[pypy-dev] feedback on PEP 421
lac at openend.se
Sun May 6 22:29:37 CEST 2012
In a message of Sun, 06 May 2012 21:29:12 +0200, Armin Rigo writes:
>The reason for that: getting details "right" might be similar to the
>sys module's documentation, which has grown a number of "CPython
>implementation detail" boxes --- which are rather meaningless for
>PyPy, in the sense that the set of functions that are dubbed "CPython
>implementation detail" and the set of functions that PyPy cannot
>reasonably implement have little to do with each other.
I think a large part of this problem is that CPython implementors are
completely unaware of what set of functions PyPy cannot implement.
And I don't blame them for that. I am often in the same way. I talk
to somebody who wants to make CPython do X, and he wants to know if
PyPy will have a problem with this. I cautiously reply 'not as
he has outlined the problem'. 3 weeks later, he comes back with
working code. And I say -- Eeek! we cannot do this, that and the
other thing, and by the way we have a much more efficient way to do this
thing over there. He quite reasonably asks me 'why didn't you tell
me this in the first place?' and I also reasonably reply 'I had no
idea that you planned this particular implementation when you asked.'
Is there a place in this PEP for 'known differences in implementations'
a.k.a. 'we know this is incompatible but we aren't going to change our
implementation to fix'?? It might save a lot of trouble.
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