From: "David A. Black" <dblack@...>
Date: 2004-11-30T07:49:46+09:00
Subject: Re: Friend class/inner class

Hi --

On Tue, 30 Nov 2004, Dan Janowski wrote:

> What I am looking for is very similar to a clone. However, instead of 
> the instance variables referring to the same objects, the variables use 
> the same reference storage. This way, 'b' which is a friend of 'a' can 
> change a value of a shared variable and 'a' has the same change. 'b' 
> can be extended via singleton methods that do not change the 'a' 
> instance definition.
> 
> I can get close with clone as long as I read-only or change! the shared 
> instances, but the replacement of a reference in one has no effect on 
> the other.
> 
> I know I can use instance_eval, but I was hoping for something like 
> 'clone' in its directness.
> 
> Is there any consideration of this? Is it possible to do with Ruby's 
> internal constructs? I think that an anonymous subclass is created when 
> singleton methods are added, but can one instance be directly related 
> to another instance with the base instance providing its variables as 
> well?

I'm tempted to say:

   b = a

but that probably isn't exactly what you're looking for :-)  I'm not
quite getting it, though.  Can you give an example of what some code
would look like that did what you're describing?


David

-- 
David A. Black
dblack@wobblini.net