1 | import { ObservableInput } from '../types';
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2 | import { Observable } from '../Observable';
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3 | /**
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4 | * Splits the source Observable into two, one with values that satisfy a
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5 | * predicate, and another with values that don't satisfy the predicate.
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6 | *
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7 | * <span class="informal">It's like {@link filter}, but returns two Observables:
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8 | * one like the output of {@link filter}, and the other with values that did not
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9 | * pass the condition.</span>
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10 | *
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11 | * ![](partition.png)
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12 | *
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13 | * `partition` outputs an array with two Observables that partition the values
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14 | * from the source Observable through the given `predicate` function. The first
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15 | * Observable in that array emits source values for which the predicate argument
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16 | * returns true. The second Observable emits source values for which the
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17 | * predicate returns false. The first behaves like {@link filter} and the second
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18 | * behaves like {@link filter} with the predicate negated.
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19 | *
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20 | * ## Example
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21 | * Partition a set of numbers into odds and evens observables
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22 | * ```ts
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23 | * import { of, partition } from 'rxjs';
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24 | *
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25 | * const observableValues = of(1, 2, 3, 4, 5, 6);
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26 | * const [evens$, odds$] = partition(observableValues, (value, index) => value % 2 === 0);
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27 | *
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28 | * odds$.subscribe(x => console.log('odds', x));
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29 | * evens$.subscribe(x => console.log('evens', x));
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30 | *
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31 | * // Logs:
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32 | * // odds 1
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33 | * // odds 3
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34 | * // odds 5
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35 | * // evens 2
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36 | * // evens 4
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37 | * // evens 6
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38 | * ```
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39 | *
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40 | * @see {@link filter}
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41 | *
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42 | * @param {function(value: T, index: number): boolean} predicate A function that
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43 | * evaluates each value emitted by the source Observable. If it returns `true`,
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44 | * the value is emitted on the first Observable in the returned array, if
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45 | * `false` the value is emitted on the second Observable in the array. The
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46 | * `index` parameter is the number `i` for the i-th source emission that has
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47 | * happened since the subscription, starting from the number `0`.
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48 | * @param {any} [thisArg] An optional argument to determine the value of `this`
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49 | * in the `predicate` function.
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50 | * @return {[Observable<T>, Observable<T>]} An array with two Observables: one
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51 | * with values that passed the predicate, and another with values that did not
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52 | * pass the predicate.
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53 | */
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54 | export declare function partition<T>(source: ObservableInput<T>, predicate: (value: T, index: number) => boolean, thisArg?: any): [Observable<T>, Observable<T>];
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