private function processParameters()
    {
        $parameters = $this->parameters;
        $string = $this->query;

        $string = str_replace('[:', '[;;', $string);

        $parameters = array_filter($parameters, function ($value) use (& $parameters, & $string)
        {
            $key = key($parameters);
            next($parameters);

            if (is_numeric($value))
            {
                $string = str_replace(":$key", $value, $string);
                return false;
            }

            else
            {
                $string = str_replace(":$key", '{' . $key . '}', $string);
                return true;
            }
        });

        $string = str_replace('[;;', '[:', $string);

        $this->query = $string;
        return $parameters;
    }