Re: NSArray - waste of time?

FROM : Philippe Mougin
DATE : Thu Apr 26 23:51:24 2007

Le 26 avr. 07 à 23:36, John Stiles a écrit :

> This is a bit confusing to me--the implementation of NSArray is 
> inside the OS, right? So what do you mean by this? Do you have a 
> custom subclass or something?


Yes. NSArray is semi-abstract, and is consequently always used 
through a concrete subclass. Cocoa provides default implementations 
(the most common is NSCFArray these days) but you can as well use 
your own concrete subclass. This is what we do in F-Script.

Philippe Mougin


> Sent: Thu 4/26/2007 2:33 PM
> To: <email_removed>
> Subject: Re: NSArray - waste of time?
>  > There is also the footprint to consider, surely?
>  > A C-style array is likely to be much smaller than
>  > an NSArray of objects, particularly in the case of
>  > primitive data types such as floats vs NSNumber objects.
>
> It depends how the NSArrays you deal with are implemented (remember
> that NSArray is a class cluster -- in other words, a semi-abstract
> class). For instance, in F-Script we make extensive usage of NSArrays
> (in particular arrays of NSNumbers), but we do so using an
> implementation that transparently make them as small and as fast as C-
> style arrays, in most cases.
>
> Philippe Mougin