[Python-Dev] PEP 455: TransformDict

[Antoine Pitrou]

Le Tue, 8 Oct 2013 22:49:28 +1000,
Nick Coghlan <ncoghlan at gmail.com> a écrit :
> > Well, you could ask the same question about OrderedDict,
> > defaultdict or Weak*Dictionary since neither of them use
> > composition :-)
> 
> We *did* ask the same question about those (except the Weak* variants,
> simply due to age).
> 
> Each time, the point that each new dict variant would be used to
> justify yet *more* variants was a cause for concern.

Could you explain? I don't understand.

> "Composition doesn't work with some mappings" isn't an adequate
> answer to the criticism that a composition based design could work
> with more mappings than just the builtin dict.

Fair enough.

Regards

Antoine.