[PEAK] Persistence styles, MDA, AOP, PyProtocols, and PEAK

Robert Brewer fumanchu at amor.org
Thu Jul 8 01:40:25 EDT 2004

Stephen Waterbury wrote:
> Robert Brewer wrote:
> > (replying off-list)
> > No, I think I got it the first time. ;) You're using 
> composition ("has
> > a") where I use subclassing ("is a").
> No, actually you *still* didn't quite get it.  ;)

I should have guessed that. ;)

> Cool -- just a slightly different approach from mine.
> Here's how it would look in PanGalactic.

Gargleblasters anyone? ;)

>     def getBalanceDue(self):
>         return self.amount - self.paid
>     def setBalanceDue(self, value):
>         raise TypeError, 'Nuh uh!'
>     def delBalanceDue(self):
>         raise TypeError, 'Hah, nice try!'
>     balance_due = property(getBalanceDue, setBalanceDue,
>                            delBalanceDue, 'balance due')

Looks good! You might want to check into coding your own descriptors
instead of using properties--it really cuts down on the boilerplate
(obviously the above is just an example, but still...).

Robert Brewer
Amor Ministries
fumanchu at amor.org

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