Re: [Pyobjc-dev] [ pyobjc-Bugs-836247 ] NSWindow.contentRectForFrameRect_styleMask_ not a class meth

[b.bum <bb...@ma...>]

Unless I'm missing something, can't we always tell at the moment of 
dispatch whether or not a particular method should be resolved in the 
class or instance context?

When objc_msgSend() is invoked, the SEL parameter is resolved 
internally based on the 'self' parameter -- on the target of 
invocation.   So, once we have an object reference and a selector, our 
bridged dispatch to the method IMP should "just work" regardless of 
whether it is a class or instance.

The only place that class vs. instance method is problematic would 
appear to be within the Python subclasses of ObjC objects where there 
is a need to define both a class and an instance method.  I.e. 
+description vs. -description.

Given that +description requires, effectively, a redeclaration through 
the use of selector(), we could change the name of the method 
slightly-- and invisibly-- at that time.

But that is ugly.

Instead, can we handle this at the time of dispatch?

I.e. if you do Foo.description to grab a reference to the description 
method of the Foo class--  which has both +description and 
-description-- then we should be able to figure out if the class or 
instance implementation should be invoked at the time of dispatch based 
on what the target of the invocation is.

There are other details that would have to be worked out.  But, for the 
most part, it would seem that this could be done in a largely automatic 
and transparent fashion.   The remaining unknowns are largely arbitrary 
in nature because they only occur due to the combined interaction of 
the ObjC and Python runtimes -- we are free to do whatever we want.

b.bum