From: John Carter <john.carter@...>
Date: 2005-05-06T13:35:26+09:00
Subject: Re: RCR 303: nil should accept missing methods and return nil

On Fri, 6 May 2005, Austin Ziegler wrote:

> But nil isn't an Anything object, it's nothing. It shouldn't respond
> to things that it doesn't know about.

Ah, but you're wrong, nil is "no thing, of any type, is here."

> If you want nil as a null object, use a module to extend the
> behaviour -- but don't be surprised if a lot of programs start dying
> for unclear reasons.

Prove me wrong, take the challenge.

Next time your pet program dies of a NoMethodError for NilClass add

class NilClass
   def method_missing(sym,*args)
     nil
   end
end

...at the head of your program.

See empirically what happens. Does it hide bugs? Does it just work? Does 
it still throw an exception or give an error message?

Try this next few occasions you get such a bug, each time email me the 
results, I will summarize to the group.


John Carter                             Phone : (64)(3) 358 6639
Tait Electronics                        Fax   : (64)(3) 359 4632
PO Box 1645 Christchurch                Email : john.carter@tait.co.nz
New Zealand


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