Proposed PEP for a Conditional Expression

[thp at cs.ucr.edu]

Terry Reedy <tjreedy at home.com> wrote:

: <thp at cs.ucr.edu> wrote in message news:9nkvss$cmq$1 at glue.ucr.edu...
:> :           WORKAROUND_2: (this SOMETIMES works)
:> :              > x = c and a or b

:> The problem of determining whether or not a given expression ever
:> evaluates to false is equivalent to determining whether a given
: Turing
:> machine halts, i.e., the general case is not algorithmically
: solvable.

: True, but so what?  Most real examples seem to involve constants that
: are triviallly either true or false or simple expressions that are
: trivial to decide in context.

I agree that "most" real examples fall into this category, but we
still need a general selection operator for the rest.  

Also, using the short-circuited evaluation of logical operators for
selection is something of a hack.  Sure it's an idiom that people
can get used to, but I would prefer code to say what it means more
directly.

Tom Payne