[Python-Dev] PEP 318 (was re: redefining is)

[Raymond Hettinger]

> > Heh, another use for the class variant of PEP 318.  Josiah's code
> > depends on knowing which classes have immutable instances, using a
> > hardcoded set of builtin types.  With PEP318, one could do
> >
> > class foo [immutable]:
> >     ...
> >
> > with an appropriate definition of immutable that either decorates
the
> > class object or adds to the set of known immutables.  Perhaps also
with
> > code to catch and warn against obvious attempts at mutation of
foos...

This PEP is losing its innocence.

Having been repeatedly confronted with FUD arguments in other contexts,
I hate to put on that hat, but I do not think it wise to support too
many varieties of weirdness.  Heck, we've already got meta-classes for
that.


> One could even include the disclaimer that any code that modifies an
> instance that is supposed to be immutable, is inherantly broken and is
> not supported

<fud>
I'm sensing an unnamed code smell.
</fud>



Raymond