From: Dan Doel <djd15@...>
Date: 2003-08-11T01:48:36+09:00
Subject: Re: Ruby and OOP-design (question of an old "procedural person" ;)

dblack@superlink.net wrote:

>Hi --
>
>On Sun, 10 Aug 2003, Dan Doel wrote:
>
>  
>
>>But why should ? methods be required to return solely true or false?
>>Isn't it enought to require that they
>>return objects that evaluate to true or false appropriately?
>>    
>>
>
>Jumping in with semi-devil's-advocate point:
>
>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.

That's a good example, though.

- Dan