From: Robert Klemme <shortcutter@...>
Date: 2009-04-04T03:34:35+09:00
Subject: Re: Class in a Class problem

On 03.04.2009 20:05, matt neuburg wrote:
> Robert Klemme <shortcutter@googlemail.com> wrote:
> 
>>> class A
>>>   def b
>>>     Class.new do
>>>       def initialize(a)
>>>         @a = a
>>>       end
>>>       attr :a
>>>     end.new(self)
>>>   end
>>>   # other stuff that an A knows how to do
>>> end
>> You are creating new classes all the time.  I don't think this is a good
>> idea.
> 
> I'm not sure what you mean about new *classes*.

There is a Class.new in your definition of method b which means, every 
time the method is invoked a new anonymous class is created - regardless 
whether b is invoked several times on one or multiple instances.

> It is certainly true
> that I didn't do anything prevent the user from calling "b" twice on the
> same A instance, thus getting two different objects pointing at that
> instance:
> 
> a = A.new
> b = a.b # b is an instance whose "@a" points at "a"
> bb = a.b # bb is a different instance whose "@a" points at "a"
> 
> But that's easy to solve if desired. Obviously the real problem here is
> that I couldn't fathom what the OP was actually trying to *do*. m.

I had similar difficulties.  That's why I asked.

Kind regards

	robert