For review: PEP 308 - If-then-else expression

[Chris Liechti]

> [Michael Hudson]
>> This has been an eye-opener for me: people really do write
>>     x and y or b

that does not surprise me, i'm using it sometimes ;-)

Tim Peters <tim.one at comcast.net> wrote in
news:mailman.1044908798.21634.python-list at python.org: 

> Offhand, at first glance I don't find
> 
>     y if x else b
> 
> any more sensible than
> 
>     x and y or b

i _was_ for a ternary op, because such a thing would show the intent of a 
programmer more precise than "c and t or f". of course i can live with the 
later and i have to use it if i want to be compatible with 2.2 (the python 
in a tie version).

on the other hand, what i see in this discussions is that i rather live 
forever with "and or" than having some of the ugly proposals in the 
language ;-) (Guidos is not bad, but "if t if cond else f" doesn't look 
exactly good and such things will come up even if and/or would be better 
placed here)

how about a ifte(cond, true_v, false_v) function in a "functional" module. 
that could also take a curry(f, *args, **kwargs) function and some other 
functional style helpers.

and for those realy rare cases where lazy eval matters, there is the "and 
or" solution or the form as a statement. especialy if an expression has so 
drastical consequences that it must no be evalueted (if the other is 
taken), it should go in a ordinary "if", that is much clearer and you have 
space to put comments on why it is so important to take care.

chris

-- 
Chris <cliechti at gmx.net>