Example.hs

import Prelude hiding (log)
import Control.Monad ( (<$>) )
import Control.Monad.Trans ( liftIO, when, baz, Bar(..) ) -- some made up names

{- | Our very important FOO compilation option -}
#ifdef FOO
foo = 1
#endif

{- {- Nested comments aren't quite right -} nope... -}

-- Sample Hello, World program

main :: IO ()
main = do
  (x:xs) <- getArgs
  let y = tail xs
  putStrLn "hello, world!"
  return ()

a :: Char
a = 'a'

fibs :: [Integer]
fibs = 0 : 1 : zipWith (+) fibs (tail fibs)

foo :: Num a => a -> a
foo 1 = 4
foo n = n+1

-- | baz combines map and Maybe.
baz :: (a -> Maybe b) -> [a] -> [Maybe b]
baz _ [] = [Nothing]
baz f (x:xs) = f x : baz f xs

integers = [1,2,3,4,5 ..]

pi :: Maybe Double
pi = Just 3.14159