Added visibility to cards

lib/CardDeck.hs

@@ -1,6 +1,13 @@
-module CardDeck (
-    generateCards,
-    generateShuffledCards
+module CardDeck
+( Card
+, CardStatus(..)
+, Stack
+
+, generateDeck
+, generateShuffledDeck
+, showCard
+, hideCard
+, flipCard
 ) where
 
 import Shuffle
@@ -30,17 +37,31 @@ data CardValue = Ace
                | NoneValue
                deriving (Show, Enum, Eq)
 
--- A card has a type and a value
-type Card = (CardType, CardValue)
+data CardStatus = Hidden
+                | Visible
+                deriving (Show)
 
--- A deck of cards
-type Deck = [Card]
+-- A card has a type and a value and is either shown or hidden.
+type Card = (CardType, CardValue, CardStatus)
 
-generateCards :: Deck
-generateCards = [(cType, cValue) | cType <- types, cValue <- values]
+-- A stack of cards
+type Stack = [Card]
+
+-- Generate a standard 52-card deck, given by CardValue and CardType
+generateDeck :: Stack
+generateDeck = [(cType, cValue, Hidden) | cType <- types, cValue <- values]
     where types  = init $ enumFrom Clubs
           values = init $ enumFrom Ace 
 
-generateShuffledCards :: Deck
-generateShuffledCards = shuffle generateCards
+generateShuffledDeck :: Stack
+generateShuffledDeck = shuffle generateDeck
 
+showCard :: Card -> Card
+showCard (t, v, _) = (t,v,Visible)
+
+hideCard :: Card -> Card
+hideCard (t, v, _) = (t,v,Hidden)
+
+flipCard :: Card -> Card
+flipCard c@(_, _, Visible) = hideCard c
+flipCard c@(_, _, Hidden)  = showCard c