/
filter_values.ts
42 lines (39 loc) · 1.1 KB
/
filter_values.ts
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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
// This module is browser compatible.
/**
* Returns a new record with all entries of the given record except the ones that have a value that does not match the given predicate
*
* Example:
*
* ```ts
* import { filterValues } from "https://deno.land/std@$STD_VERSION/collections/mod.ts";
* import { assertEquals } from "https://deno.land/std@$STD_VERSION/testing/asserts.ts";
*
* type Person = { age: number };
*
* const people: Record<string, Person> = {
* 'Arnold': { age: 37 },
* 'Sarah': { age: 7 },
* 'Kim': { age: 23 },
* };
* const adults = filterValues(people, it => it.age >= 18)
*
* assertEquals(adults, {
* 'Arnold': { age: 37 },
* 'Kim': { age: 23 },
* })
* ```
*/
export function filterValues<T>(
record: Readonly<Record<string, T>>,
predicate: (value: T) => boolean,
): Record<string, T> {
const ret: Record<string, T> = {};
const entries = Object.entries(record);
for (const [key, value] of entries) {
if (predicate(value)) {
ret[key] = value;
}
}
return ret;
}