Armin Rigo <[EMAIL PROTECTED]> writes:
> The drawback here is that 'self._mode' is a public and writeable
> attribute, but we probably don't care because of the leading
> underscore. If we do care, it's probably possible to have a slot
> called exactly 'mode' which is hidden by the 'mode' property, but I
> can't figure out what kind of obcure hacks are needed to do
> that... mwh? :-)
Can't do it, at least not simply, as the 'mode' __slot__ is accessed
via a (member?) descriptor in the class's dictionary, which makes it a
challenge to define a property with the same name! Hmm, you can
probably do some gross metaclass hackery, like so:
class ReadOnlySlots(type):
def __new__(cls, name, bases, ns):
nt = type.__new__(cls, name, bases, ns)
for slotname in nt.__dict__.get('__slots__', []):
descr = nt.__dict__[slotname]
def getter(ob, d=descr):
return descr.__get__(ob, type(ob))
setattr(nt, slotname, property(getter))
return nt
class Test(object):
__metaclass__ = ReadOnlySlots
__slots__ = ('a',)
But this still leaves the problem of how you actually set these slots
to anything in the first place! I presume code like
t = Test()
Test.a.fget.func_defaults[-1].__set__(t, 1)
print t.a
is to be discouraged :-)
Cheers,
mwh
--
> so python will fork if activestate starts polluting it?
I find it more relevant to speculate on whether Python would fork
if the merpeople start invading our cities riding on the backs of
giant king crabs. -- Brian Quinlan, comp.lang.python
_______________________________________________
[EMAIL PROTECTED]
http://codespeak.net/mailman/listinfo/pypy-dev
