Hello,

I have to do this :

Exercise 1 We need to first find the digits of a number. Define the
functions
toDigits :: Integer -> [Integer]
toDigitsRev :: Integer -> [Integer]
toDigits should convert positive Integers to a list of digits. (For 0 or
negative inputs, toDigits should return the empty list.) toDigitsRev
should do the same, but with the digits reversed.
Example: toDigits 1234 == [1,2,3,4]
Example: toDigitsRev 1234 == [4,3,2,1]
Example: toDigits 0 == []
Example: toDigits (-17) == []


I have this so far :

-- | convert a number to a array in pieces where a negative number will be a empty array.
toDigits :: Integer -> [Integer]
toDigits n
  | n < 0 : []
  | otherwise : n/10 : []

-- | Main entry point to the application.
module Main where

-- | The main entry point.
main :: IO ()
main = do
    toDigits 123

but now I see this error message :

src/Main.hs@5:3-5:4

parse error on input |

This is not homework because I do this as a self-study.

Roelof

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