(original) (raw)

On Oct 3, 2017 01:00, "Guido van Rossum" <guido@python.org> wrote:

Mon, Oct 2, 2017 at 2:52 PM, Koos Zevenhoven <k7hoven@gmail.com> wrote

I don't mind this (or Nathaniel ;-) being academic. The backwards incompatibility issue I've just described applies to any extension via composition, if the underlying type/protocol grows new members (like the CM protocol would have gained \_\_suspend\_\_ and \_\_resume\_\_ in PEP521).

Since you seem to have a good grasp on this issue, does PEP 550 suffer from the same problem? (Or PEP 555, for that matter? :-)

Neither has this particular issue, because they don't extend an existing protocol. If this thread has any significance, it will most likely be elsewhere.