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I've decided to teach myself Haskell and I have never been so frustrated in all my life. I am going through the tutorial at http://lisperati.com/haskell/ which is the easiest one I could find. All that I am trying to do is read a text file called people.txt which contains a list of numbers and print the length of the list. This code is straight from the tutorial. import Data.List type Person = [Int] main = do people_text <- readFile "people.txt" let people :: [Person] people = read people_text putStr "Number of people " putStr (length people_text) When I try to run the file with runHaskell tutorial03.hs I get this error message tutorial03.hs:9:13: Illegal signature in pattern: [Person] people Use -XScopedTypeVariables to permit it Using the XScopedTypeVariables flag I get tutorial03.hs:10:17: Not in scope: type variable `people' Could someone please explain what I am doing wrong.
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