Monads and Pure Functions

monad_pure.hs

module Monad where

maxPairM :: (Monad m, Ord a) => m (a, a) -> m a
maxPairM m = m >>= \p -> return (maxPair p)

maxPairM' :: (Monad m, Ord a) => m (a, a) -> m a
maxPairM' m = (return . maxPair) =<< m -- I like it because it looks like function composition

maxPair :: Ord a => (a, a) -> a
maxPair (f, s) = max f s

wSugar :: IO ()
wSugar = do
  name <- getLine
  let statement = helloPerson name
  putStrLn statement

noSugar :: IO ()
noSugar = getLine >>= \name -> putStrLn (helloPerson name)

helloPerson :: String -> String
helloPerson name = "Hello " ++ name