ꦫꦣꦺꦤ꧀ꦄꦤ꧀ꦠꦱꦺꦤ

PATH: usr / local / lib / node_modules / ghost-cli / node_modules / rxjs / src / internal / operators

import { Observable } from '../Observable';
import { Operator } from '../Operator';
import { Subscriber } from '../Subscriber';
import { OuterSubscriber } from '../OuterSubscriber';
import { InnerSubscriber } from '../InnerSubscriber';
import { subscribeToResult } from '../util/subscribeToResult';
import { MonoTypeOperatorFunction, TeardownLogic } from '../types';

/**
 * Returns an Observable that emits all items emitted by the source Observable that are distinct by comparison from previous items.
 *
 * If a keySelector function is provided, then it will project each value from the source observable into a new value that it will
 * check for equality with previously projected values. If a keySelector function is not provided, it will use each value from the
 * source observable directly with an equality check against previous values.
 *
 * In JavaScript runtimes that support `Set`, this operator will use a `Set` to improve performance of the distinct value checking.
 *
 * In other runtimes, this operator will use a minimal implementation of `Set` that relies on an `Array` and `indexOf` under the
 * hood, so performance will degrade as more values are checked for distinction. Even in newer browsers, a long-running `distinct`
 * use might result in memory leaks. To help alleviate this in some scenarios, an optional `flushes` parameter is also provided so
 * that the internal `Set` can be "flushed", basically clearing it of values.
 *
 * ## Examples
 * A simple example with numbers
 * ```ts
 * import { of } from 'rxjs';
 * import { distinct } from 'rxjs/operators';
 *
 * of(1, 1, 2, 2, 2, 1, 2, 3, 4, 3, 2, 1).pipe(
 *     distinct(),
 *   )
 *   .subscribe(x => console.log(x)); // 1, 2, 3, 4
 * ```
 *
 * An example using a keySelector function
 * ```typescript
 * import { of } from 'rxjs';
 * import { distinct } from 'rxjs/operators';
 *
 * interface Person {
 *    age: number,
 *    name: string
 * }
 *
 * of<Person>(
 *     { age: 4, name: 'Foo'},
 *     { age: 7, name: 'Bar'},
 *     { age: 5, name: 'Foo'},
 *   ).pipe(
 *     distinct((p: Person) => p.name),
 *   )
 *   .subscribe(x => console.log(x));
 *
 * // displays:
 * // { age: 4, name: 'Foo' }
 * // { age: 7, name: 'Bar' }
 * ```
 * @see {@link distinctUntilChanged}
 * @see {@link distinctUntilKeyChanged}
 *
 * @param {function} [keySelector] Optional function to select which value you want to check as distinct.
 * @param {Observable} [flushes] Optional Observable for flushing the internal HashSet of the operator.
 * @return {Observable} An Observable that emits items from the source Observable with distinct values.
 * @method distinct
 * @owner Observable
 */
export function distinct<T, K>(keySelector?: (value: T) => K,
                               flushes?: Observable<any>): MonoTypeOperatorFunction<T> {
  return (source: Observable<T>) => source.lift(new DistinctOperator(keySelector, flushes));
}

class DistinctOperator<T, K> implements Operator<T, T> {
  constructor(private keySelector: (value: T) => K, private flushes: Observable<any>) {
  }

call(subscriber: Subscriber<T>, source: any): TeardownLogic {
    return source.subscribe(new DistinctSubscriber(subscriber, this.keySelector, this.flushes));
  }
}

/**
 * We need this JSDoc comment for affecting ESDoc.
 * @ignore
 * @extends {Ignored}
 */
export class DistinctSubscriber<T, K> extends OuterSubscriber<T, T> {
  private values = new Set<K>();

constructor(destination: Subscriber<T>, private keySelector: (value: T) => K, flushes: Observable<any>) {
    super(destination);

if (flushes) {
      this.add(subscribeToResult(this, flushes));
    }
  }

notifyNext(outerValue: T, innerValue: T,
             outerIndex: number, innerIndex: number,
             innerSub: InnerSubscriber<T, T>): void {
    this.values.clear();
  }

notifyError(error: any, innerSub: InnerSubscriber<T, T>): void {
    this._error(error);
  }

protected _next(value: T): void {
    if (this.keySelector) {
      this._useKeySelector(value);
    } else {
      this._finalizeNext(value, value);
    }
  }

private _useKeySelector(value: T): void {
    let key: K;
    const { destination } = this;
    try {
      key = this.keySelector(value);
    } catch (err) {
      destination.error(err);
      return;
    }
    this._finalizeNext(key, value);
  }

private _finalizeNext(key: K|T, value: T) {
    const { values } = this;
    if (!values.has(<K>key)) {
      values.add(<K>key);
      this.destination.next(value);
    }
  }

}

[-] toArray.ts [edit]
[-] window.ts [edit]
[-] retry.ts [edit]
[-] mergeAll.ts [edit]
[-] windowWhen.ts [edit]
[-] every.ts [edit]
[-] timeout.ts [edit]
[-] debounceTime.ts [edit]
[-] index.ts [edit]
[-] takeWhile.ts [edit]
[-] audit.ts [edit]
[-] reduce.ts [edit]
[-] mapTo.ts [edit]
[-] count.ts [edit]
[-] debounce.ts [edit]
[-] throwIfEmpty.ts [edit]
[-] auditTime.ts [edit]
[-] scan.ts [edit]
[-] switchAll.ts [edit]
[-] map.ts [edit]
[-] bufferCount.ts [edit]
[-] mergeScan.ts [edit]
[-] publish.ts [edit]
[-] min.ts [edit]
[+] ..
[-] publishReplay.ts [edit]
[-] bufferTime.ts [edit]
[-] share.ts [edit]
[-] repeat.ts [edit]
[-] distinct.ts [edit]
[-] concatMapTo.ts [edit]
[-] buffer.ts [edit]
[-] concatMap.ts [edit]
[-] max.ts [edit]
[-] partition.ts [edit]
[-] observeOn.ts [edit]
[-] bufferWhen.ts [edit]
[-] dematerialize.ts [edit]
[-] throttle.ts [edit]
[-] groupBy.ts [edit]
[-] withLatestFrom.ts [edit]
[-] exhaust.ts [edit]
[-] exhaustMap.ts [edit]
[-] retryWhen.ts [edit]
[-] zipAll.ts [edit]
[-] find.ts [edit]
[-] mergeMap.ts [edit]
[-] single.ts [edit]
[-] last.ts [edit]
[-] combineLatest.ts [edit]
[-] publishLast.ts [edit]
[-] pluck.ts [edit]
[-] pairwise.ts [edit]
[-] distinctUntilChanged.ts [edit]
[-] timeInterval.ts [edit]
[-] shareReplay.ts [edit]
[-] skipUntil.ts [edit]
[-] findIndex.ts [edit]
[-] windowToggle.ts [edit]
[-] startWith.ts [edit]
[-] timeoutWith.ts [edit]
[-] concat.ts [edit]
[-] materialize.ts [edit]
[-] timestamp.ts [edit]
[-] onErrorResumeNext.ts [edit]
[-] subscribeOn.ts [edit]
[-] takeUntil.ts [edit]
[-] skipLast.ts [edit]
[-] throttleTime.ts [edit]
[-] mergeMapTo.ts [edit]
[-] multicast.ts [edit]
[-] merge.ts [edit]
[-] takeLast.ts [edit]
[-] delayWhen.ts [edit]
[-] sampleTime.ts [edit]
[-] tap.ts [edit]
[-] take.ts [edit]
[-] sample.ts [edit]
[-] filter.ts [edit]
[-] skip.ts [edit]
[-] expand.ts [edit]
[-] publishBehavior.ts [edit]
[-] sequenceEqual.ts [edit]
[-] ignoreElements.ts [edit]
[-] catchError.ts [edit]
[-] endWith.ts [edit]
[-] refCount.ts [edit]
[-] windowCount.ts [edit]
[-] defaultIfEmpty.ts [edit]
[-] windowTime.ts [edit]
[-] switchMapTo.ts [edit]
[-] switchMap.ts [edit]
[-] delay.ts [edit]
[-] bufferToggle.ts [edit]
[-] repeatWhen.ts [edit]
[-] concatAll.ts [edit]
[-] first.ts [edit]
[-] zip.ts [edit]
[-] elementAt.ts [edit]
[-] skipWhile.ts [edit]
[-] race.ts [edit]
[-] finalize.ts [edit]
[-] combineAll.ts [edit]
[-] distinctUntilKeyChanged.ts [edit]
[-] isEmpty.ts [edit]