Mine

cpsGetChar :: ContT r IO Char
cpsGetChar = do
    c <- liftIO getChar
    return c

cpsProcessChar :: Char -> ContT r IO ()
cpsProcessChar c = do
    liftIO $ putChar c
    return ()


-- New version of cpsProcessChar
cpsProcessChar fk c = do
    liftIO $ putChar c
    callCC $ \ k -> forever (cpsGetChar >>= cpsProcessChar k)