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List:       python-dev
Subject:    Re: [Python-Dev] constant/enum type in stdlib
From:       Nick Coghlan <ncoghlan () gmail ! com>
Date:       2010-11-30 2:23:04
Message-ID: AANLkTi=Mer3hoivxp4HtHSnq+jjVy4zVYuzEJ=0hx5g- () mail ! gmail ! com
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On Tue, Nov 30, 2010 at 7:36 AM, Greg Ewing <greg.ewing@canterbury.ac.nz> wrote:
> I don't see how the grouping can be completely separated
> from the value-naming. If the named values are to be
> subclassed from the base values, then you want all the
> members of a group to belong to the *same* subclass.
> You can't get that by treating each named value on its
> own and then trying to group them together afterwards.

Note that my sample implementation cached the created types, so that
(for example) there was only ever one "Named<int>" type (my
implementation wasn't quite kosher in that respect, since
functools.lru_cache has a non-optional size limit - setting maxsize to
float('inf') deals with that). A grouping API would use either single
or multiple inheritance to create members that supported both the
naming aspects as well as the grouping aspects.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan@gmail.com   |   Brisbane, Australia
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