numbers.hs

import System.Random 
import Data.Char
import Text.Printf
import Debug.Trace


-- <number-to-guess> <display-string> <character-guessed>
--  Returns: (Guessed correctly T/F , display-string)
check :: Int -> String -> Char -> (Bool,String)
check number display c = 
   (ord(c) == number, [c])


-- n is number of remaining turns word is the word to guess
turn :: Int -> String -> Int -> IO ()
turn number display n =
  do 
     if n==0                          -- No remaining guesses
     then putStrLn "You lose"
     else if number == (read display :: Int)  -- number is correctly guessed
          then putStrLn "You win!"
          else mkguess number display n -- Make a guess


-- Make a guess 
-- <word> <word-count dashes> <number of guesses>
mkguess :: Int -> String -> Int -> IO () 
mkguess number display n =
  do 
     putStrLn (display ++ "  " ++ take n (repeat '*')) -- Stars mean # of guesses
     putStr "  Enter your guess: "
     q <- getLine                   -- Get character guessed 
     let (correct, display') = check number display (q!!0)
     let n' = if correct then n else n-1 -- Reduce # guesses if incorrect
     turn number display' n'



randomNumberRange :: [Int]
randomNumberRange = [1..10]


randomNumber :: IO Int
randomNumber = do
  let numbers = randomNumberRange
  index <- randomRIO (0, length numbers -1)
  return (numbers !! index)


numberGame :: Int -> IO ()
numberGame numberGuesses = 
  do 
     number <- randomNumber
     turn number "-1" numberGuesses