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std/collections/map_entries.ts

Deno standard library
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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
/** * Applies the given transformer to all entries in the given record and returns a new record containing the results * * Example: * * ```ts * import { mapEntries } from "https://deno.land/std@$STD_VERSION/collections/mod.ts"; * import { assertEquals } from "https://deno.land/std@$STD_VERSION/testing/asserts.ts"; * * const usersById = { * 'a2e': { name: 'Kim', age: 22 }, * 'dfe': { name: 'Anna', age: 31 }, * '34b': { name: 'Tim', age: 58 }, * } as const; * * const agesByNames = mapEntries(usersById, * ([ id, { name, age } ]) => [ name, age ], * ) * * assertEquals(agesByNames, { * 'Kim': 22, * 'Anna': 31, * 'Tim': 58, * }) * ``` */export function mapEntries<T, O>( record: Readonly<Record<string, T>>, transformer: (entry: [string, T]) => [string, O],): Record<string, O> { const ret: Record<string, O> = {}; const entries = Object.entries(record);
for (const entry of entries) { const [mappedKey, mappedValue] = transformer(entry);
ret[mappedKey] = mappedValue; }
return ret;}