55 lines
2.3 KiB
TypeScript
55 lines
2.3 KiB
TypeScript
|
import { ObservableInput } from '../types';
|
||
|
|
import { Observable } from '../Observable';
|
||
|
|
/**
|
||
|
|
* 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 a set of numbers into odds and evens observables
|
||
|
|
* ```ts
|
||
|
|
* import { of, partition } from 'rxjs';
|
||
|
|
*
|
||
|
|
* const observableValues = of(1, 2, 3, 4, 5, 6);
|
||
|
|
* const [evens$, odds$] = partition(observableValues, (value, index) => value % 2 === 0);
|
||
|
|
*
|
||
|
|
* odds$.subscribe(x => console.log('odds', x));
|
||
|
|
* evens$.subscribe(x => console.log('evens', x));
|
||
|
|
*
|
||
|
|
* // Logs:
|
||
|
|
* // odds 1
|
||
|
|
* // odds 3
|
||
|
|
* // odds 5
|
||
|
|
* // evens 2
|
||
|
|
* // evens 4
|
||
|
|
* // evens 6
|
||
|
|
* ```
|
||
|
|
*
|
||
|
|
* @see {@link filter}
|
||
|
|
*
|
||
|
|
* @param {function(value: T, index: number): boolean} 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 {any} [thisArg] An optional argument to determine the value of `this`
|
||
|
|
* in the `predicate` function.
|
||
|
|
* @return {[Observable<T>, Observable<T>]} An array with two Observables: one
|
||
|
|
* with values that passed the predicate, and another with values that did not
|
||
|
|
* pass the predicate.
|
||
|
|
*/
|
||
|
|
export declare function partition<T>(source: ObservableInput<T>, predicate: (value: T, index: number) => boolean, thisArg?: any): [Observable<T>, Observable<T>];
|