AW: WG: [xml] WG: Document traversing interface for libxml2

["Mickautsch, Alfred" <alfred mickautsch schuler-ag com>]

> I still have a fundamental question left which is:
>    - shouldn't it be better from an API and implementation 
> point of view
>      to instead make the xmlDocWalker a "subclass" of the xmlReader,
>      basically creating an xmlTextReader from an xmlDocPtr, 
> adding the 
>      options to go forward and backward in that case and reuse most of
>      the code from the xmlTextReader to reimplement the xmlDocWalker
>      in just a slightly different way
>      pros:
>         - share code
>       - less APIs entry points
I find this idea very attractive. You could go even further and give the xmlTextReader a callback function, 
say xmlGetNextElement, used internally by xmlTextReaderRead so that one can, just by using another 
xmlGetNextElement, process virtually any kind of input data (XML/HTML files, DOM trees, config files, 
in-memory structured data,...).