packages feed

haskell-snake (empty) → 1.0.0

raw patch · 13 files changed

+1424/−0 lines, 13 filesdep +basedep +containersdep +haskell-snakesetup-changed

Dependencies added: base, containers, haskell-snake, lens, linear, mtl, random, sdl2, sdl2-ttf, text, vector

Files

+ CHANGELOG.md view
@@ -0,0 +1,8 @@+# Changelog++## [Unreleased]++## [1.0.0] -- 2018-05-24+### Added+- `stack` support+- complete rewrite for `SDL2`
+ LICENSE view
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+ Setup.hs view
@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain
+ driver/Main.hs view
@@ -0,0 +1,220 @@+module Main where++import Control.Lens++import Game.HSnake.AI+import Game.HSnake.Basic+import Game.HSnake.Game+import Game.HSnake.Graphics+import Game.HSnake.Player+import Game.HSnake.Snake++import Control.Monad+import Control.Monad.State+import Control.Monad.Reader+import Data.List+import Foreign.C.Types (CInt(..))+import qualified SDL+import qualified SDL.Font as SDLF+++data MessageDir = MessageDir {+    quitMessage     :: Bool+}++data AppConfig = AppConfig {+    window      :: SDL.Window,+    renderer    :: SDL.Renderer,+    gameScreen  :: SDL.Surface,+    messageDir  :: MessageDir+}++type AppState = StateT GameState IO+type AppEnv = ReaderT AppConfig AppState+++initEnv :: IO (AppConfig, GameState)+initEnv = do+  let windowSize = SDL.V2 (fromIntegral screenWidth :: CInt) (fromIntegral screenHeight :: CInt)+  let p = SDL.defaultWindow {SDL.windowInitialSize = windowSize}+  window <- SDL.createWindow "Haskell Snake" p+  SDL.showWindow window+  let screenSize = SDL.V2 (fromIntegral gameScreenWidth :: CInt) (fromIntegral gameScreenHeight :: CInt)+  gameScreen <- SDL.createRGBSurface screenSize SDL.RGB24+  -- Renderer renders to gameScreen, not to window+  -- We have text additionally to render to other parts of the window+  -- If we rendered directly to window and then rendered text, this+  -- would result in flickering+  renderer <- SDL.createSoftwareRenderer gameScreen++  let msgDir = MessageDir False++  applePos <- getRandomApple initialSnakePosition+  tick <- SDL.ticks++  return (AppConfig window renderer gameScreen msgDir,+            applePosition .~ applePos $+            lastTick .~ tick $ initialGameState) -- timerState+++runLoop :: AppConfig -> GameState -> IO ()+runLoop = evalStateT . runReaderT loop+++handleInputHuman :: GameState -> (Maybe SDL.Event) -> ReaderT AppConfig AppState ()+handleInputHuman gs (Just (SDL.Event _ (SDL.KeyboardEvent k))) =+  handleInputKeyboard gs k+handleInputHuman _ _ = return ()++handleInputKeyboard :: MonadState GameState m => GameState -> SDL.KeyboardEventData -> m ()+handleInputKeyboard gs (SDL.KeyboardEventData _ SDL.Pressed False keysym) =+  case SDL.keysymKeycode keysym of+      SDL.KeycodeDown  -> do+        put $ players .~ moveHuman South $ gs+      SDL.KeycodeUp    -> do+        put $ players .~ moveHuman North $ gs+      SDL.KeycodeLeft  -> do+        put $ players .~ moveHuman West $ gs+      SDL.KeycodeRight -> do+        put $ players .~ moveHuman East $ gs+      _          -> return ()+    where+      moveHuman dir = mapToIndices (\pl -> setNextPlayerDirection pl dir) (gs^.players) humanPlayerIndices+          where+              humanPlayerIndices = findIndices isHuman (gs^.players)+handleInputKeyboard _ _ = return ()++++-- | poll for event until it is SDL_QUIT or NoEvent+whileEvents :: MonadIO m => (Maybe SDL.Event -> m ()) -> m Bool+whileEvents act = do+    event <- liftIO SDL.pollEvent+    case event of+        Just (SDL.Event _ SDL.QuitEvent) -> return True+        _                                -> do+            act event+            return False+++loop :: AppEnv ()+loop = do+  gameState <- get+  quit <- whileEvents $ handleInputHuman gameState+  computeAINextMoves++  gameState <- get++  let apple = gameState^.applePosition+  let ps = gameState^.players++  if checkPlayersCollision ps+      then error "Game over"+      else return ()++  tick <- liftIO SDL.ticks++  let tickDifference = fromIntegral tick - fromIntegral (gameState^.lastTick)++  if (tickDifference > speedFromLevel (fromIntegral $ gameState^.level))+      then+          do+              -- Move the snake first, only then check for apple eating.+              -- Otherwise we would eat the apple, then immediately move+              -- the snake, which is wrong.+              updatePlayerDirections+              movePlayers+              gameState <- get+              put $ lastTick .~ tick $ gameState++              drawGame++              let appleEatersInd = findIndices (playerEatsApple apple) ps+              if (length appleEatersInd > 0)+                  then do+                      newApplePosition <- liftIO $ getRandomApple (totalPlayersPosition ps)+                      -- increase snake's length+                      increaseAppleEatersLength appleEatersInd+                      gameState <- get+                      put $ applePosition .~ newApplePosition $ gameState++                  else return ()+      else return ()++  if (shouldIncreaseLevel ps)+      then do+          newApplePosition <- liftIO $ getRandomApple (totalPlayersPosition ps)+          -- start new level after apple is eaten+          put $ applePosition .~ newApplePosition $+                level .~ (gameState^.level) + 1 $ initialGameState+      else return ()++  unless quit loop++  loop+++computeAINextMoves :: ReaderT AppConfig AppState ()+computeAINextMoves = do+        gameState <- get+        put $ players .~ movedAI gameState $ gameState+    where+        aiIndices gs = findIndices (not . isHuman) (gs^.players)+        movedAI gs = mapToIndices (\pl -> setNextPlayerDirection pl (computeAIPlayerMove pl gs)) (gs^.players) (aiIndices gs)+++updatePlayerDirections :: ReaderT AppConfig AppState ()+updatePlayerDirections = do+           gameState <- get+           put $ players .~ map updatePlayerDirection (gameState^.players) $ gameState+++movePlayers :: ReaderT AppConfig AppState ()+movePlayers = do+            gameState <- get+            put $  players .~ map movePlayer (gameState^.players) $ gameState+++increaseAppleEatersLength :: [Int] -> ReaderT AppConfig AppState ()+increaseAppleEatersLength appleEatersIndices = do+            gameState <- get+            put $ players .~ mapToIndices increasePlayerSnakeLength (gameState^.players) appleEatersIndices $ gameState+++drawGame :: ReaderT AppConfig AppState ()+drawGame = do+  window      <- window `liftM` ask+  renderer    <- renderer `liftM` ask+  gameScreen  <- gameScreen `liftM` ask+  gameState   <- get++  liftIO $ do+    -- clear window surface first+    screen <- SDL.getWindowSurface window+    clearSurface screen++    paintBoard renderer+    paintApple renderer (gameState^.applePosition)+    mapM_ (paintPlayer renderer) (gameState^.players)++    SDL.present renderer++    showGameMessages window gameState++    _ <- SDL.surfaceBlit gameScreen Nothing screen Nothing++    SDL.updateWindowSurface window++    SDL.freeSurface screen++    return ()+++main :: IO ()+main = do+  SDL.initializeAll+  SDLF.initialize++  (env, snakeState) <- initEnv++  runLoop env snakeState
+ driver/MainWrapper.hs view
@@ -0,0 +1,5 @@+{-# LANGUAGE ForeignFunctionInterface #-}++module MainWrapper where+import Main (main)+foreign export ccall "haskell_main" main :: IO ()
+ haskell-snake.cabal view
@@ -0,0 +1,76 @@+-- This file has been generated from package.yaml by hpack version 0.27.0.+--+-- see: https://github.com/sol/hpack+--+-- hash: 60583e315dd2851d455eb1c3beba4cfd260b5fecb8b670efc23c1f0c6070679a++name:           haskell-snake+version:        1.0.0+synopsis:       Snake game implemetation in Haskell using SDL2+description:    See README at <https://github.com/CGenie/haskell-snake>+category:       Games+homepage:       https://github.com/CGenie/haskell-snake#readme+bug-reports:    https://github.com/CGenie/haskell-snake/issues+maintainer:     Przemysław Kamiński <cgenie@gmail.com>+license:        GPL-3+license-file:   LICENSE+build-type:     Simple+cabal-version:  >= 1.10++extra-source-files:+    CHANGELOG.md++source-repository head+  type: git+  location: https://github.com/CGenie/haskell-snake++library+  exposed-modules:+      Game.HSnake.AI+      Game.HSnake.Basic+      Game.HSnake.Board+      Game.HSnake.Game+      Game.HSnake.Graphics+      Game.HSnake.Player+      Game.HSnake.Snake+  other-modules:+      Paths_haskell_snake+  hs-source-dirs:+      src+  default-extensions: EmptyCase FlexibleContexts FlexibleInstances InstanceSigs MultiParamTypeClasses LambdaCase MultiWayIf NamedFieldPuns TupleSections DeriveFoldable DeriveFunctor DeriveGeneric DeriveLift DeriveTraversable DerivingStrategies GeneralizedNewtypeDeriving StandaloneDeriving BangPatterns KindSignatures TypeOperators OverloadedStrings ScopedTypeVariables TypeApplications ConstraintKinds RankNTypes DefaultSignatures PatternSynonyms TemplateHaskell+  ghc-options: -Wall -Wincomplete-patterns -Wincomplete-uni-patterns -Wredundant-constraints+  build-depends:+      base >=4.9 && <5+    , containers+    , lens+    , linear+    , mtl+    , random+    , sdl2+    , sdl2-ttf+    , text+    , vector+  default-language: Haskell2010++executable haskell-snake+  main-is: Main.hs+  other-modules:+      MainWrapper+      Paths_haskell_snake+  hs-source-dirs:+      driver+  default-extensions: EmptyCase FlexibleContexts FlexibleInstances InstanceSigs MultiParamTypeClasses LambdaCase MultiWayIf NamedFieldPuns TupleSections DeriveFoldable DeriveFunctor DeriveGeneric DeriveLift DeriveTraversable DerivingStrategies GeneralizedNewtypeDeriving StandaloneDeriving BangPatterns KindSignatures TypeOperators OverloadedStrings ScopedTypeVariables TypeApplications ConstraintKinds RankNTypes DefaultSignatures PatternSynonyms TemplateHaskell+  ghc-options: -Wall -Wincomplete-patterns -Wincomplete-uni-patterns -Wredundant-constraints+  build-depends:+      base >=4.9 && <5+    , containers+    , haskell-snake+    , lens+    , linear+    , mtl+    , random+    , sdl2+    , sdl2-ttf+    , text+    , vector+  default-language: Haskell2010
+ src/Game/HSnake/AI.hs view
@@ -0,0 +1,33 @@+module Game.HSnake.AI where++import Control.Lens++import Game.HSnake.Basic+import Game.HSnake.Game+import Game.HSnake.Player+import Game.HSnake.Snake++computeAIPlayerMove :: Player -> GameState -> Direction+computeAIPlayerMove pl gameState = circleAIPlayer pl+++circleAIPlayer :: Player -> Direction+circleAIPlayer pl+    -- corner cases+    | headPos^.x == 1 && dir == West && headPos^.y <= 2                 = South+    | headPos^.x == 1 && dir == West && headPos^.y > 2                  = North+    | headPos^.x == (numRectsX - 1) && dir == East && headPos^.y <= 2   = South+    | headPos^.x == (numRectsX - 1) && dir == East && headPos^.y > 2    = North+    | headPos^.y == 1 && dir == North && headPos^.x >= 2                = West+    | headPos^.y == 1 && dir == North && headPos^.x < 2                 = East+    | headPos^.y == (numRectsY - 1) && dir == South && headPos^.x >= 2  = West+    | headPos^.y == (numRectsY - 1) && dir == South && headPos^.x < 2   = East+    -- normal operation+    | headPos^.y <= 2                                                   = South+    | headPos^.y >= (numRectsX - 2)                                     = North+    | headPos^.y <= 2                                                   = West+    | headPos^.y >= (numRectsY - 2)                                     = East+    | otherwise                                                         = pl^.snake^.direction+    where+        headPos = head $ pl^.snake^.position+        dir     = pl^.snake^.direction
+ src/Game/HSnake/Basic.hs view
@@ -0,0 +1,71 @@+-- Basic.hs -- basic functions and datatypes+module Game.HSnake.Basic where++import Control.Lens++import Data.List+import System.Random++--data Colors = White | Black++data Colour = White | Red | Blue | Green | Yellow | Black+  deriving (Eq, Show)++data Point = Point {+     _x          :: Int,+     _y          :: Int+} deriving (Show, Eq, Ord)++makeLenses ''Point++infixl 6 |+|+(|+|) :: Point -> Point -> Point+pt1 |+| pt2 = Point (pt1^.x + pt2^.x) (pt1^.y + pt2^.y)++data Direction = North | South | East | West+     deriving (Show, Eq, Ord)++-- | board size+numRectsX :: Int+numRectsX     = 11+-- | board size+numRectsY :: Int+numRectsY     = 11++oppositeDirections :: Direction -> Direction -> Bool+oppositeDirections dir1 dir2+            | ss == sort [North, South] = True+            | ss == sort [East, West]   = True+            | otherwise                 = False+        where+            ss = sort [dir1, dir2]++directionToPoint :: Direction -> Point+directionToPoint North = Point 0 (-1)+directionToPoint South = Point 0 1+directionToPoint East = Point 1 0+directionToPoint West = Point (-1) 0++randomListGenerator = do+            seed <- newStdGen+            return $ randomlist seed+        where+            randomlist = unfoldr (Just . random)++getRandomApple snakePosition = do+                r1 <- randomListGenerator+                r2 <- randomListGenerator+                let pts = map modPoint (zip r1 r2)+                return $ head $ filter (\pt -> (not . elem pt) snakePosition) pts+            where+                modPoint (x, y) = Point ((x `mod` numRectsX) + 1) ((y `mod` numRectsY) + 1)++-- | maps function to list, but only to specific indices+mapToIndices :: (Eq a) => (a -> a) -> [a] -> [Int] -> [a]+mapToIndices f xs ind = mapToIndices' f xs ind 0+        where+            mapToIndices' f' (x':xs') (ind':inds') i+                | ind' == i    = (f' x':mapToIndices' f' xs' inds' (i + 1))+                | otherwise    = (x':mapToIndices' f' xs' (ind':inds') (i + 1))+            mapToIndices' f' [] _ _ = []+            mapToIndices' f' xs' [] _ = xs'
+ src/Game/HSnake/Board.hs view
@@ -0,0 +1,15 @@+-- Board.hs -- board logic+module Game.HSnake.Board where++import Control.Lens++import Game.HSnake.Basic++data Board = Board {+     _xSize   :: Int,+     _ySize   :: Int+} deriving (Eq, Show)++makeLenses ''Board++initialBoard = Board numRectsX numRectsY
+ src/Game/HSnake/Game.hs view
@@ -0,0 +1,33 @@+module Game.HSnake.Game where++import Game.HSnake.Basic+import Game.HSnake.Board+import Game.HSnake.Player+import Game.HSnake.Snake++import Control.Lens+import Data.Word++data GameState = GameState {+     _players            :: [Player],+     _applePosition      :: Game.HSnake.Basic.Point,+     _board              :: Board,+     _level              :: Int,+     _lastTick           :: Word32+}+makeLenses ''GameState++initialGameState :: GameState+initialGameState = GameState+                 [initialPlayer, initialComputer]+                 (Game.HSnake.Basic.Point 0 0)+                 initialBoard+                 1+                 0++speedFromLevel :: Integer -> Integer+speedFromLevel l = toInteger $ floor $ (380 * (0.5**(0.1 * (fromIntegral l))) + 20)++-- if snake's length is greater than 10, then increase level+shouldIncreaseLevel :: [Player] -> Bool+shouldIncreaseLevel ps = length (filter (>=10) (map (\pl -> pl^.snake^.len) ps)) > 0
+ src/Game/HSnake/Graphics.hs view
@@ -0,0 +1,137 @@+module Game.HSnake.Graphics where++import Game.HSnake.Basic+import Game.HSnake.Board+import Game.HSnake.Game+import Game.HSnake.Player+import Game.HSnake.Snake+++import Control.Lens+import Control.Monad.IO.Class (MonadIO(..))+import Data.Text (pack)+import qualified Data.Vector.Storable as DVS+import Data.Word+import Linear+import Linear.Affine+import Foreign.C.Types (CInt(..))+import qualified SDL+import qualified SDL.Font as SDLF+++type SDLRect = SDL.Rectangle CInt+++setColor :: SDL.Renderer -> Colour -> IO ()+setColor r White  = SDL.rendererDrawColor r SDL.$= SDL.V4 maxBound maxBound maxBound maxBound+setColor r Red    = SDL.rendererDrawColor r SDL.$= SDL.V4 maxBound 0 0 maxBound+setColor r Green  = SDL.rendererDrawColor r SDL.$= SDL.V4 0 maxBound 0 maxBound+setColor r Blue   = SDL.rendererDrawColor r SDL.$= SDL.V4 0 0 maxBound maxBound+setColor r Yellow = SDL.rendererDrawColor r SDL.$= SDL.V4 maxBound maxBound 0 maxBound+setColor r Black = SDL.rendererDrawColor r SDL.$= SDL.V4 0 0 0 maxBound++sdlColor :: Colour -> SDLF.Color+sdlColor Black = SDL.V4 0 0 0 maxBound+sdlColor White = SDL.V4 maxBound maxBound maxBound maxBound++screenWidth :: Int+screenWidth   = 640+screenHeight :: Int+screenHeight  = 480+screenBpp :: Int+screenBpp     = 32++gameScreenWidth :: Int+gameScreenWidth   = 540+gameScreenHeight :: Int+gameScreenHeight  = 400++messageScreenWidth :: Int+messageScreenWidth = screenWidth - gameScreenWidth+messageScreenHeight :: Int+messageScreenHeight = screenHeight - gameScreenHeight++rectWidth :: Int+rectWidth  = gameScreenWidth `div` numRectsX+rectHeight :: Int+rectHeight = gameScreenHeight `div` numRectsY+++rectFromPoint :: Game.HSnake.Basic.Point -> SDLRect+rectFromPoint (Game.HSnake.Basic.Point x y) = SDL.Rectangle startPoint size+                where+                    startX = (x - 1)*rectWidth + 1+                    startY = (y - 1)*rectHeight + 1+                    width  = rectWidth - 1+                    height = rectHeight - 1+                    startPoint = P $ V2 (fromIntegral startX) (fromIntegral startY)+                    size = V2 (fromIntegral width) (fromIntegral height)+++rects = [rectFromPoint (Game.HSnake.Basic.Point ptx pty) | ptx <- [1..numRectsX], pty <- [1..numRectsY]]+rectsVec = DVS.generate (numRectsX * numRectsY)+  (\i -> rects !! i )+++paintRects :: SDL.Renderer -> Colour -> IO ()+paintRects r color = do+  setColor r color+  SDL.fillRects r rectsVec++paintBoard :: SDL.Renderer -> IO ()+paintBoard r = do+  paintRects r White++paintApple :: SDL.Renderer -> Game.HSnake.Basic.Point -> IO ()+paintApple r ap = do+  setColor r Red+  SDL.fillRect r $ Just rect+  where+    rect = rectFromPoint ap++-- | TODO: paint different snakes with different colors+paintPlayer :: SDL.Renderer -> Player -> IO ()+paintPlayer r p = paintSnake r (p^.snake) (p^.colour)+++paintSnake :: SDL.Renderer -> Snake -> Colour -> IO ()+paintSnake r s c =+  mapM_ (\p -> paintSnakePiece r (rectFromPoint p) c) (s^.position)++paintSnakePiece :: SDL.Renderer -> SDLRect -> Colour -> IO ()+paintSnakePiece r rect c = do+  setColor r c+  SDL.fillRect r $ Just rect++showGameMessages :: SDL.Window -> GameState -> IO ()+showGameMessages w gameState = do+  font <- SDLF.load "liberation.ttf" 25++  surface <- SDLF.solid font color levelMessage++  screen <- SDL.getWindowSurface w++  renderSurfaceToWindow w screen surface startPoint++  SDL.freeSurface screen+  SDL.freeSurface surface+  SDLF.free font++  where+    levelMessage = pack $ "Level " ++ (show $ gameState^.level)+    color = sdlColor White+    startPoint = P $ V2 (fromIntegral gameScreenWidth) 0++renderSurfaceToWindow :: (MonadIO m) => SDL.Window -> SDL.Surface -> SDL.Surface -> (SDL.Point V2 CInt) -> m ()+renderSurfaceToWindow w s i startPoint = do+  SDL.surfaceBlit i Nothing s (Just startPoint)+  return ()++clearScreen :: SDL.Renderer -> IO ()+clearScreen r = do+  setColor r Black+  SDL.clear r++clearSurface :: SDL.Surface -> IO ()+clearSurface s = do+  SDL.surfaceFillRect s Nothing (sdlColor Black)
+ src/Game/HSnake/Player.hs view
@@ -0,0 +1,78 @@+module Game.HSnake.Player where++import Control.Lens++import Game.HSnake.Basic+import Game.HSnake.Snake++import Data.List++data PlayerType = AI | Human+    deriving (Eq, Show)++data Player = Player {+    _playerType         :: PlayerType+   ,_snake              :: Snake+     {-|+          Temporary state variable to store next move's snake direction+          Without this when snake went North, and user quickly typed+          West, then South, snake would bump into itself+     -}+   ,_nextSnakeDirection :: Direction+   ,_colour             :: Colour+} deriving (Eq, Show)++makeLenses ''Player++initialPlayer :: Player+initialPlayer = Player+              Human+              initialSnake+              (initialSnake^.direction)+              Green++initialPlayerBottom :: Player+initialPlayerBottom = Player+              Human+              initialSnakeBottom+              (initialSnakeBottom^.direction)+              Green++initialComputer :: Player+initialComputer = Player+              AI+              initialSnakeBottom+              (initialSnakeBottom^.direction)+              Blue++isHuman :: Player -> Bool+isHuman (Player Human _ _ _) = True+isHuman _ = False++checkPlayerCollision :: Player -> Bool+checkPlayerCollision player = checkCollision $ player^.snake++movePlayer :: Player -> Player+movePlayer pl = snake .~ (moveSnake $ pl^.snake) $ pl++playerEatsApple :: Point -> Player -> Bool+playerEatsApple apple player = snakeEatsApple (player^.snake) apple++sumPlayersPosition :: [Player] -> [Point]+sumPlayersPosition ps = foldl (++) [] $ map (\pl -> pl^.snake^.position) ps++totalPlayersPosition :: [Player] -> [Point]+totalPlayersPosition = nub . sumPlayersPosition++checkPlayersCollision :: [Player] -> Bool+checkPlayersCollision ps = (length (filter checkPlayerCollision ps) > 0) ||+                          (length (totalPlayersPosition ps) < (length (sumPlayersPosition ps)))++increasePlayerSnakeLength :: Player -> Player+increasePlayerSnakeLength pl = snake .~ (increaseSnakeLength $ pl^.snake) $ pl++setNextPlayerDirection :: Player -> Direction -> Player+setNextPlayerDirection pl dir = nextSnakeDirection .~ dir $ pl++updatePlayerDirection :: Player -> Player+updatePlayerDirection pl = snake .~ changeSnakeDirection (pl^.snake) (pl^.nextSnakeDirection) $ pl
+ src/Game/HSnake/Snake.hs view
@@ -0,0 +1,71 @@+-- Snake.hs: Snake-control logic+module Game.HSnake.Snake where++import Control.Lens++import Game.HSnake.Basic++import Data.List (nub, sort)++data Snake = Snake {+    -- | Snake's position is a list containing all its elements.+    -- The first element of this list is snake's head.+    _position    :: [Point],+    _direction   :: Direction,+    -- | Snake's length+    -- We need to keep it -- if we initialize new level with large+    -- snake length, we initially get a shorter snake so+    -- snake^.position is not the correct snake's measure+    _len         :: Int+} deriving (Show, Eq)++makeLenses ''Snake++-- | Increases snake's length by 1+increaseSnakeLength :: Snake -> Snake+increaseSnakeLength = len +~ 1++-- | Moves snake according to it's direction+moveSnake :: Snake -> Snake+moveSnake snake = position .~ newPosition $ snake+             where+                -- |check snake's length, if newPosition contains too many elements, remove them+                newPosition = take (snake^.len)+                    ((head (snake^.position) |+| directionToPoint (snake^.direction)) :+                     (snake^.position))++-- | Basically we check if there are 2 same elements in the 'position' list+checkCollision :: Snake -> Bool+checkCollision snake = outOfBoundary || selfCollision+                where+                    snakePosition = snake^.position+                    mini          = head $ sort snakePosition+                    maxi          = head $ reverse $ sort snakePosition+                    outOfBoundary = (mini^.x < 1) || (mini^.y < 1) ||+                                    (maxi^.x > numRectsX) || (maxi^.y > numRectsY)+                    selfCollision = (length (nub snakePosition)) /= (length snakePosition)++-- | Starting position & body+initialSnakePosition :: [Point]+initialSnakePosition = [Point 6 6]++initialSnakePositionBottom :: [Point]+initialSnakePositionBottom = [Point 6 11]++initialSnake :: Snake+initialSnake = Snake initialSnakePosition North 1++initialSnakeBottom :: Snake+initialSnakeBottom = Snake initialSnakePositionBottom North 1++snakeEatsApple :: Snake -> Point -> Bool+snakeEatsApple snake apple = apple `elem` (snake^.position)++-- | Don't allow to change to opposite direction immediately+tryChangeSnakeDirection :: Direction -> Direction -> Direction+tryChangeSnakeDirection d sd+  | oppositeDirections d sd = sd+  | otherwise    = d++changeSnakeDirection :: Snake -> Direction -> Snake+changeSnakeDirection s d = direction .~ (tryChangeSnakeDirection d (s^.direction)) $ s