[Python-Dev] PEP 384 status

[Antoine Pitrou]

On Sun, 12 Sep 2010 19:38:33 +0200
"Martin v. Löwis" <martin at v.loewis.de> wrote:
> > On http://bugs.python.org/issue9778 you elaborated on what the PEP would
> > entail in its current state:
> > 
> > “No, vice versa. The PEP promises that the ABI won't change until
> > Python 4. For any change that might break the ABI, either a
> > backwards-compatible solution needs to be found, or the change be
> > deferred to Python 4.”
> > 
> > This sounds like it could be detrimental by blocking desired
> > improvements (the aforementioned issue is a potential example of this).
> 
> Notice that it's only potential: in the specific case, there would be
> an ABI-compatible way of introducing wide hashes, using a second type
> slot.

Yes, but it would add complication, and be potentially detrimental to
performance.

> If you think this is too restrictive, please point out specific aspects
> that you think might need to change in the mid-term future. They should
> then be excluded from the ABI.

I have no a priori knowledge of what might happen in the future :)

That said, looking at the PEP, I was wondering whether fields such as
ob_type, ob_refcnt, ob_size have to be directly accessible, rather than
through a macro-turned-into-a-function such as Py_REFCNT().