$iterable * @param (Closure(Tv): Ts) $scalar_func * @param (Closure(Ts, Ts): int)|null $comparator * * @return list */ function sort_by(iterable $iterable, Closure $scalar_func, null|Closure $comparator = null): array { /** @var array $order_by */ $order_by = []; /** @var array $values */ $original_values = []; $i = 0; foreach ($iterable as $v) { $original_values[$i] = $v; $order_by[$i] = $scalar_func($v); $i++; } if (null !== $comparator) { uasort($order_by, $comparator); } else { asort($order_by); } $result = []; foreach ($order_by as $k => $_) { $result[] = $original_values[$k]; } return $result; }