Jim Fulton wrote at 2008-1-7 16:04 -0500:
>> If "__implements__" is inherited, why is "__provides__" not
>__provides__ (in this context) is a class attribute. I don't support
>(and don't want to support) inheritance between class objects.
Where can I read about the "__provides__" semantics?
Where is it documented?
Python does support class attribute inheritance as can be seen
by this small transscript:
>>> class C(object): x=1 # class attribute "x"
>>> class CD(C): pass
>>> CD.x # class attribute "x" inherited by "CD"
Why do you think that "zope.interface" should not support
class attribute inheritance.
>> This fails for classes magically stuffed with a "__provides__"
>It also fails for any descriptor that sometimes raises attribute
>errors. Someone should report this as an inspect bug. This would be
>so easy to fix.
True -- but if they are not far more ready to admit a bug,
there is little chance that this gets fixed.
>I suggest monkey-fixing inspect.getmembers. This is a small function
>that should be easy to replace with a non-broken version.
This is already done. "dm.reuse" allows in many cases to
fix functions without code duplication.
Nevertheless, I am convinced to face a bug both in "zope.interface"
as well as in "inspect".
>>> My main gripe with the way this works is that classes get mutated.
>>> I ever redo this someday, I'd use a data structure external to the
>>> classes. Modifying the classes was a mistake.
>> Yes. That, too, would have avoided the bug.
>Yes, it would have avoided the inspect bug. IMO, it would also have
>been cleaner. If someone wants to volunteer to change it, I'll try to
>provide some oversight. Unfortunately, it's not a small task, which is
>why I'm not volunteering to do it.
You probably have already a notion about the semantics of "__provides__".
If someone else should change anything with it, he will need
a precise understanding what "__provides__" means, which properties
is has and which not.
Moreover, backward compatibility needs to be taken into account.
When "__provides__" stops to be an ill behaving class attribute,
then this obviously is a change in behavior.
Zope-Dev maillist - Zope-Dev@zope.org
** No cross posts or HTML encoding! **
(Related lists -