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- import { not } from '../util/not';
- import { filter } from './filter';
- import { Observable } from '../Observable';
- import { UnaryFunction } from '../types';
- /**
- * Splits the source Observable into two, one with values that satisfy a
- * predicate, and another with values that don't satisfy the predicate.
- *
- * <span class="informal">It's like {@link filter}, but returns two Observables:
- * one like the output of {@link filter}, and the other with values that did not
- * pass the condition.</span>
- *
- * 
- *
- * `partition` outputs an array with two Observables that partition the values
- * from the source Observable through the given `predicate` function. The first
- * Observable in that array emits source values for which the predicate argument
- * returns true. The second Observable emits source values for which the
- * predicate returns false. The first behaves like {@link filter} and the second
- * behaves like {@link filter} with the predicate negated.
- *
- * ## Example
- *
- * Partition click events into those on DIV elements and those elsewhere
- *
- * ```ts
- * import { fromEvent } from 'rxjs';
- * import { partition } from 'rxjs/operators';
- *
- * const div = document.createElement('div');
- * div.style.cssText = 'width: 200px; height: 200px; background: #09c;';
- * document.body.appendChild(div);
- *
- * const clicks = fromEvent(document, 'click');
- * const [clicksOnDivs, clicksElsewhere] = clicks.pipe(partition(ev => (<HTMLElement>ev.target).tagName === 'DIV'));
- *
- * clicksOnDivs.subscribe(x => console.log('DIV clicked: ', x));
- * clicksElsewhere.subscribe(x => console.log('Other clicked: ', x));
- * ```
- *
- * @see {@link filter}
- *
- * @param predicate A function that evaluates each value emitted by the source
- * Observable. If it returns `true`, the value is emitted on the first Observable
- * in the returned array, if `false` the value is emitted on the second Observable
- * in the array. The `index` parameter is the number `i` for the i-th source
- * emission that has happened since the subscription, starting from the number `0`.
- * @param thisArg An optional argument to determine the value of `this` in the
- * `predicate` function.
- * @return A function that returns an array with two Observables: one with
- * values that passed the predicate, and another with values that did not pass
- * the predicate.
- * @deprecated Replaced with the {@link partition} static creation function. Will be removed in v8.
- */
- export function partition<T>(
- predicate: (value: T, index: number) => boolean,
- thisArg?: any
- ): UnaryFunction<Observable<T>, [Observable<T>, Observable<T>]> {
- return (source: Observable<T>) =>
- [filter(predicate, thisArg)(source), filter(not(predicate, thisArg))(source)] as [Observable<T>, Observable<T>];
- }
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