From: dblack@...
Date: 2003-08-11T02:02:33+09:00
Subject: Re: Ruby and OOP-design (question of an old "procedural person" ;)

Hi --

On Mon, 11 Aug 2003, Dan Doel wrote:

> dblack@superlink.net wrote:
>
> >One situation I can think of in which it would be handy to rely on this
> >would be:
> >
> >  if a.nil? == b.nil?
> >
> >which of course could also be written:
> >
> >  if (a.nil? && b.nil?) ||! (a.nil? || b.nil?)
> >
> >or something, but obviously version 1 is nice and concise.  Then again,
> >it's a pretty marginal case, I guess.
> >
> >
> >David
> >
> >
> >
> That is a good example.
>
> Does ruby not have exclusive or? I can't remember at the moment. If it
> did, I think the top is the same
> as:
>
> unless a.nil? ^ b.nil?
>
> Which is still somewhat unclear, I agree.

I, however, no long agree with myself :-)  I just forgot about ^.

> That's a good example, though.

Hmmm... I wonder if it could be strengthened by finding a case where
there actually isn't an equally short (or shorter) alternative.  I
can't think of one.  Of course, as I mentioned, I've sort of playing
devil's advocate -- I don't think the non-true-or-false return value
actually bothers me.


David

-- 
David Alan Black
home: dblack@superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav