1 files changed, 20 insertions, 0 deletions
diff --git a/stdlib/map.mli b/stdlib/map.mli
new file mode 100644
index 000000000..38e2e85e7
--- /dev/null
+++ b/stdlib/map.mli
@@ -0,0 +1,20 @@
+(* Maps over ordered types *)
+
+module type OrderedType =
+  sig
+    type t
+    val compare: t -> t -> int
+  end
+
+module type S =
+  sig
+    type key
+    type 'a t
+    val empty: 'a t
+    val add: key -> 'a -> 'a t -> 'a t
+    val find: key -> 'a t -> 'a
+    val iter: (key -> 'a -> 'b) -> 'a t -> unit
+    val fold: (key -> 'a -> 'b -> 'b) -> 'a t -> 'b -> 'b
+  end
+
+module Make(Ord: OrderedType): (S with key = Ord.t)