import {isArray} from '../util/isArray';
import {Operator} from '../Operator';
import {Observer} from '../Observer';
import {Observable} from '../Observable';
import {Subscriber} from '../Subscriber';
import {tryCatch} from '../util/tryCatch';
import {errorObject} from '../util/errorObject';
import {OuterSubscriber} from '../OuterSubscriber';
import {subscribeToResult} from '../util/subscribeToResult';
import {SymbolShim} from '../util/SymbolShim';
export class ZipOperator<T, R> implements Operator<T, R> {
project: (...values: Array<any>) => R;
constructor(project?: (...values: Array<any>) => R) {
this.project = project;
}
call(subscriber: Subscriber<R>): Subscriber<T> {
return new ZipSubscriber<T, R>(subscriber, this.project);
}
}
export class ZipSubscriber<T, R> extends Subscriber<T> {
private index = 0;
private values: any;
private project: (...values: Array<any>) => R;
private iterators = [];
private active = 0;
constructor(destination: Subscriber<R>,
project?: (...values: Array<any>) => R,
Evalues: any = Object.create(null)) {
super(destination);
this.project = (typeof project === 'function') ? project : null;
this.values = values;
}
_next(value) {
const iterators = this.iterators;
const index = this.index++;
if (isArray(value)) {
iterators.push(new StaticArrayIterator(value));
} else if (typeof value[SymbolShim.iterator] === 'function') {
iterators.push(new StaticIterator(value[SymbolShim.iterator]()));
} else {
iterators.push(new ZipBufferIterator(this.destination, this, value, index));
}
}
_complete() {
const iterators = this.iterators;
const len = iterators.length;
this.active = len;
for (let i = 0; i < len; i++) {
let iterator = iterators[i];
if (iterator.stillUnsubscribed) {
this.add(iterator.subscribe(iterator, i));
} else {
this.active--; // not an observable
}
}
}
notifyInactive() {
this.active--;
if (this.active === 0) {
this.destination.complete();
}
}
checkIterators() {
const iterators = this.iterators;
const len = iterators.length;
const destination = this.destination;
// abort if not all of them have values
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();
// check to see if it's completed now that you've gotten
// the next value.
if (iterator.hasCompleted()) {
shouldComplete = true;
}
Iif (result.done) {
destination.complete();
return;
}
args.push(result.value);
}
const project = this.project;
if (project) {
let result = tryCatch(project).apply(this, args);
if (result === errorObject) {
destination.error(errorObject.e);
} else {
destination.next(result);
}
} else {
destination.next(args);
}
if (shouldComplete) {
destination.complete();
}
}
}
interface LookAheadIterator<T> extends Iterator<T> {
hasValue(): boolean;
hasCompleted(): boolean;
}
class StaticIterator<T> implements LookAheadIterator<T> {
private nextResult: IteratorResult<T>;
constructor(private iterator: Iterator<T>) {
this.nextResult = iterator.next();
}
hasValue() {
return true;
}
next(): IteratorResult<T> {
const result = this.nextResult;
this.nextResult = this.iterator.next();
return result;
}
hasCompleted() {
const nextResult = this.nextResult;
return nextResult && nextResult.done;
}
}
class StaticArrayIterator<T> implements LookAheadIterator<T> {
private index = 0;
private length = 0;
constructor(private array: T[]) {
this.length = array.length;
}
[SymbolShim.iterator]() {
return this;
}
next(value?: any): IteratorResult<T> {
const i = this.index++;
const array = this.array;
return i < this.length ? { value: array[i], done: false } : { done: true };
}
hasValue() {
return this.array.length > this.index;
}
hasCompleted() {
return this.array.length === this.index;
}
}
class ZipBufferIterator<T, R> extends OuterSubscriber<T, R> implements LookAheadIterator<T> {
stillUnsubscribed = true;
buffer: T[] = [];
isComplete = false;
constructor(destination: Observer<T>,
private parent: ZipSubscriber<T, R>,
private observable: Observable<T>,
private index: number) {
super(destination);
}
[SymbolShim.iterator]() {
return this;
}
// NOTE: there is actually a name collision here with Subscriber.next and Iterator.next
// this is legit because `next()` will never be called by a subscription in this case.
next(): IteratorResult<T> {
const buffer = this.buffer;
Iif (buffer.length === 0 && this.isComplete) {
return { 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(outerValue, innerValue, outerIndex, innerIndex) {
this.buffer.push(innerValue);
this.parent.checkIterators();
}
subscribe(value: any, index: number) {
return subscribeToResult<any, any>(this, this.observable, this, index);
}
}
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