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- import { MonoTypeOperatorFunction, ObservableInput } from '../types';
- /**
- * Returns an Observable that emits all items emitted by the source Observable that are distinct by comparison from previous items.
- *
- * If a `keySelector` function is provided, then it will project each value from the source observable into a new value that it will
- * check for equality with previously projected values. If the `keySelector` function is not provided, it will use each value from the
- * source observable directly with an equality check against previous values.
- *
- * In JavaScript runtimes that support `Set`, this operator will use a `Set` to improve performance of the distinct value checking.
- *
- * In other runtimes, this operator will use a minimal implementation of `Set` that relies on an `Array` and `indexOf` under the
- * hood, so performance will degrade as more values are checked for distinction. Even in newer browsers, a long-running `distinct`
- * use might result in memory leaks. To help alleviate this in some scenarios, an optional `flushes` parameter is also provided so
- * that the internal `Set` can be "flushed", basically clearing it of values.
- *
- * ## Examples
- *
- * A simple example with numbers
- *
- * ```ts
- * import { of, distinct } from 'rxjs';
- *
- * of(1, 1, 2, 2, 2, 1, 2, 3, 4, 3, 2, 1)
- * .pipe(distinct())
- * .subscribe(x => console.log(x));
- *
- * // Outputs
- * // 1
- * // 2
- * // 3
- * // 4
- * ```
- *
- * An example using the `keySelector` function
- *
- * ```ts
- * import { of, distinct } from 'rxjs';
- *
- * of(
- * { age: 4, name: 'Foo'},
- * { age: 7, name: 'Bar'},
- * { age: 5, name: 'Foo'}
- * )
- * .pipe(distinct(({ name }) => name))
- * .subscribe(x => console.log(x));
- *
- * // Outputs
- * // { age: 4, name: 'Foo' }
- * // { age: 7, name: 'Bar' }
- * ```
- * @see {@link distinctUntilChanged}
- * @see {@link distinctUntilKeyChanged}
- *
- * @param keySelector Optional `function` to select which value you want to check as distinct.
- * @param flushes Optional `ObservableInput` for flushing the internal HashSet of the operator.
- * @return A function that returns an Observable that emits items from the
- * source Observable with distinct values.
- */
- export declare function distinct<T, K>(keySelector?: (value: T) => K, flushes?: ObservableInput<any>): MonoTypeOperatorFunction<T>;
- //# sourceMappingURL=distinct.d.ts.map
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