import { ObservableInputTuple, OperatorFunction, Cons } from '../types';
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import { combineLatest } from './combineLatest';
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/**
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* Create an observable that combines the latest values from all passed observables and the source
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* into arrays and emits them.
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*
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* Returns an observable, that when subscribed to, will subscribe to the source observable and all
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* sources provided as arguments. Once all sources emit at least one value, all of the latest values
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* will be emitted as an array. After that, every time any source emits a value, all of the latest values
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* will be emitted as an array.
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*
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* This is a useful operator for eagerly calculating values based off of changed inputs.
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*
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* ## Example
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*
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* Simple concatenation of values from two inputs
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*
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* ```ts
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* import { fromEvent, combineLatestWith, map } from 'rxjs';
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*
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* // Setup: Add two inputs to the page
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* const input1 = document.createElement('input');
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* document.body.appendChild(input1);
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* const input2 = document.createElement('input');
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* document.body.appendChild(input2);
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*
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* // Get streams of changes
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* const input1Changes$ = fromEvent(input1, 'change');
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* const input2Changes$ = fromEvent(input2, 'change');
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*
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* // Combine the changes by adding them together
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* input1Changes$.pipe(
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* combineLatestWith(input2Changes$),
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* map(([e1, e2]) => (<HTMLInputElement>e1.target).value + ' - ' + (<HTMLInputElement>e2.target).value)
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* )
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* .subscribe(x => console.log(x));
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* ```
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*
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* @param otherSources the other sources to subscribe to.
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* @return A function that returns an Observable that emits the latest
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* emissions from both source and provided Observables.
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*/
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export function combineLatestWith<T, A extends readonly unknown[]>(
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...otherSources: [...ObservableInputTuple<A>]
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): OperatorFunction<T, Cons<T, A>> {
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return combineLatest(...otherSources);
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}
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