> On Fri, Aug 11, 2017 at 10:17 PM, Guido van Rossum <gu...@python.org> wrote: > > I may have missed this (I've just skimmed the doc), but what's the rationale > > for making the EC an *immutable* mapping? It's impressive that you managed > > to create a faster immutable dict, but why does the use case need one?
> In this proposal, you have lots and lots of semantically distinct ECs. > Potentially every stack frame has its own (at least in async code). So > instead of copying the EC every time they create a new one, they want > to copy it when it's written to. This is a win if writes are > relatively rare compared to the creation of ECs. Correct. If we decide to use HAMT, the ratio of writes/reads becomes less important though. Yury _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
