From: Florian Gross <flgr@...>
Date: 2005-01-26T05:25:48+09:00
Subject: Re: Self and Ruby Comparisons

Trans wrote:

> Quite right, I'm not sure Ruby is particularly suited for role
> swapping. (Prototype-based OOP handles it gracefully) And I don't know
> how inefficent #become would be. It would be nice to think its just a
> matter of changing one pointer, but I know that's not the case.

It's still not too much work. Ignoring the checks that need to be done 
the basic task works like this: Create a copy of the object and swap the 
five fields of their internal structs -- after that invalidate the 
method cache and optionally migrate exivars and perhaps also the 
finalizer. I think you can safely assume that this overhead is constant.