* ).pipe(
* map(values => values[1])
* );
*
* source$.pipe(
* publish(multicasted$ => {
* return merge(
* multicasted$.pipe(tap(x => console.log('Stream 1:', x))),
* multicasted$.pipe(tap(x => console.log('Stream 2:', x))),
* multicasted$.pipe(tap(x => console.log('Stream 3:', x))),
* );
* })).subscribe();
*
/* Results every two seconds
* Stream 1: 1
* Stream 2: 1
* Stream 3: 1
*
* ...
*
* Stream 1: 9
* Stream 2: 9
* Stream 3: 9
* ```
*
* @param {Function} [selector] - Optional selector function which can use the multicasted source sequence as many times
* as needed, without causing multiple subscriptions to the source sequence.
* Subscribers to the given source will receive all notifications of the source from the time of the subscription on.
* @return A ConnectableObservable that upon connection causes the source Observable to emit items to its Observers.
* @method publish
* @owner Observable
*
*
*/
export function publish<T, R>(selector?: OperatorFunction<T, R>): MonoTypeOperatorFunction<T> | OperatorFunction<T, R> {
return selector ?
multicast(() => new Subject<T>(), selector) :
multicast(new Subject<T>());
}