[XML-SIG] SAX parser factories (Was: PyTRaX?)

[Martin v. Loewis]

> Good point. There does need to be something along the lines of the
> make_parser function in SAX.

My proposal would be to add two keyword arguments, properties= and
features=. Each is a list of binary tuples, each tuple has name and
value. Alternatively, dictionaries might be better.

make_parser will the iterate over all known parser factories, invoking
create_parser for each, then trying to set all the properties and
features. It will return the first parser that supports all of them,
and return a configured instance.

There should also be a function xml.sax.register_parser, which accepts
an object that has a create_parser function, or a string naming a
module that has a create_parser function.

What do you think?

Regards,
Martin