Merge pull request #3177 from benlesh/smaller-timeInterval

refactor(timeInterval): implement in terms of scan

src/internal/operators/timeInterval.ts

@@ -1,48 +1,24 @@
-import { Operator } from '../Operator';
+
 import { Observable } from '../Observable';
-import { Subscriber } from '../Subscriber';
 import { async } from '../scheduler/async';
-import { OperatorFunction, SchedulerLike, TimeInterval as TimeIntervalInterface } from '../types';
+import { SchedulerLike, OperatorFunction } from '../types';
+import { scan } from './scan';
+import { defer } from '../observable/defer';
+import { map } from './map';
 
 export function timeInterval<T>(scheduler: SchedulerLike = async): OperatorFunction<T, TimeInterval<T>> {
- return (source: Observable<T>) => source.lift(new TimeIntervalOperator(scheduler));
-}
-
-export class TimeInterval<T> implements TimeIntervalInterface<T> {
- constructor(public value: T, public interval: number) {
-
- }
-}
-
-class TimeIntervalOperator<T> implements Operator<T, TimeInterval<T>> {
- constructor(private scheduler: SchedulerLike) {
-
- }
-
- call(observer: Subscriber<TimeInterval<T>>, source: any): any {
- return source.subscribe(new TimeIntervalSubscriber(observer, this.scheduler));
- }
+ return (source: Observable<T>) => defer(() => {
+ return source.pipe(
+ // HACK: the typings seem off with scan
+ scan(
+ ({ current }, value) => ({ value, current: scheduler.now(), last: current }),
+ { current: scheduler.now(), value: undefined, last: undefined }
+ ) as any,
+ map<any, TimeInterval<T>>(({ current, last, value }) => new TimeInterval(value, current - last)),
+ );
+ });
 }
 
-/**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
-class TimeIntervalSubscriber<T> extends Subscriber<T> {
- private lastTime: number = 0;
-
- constructor(destination: Subscriber<TimeInterval<T>>, private scheduler: SchedulerLike) {
- super(destination);
-
- this.lastTime = scheduler.now();
- }
-
- protected _next(value: T) {
- let now = this.scheduler.now();
- let span = now - this.lastTime;
- this.lastTime = now;
-
- this.destination.next(new TimeInterval(value, span));
- }
+export class TimeInterval<T> {
+ constructor(public value: T, public interval: number) {}
 }