Hi Emmanuel, On Wed, Oct 31, 2012 at 11:25:05AM +0100, Emmanuel Touzery wrote:
But this function is already in the IO monad (maybe I'm thinking about this in the wrong way though).
A huge step in understanding monads for myself was to realize, that you can put any monadic computation (IO is the exception) inside an other monadic computation. e.g. ioComputation :: IO () ioComputation = do let maybe = do maybeComputation1 maybeComputation2 ... return () Most monads have some kind of execution function, like the state monad (runState, evalState): ioComputation :: IO () let initalState = ... result = evalState $ do stateComputation1 stateComputation2 initalState return () In your case the Maybe monad doesn't help that much, because the functions you're calling doesn't return a Maybe value. In your case, why having a 'needToFetchAgain' and probably a 'fetch' function instead of just a 'refetch' function, which encapsulates the whole fetching? Greetings, Daniel