From: David Masover <ninja@...>
Date: 2008-06-03T06:51:21+09:00
Subject: Re: The duck's backside

On Monday 02 June 2008 08:13:22 Robert Dober wrote:
> On Mon, Jun 2, 2008 at 4:04 AM, David Masover <ninja@slaphack.com> wrote:
> > On Friday 30 May 2008 08:12:35 Mark Wilden wrote:
> >
> >> If classes are not categories, what are they?
> >
> > Classes are categories. But not all categories are classes.
> 
> IMHO this is a gross generalization!
> 
> I guess that you might indeed use Ruby classes as categories in your
> designs. I do not know what others do, but the simple fact that I use
> Ruby classes for other things falsifies your statement.

Give me an example of a class that isn't a category.

It might not be a category as far as your program logic is concerned, but it's 
certainly a category of some kind. NilClass is a category of objects for whom 
#nil? returns true, for example.