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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
import { mapValues } from "./map_values.ts";
/** * Applies the given reducer to each group in the given Grouping, returning the * results together with the respective group keys. * * @example * ```ts * import { reduceGroups } from "https://deno.land/std@$STD_VERSION/collections/reduce_groups.ts"; * import { assertEquals } from "https://deno.land/std@$STD_VERSION/testing/asserts.ts"; * * const votes = { * "Woody": [2, 3, 1, 4], * "Buzz": [5, 9], * }; * * const totalVotes = reduceGroups(votes, (sum, it) => sum + it, 0); * * assertEquals(totalVotes, { * "Woody": 10, * "Buzz": 14, * }); * ``` */export function reduceGroups<T, A>( record: Readonly<Record<string, Array<T>>>, reducer: (accumulator: A, current: T) => A, initialValue: A,): Record<string, A> { return mapValues(record, (it) => it.reduce(reducer, initialValue));}