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import { OperatorFunction, MonoTypeOperatorFunction, TruthyTypesOf } from '../types';
import { operate } from '../util/lift';
import { createOperatorSubscriber } from './OperatorSubscriber';
export function takeWhile<T>(predicate: BooleanConstructor, inclusive: true): MonoTypeOperatorFunction<T>;
export function takeWhile<T>(predicate: BooleanConstructor, inclusive: false): OperatorFunction<T, TruthyTypesOf<T>>;
export function takeWhile<T>(predicate: BooleanConstructor): OperatorFunction<T, TruthyTypesOf<T>>;
export function takeWhile<T, S extends T>(predicate: (value: T, index: number) => value is S): OperatorFunction<T, S>;
export function takeWhile<T, S extends T>(predicate: (value: T, index: number) => value is S, inclusive: false): OperatorFunction<T, S>;
export function takeWhile<T>(predicate: (value: T, index: number) => boolean, inclusive?: boolean): MonoTypeOperatorFunction<T>;
/**
* Emits values emitted by the source Observable so long as each value satisfies
* the given `predicate`, and then completes as soon as this `predicate` is not
* satisfied.
*
* <span class="informal">Takes values from the source only while they pass the
* condition given. When the first value does not satisfy, it completes.</span>
*
* 
*
* `takeWhile` subscribes and begins mirroring the source Observable. Each value
* emitted on the source is given to the `predicate` function which returns a
* boolean, representing a condition to be satisfied by the source values. The
* output Observable emits the source values until such time as the `predicate`
* returns false, at which point `takeWhile` stops mirroring the source
* Observable and completes the output Observable.
*
* ## Example
*
* Emit click events only while the clientX property is greater than 200
*
* ```ts
* import { fromEvent, takeWhile } from 'rxjs';
*
* const clicks = fromEvent<PointerEvent>(document, 'click');
* const result = clicks.pipe(takeWhile(ev => ev.clientX > 200));
* result.subscribe(x => console.log(x));
* ```
*
* @see {@link take}
* @see {@link takeLast}
* @see {@link takeUntil}
* @see {@link skip}
*
* @param {function(value: T, index: number): boolean} predicate A function that
* evaluates a value emitted by the source Observable and returns a boolean.
* Also takes the (zero-based) index as the second argument.
* @param {boolean} inclusive When set to `true` the value that caused
* `predicate` to return `false` will also be emitted.
* @return A function that returns an Observable that emits values from the
* source Observable so long as each value satisfies the condition defined by
* the `predicate`, then completes.
*/
export function takeWhile<T>(predicate: (value: T, index: number) => boolean, inclusive = false): MonoTypeOperatorFunction<T> {
return operate((source, subscriber) => {
let index = 0;
source.subscribe(
createOperatorSubscriber(subscriber, (value) => {
const result = predicate(value, index++);
(result || inclusive) && subscriber.next(value);
!result && subscriber.complete();
})
);
});
}