[Zope-dev] ExtensionClass question

[Michel Pelletier]

"Phillip J. Eby" wrote:
> 
> At 05:33 PM 2/24/00 -0800, Michel Pelletier wrote:
> >
> >So if I understand your original question right (which I may not), you
> >want to use some sort of mechanism in C to generalize one ExtensionClass
> >type with another *in C*.  I don't think this is possible (it might be
> >possible with some sort of C++ mechanism, but I haven't delved into that
> >beast of a language in years...).
> >
> 
> The method chain of an ExtensionClass type structure can point back to a
> previous method chain, thus allowing extension of the type.

Ah!

>  Similarly, the
> other members of the type structure can point to existing routines.  And,
> as long as one uses a backwardly compatible data structure for the type,
> one can subclass an existing ExtensionClass.  

I see, it's one of those using-C-in-an-OO-way kind of things without
there being an explicit language mechanism to get it done.

> It is usually easier,
> however, to just create mixin ExtensionClasses for the different bits you
> need, and combine them together as base classes for a Python class.

Understood.

-Michel