(test) ? a:b
Marko Rauhamaa
marko at pacujo.net
Thu Oct 23 09:44:06 EDT 2014
"BartC" <bc at freeuk.com>:
>> Ah, but what would
>>
>> x = [f, g][cond]()
>>
>> produce?
>
> It will select f or g (which should refer to functions), and call one of
> those depending on cond. That's not a problem.
>
> The problem is it will still evaluate both f and g,
That's not really the problem. The problem is in readability.
However, the "[f, g][cond]()" technique is how pure lambda calculus
implements conditional branching so it is interesting in its own right.
IOW, you can do "short-circuiting" in purely functional programming:
j = j + 1 if j < 10 else 3
<=>
j = (lambda: 3, lambda: j + 1)[j < 10]()
Marko
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