// Copyright 2018-2025 the Deno authors. MIT license.
// This module is browser compatible.
/**
* Applies the given selector to all elements of the given collection and
* returns the min value of all elements. If an empty array is provided the
* function will return undefined.
*
* @typeParam T The type of the elements in the array.
*
* @param array The array to find the minimum element in.
* @param selector The function to get the value to compare from each element.
*
* @returns The smallest value of the given function or undefined if there are
* no elements.
*
* @example Basic usage
* ```ts
* import { minOf } from "@std/collections/min-of";
* import { assertEquals } from "@std/assert";
*
* const inventory = [
* { name: "mustard", count: 2 },
* { name: "soy", count: 4 },
* { name: "tomato", count: 32 },
* ];
*
* const minCount = minOf(inventory, (item) => item.count);
*
* assertEquals(minCount, 2);
* ```
*/
export function minOf<T>(
array: Iterable<T>,
selector: (el: T) => number,
): number | undefined;
/**
* Applies the given selector to all elements of the given collection and
* returns the min value of all elements. If an empty array is provided the
* function will return undefined.
*
* @typeParam T The type of the elements in the array.
*
* @param array The array to find the minimum element in.
* @param selector The function to get the value to compare from each element.
*
* @returns The first element that is the smallest value of the given function
* or undefined if there are no elements.
*
* @example Basic usage
* ```ts
* import { minOf } from "@std/collections/min-of";
* import { assertEquals } from "@std/assert";
*
* const inventory = [
* { name: "mustard", count: 2n },
* { name: "soy", count: 4n },
* { name: "tomato", count: 32n },
* ];
*
* const minCount = minOf(inventory, (item) => item.count);
*
* assertEquals(minCount, 2n);
* ```
*/
export function minOf<T>(
array: Iterable<T>,
selector: (el: T) => bigint,
): bigint | undefined;
export function minOf<T, S extends ((el: T) => number) | ((el: T) => bigint)>(
array: Iterable<T>,
selector: S,
): ReturnType<S> | undefined {
let minimumValue: ReturnType<S> | undefined;
for (const element of array) {
const currentValue = selector(element) as ReturnType<S>;
if (minimumValue === undefined || currentValue < minimumValue) {
minimumValue = currentValue;
continue;
}
if (Number.isNaN(currentValue)) {
return currentValue;
}
}
return minimumValue;
}
|