From: Sean O'Dell <sean@...>
Date: 2004-06-26T02:09:00+09:00
Subject: Re: Is it considered Harmful?

On Friday 25 June 2004 09:55, ts wrote:
> >>>>> "D" == Dave Thomas <dave@pragprog.com> writes:
>
> D> Modules (such as Enumerable) only add methods.
>
>  This is worst than this : Enumerable rely on the method #each which is
>  implemented differently by each class, this is why it work

I have to admit when I'm wrong.

At least doing it brute-force, changing an object's class DOES crash Ruby.  
But I've only done a rudimentary test where I simply replaced the klass VALUE 
(in C) with something else.  I can't understand why Ruby would crash, except 
that internally there must be a whole lot of code that doesn't do any kind of 
checking of internal values.

I think I can see why Guy says this can't be done.  I haven't seen much of the 
internal Ruby implementations, but my initial guess is that Ruby makes an 
assumption about the presence, and state, of internal data kept with each 
object/class.

If that's the case, it would probably be a mountain of work to back through it 
all and place checks on that internal data.

	Sean O'Dell