Haskell interact function

Question

I’m new to Haskell and have a problem with interact function. This is my sample program:

main :: IO ()
main = interact inputLength

inputLength          


        

Answer 1

A more reusable solution:

main = interactLineByLine processLine

-- this wrapper does the boring thing of mapping, unlining etc.... you have to do all the times for user interaction
interactLineByLine:: (String -> String) -> IO ()
interactLineByLine f = interact (unlines . (map processLine) . lines) 

-- this function does the actual work line by line, i.e. what is
-- really desired most of the times
processLine:: String -> String
processLine line = "<" ++ line ++ ">"