On Mon, Sep 18, 2006 at 12:54:34PM +0200, Albert Crespi wrote:
Thank you very much for your reply! As I said, it is my first experience with Haskell, I have been programming in Java and C for some years, and I find this language very different from them. Anyway I'll try to fix the function with the information that you gave me. Thanks again!
You're welcome. By the way, this is what the comments say you are trying to do: -- Replaces a wildcard in a list with the list given as the third argument substitute :: Eq a => a -> [a] -> [a] -> [a] substitute e l1 l2= [c | c <- check_elem l1] where check_elem [] = l1 check_elem (x:xs) = if x == e then (l2 ++ xs) else check_elem xs This is the result: *Main> substitute 1 [1,2,3] [] [2,3] *Main> substitute 1 [1,2,3] [7,8,9] [7,8,9,2,3] *Main> Have fun with Haskell. Ciao Andrea