zip.js 5.7 KB
import { fromArray } from './fromArray';
import { isArray } from '../util/isArray';
import { Subscriber } from '../Subscriber';
import { iterator as Symbol_iterator } from '../../internal/symbol/iterator';
import { SimpleOuterSubscriber, SimpleInnerSubscriber, innerSubscribe } from '../innerSubscribe';
export function zip(...observables) {
    const resultSelector = observables[observables.length - 1];
    if (typeof resultSelector === 'function') {
        observables.pop();
    }
    return fromArray(observables, undefined).lift(new ZipOperator(resultSelector));
}
export class ZipOperator {
    constructor(resultSelector) {
        this.resultSelector = resultSelector;
    }
    call(subscriber, source) {
        return source.subscribe(new ZipSubscriber(subscriber, this.resultSelector));
    }
}
export class ZipSubscriber extends Subscriber {
    constructor(destination, resultSelector, values = Object.create(null)) {
        super(destination);
        this.resultSelector = resultSelector;
        this.iterators = [];
        this.active = 0;
        this.resultSelector = (typeof resultSelector === 'function') ? resultSelector : undefined;
    }
    _next(value) {
        const iterators = this.iterators;
        if (isArray(value)) {
            iterators.push(new StaticArrayIterator(value));
        }
        else if (typeof value[Symbol_iterator] === 'function') {
            iterators.push(new StaticIterator(value[Symbol_iterator]()));
        }
        else {
            iterators.push(new ZipBufferIterator(this.destination, this, value));
        }
    }
    _complete() {
        const iterators = this.iterators;
        const len = iterators.length;
        this.unsubscribe();
        if (len === 0) {
            this.destination.complete();
            return;
        }
        this.active = len;
        for (let i = 0; i < len; i++) {
            let iterator = iterators[i];
            if (iterator.stillUnsubscribed) {
                const destination = this.destination;
                destination.add(iterator.subscribe());
            }
            else {
                this.active--;
            }
        }
    }
    notifyInactive() {
        this.active--;
        if (this.active === 0) {
            this.destination.complete();
        }
    }
    checkIterators() {
        const iterators = this.iterators;
        const len = iterators.length;
        const destination = this.destination;
        for (let i = 0; i < len; i++) {
            let iterator = iterators[i];
            if (typeof iterator.hasValue === 'function' && !iterator.hasValue()) {
                return;
            }
        }
        let shouldComplete = false;
        const args = [];
        for (let i = 0; i < len; i++) {
            let iterator = iterators[i];
            let result = iterator.next();
            if (iterator.hasCompleted()) {
                shouldComplete = true;
            }
            if (result.done) {
                destination.complete();
                return;
            }
            args.push(result.value);
        }
        if (this.resultSelector) {
            this._tryresultSelector(args);
        }
        else {
            destination.next(args);
        }
        if (shouldComplete) {
            destination.complete();
        }
    }
    _tryresultSelector(args) {
        let result;
        try {
            result = this.resultSelector.apply(this, args);
        }
        catch (err) {
            this.destination.error(err);
            return;
        }
        this.destination.next(result);
    }
}
class StaticIterator {
    constructor(iterator) {
        this.iterator = iterator;
        this.nextResult = iterator.next();
    }
    hasValue() {
        return true;
    }
    next() {
        const result = this.nextResult;
        this.nextResult = this.iterator.next();
        return result;
    }
    hasCompleted() {
        const nextResult = this.nextResult;
        return Boolean(nextResult && nextResult.done);
    }
}
class StaticArrayIterator {
    constructor(array) {
        this.array = array;
        this.index = 0;
        this.length = 0;
        this.length = array.length;
    }
    [Symbol_iterator]() {
        return this;
    }
    next(value) {
        const i = this.index++;
        const array = this.array;
        return i < this.length ? { value: array[i], done: false } : { value: null, done: true };
    }
    hasValue() {
        return this.array.length > this.index;
    }
    hasCompleted() {
        return this.array.length === this.index;
    }
}
class ZipBufferIterator extends SimpleOuterSubscriber {
    constructor(destination, parent, observable) {
        super(destination);
        this.parent = parent;
        this.observable = observable;
        this.stillUnsubscribed = true;
        this.buffer = [];
        this.isComplete = false;
    }
    [Symbol_iterator]() {
        return this;
    }
    next() {
        const buffer = this.buffer;
        if (buffer.length === 0 && this.isComplete) {
            return { value: null, done: true };
        }
        else {
            return { value: buffer.shift(), done: false };
        }
    }
    hasValue() {
        return this.buffer.length > 0;
    }
    hasCompleted() {
        return this.buffer.length === 0 && this.isComplete;
    }
    notifyComplete() {
        if (this.buffer.length > 0) {
            this.isComplete = true;
            this.parent.notifyInactive();
        }
        else {
            this.destination.complete();
        }
    }
    notifyNext(innerValue) {
        this.buffer.push(innerValue);
        this.parent.checkIterators();
    }
    subscribe() {
        return innerSubscribe(this.observable, new SimpleInnerSubscriber(this));
    }
}
//# sourceMappingURL=zip.js.map