X-Git-Url: http://git.nguyen.vg/gitweb/?a=blobdiff_plain;f=finiteCofinite.ml;h=907b604c9664abce9bd5ea059b2cb01126b8ed4f;hb=3445f7f08f15fe41e0d1bfaaabaacf60cdc10b61;hp=32f0e4887a16f45370303f2d34267bf052933b7e;hpb=d04661689691b4587cfc45a35e98604fcdc2b878;p=SXSI%2Fxpathcomp.git

diff --git a/finiteCofinite.ml b/finiteCofinite.ml
index 32f0e48..907b604 100644
--- a/finiteCofinite.ml
+++ b/finiteCofinite.ml
@@ -10,6 +10,7 @@ module type S =
 sig
   type elt
   type t
+  type set
   val empty : t
   val any : t
   val is_empty : t -> bool
@@ -38,14 +39,18 @@ sig
   val choose : t -> elt
   val hash : t -> int
   val equal : t -> t -> bool
+  val positive : t -> set
+  val negative : t -> set
+  val inj_positive : set -> t
+  val inj_negative : set -> t
 end
 
-module Make (E : Sigs.Set) : S with type elt = E.elt =
+module Make (E : Sigs.Set) : S with type elt = E.elt and type set = E.t =
 struct
 
   type elt = E.elt
   type t = Finite of E.t | CoFinite of E.t
-
+  type set = E.t
 
   let empty = Finite E.empty
   let any = CoFinite E.empty
@@ -179,5 +184,17 @@ struct
     function Finite x -> (E.hash x)
       | CoFinite x -> ( ~-(E.hash x) land max_int)
 
+  let positive = 
+    function
+      | Finite x -> x
+      | _ -> E.empty
+
+  let negative = 
+    function
+      | CoFinite x -> x
+      | _ -> E.empty
+
+  let inj_positive t = Finite t
+  let inj_negative t = CoFinite t
 end