From: Logan Capaldo <logancapaldo@...>
Date: 2006-10-04T11:35:03+09:00
Subject: Re: dynamically changing superclass/mixins

On Tue, Oct 03, 2006 at 07:10:10PM +0900, Michael Keller wrote:
> I have strong interest in highly dynamic languages, particularly
> prototype-based languages - and am still looking for the language that I
> have to "abuse least" to achieve what I want (for my attempt in Java,
This may be considered blashpemous, but have you seen Io?
(http://www.iolanguage.com) It lets you alter the prototypes for an
object dynamic, which effectively gives you the abilities of removing
mixins and changing the superclass.

> see http://diamondmud.sourceforge.net/, particularly
> http://diamondmud.sourceforge.net/architecture.html)
> 
> Ruby, apart from just being a great language, has two features that are
> fantastic for me:
> - open classes: I can add and remove methods "at runtime"
> - mixins; this is highly reminiscient of prototype based languages anyway.
> 
> Now I have two questions:
> 
> 1. Can I change the superclass for an already defined class? That is,
> remove an existing relationship or add a new one? I haven't been able to
> figure that out.
> 
> 2. Can I also remove modules that I included into a class? I have only
> found a very ugly way to do this: undefine the class (Klass = nil) and
> define it anew. I am not sure even, what the effect was on existing
> instances; if they adapted the new behaviour or not.
> 
Setting the constant to nil will not effect existing instances. 
> I am fairly new to Ruby, so please forgive fundamental misunderstandings!