[Python-Dev] What's the status of PEP 505: None-aware operators?

[Random832]

On Thu, Nov 30, 2017, at 17:26, Greg Ewing wrote:
> Eric Fahlgren wrote:
> > ​I think you're missing something here, since it seems clear to me that 
> > indeed the arguments are evaluated prior to the function call.​
> 
> I think the OP may be confusing "evaluating the function" with
> "calling the function".
> 
> If the function being called is determined by some computation,
> that computation may be performed before its arguments are
> evaluated (and is probably required to be, by the "left to
> right" rule). But the arguments will always be evaluated
> before the actual call happens.

Right, but if the function is evaluated before either of those things
happen, then it can indeed short-circuit the argument evaluation.

The OP isn't confusing anything; it's Eric who is confused. The quoted
paragraph of the PEP clearly and unambiguously claims that the sequence
is "arguments -> function -> call", meaning that something happens after
the "function" stage [i.e. a None check] cannot short-circuit the
"arguments" stage. But in fact the sequence is "function -> arguments ->
call".