On Wed, May 31, 2017 at 2:16 AM, Ivan Levkivskyi <levkivskyi@gmail.com> wrote:

On 31 May 2017 at 00:58, Guido van Rossum <guido@python.org> wrote:
[...]

Thank you for very detailed answers! I have practically nothing to add.
It seems to me that most of the Kevin's questions stem from unnecessary focus
on runtime type checking. Here are two ideas about how to fix this:

* Add the word "static" somewhere in the PEP title.

So the title could become "Protocols: Static structural subtyping (duck typing)" -- long, but not record-setting.

* Add a short note at the start mentioning this is an extension of the type system proposed in PEP 484 and recommending to read PEP 484 first.

Hm, the Abstract already spells that out. I suspect that many people react to the discussion without first reading the PEP itself (I do this myself :-). The only thing that could possibly be confusing about the abstract is that it claims to specify "static and runtime semantics" -- but that's reasonable, since the runtime semantics must somehow be specified even if they're minimal.

--Guido van Rossum (python.org/~guido)