Data commit

Task/21-game/Haskell/21-game.hs

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+import System.Random
+import System.IO
+import System.Exit
+import Control.Monad
+import Text.Read
+import Data.Maybe
+
+promptAgain :: IO Int
+promptAgain = do
+  putStrLn "Invalid input - must be a number among 1,2 or 3. Try again."
+  playerMove
+
+playerMove :: IO Int
+playerMove = do
+  putStr "Your choice(1 to 3):"
+  number <- getLine
+  when (number == "q") $ do
+    exitWith ExitSuccess
+  let n = readMaybe number :: Maybe Int
+  x <- if isNothing n
+             then promptAgain
+             else let val = read number
+                   in if (val > 3 || val < 1)
+                      then promptAgain
+                      else return val
+  return x
+
+computerMove :: IO Int
+computerMove = do
+  x <- randomRIO (1, 3)
+  putStrLn $ "Computer move:" ++ (show x)
+  return x
+
+gameLoop :: (IO Int, IO Int) -> IO Int
+gameLoop moveorder = loop moveorder 0
+  where loop moveorder total = do
+        number <- fst moveorder
+        let total1 = number + total
+        putStrLn $ "Running total:" ++ (show total1)
+        if total1 >= 21
+           then return 0
+           else do
+             number <- snd moveorder
+             let total2 = number + total1
+             putStrLn $ "Running total:" ++ (show total2)
+             if total2 >= 21
+                then return 1
+                else loop moveorder total2
+
+main :: IO ()
+main = do
+  hSetBuffering stdout $ BlockBuffering $ Just 1
+  putStrLn "Enter q to quit at any time"
+  x <- randomRIO (0, 1) :: IO Int
+  let (moveorder, names) = if x == 0
+                 then ((playerMove, computerMove), ("Player", "Computer"))
+                 else ((computerMove, playerMove), ("Computer", "Player"))
+  when (x == 1) $ do
+    putStrLn "Computer will start the game"
+  y <- gameLoop moveorder
+  when (y == 0) $ do
+    putStrLn $ (fst names) ++ " has won the game"
+  when (y == 1) $ do
+    putStrLn $ (snd names) ++ " has won the game"