[Persistence-sig] "Straw Baby" Persistence API

[Kevin Jacobs]

On Mon, 22 Jul 2002, Steve Menard wrote:
> At 10:05 AM 7/22/2002 -0400, Jeremy Hylton wrote:
> >One small comment.  (I owe more substantial comment on Phillip's
> >earlier proposals.)  The persistent versions of dict and list can't
> >extend the builtin types, because they need to hook __getitem__() and
> >__setitem__().  The overridden methods may not be called if we extend
> >the builtin types.
> 
> hum, if those method are not guaranteed to be called by subclassing dict or 
> list, then there is something broken. Either that or there is a subtle 
> thing I do not understand.

In fact, I am quite sure that one can inherit from list or dict and override
__getitem__ and __setitem__ in a cooperative fashion.  Can you provide a
little more information on why you think otherwise?

> On a side note, as I have said in another post, I have done exactly that, 
> subclassing dict and list. While my model didn't need to override 
> __getitem__(), the __setitem__() at least seemed to act properly. In fact 
> the only problem I have found is that it was not possible to mix __slots__ 
> and dict/list.

For all strange and perverse things I've done, slots work just fine when
inheriting from list and dict.  Again, can you provide an example of where
you found otherwise?

Thanks,
-Kevin

--
Kevin Jacobs
The OPAL Group - Enterprise Systems Architect
Voice: (216) 986-0710 x 19         E-mail: jacobs@theopalgroup.com
Fax:   (216) 986-0714              WWW:    http://www.theopalgroup.com