On Mon, Nov 6, 2017 at 10:18 AM, Paul Sokolovsky <pmiscml@gmail.com> wrote:
Hello,

What happens now borders on technologic surrealism - the CPython, after
many years of persuasion, switched its dict algorithm, rather
inefficient in terms of memory, to something else, less inefficient
(still quite inefficient, taking "no overhead" as the baseline). That
algorithm randomly had another property. Now there's a seemingly
serious talk of letting that property leak into the *language spec*,
despite the fact that there can be unlimited number of dictionary
algorithms, most of them not having that property.

I have to agree: I find the elevation of a CPython implementation detail to a language feature ​somewhat hard to comprehend. Maybe it's more to do with the way it's been presented, but this is hardly an enhancement the language has been screaming for for years.

​Presumably there is little concern that algorithms that rely on this behaviour will be perfectly syntactically conformant with earlier versions​ but will fail subtly and without explanation? It's a small concern, but a real one - particularly for learners.

regards
 Steve