1 files changed, 17 insertions, 2 deletions
diff --git a/stdlib/source/lux/abstract/hash.lux b/stdlib/source/lux/abstract/hash.lux
index 62e72e52a..df2dd2e27 100644
--- a/stdlib/source/lux/abstract/hash.lux
+++ b/stdlib/source/lux/abstract/hash.lux
@@ -11,14 +11,29 @@
   (: (-> a Nat)
      hash))
 
+(def: #export (sum left right)
+  (All [l r] (-> (Hash l) (Hash r) (Hash (| l r))))
+  (structure
+   (def: &equivalence
+     (equivalence.sum (:: left &equivalence)
+                      (:: right &equivalence)))
+   (def: (hash value)
+     (<| (:coerce Nat)
+         (case value
+           (#.Left value)
+           ("lux i64 *" +2 (:coerce Int (:: left hash value)))
+
+           (#.Right value)
+           ("lux i64 *" +3 (:coerce Int (:: right hash value))))))))
+
 (def: #export (product left right)
-  (All [l r] (-> (Hash l) (Hash r) (Hash [l r])))
+  (All [l r] (-> (Hash l) (Hash r) (Hash (& l r))))
   (structure
    (def: &equivalence
      (equivalence.product (:: left &equivalence)
                           (:: right &equivalence)))
    (def: (hash [leftV rightV])
      (:coerce Nat
-              ("lux i64 *"
+              ("lux i64 +"
                (:coerce Int (:: left hash leftV))
                (:coerce Int (:: right hash rightV)))))))