[Zope-dev] New-style ExtensionClasses (Zope 2.8) -- MRO issue

[Jim Fulton]

Sidnei da Silva wrote:
> | Ooooohkay.  If anyone has a problem, I'll send them to you and Sidnei. :)
> 
> /me takes his iBook and a plane to The Amazon
> 
> | Note that, in many cases, the people having problems will *not* be the
> | product authors. They'll be people who just want to upgrade thier Zope
> | installationa that use third-party products.
> 
> Most of the time, this is the same people who can't update their
> products, so if they *do* want a new zope, they will need to get a new
> product as well. I think its safe to make that assumption.

I don't follow this.  What do you mean be "Can't update their products"?
Are you saying that to upgrade to a new Zope, they should actually have to
replace the products they are using with different ones?

..

> | > as opposed to a
> | >short-term problem of updating existing code. 
> | 
> | It won't be that short term. It will come up each time someone wants to
> | use a product that hasn't been converted before.
> 
> Considering that 2.8 may be at least 6-8 months in the future (is that
> a nice assumption?)

I hope that 2.8 will come out much sooner than that. I hope to see 2.9
in that timeframe.  Remember that 2.8 will have just nsEC, ZODB 3.3, and
any other stuff that's piled up in the interim. :)

...

> | I don't think it makes the code any clearer.  Zope 2 has an extremely
> | complex inheritence graph.  Changing the mro algorithm won't change that.
> | 
> | Zope 3, of course, makes much less use of inheritence and has clearer
> | code.  It also uses new-style classes and, thus, uses the new algorithm.
> 
> Now *that* is a good point for going with the new algorithm. We don't
> want to have even another round later on to make it compatible with
> Zope 3.  If we could do it at the same time it would be a
> bonus. Though, from what I understand, your custom algorithm would
> provide that.

Huh?  That doesn't make sense.  As long as people use EC, they will use
whatever algorthm we pick now.  If people use ExtensionClasses in Zope 3,
then those classes will use the algorithm we pick now.  People would
switch to the new algorithm when they convert (or mor likely rewrite)
their products to be ExtensionClass-less and Zope3-ish.  If they
make their products Zope 3-ish, the lookup algorithm won't matter much.

Jim

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