| Thanks for the tip, Ozgur. It worked for me. Is this what you had in mind, Ryan? Michael ============== import Control.Monad.State.Lazy import Control.Monad import System.Random type GeneratorState = State StdGen data Craps a = Roll a | Win a | Lose a deriving (Show) genRandomR :: Random a => (a,a) -> GeneratorState a genRandomR = state . randomR rollDie :: GeneratorState Int rollDie = genRandomR (1,6) roll2Dice :: GeneratorState Int roll2Dice = liftM2 (+) rollDie rollDie f :: Craps [Int] -> GeneratorState (Craps [Int]) f (Roll []) = do g0 <- get let (throw1,g1) = runState roll2Dice g0 put g1 case throw1 of 2 -> return (Lose [throw1]) 3 -> return (Lose [throw1]) 7 -> return (Win [throw1]) 11 -> return (Win [throw1]) _ -> do g1 <- get let (throw2,g2) = runState roll2Dice g1 put g2 if throw2 == throw1 then do return (Win [throw1,throw2]) else if throw2 == 7 then do return (Lose [throw1,throw2]) else do f (Roll [throw1,throw2]) f (Roll z@(throw1:throws)) = do g0 <- get let (throw,g1) = runState roll2Dice g0 put g1 if throw == throw1 then do return (Win (z ++ [throw])) else if throw == 7 then do return (Lose (z ++ [throw])) else do f (Roll (z ++ [throw])) --- On Wed, 12/22/10, Ozgur Akgun <ozgurakgun@gmail.com> wrote:
|