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
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.
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