$numbers * @param (Closure(T): numeric) $numeric_function * * @return T|null */ function min_by(iterable $numbers, Closure $numeric_function): mixed { $min = null; $min_num = null; foreach ($numbers as $value) { $value_num = $numeric_function($value); if (null === $min_num || $value_num <= $min_num) { $min = $value; $min_num = $value_num; } } return $min; }