[Haskell-beginners] Function to compute the mean

[Tarik ÖZKANLI]

No sorry,

Both are the same,
Discard my previous mail

Regards.

Tarık

On Sat, 8 May 2021 at 16:07, Tarik ÖZKANLI <tozkanli2023 at gmail.com> wrote:

> Hello,
>
> In standard usage there is not much difference. But in Haskell, people
> prefer to write in curried form (first implementation of yours) which has
> the advantage of using partially applied form when suitable.
>
> Regards.
>
> Tarık Özkanlı
>
>
> On Sat, 8 May 2021 at 12:43, Joe King <joeking1809 at yahoo.com> wrote:
>
>> Greeetings I am new here and pretty new to Haskell.
>>
>> I was wondering what are the relative advanatges/disadvatnages of
>> specifying a mean function in these two ways:
>>
>> mean :: [Double] -> Double
>> mean xs = sum xs / fromIntegral (length xs)
>>
>> and
>>
>> mean1 :: (Real a, Fractional b) => [a] -> b
>> mean1 xs = realToFrac (sum xs) / genericLength xs
>>
>> I understand that mean1 has the advantage that it can be called with
>> lists of any Real type, so would work with things like
>>
>> foo :: [Int]
>> foo = [1,2,3]
>>
>> mean foo
>> -- type mismatch error
>>
>> mean1 foo
>> -- no error
>>
>> But suppose that I know I will only ever use lists of Double, is there
>> still any advantage (or disadvantage of using mean1). For example is there
>> any performance benefit by using mean in that case since mean1 has
>> additional function evaluation.
>>
>> Are there any other considerations ?
>>
>> Thanks in advance
>> JK
>> _______________________________________________
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>> Beginners at haskell.org
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>>
>
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