work.suroh.tk/node_modules/rxjs/_esm2015/operators/skipWhile.js

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2019-12-02 12:22:45 +00:00
import { Subscriber } from '../Subscriber';
/**
* Returns an Observable that skips all items emitted by the source Observable as long as a specified condition holds
* true, but emits all further source items as soon as the condition becomes false.
*
* <img src="./img/skipWhile.png" width="100%">
*
* @param {Function} predicate - A function to test each item emitted from the source Observable.
* @return {Observable<T>} An Observable that begins emitting items emitted by the source Observable when the
* specified predicate becomes false.
* @method skipWhile
* @owner Observable
*/
export function skipWhile(predicate) {
return (source) => source.lift(new SkipWhileOperator(predicate));
}
class SkipWhileOperator {
constructor(predicate) {
this.predicate = predicate;
}
call(subscriber, source) {
return source.subscribe(new SkipWhileSubscriber(subscriber, this.predicate));
}
}
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
class SkipWhileSubscriber extends Subscriber {
constructor(destination, predicate) {
super(destination);
this.predicate = predicate;
this.skipping = true;
this.index = 0;
}
_next(value) {
const destination = this.destination;
if (this.skipping) {
this.tryCallPredicate(value);
}
if (!this.skipping) {
destination.next(value);
}
}
tryCallPredicate(value) {
try {
const result = this.predicate(value, this.index++);
this.skipping = Boolean(result);
}
catch (err) {
this.destination.error(err);
}
}
}
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