module IO where

import ST

type MyState s = (s, String, String)
type MyIO s a    = ST (MyState s) a

unitIO :: a -> MyIO s a
unitIO = unitST

bindIO :: MyIO s a -> (a -> MyIO s b) -> MyIO s b
bindIO = bindST

setIO :: Pos s a -> a -> MyIO s ()
setIO p v = \ (s, i, o) -> ((), (snd (p s) v, i, o))

getIO :: Pos s a -> MyIO s a  
getIO p = \ (s, i, o) -> (fst (p s), (s, i, o))

readIO :: () -> MyIO s Char
readIO () = \ (s, c:cs, o) -> (c, (s, cs, o))

eofIO :: () -> MyIO s Bool
eofIO () = \ (s, i, o) -> (null i, (s, i, o))

writeIO :: Show v => v -> MyIO s ()
writeIO v  = \ (s, i, o) -> ((), (s, i, o ++ show v))

putStrIO :: String -> MyIO s ()
putStrIO o'  = \ (s, i, o) -> ((), (s, i, o ++ o'))

fst3 (x, _, _) = x
snd3 (_, y, _) = y  
thd3 (_, _, z) = z 

atoi :: String -> Integer
atoi = read

atof :: String -> Double
atof = read