Thanks a ton Hal for the quick clarification. It worked .
Cheers
Karthik.
--- Hal Daume III
Hi,
On Mon, 3 Nov 2003, Karthik Kumar wrote:
-- Convert a string to an integer. -- This works perfectly fine. atoi :: [Char] -> Int atoi (h : []) = if isDigit h then digitToInt h else 0 atoi (h : t) = if isDigit h then digitToInt h * ( 10 ^ length t) + atoi t else 0
you can use "read" for this.
-- validateBoardSize -- To validate the board size validateBoardSize :: Int -> Bool validateBoardSize d = (d == 9 || d == 13 || d == 19 )
this looks fine
getBoardSize :: IO Bool -- TODO : What could be the type of getBoardSize getBoardSize = do c <- getLine validateBoardSize ( atoi c )
ERROR "test1.hs":21 - Type error in final generator *** Term : validateBoardSize (atoi c) *** Type : Bool *** Does not match : IO a
this is telling you something important. it's saying that the final generator, "validateBoardSize (atoi c)" has type Bool, but it's expecting it to have type IO something. You need to "lift" the pure Bool value into IO by saying return:
getBoardSize = do c <- getLine return (validateBoardSize (read c))
-- Hal Daume III | hdaume@isi.edu "Arrest this man, he talks in maths." | www.isi.edu/~hdaume
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