From: Archit Baweja <bighead@...>
Date: 2004-05-19T14:55:58+09:00
Subject: Re: Zero is true ... whoda thunk?

By far the best explanation IMHO.

*claps*
Archit

Claus Spitzer <DocBoobenstein@gmail.com> writes:

> Well, we're deving into semantics here, and I don't want to start a
> flamewar but I certainly have to concur that milk.volume == 0 is not
> the same as milk == 0. In other words, because _I_ don't have any milk
> doesn't mean that the world has run out of milk. The milk in my fridge
> is just an instance of the Milk class. Unlike the Matrix, we can't say
> that "there is no Milk".
> But let's take another example for zero -let f(x) = x^2 - 4. Now, when
> x is 2 then f(x) is zero. Does that mean that f(x) is false too? No.
> Before anyone starts to cry foul let me state the following: zero has
> instances where it is not false, as shown above. It also has instances
> where it could be considered false (albeit with warnings). Compare
> that to "false" and "nil", which are false in every situation. The
> latter are more consistent, don't you think?
>  Cheers, 
>     Claus
> 
> 
> On Wed, 19 May 2004 12:53:56 +0900, David Naseby
> <david.naseby@eonesolutions.com.au> wrote:
> > 
> > >-----Original Message-----
> > >From: Hal Fulton [mailto:hal9000@hypermetrics.com]
> > >>> if got_milk?  ... end
> > >>>
> > >>>where
> > >>>
> > >>> def got_milk?
> > >>>   @milk_volume.zero?
> > >>
> > >>
> > >> Bugger. I mean !@milk_volume.zero? of course.  So this whole
> > >problem could
> > >> be avoided by making 0==false, thus proving your point. THIS
> > >is why I don't
> > >> post normally....
> > >
> > >Haha... well, the got-milk logic would mean that negative numbers
> > >would also be false, right? "I've got -5 gallons of milk. Give me
> > >5 gallons, and I still won't have any!"
> > >
> > >Now you've got me thinking about the Mad Hatter's tea party...
> > 
> > You are just making the foolish mistake of assuming that just because my
> > @milk_volume attribute responds to #zero? its a number, which, of course, in
> > this mythical example, it isn't. It's a volume type (quart, in this case, as
> > I'm speaking to old-fashioned types...), quite well defined, so when Rover
> > checks if his milk volume, he finds out the answer in only ONE unit of
> > measurement....
> > 
> > David.
> > 
> >
> 
> 

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