Main.hs

module Main where

import Test
import Data.Typeable

main :: IO ()
main = do
    putStrLn $ show $ double 2
    putStrLn $ show $ quadruple 2
    putStrLn $ show $ factorial 10
    putStrLn "Welcome to FP"
    putStrLn $ "typeOf [\"foo\"] = " ++ show (typeOf ["foo"])

Test.hs

module Test where
double x = x + x
quadruple x = double (double x)

factorial n = product [1..n]
average ns = sum ns `div` length ns

somefun = a `div` length xs
             where
                 a = 10
                 xs = [1..5]