What's the best way to end up with a list composed of only the Just values,no
Nothings?
Michael
==========================
import Control.Monad.Stateimport 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]-}
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
