[Vala] libxml2 question

[Giulio Paci <giuliopaci interfree it>]

Hi to all,
        I am learning libxml2 and trying to use it in a vala program.

I have just implemented a SAX parser that I am using like this:

class Parser {

        ...

        public void parse_file(string path) {
                SAXHandler handler = SAXHandler();
                handler.startElement = start_element_new;
                handler.endElement = end_element_new;
                handler.characters = characters_new;
                handler.user_parse_file(this, path);
        }

        ...

}

Now I want to be able to provide XML input using my own functions, 
instead of reading it from files. So here: 
http://xmlsoft.org/html/libxml-parser.html I found 
xmlCreatePushParserCtxt() and xmlCreateIOParserCtxt() that seem to do 
what I want, however I was not able to find how to call those methods 
from vala (the libxml2.vapi provides access to 
htmlCreatePushParserCtxt() and htmlCreateIOParserCtxt()).

Is there any reason why xml- methods cannot be accessed in vala? How can 
I implement what I want?

Bests,
        Giulio.