starman.hs

check :: String -> String -> Char -> (Bool, String)
check word display c =
  ( c `elem` word,
    [ if x == c
        then c
        else y
      | (x, y) <- zip word display
    ]
  )

turn :: String -> String -> Int -> IO ()
turn word display n =
  do
    if n == 0
      then putStrLn "You lose"
      else
        if word == display
          then putStrLn "You win!"
          else mkguess word display n

mkguess word display n =
  do
    putStrLn (display ++ "  " ++ take n (repeat '*'))
    putStr "  Enter your guess: "
    q <- getLine
    let (correct, display') = check word display (q !! 0)
    let n' = if correct then n else n -1
    turn word display' n'

starman :: String -> Int -> IO ()
starman word n = turn word ['-' | x <- word] n