1 files changed, 17 insertions, 10 deletions
diff --git a/stdlib/source/lux/target/jvm/encoding/unsigned.lux b/stdlib/source/lux/target/jvm/encoding/unsigned.lux
index 15dd7a07e..86495f38e 100644
--- a/stdlib/source/lux/target/jvm/encoding/unsigned.lux
+++ b/stdlib/source/lux/target/jvm/encoding/unsigned.lux
@@ -17,18 +17,18 @@
 
 (abstract: #export (Unsigned brand)
   {}
-  (I64 Any)
+  Nat
 
   (def: #export nat
-    (-> (Unsigned Any) (I64 Any))
+    (-> (Unsigned Any) Nat)
     (|>> :representation))
 
   (structure: #export equivalence
     (All [brand] (Equivalence (Unsigned brand)))
     (def: (= reference sample)
-      ("lux i64 =" (:representation reference) (:representation sample))))
+      (n/= (:representation reference) (:representation sample))))
 
-  (template [<bytes> <name> <size> <constructor> <max>]
+  (template [<bytes> <name> <size> <constructor> <max> <+>]
     [(with-expansions [<raw> (template.identifier [<name> "'"])]
        (abstract: #export <raw> {} Any)
        (type: #export <name> (Unsigned <raw>)))
@@ -40,19 +40,26 @@
        (|> <bytes> (n/* i64.bits-per-byte) i64.mask :abstraction))
      
      (def: #export <constructor>
-       (-> (I64 Any) <name>)
-       (|>> (i64.and (:representation <max>)) :abstraction))]
+       (-> Nat <name>)
+       (|>> (i64.and (:representation <max>)) :abstraction))
 
-    [1 U1 u1-bytes u1 max-u1]
-    [2 U2 u2-bytes u2 max-u2]
-    [4 U4 u4-bytes u4 max-u4]
+     (def: #export (<+> parameter subject)
+       (-> <name> <name> <name>)
+       (:abstraction
+        (i64.and (:representation <max>)
+                 (n/+ (:representation parameter)
+                      (:representation subject)))))]
+
+    [1 U1 u1-bytes u1 max-u1 u1/+]
+    [2 U2 u2-bytes u2 max-u2 u2/+]
+    [4 U4 u4-bytes u4 max-u4 u4/+]
     )
   )
 
 (template [<parser-name> <writer-name> <type> <parser> <writer> <post-read>]
   [(def: #export <parser-name>
      (Parser <type>)
-     (<>@map <post-read> <parser>))
+     (<>@map (|>> .nat <post-read>) <parser>))
 
    (def: #export <writer-name>
      (Writer <type>)