[Python-Dev] Guarantee ordered dict literals in v3.7?

[Steve Holden]

On Mon, Nov 6, 2017 at 10:18 AM, Paul Sokolovsky <pmiscml at 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20171106/ecf6d34f/attachment.html>