Python and Ruby

MRAB python at mrabarnett.plus.com
Tue Feb 2 03:14:03 CET 2010


Nobody wrote:
> On Sun, 31 Jan 2010 22:36:32 +0000, Steven D'Aprano wrote:
> 
>>> for example, in if you have a function 'f' which takes two parameters to
>>> call the function and get the result you use:
>>>
>>>  f 2 3
>>>
>>> If you want the function itself you use:
>>>
>>>    f
>> How do you call a function of no arguments?
> 
> There's no such thing. All functions take one argument and return a value.
> 
> As functions don't have side-effects, there is seldom much point in having
> a function with no arguments or which doesn't return a value. In cases
> where it is useful (i.e. a value must have function type), you can use the
> unit type "()" (essentially a zero-element tuple), e.g.:
> 
> 	f () = 1
> or:
> 	f x = ()
> 
A function with no arguments could be used as a lazy constant, generated
only on demand.



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