Why “Empty do” error when my do isn't empty?

Question

I am trying to create a menu which gives output based on user input. However, I get a empty do error even though I have code for it to do underneath it. Am I missing something?<

Answer 1

Try this:

main :: IO()
main = do 
       contents <- readFile "spa.txt"
       let storage = (read contents :: [Spa])
       putStrLn "Please Enter Your Name: "
       name <- getLine
       putStrLn ""
       putStrLn ("Welcome " ++ name)
       menu storage
       putStrLn "" where
            menu resDB = do
                putStrLn "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~" 
                putStrLn "\nPlease select an option:"
                putStrLn "1: Add a new spa to the database "
                putStrLn "2: Show all spas in the database"
                putStrLn "3: Give all spas operating in a certain area"
                putStrLn "4: Give all spas that have a performance of 8 or higher "
                putStrLn "5: Give the average performance for the spas in a certain area "
                putStrLn "6: Give the names of the spas a given supervisor has rated the service level, along with that rating result for each spa."
                putStrLn "7: Give the names of the spas a given supervisor has yet to rate the service level, along with that spa performance."
                putStrLn "8: Allow a given chef rating to be entered (or updated) for a restaurant he has rated (note that only the latest result from the supervsior should remain recorded)"
                putStrLn "9: Exit"                      
                putStr "\nSelected option: "
                putStrLn ""
                option <- getLine    
                putStrLn "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"

            output :: Int -> IO ()
            output option = do 
                case option of
                    1 -> putStrLn "Enter Spa ID: "