Hi, > shuffle :: int -> [a] -> [a] > shuffle i [cards] = ... So 'cards' is of type 'a' : cards :: a
> ... = (cards!!i) So 'cards' is a list of something: cards :: [b] > ... = (cards!!i) + ... (+) :: b -> b -> b, the result of the 'shuffle' should be of type [a], so b :: [a], cards :: [[a]] 2010/3/20 boblettoj <bobletto...@msn.com>: > > Hi i am writing a shuffle function which takes in a random number i and a > list and then produces a jumbled up version of the list at the end. Here is > what i have at the moment (i'm not sure if it works yet as it won't compile! > > --function used to shuffle cards > --list equals random member of array plus the rest of the array > --i is randomly generated from range of length equal to that of cards. > shuffle :: int -> [a] -> [a] > shuffle i [] = [] > shuffle i [cards] = (cards!!i) + > (shuffle (randomR (0, ((length cards)-2))) > (delete (cards!!i) cards)) > > > I get this error message when i try to compile: > > Occurs check: cannot construct the infinite type: a = [[a]] > > I'm very new to haskell so you'll have to excuse any ignorance! > thanks > -- > View this message in context: > http://old.nabble.com/Occurs-check-error%2C-help%21-tp27966341p27966341.html > Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
