+++ /dev/null
-import { Observable } from '../Observable';
-import { Operator } from '../Operator';
-import { Subscriber } from '../Subscriber';
-import { EmptyError } from '../util/EmptyError';
-import { OperatorFunction } from '../../internal/types';
-import { filter } from './filter';
-import { takeLast } from './takeLast';
-import { throwIfEmpty } from './throwIfEmpty';
-import { defaultIfEmpty } from './defaultIfEmpty';
-import { identity } from '../util/identity';
-
-/* tslint:disable:max-line-length */
-export function last<T, D = T>(
- predicate?: null,
- defaultValue?: D
-): OperatorFunction<T, T | D>;
-export function last<T, S extends T>(
- predicate: (value: T, index: number, source: Observable<T>) => value is S,
- defaultValue?: S
-): OperatorFunction<T, S>;
-export function last<T, D = T>(
- predicate: (value: T, index: number, source: Observable<T>) => boolean,
- defaultValue?: D
-): OperatorFunction<T, T | D>;
-/* tslint:enable:max-line-length */
-
-/**
- * Returns an Observable that emits only the last item emitted by the source Observable.
- * It optionally takes a predicate function as a parameter, in which case, rather than emitting
- * the last item from the source Observable, the resulting Observable will emit the last item
- * from the source Observable that satisfies the predicate.
- *
- * ![](last.png)
- *
- * @throws {EmptyError} Delivers an EmptyError to the Observer's `error`
- * callback if the Observable completes before any `next` notification was sent.
- * @param {function} [predicate] - The condition any source emitted item has to satisfy.
- * @param {any} [defaultValue] - An optional default value to provide if last
- * predicate isn't met or no values were emitted.
- * @return {Observable} An Observable that emits only the last item satisfying the given condition
- * from the source, or an NoSuchElementException if no such items are emitted.
- * @throws - Throws if no items that match the predicate are emitted by the source Observable.
- */
-export function last<T, D>(
- predicate?: ((value: T, index: number, source: Observable<T>) => boolean) | null,
- defaultValue?: D
-): OperatorFunction<T, T | D> {
- const hasDefaultValue = arguments.length >= 2;
- return (source: Observable<T>) => source.pipe(
- predicate ? filter((v, i) => predicate(v, i, source)) : identity,
- takeLast(1),
- hasDefaultValue ? defaultIfEmpty<T | D>(defaultValue) : throwIfEmpty(() => new EmptyError()),
- );
-}