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std/collections/take_while.ts

Deno standard library
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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
/** * Returns all elements in the given collection until the first element that does not match the given predicate. * * Example: * ```ts * import { takeWhile } from "https://deno.land/std@$STD_VERSION/collections/take_while.ts"; * import { assertEquals } from "https://deno.land/std@$STD_VERSION/testing/asserts.ts"; * * const arr = [1, 2, 3, 4, 5, 6]; * * assertEquals( * takeWhile(arr, (i) => i !== 4), * [1, 2, 3], * ); * ``` */export function takeWhile<T>( array: readonly T[], predicate: (el: T) => boolean,): T[] { let offset = 0; const length = array.length;
while (length > offset && predicate(array[offset])) { offset++; }
return array.slice(0, offset);}