From: Robert Klemme <bob.news@...>
Date: 2005-09-23T00:51:40+09:00
Subject: Re: Instantiating a subclass of NilClass.

Trans <transfire@gmail.com> wrote:
> Robert Klemme wrote:
>> Hm...  I guess NilClass in Java lingo would be a final class, i.e.,
>> no inheritance allowed.
>>
>> Btw, why do you want to do that?  I mean, you can create a class with
>> nil-like behavior (apart from the boolean behavior I guess) without
>> inheriting NilClass, can't you?
>
> Yea, but the boolean behavior is important. I'm using it in a
> OpenStruct like class, so that:
>
>  o = OpenStructLike.new
>  o.foo          #=> null
>  o.foo.bar      #=> null
>
> As it is:
>
>  o.foo          #=> nil
>  o.foo.bar      #=> ERROR

<snip/>

> Thanks, unfortunately w/o the boolean behavior it won't work
> transparently.

It's still not clear to me why you need that.  Why can't you simply use nil? 
If we know the whole story we might be able to come up with a different 
solution.  I mean, why do you need to be able to invoke methods on 
uninitialized members?  I can remember that we had a similar discussion a 
while ago and your implementation of method_missing might lead to undetected 
errors.  So I personally would not find this desirable.  What makes you 
think differently here?

Kind regards

    robert