[Python-Dev] PEP 509: Add a private version to dict

[Yury Selivanov]

On 2016-01-20 1:36 PM, Maciej Fijalkowski wrote:
> On Wed, Jan 20, 2016 at 7:22 PM, Brett Cannon <brett at python.org> wrote:
>>
>> On Wed, 20 Jan 2016 at 10:11 Yury Selivanov <yselivanov.ml at gmail.com> wrote:
[..]
>>> "ma_extra" would also make it easier for us to extend dicts
>>> in the future.
>>
>> Why can't you simply use the id of the dict object as the globally unique
>> dict ID? It's already globally unique amongst all Python objects which makes
>> it inherently unique amongst dicts.
>>
>>
> Brett, you need two things - the ID of the dict and the version tag.
> What we do in pypy is we have a small object (called, surprisingly,
> VersionTag()) and we use the ID of that. That way you can change the
> version id of an existing dict and have only one field.


Yeah, that's essentially what I propose with ma_extra.

Yury