[Python-ideas] Fwd: Consider allowing the use of abstractmethod without metaclasses

[Ivan Levkivskyi]

On 20 July 2017 at 19:51, INADA Naoki <songofacandy at gmail.com> wrote:

> On Fri, Jul 21, 2017 at 12:12 AM, Ivan Levkivskyi <levkivskyi at gmail.com>
> wrote:
> > To be honest, I am not very happy with addition of a new special class.
> > Imagine that the PEP 544 will be accepted (and I hope so).
> > Then we would have, abstract classes, abstract base classes, and
> protocols.
> > I think users will be overwhelmed by having
> > three similar concepts instead of one.
>
> Hmm, couldn't split protocol and ABC?
>
>
Unfortunately no, it was considered and rejected for various reasons (in
particular to provide smooth transition to protocols).


> > I think we still could squeeze a lot of performance from good old ABCs by
> > optimizing various parts and reimplementing some parts in C.
> > In fact, my desire to optimize and rewrite ABCMeta in C is partially due
> to
> > reluctance to add yet another concept of "abstractness".
> >
>
> Even if it's implemented in C, issubclass implementation is much
> complicated
> than normal type.
> I don't want to introduce unnecessary complexity because I'm minimalist.
>
>
This complexity is already there, and attempt to reduce might lead to
actually an increase of complexity.
This is probably the case where I would be with Raymond in terms of
performance vs ease of maintenance.

--
Ivan
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