Super-simple number guessing game in Haskell. Took me a day or so to make... Needs 'random' package!

guess.hs

import Text.Read (readMaybe)
import System.Random
import System.IO

readGuess :: Integer -> IO Integer
readGuess no = do
    let str = "Please enter your " ++ show no ++ "th guess:"
    putStr str
    hFlush stdout -- need that coz we don't print a \n
    name <- getLine
    case readMaybe name of
        Just x -> return x
        Nothing -> putStrLn "That's not a number!" >> readGuess no

getMessage x cnt
    | x>0   = "That's too big"
    | x<0   = "That's too small!"
    | x==0  = "Congratulations, you won!\nNo. of tries: " ++ show cnt

doGuess :: Integer -> Integer -> IO Integer
doGuess secret count = do
    x<-readGuess count
    let d = x - secret
    putStrLn $ getMessage d count
    case d of
        y | y == 0      -> return 0
        otherwise       -> doGuess secret (count+1)

main = do
    secretRaw <- randomIO
    let secret = (mod secretRaw 100) + 1
    putStrLn "I picked a random number between 1 and 100. Can you guess it?"
    doGuess secret 1