[Pyobjc-dev] Re: [Pythonmac-SIG] pyobjc / cocoa

[Jack J. <Jac...@cw...>]

[I've added pyobjc-dev to the distribution]

On Wednesday, October 16, 2002, at 02:28 , Ronald Oussoren wrote:
>> Something that is open to discussion, I think, is how to map ObjC 
>> names to Python names. The current PyObjC code supports two 
>> compile-time options, object.message_withFoo_(arg1, arg2) and another 
>> that I forget with even more underscores in there (this mapping is 
>> ambiguous: it maps to both [object message: withFoo:] and to [object 
>> message_withFoo:]). The Java-ObjC brigde has simply defined sensible 
>> static mappings for all names used in Cocoa, and the above would 
>> probably become something like object.messagewithFoo() or 
>> object.messageWithFoo(). Python's current method is more flexible, but 
>> boy does it lead to ugly method names in your code...
>
> Changing the mapping from Objective-C names to/from Python names is 
> definitely open for discusion.
>
> BTW. The current PyObjC no longer supports object.message__withFoo__.

I think that what I would like is one static scheme that is the same (or 
almost the same) as the Java/ObjC naming scheme, plus a fallback scheme 
(which could be the current message_withFoo_ scheme). There may be a 
problem here with overloading, though: if I look at AppKitJava there's 
often multiple ObjC selectors that map to one Java method name, I'm not 
sure how they handle this, especially in the face of overriding ObjC 
methods from Java.

The static scheme could simply be a Python dictionary (or an 
NSDictionary, but a Python dictionary is easier to initialize, I guess) 
that we initialize with Python code, where the Python code is generated 
by running /Developer/Java/Jobs/*.jobs through a script. Fastest is 
probably to create both Python->ObjC and ObjC->Python dictionaries.

Is it still possible to have two name mapping schemes, where first one 
is tried and then the other? Or would this wreak havoc now that we have 
two-way inheritance and such?

Hmm, even if that isn't possible we could cop out: if the method name 
translation routine finds that a certain name isn't in the dictionaries 
it would simply add it. Or (more cumbersome, but safer) there could be a 
(Python) API MapObjCSelector('message:withFoo', 'messageWithFoo') which 
could then also check that this mapping doesn't conflict with another 
one. With such a scheme the Python programmer would have to declare any 
new ObjC messages it uses, but the question is how often this will 
happen.
--
- Jack Jansen        <Jac...@or...>        
http://www.cwi.nl/~jack -
- If I can't dance I don't want to be part of your revolution -- Emma 
Goldman -