Library function to compose a function with itself n times

Question

Is there a library function available in Haskell to compose a function with itself n times?

For example I have this function:

func :: a ->         


        

Answer 1

Here's a version that has complexity O(log n) instead of O(n) (to build the function, not to apply it):

composeN 0 f = id
composeN n f
    | even n = g
    | odd  n = f . g
    where g = g' . g'
          g' = composeN (n `div` 2) f