[Haskell-beginners] recursion problem.

Hello, I have figured out how I can make from 123 [1,2,3] I did it this way : -- | 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 = toDigits (n `div` 10) ++ [n `mod` 10] but now when I do toDigits 0 , I see [] as output where I was expected [0] But when I do toDigits 100 I see the right output [ 1,0,0] which surprises me because I tought that with the first 0 there will be a [] Or is the n the second time [0,0] and the thirth time [0] So it will be like this : toDigits 100 to Digits [1] ++ [ 0,0] toDigits [1] ++ [0] ++ [0] which leads to [1,0,0] Roelof