[Biococoa-dev] ambiguous symbols

[Alexander Griekspoor]

Da's mooi! Sorry I'll translate to english

I hadn't seen your post op cocoa-dev, but I remember talking about 
performSelector and if you could send it to classes a while ago. I 
understand the problem. Could the following perhaps help?

temp = [(BCSymbol *)[self class] performSelector: NSSelectorFromString( 
)

I wonder, because you never know what class it will be in the end 
(hence the warning ;-), but who knows.
Just for the fun, also try:
temp = [(BCAminoAcid *)[self class] performSelector: 
NSSelectorFromString( ) At least, I think that's the class you are 
trying to partially "upgrade" to super, doing this would give the 
compiler just as much knowledge as it has now...

Back then we had a discussion about this with Jim, I'll copy a few 
snippets from those emails, perhaps it helps...
Cheers,
Alex

****

> Well, the problem really is that we get the name of the method from a 
> plist (the plist would contain all the complementary bases), so as a 
> NSString. The trick is how to convert the name into a selector that we 
> can call. Another complicating factor is that the performSelector: 
> method is a NSObject instance method, so won't work on a class. I have 
> found an ObjC function that gets you to the method location (it works 
> because in my simple test it did not return NULL). But how does the 
> ObjC runtime invokes a class method? My knowledge on the runtime 
> architecture is clearly insufficient here...
> Alex
>
>> On Aug 13, 2004, at 3:22 PM, Jim Balhoff wrote:
>>
>>> On Aug 13, 2004, at 3:15 PM, Alexander Griekspoor wrote:
>>>
>>>>> Not true, all classes are objects too, it seems like it would work.
>>>>
>>>> I'm not so sure about that, but probably you are right. Anyway, the 
>>>> description says:
>>>>
>>>> objc_msgSend
>>>>
>>>> Sends a message with a simple return value to an instance of a 
>>>> class.
>>>>
>>>> So I'm afraid it doesn't work on the class itself. I couldn't get 
>>>> it to work either, but perhaps I'm doing something else wrong 
>>>> here...
>>>>
>>>>
>>>
>>> It works, try this:
>>>
>> <snip code>
>> Actually you can just send the performSelector: message to the class. 
>>  I wasn't sure if class objects conformed to the NSObject protocol, 
>> but if you try sending the message [MyClass performSelector:message], 
>> you get the same result as the objc_msgSend() stuff.
>>
>> - Jim

****
>
>> That's even nicer! So should we file a bug against the documentation? 
>> :-)
>> A.
>>
>
> I don't know - maybe the Cocoa-dev list could help with this.  There 
> is a type, Class, and classes are objects, according to the 
> Objective-C manual.  But I can't find anywhere that says it inherits 
> from NSObject (I guess that would be impossible) or conforms to the 
> NSObject protocol.  So I'm not sure how you know what messages you can 
> send to it as an object.  It would be nice to have a better 
> understanding before relying too heavily on the result of 
> performSelector.
>


++++++++++++++




Op 14-nov-04 om 21:10 heeft Koen van der Drift het volgende geschreven:

>
> On Nov 14, 2004, at 2:47 PM, Alexander Griekspoor wrote:
>
>> Nope ;-)
>>
>>
>>
>
> Mooi - het werkt allemaal soepeltjes. Lang leve inheritance :D
>
> Ik denk dat ik alles uit initializeSymbolRelationships verplaats naar 
> BCSymbol. Aminozuren hebben weliswaar geen complements, dus blijven ze 
> daar nil, maar dat maakt niet zoveel uit. Ik wacht nog even met een 
> commit totdat ik een duidelijk antwoord krijg over mijn vraag over 
> performSelector op cocoa-dev.
>
>
> - Koen.
>
>
>
*********************************************************
                     ** Alexander Griekspoor **
*********************************************************
               The Netherlands Cancer Institute
               Department of Tumorbiology (H4)
          Plesmanlaan 121, 1066 CX, Amsterdam
                     Tel:  + 31 20 - 512 2023
                     Fax:  + 31 20 - 512 2029
                     AIM: mekentosj at mac.com
                     E-mail: a.griekspoor at nki.nl
                 Web: http://www.mekentosj.com

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*********************************************************


**************************************************************
                         ** Alexander Griekspoor **
**************************************************************
                  The Netherlands Cancer Institute
                  Department of Tumorbiology (H4)
             Plesmanlaan 121, 1066 CX, Amsterdam
                        Tel:  + 31 20 - 512 2023
                        Fax:  + 31 20 - 512 2029
                       AIM: mekentosj at mac.com
                       E-mail: a.griekspoor at nki.nl
                    Web: http://www.mekentosj.com

MacOS X: The power of UNIX with the simplicity of the Mac

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