rearrage_stuff

node_modules/rxjs/src/internal/operators/exhaustMap.ts

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+import { Observable } from '../Observable';
+import { Subscriber } from '../Subscriber';
+import { ObservableInput, OperatorFunction, ObservedValueOf } from '../types';
+import { map } from './map';
+import { innerFrom } from '../observable/innerFrom';
+import { operate } from '../util/lift';
+import { createOperatorSubscriber } from './OperatorSubscriber';
+
+/* tslint:disable:max-line-length */
+export function exhaustMap<T, O extends ObservableInput<any>>(
+  project: (value: T, index: number) => O
+): OperatorFunction<T, ObservedValueOf<O>>;
+/** @deprecated The `resultSelector` parameter will be removed in v8. Use an inner `map` instead. Details: https://rxjs.dev/deprecations/resultSelector */
+export function exhaustMap<T, O extends ObservableInput<any>>(
+  project: (value: T, index: number) => O,
+  resultSelector: undefined
+): OperatorFunction<T, ObservedValueOf<O>>;
+/** @deprecated The `resultSelector` parameter will be removed in v8. Use an inner `map` instead. Details: https://rxjs.dev/deprecations/resultSelector */
+export function exhaustMap<T, I, R>(
+  project: (value: T, index: number) => ObservableInput<I>,
+  resultSelector: (outerValue: T, innerValue: I, outerIndex: number, innerIndex: number) => R
+): OperatorFunction<T, R>;
+/* tslint:enable:max-line-length */
+
+/**
+ * Projects each source value to an Observable which is merged in the output
+ * Observable only if the previous projected Observable has completed.
+ *
+ * <span class="informal">Maps each value to an Observable, then flattens all of
+ * these inner Observables using {@link exhaustAll}.</span>
+ *
+ * ![](exhaustMap.png)
+ *
+ * Returns an Observable that emits items based on applying a function that you
+ * supply to each item emitted by the source Observable, where that function
+ * returns an (so-called "inner") Observable. When it projects a source value to
+ * an Observable, the output Observable begins emitting the items emitted by
+ * that projected Observable. However, `exhaustMap` ignores every new projected
+ * Observable if the previous projected Observable has not yet completed. Once
+ * that one completes, it will accept and flatten the next projected Observable
+ * and repeat this process.
+ *
+ * ## Example
+ *
+ * Run a finite timer for each click, only if there is no currently active timer
+ *
+ * ```ts
+ * import { fromEvent, exhaustMap, interval, take } from 'rxjs';
+ *
+ * const clicks = fromEvent(document, 'click');
+ * const result = clicks.pipe(
+ *   exhaustMap(() => interval(1000).pipe(take(5)))
+ * );
+ * result.subscribe(x => console.log(x));
+ * ```
+ *
+ * @see {@link concatMap}
+ * @see {@link exhaust}
+ * @see {@link mergeMap}
+ * @see {@link switchMap}
+ *
+ * @param project A function that, when applied to an item emitted by the source
+ * Observable, returns an Observable.
+ * @return A function that returns an Observable containing projected
+ * Observables of each item of the source, ignoring projected Observables that
+ * start before their preceding Observable has completed.
+ */
+export function exhaustMap<T, R, O extends ObservableInput<any>>(
+  project: (value: T, index: number) => O,
+  resultSelector?: (outerValue: T, innerValue: ObservedValueOf<O>, outerIndex: number, innerIndex: number) => R
+): OperatorFunction<T, ObservedValueOf<O> | R> {
+  if (resultSelector) {
+    // DEPRECATED PATH
+    return (source: Observable<T>) =>
+      source.pipe(exhaustMap((a, i) => innerFrom(project(a, i)).pipe(map((b: any, ii: any) => resultSelector(a, b, i, ii)))));
+  }
+  return operate((source, subscriber) => {
+    let index = 0;
+    let innerSub: Subscriber<T> | null = null;
+    let isComplete = false;
+    source.subscribe(
+      createOperatorSubscriber(
+        subscriber,
+        (outerValue) => {
+          if (!innerSub) {
+            innerSub = createOperatorSubscriber(subscriber, undefined, () => {
+              innerSub = null;
+              isComplete && subscriber.complete();
+            });
+            innerFrom(project(outerValue, index++)).subscribe(innerSub);
+          }
+        },
+        () => {
+          isComplete = true;
+          !innerSub && subscriber.complete();
+        }
+      )
+    );
+  });
+}