[Haskell-beginners] IO operations

Hi, module Main where allwords :: IO Int allwords  = do     dict <- readFile "data/dict.txt"     return  $ length [x | x <- dict , not $ '-' `elem` x]      main :: IO Int main = do allwords error * Couldn't match expected type `t0 Char' with actual type `Char' * In the second argument of `elem', namely `x'   In the second argument of `($)', namely '-' `elem` x   In the expression: not $ '-' `elem` x could someone tell me what I am doing wrong? thanks!