data_and_typeable.hs

{-# LANGUAGE DeriveDataTypeable #-}

import Control.Monad.Random
import System.Random.Shuffle
import Data.Typeable
import Data.Data

data Suit = Hearts | Clubs | Diamonds | Spades
  deriving (Eq, Enum, Bounded, Ord, Data, Typeable)

data Value = Ace | King | Queen | Jack | Number Int
  deriving (Eq, Data, Typeable)

newtype Card = Card (Suit, Value)

type Deck = [Card]

headCharOfType :: Data a => a -> String
headCharOfType a = [head $ show $ toConstr a]

instance Show Card where
  show (Card (s, Number x)) = headCharOfType s ++ ":" ++ show x
  show (Card (s, v)) = headCharOfType s ++ ":" ++ headCharOfType v

deck :: Deck
deck = zipWith card suits values
  where reps n a = concat $ replicate n a
        card s v = Card (s, v)
        values = reps 4 $ [Ace, King, Queen, Jack] ++ map Number [2..10]
        suits = reps 16 [Hearts .. Spades]

main = do
  deck <- evalRandIO $ shuffleM $ concat $ replicate 1 deck
  print deck

sad_face.hs

import Control.Monad.Random
import System.Random.Shuffle

data Suit = Hearts | Clubs | Diamonds | Spades
  deriving (Eq, Enum, Bounded, Ord)

data Value = Ace | King | Queen | Jack | Number Int
  deriving (Eq)

newtype Card = Card (Suit, Value)

type Deck = [Card]

instance Show Suit where
  show Hearts = "H"
  show Clubs = "C"
  show Diamonds = "D"
  show Spades = "S"

instance Show Value where
  show Ace = "A"
  show King = "K"
  show Queen = "Q"
  show Jack = "J"
  show (Number x) = show x

instance Show Card where
  show (Card (s, v)) = show s ++ show v

deck :: Deck
deck = zipWith card suits values
  where reps n a = concat $ replicate n a
        card s v = Card (s, v)
        values = reps 4 $ [Ace, King, Queen, Jack] ++ map Number [2..10]
        suits = reps 16 [Hearts .. Spades]

main = do
  deck <- evalRandIO $ shuffleM deck
  print deck