[Types-sig] QueryProtocol

[Clark C. Evans]

On Sat, 24 Mar 2001, Michel Pelletier wrote:
> >         # first check to see if object has the exact protocol
> >     >   if type(protocol) is types.InterfaceType and \
> >     >       instance(obj,protocol): return obj
> >         if type(obj) is types.InstanceType and \
> >            obj.__class__ is protocol: return obj
> >         if type(obj) is protocol: return obj
> >
> >         # procedure to execute on success
> >         def succeed(retval,obj,protocol,can_wrap):
> >     >       if type(protocol) is types.InterfaceType:
> >     >           if not instance(retval,protocol):
> >     >               raise "Bad __adapt__ or __prodapt__!"
> >             if can_wrap: return retval
> >             return obj
> 
> Actually, you would say:
> 
>   if implements(obj, protocol): return obj
> 
> An object that implements an interface is not an instance of that
> interface, so 'instance' would fail (did you mean 'isinstance'?).

Typo.  Darn fingers, typing in wrong words on me.  
Thank you for pointing it out.  

;) Clark