Merge pull request #4 from purescript-contrib/unions

Add `unions`

Author: paf31

src/Data/Map.purs

@@ -9,6 +9,7 @@ module Data.Map
     toList,
     fromList,
     union,
+    unions,
     map
   ) where
 
@@ -85,6 +86,9 @@ fromList = foldl (\m (Tuple k v) -> insert k v m) empty
 union :: forall k v. (P.Eq k, P.Ord k) => Map k v -> Map k v -> Map k v
 union m1 m2 = foldl (\m (Tuple k v) -> insert k v m) m2 (toList m1)
 
+unions :: forall k v. (P.Ord k) => [Map k v] -> Map k v
+unions = foldl union empty
+
 map :: forall k v1 v2. (P.Eq k, P.Ord k) => (v1 -> v2) -> Map k v1 -> Map k v2
 map _ Leaf = Leaf
 map f (Branch b) = Branch (b { value = f b.value, left = map f b.left, right = map f b.right })

src/Data/Set.purs

@@ -7,7 +7,8 @@ module Data.Set
     delete,
     toList,
     fromList,
-    union
+    union,
+    unions
   ) where
 
 import qualified Prelude as P
@@ -69,3 +70,5 @@ fromList = foldl (\s a -> insert a s) empty
 union :: forall a. (P.Eq a, P.Ord a) => Set a -> Set a -> Set a
 union s1 s2 = foldl (\s a -> insert a s) s2 (toList s1)
 
+unions :: forall a. (P.Ord a) => [Set a] -> Set a
+unions = foldl union empty