import { Subscriber } from '../Subscriber'; export function pairwise() { return (source) => source.lift(new PairwiseOperator()); } class PairwiseOperator { call(subscriber, source) { return source.subscribe(new PairwiseSubscriber(subscriber)); } } class PairwiseSubscriber extends Subscriber { constructor(destination) { super(destination); this.hasPrev = false; } _next(value) { if (this.hasPrev) { this.destination.next([this.prev, value]); } else { this.hasPrev = true; } this.prev = value; } } //# sourceMappingURL=pairwise.js.map