Re: [boost] [Boost Review] Property Tree Library

From: Marcin Kalicinski (kalita_at_[hidden])
Date: 2006-04-22 06:02:05

> // Data structure itself
> template<typename ValueType,typename KeyType>
> struct Node;
>
> template<typename ValueType,typename KeyType>
> struct ptree_gen {
>    typedef std::pair<KeyType,Node<ValueType,KeyType> > mi_value;
>    typedef multi_index<mi_value, indexed_by<...> > type;
> };
>
> template<typename ValueType,typename KeyType>
> struct Node {
>    ValueType v;
>    ptree_gen<ValueType,KeyType>::type children;
> };
>
> // serilization support
> template<class Archive,typename ValueType,typename KeyType>
> void serialize(Archive & ar, Node<ValueType,KeyType>& n, const unsigned 
> int version)
> {
>    ar & n.v;
>    ar & n.children;
> }
>
> // some access methods
> template<typename ValueType,typename KeyType>
> ValueType const&
> get( string const& keys, ptree_gen<ValueType,KeyType>::type const& src )
> {
>   std::pait<string,string> sk = split( keys, "." );
>
>   Node const& N = src.find( sk.first );
>
>   return sk.second.empty() ? N.v : get( sk.second, N.children );
> }
>

What you just implemented is stripped down, bare bones version of 
property_tree that, among other things, does not allow you to produce human 
editable XML files. Now add more interface (aka get functions), add more 
archives to serialization lib, add customization, add transparent 
translation from strings to arbitrary types and vice versa. Spend some weeks 
trying to get all the corner cases right, and then some more weeks trying to 
smooth rough edges in the interface. Then write tests. Write docs. At the 
end, I believe you will not get much less code than there is in the library 
already. Maybe you get some savings by using multi_index instead of manual 
indexing.

Best regards,
Marcin