150 lines
4.8 KiB
JavaScript
Executable File
150 lines
4.8 KiB
JavaScript
Executable File
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
|