[Haskell-beginners] foldr problem

[Emanuel Koczwara]

Hi,

W dniu 02.03.2014 22:44, Roelof Wobben pisze:
> Hello,
>
> I now have to use foldr to find the max value in a list.
>
> So I do this:
>
> import Data.Char
>
> x = foldr max [5,10,2,8.1]
> -- Note that comments are preceded by two hyphens
> {- or enclosed
>    in curly brace/hypens pairs. -}
> main = print x
>
> But now I see this error message:
> Active code from: 1: Haskell Basics
> main.hs at 7:8-7:13
>     No instance for (Show ([[t0]] -> [t0])) arising from a use of 
> `print' Possible fix: add an instance declaration for (Show ([[t0]] -> 
> [t0])) In the expression: print x In an equation for `main': main = 
> print x
>
> Active code from: 1: Haskell Basics Active code from: 1: Haskell Basics

   Please look at foldr type and documentation. There is one argument 
missing in your code.

Regards,
Emanuel

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