[Python-Dev] PyPy 1.7 - widening the sweet spot

Philip Jenvey pjenvey at underboss.org
Tue Nov 22 21:28:54 CET 2011

On Nov 22, 2011, at 7:35 AM, Stefan Behnel wrote:

> Maciej Fijalkowski, 22.11.2011 15:46:
>> PyPy's py3k branch targets Python 3.2 until 3.3 is released and very
>> likely 3.3 afterwards. Optimizations are irrelevant really in the case
>> of PyPy.
> I admit that I wasn't very clear in my wording. As Terry pointed out, the Unicode changes in Py3.3 are not only for speed and/or memory performance improvements, they also improve the compliance of the Unicode implementation, which implies a behavioural change. Since PyPy appears to have implemented the current wide/narrow behaviour of Py2 and Py3.[012] already, I see no reason not to target 3.2 for the time being as it does not require substantial changes in this part. Compliance with Py3.3 will then require implementing the new behaviour.

One reason to target 3.2 for now is it's not a moving target. There's overhead involved in managing modifications to the pure python standard lib needed for PyPy, tracking 3.3 changes as they happen as well exacerbates this.

The plans to split the standard lib into its own repo separate from core CPython will of course help alternative implementations here.

Philip Jenvey

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