import System.Random
import System.IO.Unsafe

data Maze = Maze { cells :: [(Bool, Bool)]  -- [(rightWall, downWall)]
                 , width :: Int
                 , height :: Int
                 }

rand :: Int -> Int
-- Returns a random integer from 0 to max-1
rand max = unsafePerformIO $ randomRIO (0, max-1)

shuffle :: [a] -> [a]
-- Randomly shuffles a list
shuffle = unsafePerformIO . shuffleM

shuffleM :: [a] -> IO [a]
-- DON'T BOTHER! Helper for shuffle
shuffleM [] = return []
shuffleM n = do {
                r <- fmap (flip mod $ length n) randomIO;
                n1 <- return $ n !! r;
                fmap ((:) n1) $ shuffleM $ (take r n) ++ (drop (r+1) n)
             }