Hangman game written in Haskell

hangman.hs

import qualified Data.Set as Set
import Data.Random
import Data.Random.Extras

data State = State { word :: String, typed :: [Char] }

randomWords :: [String]
randomWords = ["banana", "uva", "abacaxi"]

getRandomWord :: IO String
getRandomWord = runRVar (choice randomWords) StdRandom

-- Logic
charState :: (Char, [Char]) -> Char
charState (char, typedChars)
  | char `elem` typedChars = char
  | otherwise = '_'

isEndGame :: State -> Bool
isEndGame (State { word = w, typed = t }) = do
  Set.fromList w `Set.isSubsetOf` Set.fromList t

-- IO
showWordGame :: (String, [Char]) -> [Char]
showWordGame (word, tc) = map(\x -> charState(x, tc)) word

printWordGame :: (String, [Char]) -> IO ()
printWordGame (word, tc) = print(showWordGame (word, tc))

printState :: State -> IO ()
printState (State { word = w, typed = t }) = do
  printWordGame(w, t)
  print(["Chars typeds: ", t])
  print("Is end of game?")
  print(isEndGame State {word = w, typed = t})

-- gameLoop
gameLoop :: State -> IO ()
gameLoop (State { word = w, typed = t }) = do
  input <- getLine
  printState(State {word = w, typed = head input : t})
  gameLoop (State {word = w, typed = head input : t})

main = do
  w <- getRandomWord
  let initialState = State {word = w, typed = []} 
  printState initialState
  gameLoop initialState