Re: [boost] RFC: Boost.XML API prototype in the sandbox -> generation form xsd

From: Oliver.Kowalke_at_[hidden]
Date: 2007-07-12 00:52:26

> As well as a harder-to-implement direction. Having to make a 
> struct for every tag you implement seems a little 
> user-unfriendly. For a constrained format (like SVG) I could 
> agree, but I think for Boost.XML library, there should be easy naming.
> 
> Splitting the difference (or so I hope) between easy 
> trees/expressiveness and standard syntax, how about something 
> like this?
> 
> root.push_front
> (
>   tag("Article Info",
>      (title ? (comment("This title was moved"), title) : NULL)
>      (tag("author",
>           (tag("firstname", "Joe"))
>           (tag("surname", "Random"))
>       ))
>   )
> );

I find it relay hard to read and I'm missing the typesafety. Nothing 
prevents you to put tag("firstname", "Joe") in place of article info
tag!
You are forced to validate it at runtime.

Phils suggestion is more typesafe:

articleinfo ai;
{
   if (title) ai.push_back(comment("This title was moved"));
   author a;
   {
     a.push_back(firstname("Joe"));
     a.push_back(surname("Random"));
     ai.push_back(a);
   }
   root.push_back(ai);
}

I would like to see translating xsd (xml schemas) to c++ classes 
(but this could be a further improvment).

A good idea would be providing an iterator which can be used traverse
the xml-tree.

Oliver