From: Dan Doel <djd15@...>
Date: 2003-08-11T08:25:26+09:00
Subject: Re: Ruby and OOP-design (question of an old "procedural person" ;)

Brian Candler wrote:

>On Mon, Aug 11, 2003 at 03:16:55AM +0900, Dan Doel wrote:
>  
>
>>It was just an example.  #nil? could be written that way, although then 
>>it'd be pointless, since
>>
>>   if  obj ...
>>
>>Would be exactly the same as
>>
>>   if obj.nil? ...
>>    
>>
>
>I think you mean 'if obj.notnil?' could be written that way.
>
>     if obj...
>
>is equivalent to
>
>     unless obj.nil? ...
>
>with the exception of obj == false.
>
>Cheers,
>
>Brian.
>
>  
>
Right, of course. Most of the time it would be

def nil?
    !self
end

Which would be a boolean anyway.

Of course, it's even simpler than that, because you can do:

class Object
    def nil?
       false
    end
end

class NilClass
    def nil?
       true
    end
end

So you really never save any typing at all.  #nil? is a bad
example, it seems.

- Dan