Re: [Haskell-cafe] Noob question and sequence of operations (print then do something else)

John Wicket wrote:

I am still in an imperative way of thinking. In this example here; how would I call "putStrLn" and then set the function with a value. Eg:

aa :: String -> IO () aa instr = do putStrLn "abc" putStrLn "abc" return "123"

--- The error I am getting.

Couldn't match expected type `()' against inferred type `[Char]' In the first argument of `return', namely `"123"' In the expression: return "123" In the expression: do putStrLn "abc" putStrLn "abc" return "123"

Your type signature is wrong. If you want an IO action whose return value is a String, say so: aa :: String -> IO String