[Zope-dev] Questions, Jar, Transactions, Metaclassess, ZPatterns

[Ender]

sorry for the poorly worded question (midnight madness), let me try and
restate them a bit better in the fond hope that someone will answer any
of them.

whats is a jar? as far as i know its just the data  representation of
the object that gets stored in the zodb, hence its directly related to
the __dict__ of the object. but then what is the signifigance of calling
methods directly on the jar like i see in some of the transaction
machinery, is this an indirect call to the thread's zodb connection?

> does zope restrict you from doing metaprogramming with python products?
> or does zope's own metaprogramming reserve some names __klass__, etc?

i was reading through guido's essays yesterday, and happened upon the
metaprogramming essay ( i read it when i was first learning python but
it made a lot more sense now:). i was thinking about creating my own
caching metaclass, but i know that acquisition (and probably
persistence, and zclasses) use some c-based metaclasses to work. i'm
just curious what the possibilites and restrictions are of doing
metaclasses in zope, so my classes play well with others. 

in /lib/python/Shared/DC/ZRDB/TM.py, i see the class Surrogate defining
methods for __inform_commit__ and __inform_abort__, what are these for?

In ZPatterns/Transaction.py I see some talk of transaction boundaries,
namely the inability for an object participating in the transaction to
know that a transaction is finished. From my understanding of
transactions i thought that an object could assume a transaction was
over if it has its tpc_finish called on it when its not in a
subtransaction. I understand that the Zpatterns problem here might be
related to providing attrs to other objects which might be used in a
tpc_finish but i just wanted to clarify/make sure.

kapil