Andreas,

Which scenarios need this unforgable #class access?  There are certainly a 
handful of methods that a proxy would have to respond intelligently too - 
the ProtoObject protocol, basically.  It may not be the case that the 
default implementations would be used, however.  I am thinking of 
equivalence, primarily.

rob

At 08:45 AM 1/5/2002, you wrote:
>Tim,
>
>In certain places it is critical that the class of an object cannot be
>forged. Otherwise you would need to know beforehand which methods you can
>send to proxies and which ones you don't. However, I agree that there's no
>need for having #class generate that byte code so some really long and
>annoying selector (like primitiveUnforgableClassOfObject) or somesuch might
>be in order.
>
>Cheers,
>   - Andreas
>
> > -----Original Message-----
> > From: squeak-dev-admin at lists.squeakfoundation.org
> > [mailto:squeak-dev-admin at lists.squeakfoundation.org]On Behalf Of Tim
> > Rowledge
> > Sent: Saturday, January 05, 2002 7:25 AM
> > To: squeak-dev at lists.squeakfoundation.org
> > Subject: Does #class deserve to be a very-special shortcut bytecode
> > anymore?
> >
> >
> > Whilst discussing delegation and proxying with Stephen P, the
> > subject of
> > #class came up. Since #class is implemented in practice via a very
> > special case bytecode it is a royal pain for proxy work since
> > you can't
> > override it very easily.
> >
> > Now, #class is not a message one should send very often so one must
> > wonder if it is actually sensible to have the vm do this. I looked up
> > all the users of the relevant bytecode and there are in fact 1143 of
> > them in a upgrade#4478 image. Random sampling suggests that a large
> > percentage of those are case where the writer of the method
> > ought to be
> > soundly spanked for not factoring things properly. None of the random
> > sample struck me as being cases where the performance enhancement of a
> > short-circuit bytecode was interesting.
> >
> > We could, I suspect, convert the bytecode to at least do a normal
> > message send (like nearly all the other bytecode special
> > sends) and ease
> > life for proxinators without any impact on performance. Can
> > anyone come
> > up with a really good reason for the current situation? Just
> > curious...
> >
> > tim
> > --
> > Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
> > Useful random insult:- Four bits short of a full DEC.
> >
> >
> >