import { Notification } from '../Notification';
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import { OperatorFunction, ObservableNotification } from '../types';
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import { operate } from '../util/lift';
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import { createOperatorSubscriber } from './OperatorSubscriber';
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/**
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* Represents all of the notifications from the source Observable as `next`
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* emissions marked with their original types within {@link Notification}
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* objects.
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*
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* <span class="informal">Wraps `next`, `error` and `complete` emissions in
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* {@link Notification} objects, emitted as `next` on the output Observable.
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* </span>
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*
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* 
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*
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* `materialize` returns an Observable that emits a `next` notification for each
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* `next`, `error`, or `complete` emission of the source Observable. When the
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* source Observable emits `complete`, the output Observable will emit `next` as
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* a Notification of type "complete", and then it will emit `complete` as well.
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* When the source Observable emits `error`, the output will emit `next` as a
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* Notification of type "error", and then `complete`.
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*
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* This operator is useful for producing metadata of the source Observable, to
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* be consumed as `next` emissions. Use it in conjunction with
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* {@link dematerialize}.
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*
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* ## Example
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*
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* Convert a faulty Observable to an Observable of Notifications
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*
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* ```ts
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* import { of, materialize, map } from 'rxjs';
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*
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* const letters = of('a', 'b', 13, 'd');
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* const upperCase = letters.pipe(map((x: any) => x.toUpperCase()));
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* const materialized = upperCase.pipe(materialize());
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*
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* materialized.subscribe(x => console.log(x));
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*
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* // Results in the following:
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* // - Notification { kind: 'N', value: 'A', error: undefined, hasValue: true }
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* // - Notification { kind: 'N', value: 'B', error: undefined, hasValue: true }
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* // - Notification { kind: 'E', value: undefined, error: TypeError { message: x.toUpperCase is not a function }, hasValue: false }
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* ```
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*
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* @see {@link Notification}
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* @see {@link dematerialize}
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*
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* @return A function that returns an Observable that emits
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* {@link Notification} objects that wrap the original emissions from the
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* source Observable with metadata.
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*/
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export function materialize<T>(): OperatorFunction<T, Notification<T> & ObservableNotification<T>> {
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return operate((source, subscriber) => {
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source.subscribe(
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createOperatorSubscriber(
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subscriber,
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(value) => {
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subscriber.next(Notification.createNext(value));
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},
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() => {
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subscriber.next(Notification.createComplete());
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subscriber.complete();
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},
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(err) => {
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subscriber.next(Notification.createError(err));
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subscriber.complete();
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}
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)
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);
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});
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}
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