Fusonic\Linq\Linq::aggregate PHP Метод

    public function aggregate(callable $func, $seed = null)
    {
        $result = null;
        $first = true;
        if ($seed !== null) {
            $result = $seed;
            $first = false;
        }
        foreach ($this->iterator as $current) {
            if (!$first) {
                $result = $func($result, $current);
            } else {
                $result = $current;
                $first = false;
            }
        }
        if ($first) {
            throw new \RuntimeException("The input sequence contains no elements.");
        }
        return $result;
    }