I am trying to write a Spider Solitaire player as a Haskell learning exercise.

My main function will call a playGame function once for each game (using mapM), passing in the game number and a random generator (StdGen). The playGame function should return a Control.Monad.State monad and an IO monad that contains a String showing the game tableau and a Bool indicating if the game was won or lost.

How do I combine the State monad with the IO monad for the return value? What should the type declaration for `playGame be?

playGame :: Int -> StdGen a -> State IO (String, Bool)

Is the State IO (String, Bool) correct? If not, what should it be?

In main, I plan on using

do
  -- get the number of games from the command line (already written)
  results <- mapM (\game -> playGame game getStdGen) [1..numberOfGames]

Is this the correct way to call playGame?

haskell io state-monad
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