From: Sean O'Dell <sean@...>
Date: 2004-06-26T01:49:11+09:00
Subject: Re: Is it considered Harmful?

On Friday 25 June 2004 09:16, Bill Kelly wrote:
> From: "Sean O'Dell" <sean@celsoft.com>
>
> > On Friday 25 June 2004 02:19, ts wrote:
> > > >>>>> "S" == Sean O'Dell <sean@celsoft.com> writes:
> > >
> > > S> variables it might not expect (buyer beware), it seems like we ought
> > > to be S> able to do that.  I don't believe there's any solid technical
> > > block to doing S> this, is there?
> > >
> > >  If you think that the possiblity to crash ruby is not a technical
> > > reason, then you are right it don't exist solid technical reason.
> >
> > You're wrong on that.  It wouldn't crash Ruby to change the class of an
> > object.  Objects already change their class when you turn them into
> > singletons.  Changing it to any class of your choosing would be even
> > simpler, since creating a singleton involves inheriting all the old class
> > methods; changing a class wouldn't require all that work.
>
> Supposed an object's class were changed to a different class
> which was itself (or whose ancestor(s) were) implemented in 'C'
> code.  Something that expects that once it's initialized it
> can go ahead and rely on its class invariants pointing to real
> operating system file handles, window handles, etc.

No code should "expect" data to be there that isn't.  If a C extension wraps a 
native C struct as a Ruby object with Make_Struct, then when it unwraps it, 
and gets nothing or a NULL pointer, it shouldn't continue to try and use it.  
That's sloppy coding.

	Sean O'Dell