[EMAIL PROTECTED] wrote: > type BiMap a b = (Map.Map a b, Map.Map b a) Actually BiMap is not needed at all, it suffices to have
> splitStreams :: Ord a => [(a,b)] -> [(a,[b])] > splitStreams xs = > takeWhile (not . null . snd) $ toList $ splitStreams' Map.empty xs > > splitStreams' :: Ord a => Map.Map a Position -> [(a,b)] -> Imp (a,[b]) > splitStreams' map [] = > fmap (const (undefined,[])) $ fromList [1..] > splitStreams' map ((a,b):xs) = > update fun pos $ splitStreams' map' xs > where > fun ~(_,bs) = (a,b:bs) > sz = Map.size map > pos = Map.findWithDefault (sz+1) a map > map' = > (if Map.member a map then id else Map.insert a (sz+1)) map Regards, apfelmus _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
