introduce stack build system and restructure code

app/Main.hs

@@ -0,0 +1,86 @@
+module Main where
+
+import Control.Monad.State
+import Control.Monad.Reader
+import Control.Concurrent
+
+import qualified Network.WebSockets as WS
+import qualified Data.ByteString.Lazy.Char8 as BS
+
+import Skat
+import Skat.Card
+import Skat.Operations
+import Skat.Player
+import Skat.Pile
+
+import Skat.AI.Stupid
+import Skat.AI.Online
+import Skat.AI.Rulebased
+
+main :: IO ()
+main = testAI 10
+
+testAI :: Int -> IO ()
+testAI n = do
+    let acs = repeat runAI
+    vals <- sequence (take n acs)
+    putStrLn $ "average won points " ++ show (fromIntegral (sum vals) / fromIntegral n)
+
+runAI :: IO Int
+runAI = do
+    env <- shuffledEnv
+    let ps = piles env
+        cs = handCards Hand3 ps
+        trs = filter (isTrump Spades) cs
+    if length trs >= 5 && any ((==32) . getID) cs
+        then do
+            pts <- fst <$> evalStateT (turn Hand1) env
+            if pts > 60 then return 1 else return 0
+        else runAI
+
+env :: SkatEnv
+env = SkatEnv piles Nothing Spades playersExamp
+    where piles = distribute allCards 
+
+envStupid :: SkatEnv
+envStupid = SkatEnv piles Nothing Spades pls2
+    where piles = distribute allCards 
+
+playersExamp :: Players
+playersExamp = Players
+    (PL $ Stupid Team Hand1)
+    (PL $ Stupid Team Hand2)
+    (PL $ mkAIEnv Single Hand3 10)
+
+pls2 :: Players
+pls2 = Players
+    (PL $ Stupid Team Hand1)
+    (PL $ Stupid Team Hand2)
+    (PL $ Stupid Team Hand3)
+
+shuffledEnv :: IO SkatEnv
+shuffledEnv = do
+    cards <- shuffleCards
+    return $ SkatEnv (distribute cards) Nothing Spades playersExamp
+
+env2 :: SkatEnv
+env2 = SkatEnv piles Nothing Spades playersExamp
+    where hand1 = [Card Seven Clubs, Card King Clubs, Card Ace Clubs, Card Queen Diamonds]
+          hand2 = [Card Seven Hearts, Card King Hearts, Card Ace Hearts, Card Queen Spades]
+          hand3 = [Card Seven Spades, Card King Spades, Card Ace Spades, Card Queen Clubs]
+          h1 = map (putAt Hand1) hand1
+          h2 = map (putAt Hand2) hand2
+          h3 = map (putAt Hand3) hand3
+          piles = Piles (h1 ++ h2 ++ h3) [] []
+
+runWebSocketServer :: IO ()
+runWebSocketServer = do
+    WS.runServer "localhost" 4243 application
+
+application :: WS.PendingConnection -> IO ()
+application pending = do
+    conn <- WS.acceptRequest pending
+    putStrLn "someone connected"
+    forever $ do
+        msg <- WS.receiveData conn
+        putStrLn $ BS.unpack msg