Re: NSArray cluster class membership

[Marco Scheurer]

On Mar 14, 2004, at 8:24 AM, David Ayers wrote:

> Alex Perez wrote:
> > > Hello list,
> > >
> > > I was browsing the "Porting OGo to MacOSX" page at
> > > http://www.opengroupware.org/en/projects/macosx/ where I found:
> > > "on Cocoa we cannot find out whether an array is mutable - affects
> > > NGObjWeb and is hacked around using NS_DURING".
> > In the interim, can you just rip out GNUstep-base's NSArray, rename 
> > it to
> > GSArray or anything else, and use that instead of OS X's NSArray?
>
> Could someone enlighten me, why 
> respondsToSelector:@selector(addObject:) wouldn't work?

On Cocoa you mean?

For the same reason why isMemberOfClass: and isKindOfClass: are broken. 
NSArray (or more accurately its concrete subclasses) are implemented 
using CFArray, which is also used for NSMutableArray, and implements 
-addObject:. Sending addObject to an NSArray results in a runtime 
error, but the object responds to the message.

marco



Marco Scheurer
Sen:te, Lausanne, Switzerland   http://www.sente.ch