Gustaf Neumann wrote:
Donal K. Fellows schrieb:
BTW, I was wondering what happens when you do this in XOTcl (ignoring the syntax for now):
class A derived from Object defines instproc foo class B derived from A defines instproc bar class C derived from Object defines instprocs foo, bar and move
object D is a C with B mixed in call: D foo call: D move
Which implementation of foo gets called first? Which implementation of move gets called first?
as kristoffer pointed out, there is only one move, so there is no ambiguity.
There are two 'move' methods/instprocs. One is in the XOTcl base Object class, and one is in C.
In general the precedence order is per-object-mixins per-class-mixins self-procs class-hierarchy
The introspection command for this is D info precedence
Perhaps I should explain more about what I was asking about. :-)
What I did was I constructed the situation according to the attached diagram (sorry to everyone for doing an attachment, but I refuse to do ASCII art for this!) and what I wanted to know was, given that we've got a per-object mixin, would the foo inherited from A by B be mixed in at higher precedence than the foo gained by D directly from C. If that's the case, would the move inherited from Object through the mixin side override the move gained directly from C? As far as I can tell as someone who has not thought about this in detail, that's the only way to do this sort of thing consistently. But it also means that mixins will stamp all over any attempt to redefine behaviour for a particular application domain. If I'm wrong and I've overlooked something, what is it? It's certainly not clear to me. (Mind you, it's midnight as I write this so the old braincells might not be producing maximum clarity anyway. ;-) )
I hope this all explains why I was asking what appears to be on the surface a trivial question, and the answer should clear up the details of what I don't know about XOTcl inheritance rules from reading the documentation.
Donal.
