hmaurer · August 29, 2015 14:13
diff --git a/a3gis.purs b/a3gis.purs
 module A3gis where

  import Data.Traversable
  import Data.Map
  import Data.Maybe

  foo :: forall k v. (Eq v, Ord k) => Map k v -> Map k v -> Maybe (Map k v)
  foo m1 m2 = sequence $ unionWith go (Just <$> m1) (Just <$> m2)
    where
      go x y = if x == y then x else Nothing
	module A3gis where

	import Data.Traversable
	import Data.Map
	import Data.Maybe

	foo :: forall k v. (Eq v, Ord k) => Map k v -> Map k v -> Maybe (Map k v)
	foo m1 m2 = sequence $ unionWith go (Just <$> m1) (Just <$> m2)
	where
	go x y = if x == y then x else Nothing