On Mon, May 23, 2011 at 9:20 AM, michael rice <nowgate@yahoo.com> wrote:

What's the best way to end up with a list composed of only the Just values, no Nothings? Michael ==========================  import Control.Monad.State import Data.Maybe type GeneratorState = State Int tick :: GeneratorState (Maybe Int) tick = do n <- get           if ((n `mod` 7) == 0)             then               return Nothing             else do               put (n+1)               return (Just n) {- *Main> evalState (sequence $ replicate 9 tick) 1 [Just 1,Just 2,Just 3,Just 4,Just 5,Just 6,Nothing,Nothing,Nothing] -}