data-collectors
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A collection of composable reduction operations for arbitrary streams of values
5 lines (4 loc) • 526 B
TypeScript
import { Collector, Supplier } from '../collector';
export declare function groupingByMany<T, K>(mapper: (item: T) => Iterable<K>): Collector<T, Map<K, T[]>, Map<K, T[]>>;
export declare function groupingByMany<T, K, A, D>(mapper: (item: T) => Iterable<K>, collector: Collector<T, A, D>): Collector<T, Map<K, A>, Map<K, D>>;
export declare function groupingByMany<T, K, A, D, M extends Map<K, D>>(mapper: (item: T) => Iterable<K>, supplier: Supplier<M>, collector: Collector<T, A, D>): Collector<T, Map<K, A>, Map<K, D>>;