SimplePie_Parse_Date::remove_rfc2822_comments PHP Метод

    public function remove_rfc2822_comments($string)
    {
        $string = (string) $string;
        $position = 0;
        $length = strlen($string);
        $depth = 0;
        $output = '';
        while ($position < $length && ($pos = strpos($string, '(', $position)) !== false) {
            $output .= substr($string, $position, $pos - $position);
            $position = $pos + 1;
            if ($pos === 0 || $string[$pos - 1] !== '\\') {
                $depth++;
                while ($depth && $position < $length) {
                    $position += strcspn($string, '()', $position);
                    if ($string[$position - 1] === '\\') {
                        $position++;
                        continue;
                    } elseif (isset($string[$position])) {
                        switch ($string[$position]) {
                            case '(':
                                $depth++;
                                break;
                            case ')':
                                $depth--;
                                break;
                        }
                        $position++;
                    } else {
                        break;
                    }
                }
            } else {
                $output .= '(';
            }
        }
        $output .= substr($string, $position);
        return $output;
    }