On Thu, Nov 03, 2016 at 02:17:14AM +1000, Nick Coghlan wrote:
Yeah, and so far the protocol based alternative I'm working on hasn't been any less headache-inducing (Mark has been reviewing some early iterations and had to draw a diagram to try to follow the proposed control flow).
Even if your protocol idea pans out and is a good idea, it doesn't solve the use-cases that PEP 505 is intended to solve. PEP 505 is specifically for the cases where None *is* special, where you *don't* want "None or something like None", but specifically None and nothing else.
Your protocol idea is not an alternative to 505, it is independent of 505: it wants a second generalised concept of "None or something else" (distinct from falsey values), while 505 is specifically about "None and nothing else".