[Python-Dev] 308: the debate is petering out

[Samuele Pedroni]

There were a group of people that would find

a when C else B

with 'when' instead of 'if' less confusing than 'a if C else b'.

The alternative (as in Haskell, ML,...):

if C then a else b

was also mentioned a few times.

For the rest I think we have all reasonable contenders.


----- Original Message -----
From: "Raymond Hettinger" <python@rcn.com>
To: "Guido van Rossum" <guido@python.org>; <python-dev@python.org>
Sent: Wednesday, February 19, 2003 2:40 AM
Subject: Re: [Python-Dev] 308: the debate is petering out


> > Raymond, have any new proposals been suggested and not shot down?
>
> Someone re-proposed c ? a else b.  Their rationale is that the ? is a better
> marker than "then" and is suggestive enough to not need a leading "if";
> it doesn't require a new keyword and does not overload the colon.
> No one shot this down but it didn't generate any real support either.
>
> There was an interesting, weird, and fruitless discussion on how
> "c then a else b" could be implemented as a pair of binary operators
> that are not required to be used together.
>
> There was a rapidly shot down idea to use bool.choose(a, b) where
> choose() was a special method that could somehow implement
> lazy evaluation of its arguments.
>
> A recent proposal is: (? <cond1>: <expr1>, <cond2>: <expr2>, <default> ?).
> There have only been a few hours for comment.  Though the visual
> cues are there, my issue with it is that the colon usage is likely to confuse
> anyone exposed to the c?a:b form in other languages where the colon
> separates the alteratives rather than the condition and alternative.
>
>
> Raymond Hettinger
>
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