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Traversing a tree interactively

A tree of yes-no questions​

data Interaction =
      Question String Interaction Interaction
    | Result String

Constructors:

Question ::
String
-> Interaction -> Interaction -> Interaction
Result :: String -> Interaction

Pick a language​

pick :: Interaction
pick =
Question "Do you like FP?"
(Question "Do you like static types?"
(Result "Try OCaml.")
(Result "Try Clojure.")
)
(Question "Do you like dynamic types?"
(Result "Try Python.")
(Result "Try Rust.")
)

Pick a car​

ford :: Interaction
ford =
Question "Would you like a car?"
(Question "Do you like it in black?"
(Result "Good for you.")
ford
)
(Result "Never mind then.")

Asking a Boolean question​

askBool :: String -> IO Bool
askBool question = do
putStrLn (question ++ " [yN]")
x <- getChar
putStrLn ""
return (x `elem` "yY")

Traversing the tree interactively​

interaction :: Interaction -> IO ()
interaction (Question q y n) = do
b <- askBool q
if b then interaction y else interaction n
interaction (Result r) = putStrLn r

Traversing the tree non-interactively​

simulate :: Interaction -> [Bool] -> Maybe String
simulate (Question _y_) (True : bs) =
simulate y bs
simulate (Question **n) (False : bs) =
simulate n bs
simulate (Result r) [] = Just r
simulate** = Nothing