[Python-Dev] Extending types in C - help needed

[Jack Jansen]

In the discussion on my request for an ("O@", typeobject, 
void **) format for PyArg_Parse and Py_BuildValue MAL suggested 
that I could get the same functionality by creating a type 
WrapperTypeObject, which would be a subtype of TypeObject with 
extra fields pointing to the _New() and _Convert() routines to 
convert Python objects from/to C pointers. This would be good 
enough for me, because then types wanting to participate in the 
wrapper protocol would subtype WrapperTypeObject in stead of 
TypeObject, and two global routines could return the _New and 
_Convert routines given the type object, and we wouldn't need 
yet another PyArg_Parse format specifier.

However, after digging high and low I haven't been able to 
deduce how I would then use this WrapperType in C as the type 
for my extension module objects. Are there any examples? If not, 
could someone who understands the new inheritance scheme give me 
some clues as to how to do this?
--
- Jack Jansen        <Jack.Jansen@oratrix.com>        
http://www.cwi.nl/~jack -
- If I can't dance I don't want to be part of your revolution -- 
Emma Goldman -