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@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