guessing game - 2.11 - learnfuture

starman.hs

import System.Random

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 :: String -> String -> Int -> IO ()
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 :: Int -> IO ()
starman n =
  do
    let randomInt range = randomRIO range :: IO Int
    let list = ["monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday"]
    let l = length list
    num <- randomInt(0, l-1)
    let word = (list !! num)
    turn word ['-' | x <- word] n