Re: [Haskell-cafe] minor refactoring problem

On Tue, Nov 29, 2011 at 2:54 AM, Martin DeMello wrote:

On Tue, Nov 29, 2011 at 2:29 AM, Holger Siegel wrote:

...

fromRawFile, fromSavedFile :: String -> IO [PairBox] fromRawFile = mapM (\x -> makePair (x, "")) . lines fromSavedFile = mapM makePair . parseFile

setEditor :: Editor -> [PairBox] -> IO () setEditor ed = writeIORef ed . V.fromList

importFile, loadFile :: Editor -> String -> IO () importFile ed = readfile >=> fromRawFile >=> setEditor loadFile ed = readfile >=> fromSavedFile >=> setEditor

Wow, very nice! First time I've truly grasped what >=> is good for. I'll need to go see where else I can use it in my code.

Quick question: what's the difference between importFile ed = readfile >=> fromRawFile >=> setEditor ed and importFile = readfile >=> fromRawFile >=> setEditor that the former compiles but the latter doesn't? martin

martin