SlightPHP\PHPMailer::EncodeQ PHP Method

    public function EncodeQ($str, $position = 'text')
    {
        /* There should not be any EOL in the string */
        $encoded = preg_replace("[\r\n]", '', $str);
        switch (strtolower($position)) {
            case 'phrase':
                $encoded = preg_replace("/([^A-Za-z0-9!*+\\/ -])/e", "'='.sprintf('%02X', ord('\\1'))", $encoded);
                break;
            case 'comment':
                $encoded = preg_replace("/([\\(\\)\"])/e", "'='.sprintf('%02X', ord('\\1'))", $encoded);
            case 'text':
            default:
                /* Replace every high ascii, control =, ? and _ characters */
                $encoded = preg_replace('/([\\000-\\011\\013\\014\\016-\\037\\075\\077\\137\\177-\\377])/e', "'='.sprintf('%02X', ord('\\1'))", $encoded);
                break;
        }
        /* Replace every spaces to _ (more readable than =20) */
        $encoded = str_replace(' ', '_', $encoded);
        return $encoded;
    }