private function parseToken()
    {
        $token = '';

        while ($this->valid()) {
            if (ctype_space($this->current)) {
                // Skip space
                $this->next();

                break;
            }

            if ('\\' === $this->current) {
                $token .= $this->parseEscapeSequence();
            } elseif ("'" === $this->current || '"' === $this->current) {
                $token .= $this->parseQuotedString();
            } else {
                $token .= $this->current;
                $this->next();
            }
        }

        return $token;
    }