On Wed, Feb 20, 2013 at 3:27 PM, Richard <legalize+jeeves@mail.xmission.com> wrote:
Boost.Spirit.Qi to parse the stream into data structures Boost.Spirit.Karma to emit the necessary output from the data structures
Richard, Thank you. I am unfamiliar with Spirit and Karma. Your comment not only introduced me to them but highlighted just how vague my question was. I was thinking less about the actual decoding (who would have known based on what I wrote) and more on how I would "generically" and "extensibly" handle the many fields I am about to receive. For example, consider the following horrible code. Is there a "boost" way to do this kind of thing... (perhaps Spirit/Karma is the answer and I am just more out of touch than I imagine): Good things about the classes below: It is easy to add a new parameter. Just push one onto the back of EmployeePacket::Items The class EmployeePacket doesn't have hundreds of data members such as "string name_, int age_" Bad things about the classes below: Extracting data from the EmployeePacket requires hideous dynamic_casts and hard-coded vector indices Thank you again for your comments/criticisms/suggestions, Chris === class EmployeePacket { std::vector<Item*> Items; EmployeePacket() { Items.push_back(new String("name", "John Doe")); Items.push_back(new Double("salary", "USD", 1, 1)); } void Decode(istream& Stream) { for (auto pItem : Items) pItem->Decode(Stream) } double GetSalary() { return dynamic_cast<Double*>(Items[1])->value; } } class Item { virtual void Decode(istream& Stream) = 0; } class Double : public Item { string name; string units; // double decode_conversion_scale; // double decode_conversion_translate; // unsigned number_of_bits_used_to_encode // double scale_factor double value; void Decode(istream& Stream) { Stream.read(&value, 8); value = value * decode_conversion_scale + decode_conversion_translate; } class String : public Item { string name; string value; void Decode(istream& Stream); }