blob: 67ee97b96f1eec082b0cbafe4704aed04055080e [file] [log] [blame]
import { Operator } from '../Operator';
import { Observable } from '../Observable';
import { Subscriber } from '../Subscriber';
import { Observer, OperatorFunction } from '../types';
/**
* Compares all values of two observables in sequence using an optional comparator function
* and returns an observable of a single boolean value representing whether or not the two sequences
* are equal.
*
* <span class="informal">Checks to see of all values emitted by both observables are equal, in order.</span>
*
* ![](sequenceEqual.png)
*
* `sequenceEqual` subscribes to two observables and buffers incoming values from each observable. Whenever either
* observable emits a value, the value is buffered and the buffers are shifted and compared from the bottom
* up; If any value pair doesn't match, the returned observable will emit `false` and complete. If one of the
* observables completes, the operator will wait for the other observable to complete; If the other
* observable emits before completing, the returned observable will emit `false` and complete. If one observable never
* completes or emits after the other complets, the returned observable will never complete.
*
* ## Example
* figure out if the Konami code matches
* ```ts
* import { from, fromEvent } from 'rxjs';
* import { sequenceEqual, bufferCount, mergeMap, map } from 'rxjs/operators';
*
* const codes = from([
* 'ArrowUp',
* 'ArrowUp',
* 'ArrowDown',
* 'ArrowDown',
* 'ArrowLeft',
* 'ArrowRight',
* 'ArrowLeft',
* 'ArrowRight',
* 'KeyB',
* 'KeyA',
* 'Enter', // no start key, clearly.
* ]);
*
* const keys = fromEvent(document, 'keyup').pipe(map(e => e.code));
* const matches = keys.pipe(
* bufferCount(11, 1),
* mergeMap(
* last11 => from(last11).pipe(sequenceEqual(codes)),
* ),
* );
* matches.subscribe(matched => console.log('Successful cheat at Contra? ', matched));
* ```
*
* @see {@link combineLatest}
* @see {@link zip}
* @see {@link withLatestFrom}
*
* @param {Observable} compareTo The observable sequence to compare the source sequence to.
* @param {function} [comparator] An optional function to compare each value pair
* @return {Observable} An Observable of a single boolean value representing whether or not
* the values emitted by both observables were equal in sequence.
* @method sequenceEqual
* @owner Observable
*/
export declare function sequenceEqual<T>(compareTo: Observable<T>, comparator?: (a: T, b: T) => boolean): OperatorFunction<T, boolean>;
export declare class SequenceEqualOperator<T> implements Operator<T, boolean> {
private compareTo;
private comparator;
constructor(compareTo: Observable<T>, comparator: (a: T, b: T) => boolean);
call(subscriber: Subscriber<boolean>, source: any): any;
}
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
export declare class SequenceEqualSubscriber<T, R> extends Subscriber<T> {
private compareTo;
private comparator;
private _a;
private _b;
private _oneComplete;
constructor(destination: Observer<R>, compareTo: Observable<T>, comparator: (a: T, b: T) => boolean);
protected _next(value: T): void;
_complete(): void;
checkValues(): void;
emit(value: boolean): void;
nextB(value: T): void;
completeB(): void;
}