long set of code here, I think I figured out what you all were telling me. Compose small functions then compose bigger functions from smaller functions and so on... The problem I am having is I have an (IO String) where I need a (String) and it reports it as such: ERROR "C:\Documents and Settings\drunkenmike\My Documents\Programming\Csci4501\H askell\datesort.hs":41 - Type error in application *** Expression : separateIntoLines (getInput x) *** Term : getInput x *** Type : IO String *** Does not match : [Char] I am gonna mark line 41 with a * at the beginning of the line. I have been looking high and low for the answer to IOString -> String.... all I think I need to do (I think anyways) By the way, thanks to everyone for their help. import IO --- -- Control Flow --- datesort :: IO() datesort = do { putStr "Enter a filename: "; theFile <- getLine; sortAndOutput (readInAndGetReady theFile); } -- -- Composite functions -- 1) Read in & Get ready to sort -- 2) sort & output -- -- readInAndGetReady :: String -> [String] *readInAndGetReady x = fixDates (makeSortableDates (linesToDates (separateIntoLines (getInput x)))) sortAndOutput :: [String] -> IO() sortAndOutput x = writeTheFile (getOutput (makePrintableDates (qsort x))) -- -- Make the date printable. Printable means a string consisting of -- dates in the form dd mm yyyy (more or less undoes the make sortable f x) -- makePrintableDates :: [String] -> [String] makePrintableDates x = map makePrintableDate x -- -- Make the date printable. Printable means a string consisting of -- dates in the form dd mm yyyy (more or less undoes the make sortable f x) -- makePrintableDate :: String -> String makePrintableDate x = unwords (reverse (words x)) -- -- Make all the dates sortable. Sortable means a string consisting of -- dates in the form yyyy mm dd -- makeSortableDates :: [[String]] -> [String] makeSortableDates x = map makeSortableDate x -- -- Make the date sortable. Sortable means a string consisting of -- dates in the form yyyy mm dd -- makeSortableDate :: [String] -> String makeSortableDate x = unwords (reverse x) -- -- Get the input from the given file -- getInput :: String -> IO String getInput myfile = readFile myfile -- -- Seperate the input file into an list of Strings -- separateIntoLines :: String -> [String] separateIntoLines str = lines str -- -- Transform all the lines into dates -- linesToDates :: [String] -> [[String]] linesToDates x = map lineToDate x -- -- Transform the lines into dates -- lineToDate :: String -> [String] lineToDate x = words x -- -- Transform the dates into lines -- getOutput :: [String] -> String getOutput x = unlines x -- -- Fix all the dates so that they are in the form 0x if x < 10 -- fixDates:: [String] -> [String] fixDates x = map fixPrefixes x -- -- Fix the dates so that they are in the form 0x if x < 10 -- fixPrefixes :: String -> String fixPrefixes p | p == "1" = "01" | p == "2" = "02" | p == "3" = "03" | p == "4" = "04" | p == "5" = "05" | p == "6" = "06" | p == "7" = "07" | p == "8" = "08" | p == "9" = "09" | otherwise = p -- -- Quicksort the List of strings -- qsort :: [String] -> [String] qsort [] = [] qsort (x:xs) = qsort elts_lt_x ++ [x] ++ qsort elts_greq_x where elts_lt_x = [y | y <- xs, y < x] elts_greq_x = [y | y <- xs, y >= x] -- -- Write the ouput string to a file -- writeTheFile :: String -> IO() writeTheFile x = writeFile "output.txt" x _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com