@reactivex/rxjs
Version:
Reactive Extensions for modern JavaScript
186 lines • 6.96 kB
JavaScript
"use strict";
var __extends = (this && this.__extends) || (function () {
var extendStatics = function (d, b) {
extendStatics = Object.setPrototypeOf ||
({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
return extendStatics(d, b);
}
return function (d, b) {
extendStatics(d, b);
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
})();
Object.defineProperty(exports, "__esModule", { value: true });
var Subscriber_1 = require("../Subscriber");
/**
* 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` 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
*/
function sequenceEqual(compareTo, comparator) {
return function (source) { return source.lift(new SequenceEqualOperator(compareTo, comparator)); };
}
exports.sequenceEqual = sequenceEqual;
var SequenceEqualOperator = /** @class */ (function () {
function SequenceEqualOperator(compareTo, comparator) {
this.compareTo = compareTo;
this.comparator = comparator;
}
SequenceEqualOperator.prototype.call = function (subscriber, source) {
return source.subscribe(new SequenceEqualSubscriber(subscriber, this.compareTo, this.comparator));
};
return SequenceEqualOperator;
}());
exports.SequenceEqualOperator = SequenceEqualOperator;
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
var SequenceEqualSubscriber = /** @class */ (function (_super) {
__extends(SequenceEqualSubscriber, _super);
function SequenceEqualSubscriber(destination, compareTo, comparator) {
var _this = _super.call(this, destination) || this;
_this.compareTo = compareTo;
_this.comparator = comparator;
_this._a = [];
_this._b = [];
_this._oneComplete = false;
_this.destination.add(compareTo.subscribe(new SequenceEqualCompareToSubscriber(destination, _this)));
return _this;
}
SequenceEqualSubscriber.prototype._next = function (value) {
if (this._oneComplete && this._b.length === 0) {
this.emit(false);
}
else {
this._a.push(value);
this.checkValues();
}
};
SequenceEqualSubscriber.prototype._complete = function () {
if (this._oneComplete) {
this.emit(this._a.length === 0 && this._b.length === 0);
}
else {
this._oneComplete = true;
}
this.unsubscribe();
};
SequenceEqualSubscriber.prototype.checkValues = function () {
var _c = this, _a = _c._a, _b = _c._b, comparator = _c.comparator;
while (_a.length > 0 && _b.length > 0) {
var a = _a.shift();
var b = _b.shift();
var areEqual = false;
try {
areEqual = comparator ? comparator(a, b) : a === b;
}
catch (e) {
this.destination.error(e);
}
if (!areEqual) {
this.emit(false);
}
}
};
SequenceEqualSubscriber.prototype.emit = function (value) {
var destination = this.destination;
destination.next(value);
destination.complete();
};
SequenceEqualSubscriber.prototype.nextB = function (value) {
if (this._oneComplete && this._a.length === 0) {
this.emit(false);
}
else {
this._b.push(value);
this.checkValues();
}
};
SequenceEqualSubscriber.prototype.completeB = function () {
if (this._oneComplete) {
this.emit(this._a.length === 0 && this._b.length === 0);
}
else {
this._oneComplete = true;
}
};
return SequenceEqualSubscriber;
}(Subscriber_1.Subscriber));
exports.SequenceEqualSubscriber = SequenceEqualSubscriber;
var SequenceEqualCompareToSubscriber = /** @class */ (function (_super) {
__extends(SequenceEqualCompareToSubscriber, _super);
function SequenceEqualCompareToSubscriber(destination, parent) {
var _this = _super.call(this, destination) || this;
_this.parent = parent;
return _this;
}
SequenceEqualCompareToSubscriber.prototype._next = function (value) {
this.parent.nextB(value);
};
SequenceEqualCompareToSubscriber.prototype._error = function (err) {
this.parent.error(err);
this.unsubscribe();
};
SequenceEqualCompareToSubscriber.prototype._complete = function () {
this.parent.completeB();
this.unsubscribe();
};
return SequenceEqualCompareToSubscriber;
}(Subscriber_1.Subscriber));
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