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- import { Subscriber } from '../Subscriber';
- import { tryCatch } from '../util/tryCatch';
- import { errorObject } from '../util/errorObject';
- /**
- * Compares all values of two observables in sequence using an optional comparor 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>
- *
- * <img src="./img/sequenceEqual.png" width="100%">
- *
- * `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 <caption>figure out if the Konami code matches</caption>
- * var code = Rx.Observable.from([
- * "ArrowUp",
- * "ArrowUp",
- * "ArrowDown",
- * "ArrowDown",
- * "ArrowLeft",
- * "ArrowRight",
- * "ArrowLeft",
- * "ArrowRight",
- * "KeyB",
- * "KeyA",
- * "Enter" // no start key, clearly.
- * ]);
- *
- * var keys = Rx.Observable.fromEvent(document, 'keyup')
- * .map(e => e.code);
- * var matches = keys.bufferCount(11, 1)
- * .mergeMap(
- * last11 =>
- * Rx.Observable.from(last11)
- * .sequenceEqual(code)
- * );
- * 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} [comparor] 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 function sequenceEqual(compareTo, comparor) {
- return (source) => source.lift(new SequenceEqualOperator(compareTo, comparor));
- }
- export class SequenceEqualOperator {
- constructor(compareTo, comparor) {
- this.compareTo = compareTo;
- this.comparor = comparor;
- }
- call(subscriber, source) {
- return source.subscribe(new SequenceEqualSubscriber(subscriber, this.compareTo, this.comparor));
- }
- }
- /**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
- export class SequenceEqualSubscriber extends Subscriber {
- constructor(destination, compareTo, comparor) {
- super(destination);
- this.compareTo = compareTo;
- this.comparor = comparor;
- this._a = [];
- this._b = [];
- this._oneComplete = false;
- this.add(compareTo.subscribe(new SequenceEqualCompareToSubscriber(destination, this)));
- }
- _next(value) {
- if (this._oneComplete && this._b.length === 0) {
- this.emit(false);
- }
- else {
- this._a.push(value);
- this.checkValues();
- }
- }
- _complete() {
- if (this._oneComplete) {
- this.emit(this._a.length === 0 && this._b.length === 0);
- }
- else {
- this._oneComplete = true;
- }
- }
- checkValues() {
- const { _a, _b, comparor } = this;
- while (_a.length > 0 && _b.length > 0) {
- let a = _a.shift();
- let b = _b.shift();
- let areEqual = false;
- if (comparor) {
- areEqual = tryCatch(comparor)(a, b);
- if (areEqual === errorObject) {
- this.destination.error(errorObject.e);
- }
- }
- else {
- areEqual = a === b;
- }
- if (!areEqual) {
- this.emit(false);
- }
- }
- }
- emit(value) {
- const { destination } = this;
- destination.next(value);
- destination.complete();
- }
- nextB(value) {
- if (this._oneComplete && this._a.length === 0) {
- this.emit(false);
- }
- else {
- this._b.push(value);
- this.checkValues();
- }
- }
- }
- class SequenceEqualCompareToSubscriber extends Subscriber {
- constructor(destination, parent) {
- super(destination);
- this.parent = parent;
- }
- _next(value) {
- this.parent.nextB(value);
- }
- _error(err) {
- this.parent.error(err);
- }
- _complete() {
- this.parent._complete();
- }
- }
- //# sourceMappingURL=sequenceEqual.js.map
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