[Python-Dev] Python 3.6 dict becomes compact and gets a private version; and keywords become ordered

[INADA Naoki]

>
> I mean using a compact representation, if not an ordered one.
>
> I have no particular usecase in mind. As far as I understand the compact
> implementation, sets can do it just as well. The original discussion
> proposed trying to implement it for sets first.
>
> Like dict, they would (probably) use less memory, and would usually have a
> more readable (i.e. less jarring to read) print order.
>

I'll improve OrderedDict after dict in 3.6 is stable enough.
Then, I'll do same to sets.

While compact ordered split dict is very hard to implement right,
OrderedDict and set
must be easier than dict.