🚀 go-pugleaf

In article <1992Nov18.213742.493@afs.com> Michael_Pizolato@afs.com  
(Michael Pizolato) writes:
> A question of philosophy.  Consider the following classes:
> 
[...]
> I can't think of any good reason to access 'value' directly unless I  
have complete control over the implementation of the Foo class.  Even if I  
do, it's painful to change every subclass of Foo that might use 'value'  
directly if I change Foo as above. 
> Any thoughts?

Of course, there's a reason to use the variables directly: it's faster.  
But of course it's dangerous to do so, for the reasons you mentioned. In  
case of classes you didn't implement yourself, you should only directly  
acces variables, if it seems necessary and they're documented. Maybe  
someone who doesn't want the variables to be used should declare them  
private.

> 
> Thanx,
> Michael
> 
> P.S.  Given the conclusion that ivars should only ever be accessed  
through methods, it seems wrong that they appear in the @interface  
section.  Of course we can't change it now, but does anyone know why  
they're there?

I always thought, that this is, because the compiler sometimes needs to  
know the size of the object; but now that I think about it, I can't think  
of an example (at least not with nice Objective-C code).

> 
> --
> Michael_Pizolato@afs.com
> ~18 kyu
> Q16
> NeXTMail appreciated

Carsten