| 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) { |
| let pair; |
| if (this.hasPrev) { |
| pair = [this.prev, value]; |
| } |
| else { |
| this.hasPrev = true; |
| } |
| this.prev = value; |
| if (pair) { |
| this.destination.next(pair); |
| } |
| } |
| } |
| //# sourceMappingURL=pairwise.js.map |