[pypy-dev] feedback on PEP 421

[Eric Snow]

On Mon, May 7, 2012 at 2:01 AM, Armin Rigo <arigo at tunes.org> wrote:
> Hi Laura, hi Eric,
>
> On Sun, May 6, 2012 at 10:29 PM, Laura Creighton <lac at openend.se> wrote:
>> I think a large part of this problem is that CPython implementors are
>> completely unaware of what set of functions PyPy cannot implement.
>
> Indeed.  From that point of view it would make sense if CPython and
> PyPy (to start with) co-operated in writing down a list of things in
> CPython that cannot be reasonably implemented on PyPy.  We have
> already two pages listing differences, which would be a good start if
> it was brought to the attention of CPython developers; but it only
> outlines general lines, and not, I think, "sys.getrefcount() is not
> available on PyPy at all".
>
> http://pypy.org/compat.html
> http://pypy.readthedocs.org/en/latest/cpython_differences.html
>
>
> A bientôt,
>
> Armin.

This is a great point from both of you.  It'll be worth pushing this
forward, which I'll work on once I get sys.implementation sorted out.
Keep in mind that I'm not a CPython committer, but that shouldn't
matter much for pursuing this.

Anyway, the idea of cataloging incompatibilities ties in pretty
closely with sys.implementation and the PEP.  I'll add a separate note
there on how it fits into the bigger picture of making Python less
CPython-specific.

Any other feedback on the PEP?  I'm particularly interested in your
thoughts on the data structure for sys.implementation, the format for
the version attribute, and the concept of the metadata attribute.
Thanks!

-eric