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std/collections/max_of.ts

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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
/** * Applies the given selector to all elements of the provided collection and * returns the max value of all elements. If an empty array is provided the * function will return undefined * * @example * ```ts * import { maxOf } from "https://deno.land/std@$STD_VERSION/collections/max_of.ts"; * import { assertEquals } from "https://deno.land/std@$STD_VERSION/testing/asserts.ts"; * * const inventory = [ * { name: "mustard", count: 2 }, * { name: "soy", count: 4 }, * { name: "tomato", count: 32 }, * ]; * * const maxCount = maxOf(inventory, (i) => i.count); * * assertEquals(maxCount, 32); * ``` */export function maxOf<T>( array: readonly T[], selector: (el: T) => number,): number | undefined;
export function maxOf<T>( array: readonly T[], selector: (el: T) => bigint,): bigint | undefined;
export function maxOf<T, S extends ((el: T) => number) | ((el: T) => bigint)>( array: readonly T[], selector: S,): ReturnType<S> | undefined { let maximumValue: ReturnType<S> | undefined = undefined;
for (const i of array) { const currentValue = selector(i) as ReturnType<S>;
if (maximumValue === undefined || currentValue > maximumValue) { maximumValue = currentValue; continue; }
if (Number.isNaN(currentValue)) { return currentValue; } }
return maximumValue;}