Folding

import Data.Foldable

-- perform a very large foldr to test tail recursion
addAll :: (Foldable t, Num a) => t a -> a
addAll = Data.Foldable.foldr (+) 0

n :: Integer
n = 1500000

numbersList :: [Integer]
numbersList = numbersList' n []
 where
   numbersList' :: Integer -> [Integer] -> [Integer]
   numbersList' 0 xs = xs
   numbersList' k xs = numbersList' (k - 1) (fromInteger k : xs)

-- numbersVect :: Vect (length numbersList) Integer
-- numbersVect = fromList numbersList

main :: IO ()
main = do
  putStrLn . show . addAll $ numbersList -- numbersVect
--  putStrLn . show . addAll $ numbersList -- numbersList