$iterable * @param (Closure(T): bool) $predicate * * @return array{0: list, 1: list} */ function partition(iterable $iterable, Closure $predicate): array { $success = []; $failure = []; foreach ($iterable as $value) { if ($predicate($value)) { $success[] = $value; } else { $failure[] = $value; } } return [$success, $failure]; }