- Added support for natural numbers (unsigned integers).

14 files changed, 363 insertions, 24 deletions

diff --git a/src/lux/analyser.clj b/src/lux/analyser.clj
index d6cc5cfda..2ad3745d8 100644
--- a/src/lux/analyser.clj
+++ b/src/lux/analyser.clj
@@ -71,6 +71,10 @@
       (|do [_ (&type/check exo-type &type/Bool)]
         (return (&/|list (&&/|meta exo-type cursor (&&/$bool ?value)))))
 
+      (&/$NatS ?value)
+      (|do [_ (&type/check exo-type &type/Nat)]
+        (return (&/|list (&&/|meta exo-type cursor (&&/$nat ?value)))))
+
       (&/$IntS ?value)
       (|do [_ (&type/check exo-type &type/Int)]
         (return (&/|list (&&/|meta exo-type cursor (&&/$int ?value)))))
diff --git a/src/lux/analyser/base.clj b/src/lux/analyser/base.clj
index fed65bb29..45d111249 100644
--- a/src/lux/analyser/base.clj
+++ b/src/lux/analyser/base.clj
@@ -12,6 +12,7 @@
 ;; [Tags]
 (defvariant
   ("bool" 1)
+  ("nat" 1)
   ("int" 1)
   ("real" 1)
   ("char" 1)
diff --git a/src/lux/analyser/case.clj b/src/lux/analyser/case.clj
index 8b1ee3a89..bccbd4a07 100644
--- a/src/lux/analyser/case.clj
+++ b/src/lux/analyser/case.clj
@@ -18,6 +18,7 @@
 (defvariant
   ("DefaultTotal" 1)
   ("BoolTotal" 2)
+  ("NatTotal" 2)
   ("IntTotal" 2)
   ("RealTotal" 2)
   ("CharTotal" 2)
@@ -29,6 +30,7 @@
   ("NoTestAC" 0)
   ("StoreTestAC" 1)
   ("BoolTestAC" 1)
+  ("NatTestAC" 1)
   ("IntTestAC" 1)
   ("RealTestAC" 1)
   ("CharTestAC" 1)
@@ -265,6 +267,11 @@
             =kont kont]
         (return (&/T [($BoolTestAC ?value) =kont])))
 
+      (&/$NatS ?value)
+      (|do [_ (&type/check value-type &type/Nat)
+            =kont kont]
+        (return (&/T [($NatTestAC ?value) =kont])))
+
       (&/$IntS ?value)
       (|do [_ (&type/check value-type &type/Int)
             =kont kont]
@@ -394,6 +401,9 @@
       [($BoolTotal total? ?values) ($NoTestAC)]
       (return ($BoolTotal true ?values))
 
+      [($NatTotal total? ?values) ($NoTestAC)]
+      (return ($NatTotal true ?values))
+
       [($IntTotal total? ?values) ($NoTestAC)]
       (return ($IntTotal true ?values))
 
@@ -418,6 +428,9 @@
       [($BoolTotal total? ?values) ($StoreTestAC ?idx)]
       (return ($BoolTotal true ?values))
 
+      [($NatTotal total? ?values) ($StoreTestAC ?idx)]
+      (return ($NatTotal true ?values))
+
       [($IntTotal total? ?values) ($StoreTestAC ?idx)]
       (return ($IntTotal true ?values))
 
@@ -442,6 +455,12 @@
       [($BoolTotal total? ?values) ($BoolTestAC ?value)]
       (return ($BoolTotal total? (&/$Cons ?value ?values)))
 
+      [($DefaultTotal total?) ($NatTestAC ?value)]
+      (return ($NatTotal total? (&/|list ?value)))
+
+      [($NatTotal total? ?values) ($NatTestAC ?value)]
+      (return ($NatTotal total? (&/$Cons ?value ?values)))
+
       [($DefaultTotal total?) ($IntTestAC ?value)]
       (return ($IntTotal total? (&/|list ?value)))
 
@@ -527,6 +546,10 @@
       (return (or ?total
                   (= #{true false} (set (&/->seq ?values))))))
 
+    ($NatTotal ?total _)
+    (|do [_ (&type/check value-type &type/Nat)]
+      (return ?total))
+
     ($IntTotal ?total _)
     (|do [_ (&type/check value-type &type/Int)]
       (return ?total))
diff --git a/src/lux/analyser/host.clj b/src/lux/analyser/host.clj
index be69dc54c..110bf253f 100644
--- a/src/lux/analyser/host.clj
+++ b/src/lux/analyser/host.clj
@@ -1054,6 +1054,53 @@
         (return (&/|list (&&/|meta exo-type _cursor
                                    (&&/$proc (&/T ["lux" "=="]) (&/|list =left =right) (&/|list)))))))))
 
+(do-template [<name> <proc> <input-type> <output-type>]
+  (defn <name> [analyse exo-type ?values]
+    (|do [:let [(&/$Cons x (&/$Cons y (&/$Nil))) ?values]
+          =x (&&/analyse-1 analyse <input-type> x)
+          =y (&&/analyse-1 analyse <input-type> y)
+          _ (&type/check exo-type <output-type>)
+          _cursor &/cursor]
+      (return (&/|list (&&/|meta <output-type> _cursor
+                                 (&&/$proc (&/T ["nat" <proc>]) (&/|list =x =y) (&/|list)))))))
+
+  ^:private analyse-nat-add "add" &type/Nat &type/Nat
+  ^:private analyse-nat-sub "sub" &type/Nat &type/Nat
+  ^:private analyse-nat-mul "mul" &type/Nat &type/Nat
+  ^:private analyse-nat-div "div" &type/Nat &type/Nat
+  ^:private analyse-nat-rem "rem" &type/Nat &type/Nat
+  ^:private analyse-nat-eq  "eq"  &type/Nat &type/Bool
+  ^:private analyse-nat-lt  "lt"  &type/Nat &type/Bool
+  )
+
+(defn ^:private analyse-nat-encode [analyse exo-type ?values]
+  (|do [:let [(&/$Cons x (&/$Nil)) ?values]
+        =x (&&/analyse-1 analyse &type/Nat x)
+        _ (&type/check exo-type &type/Text)
+        _cursor &/cursor]
+    (return (&/|list (&&/|meta &type/Text _cursor
+                               (&&/$proc (&/T ["nat" "encode"]) (&/|list =x) (&/|list)))))))
+
+(defn ^:private analyse-nat-decode [analyse exo-type ?values]
+  (|do [:let [(&/$Cons x (&/$Nil)) ?values]
+        =x (&&/analyse-1 analyse &type/Text x)
+        _ (&type/check exo-type (&/$AppT &type/Maybe &type/Nat))
+        _cursor &/cursor]
+    (return (&/|list (&&/|meta (&/$AppT &type/Maybe &type/Nat) _cursor
+                               (&&/$proc (&/T ["nat" "decode"]) (&/|list =x) (&/|list)))))))
+
+(do-template [<name> <type> <op>]
+  (defn <name> [analyse exo-type ?values]
+    (|do [:let [(&/$Nil) ?values]
+          _ (&type/check exo-type <type>)
+          _cursor &/cursor]
+      (return (&/|list (&&/|meta <type> _cursor
+                                 (&&/$proc (&/T <op>) (&/|list) (&/|list)))))))
+
+  ^:private analyse-nat-min-value &type/Nat ["nat" "min-value"]
+  ^:private analyse-nat-max-value &type/Nat ["nat" "max-value"]
+  )
+
 (defn analyse-host [analyse exo-type compilers category proc ?values]
   (|let [[_ _ compile-class compile-interface] compilers]
     (case category
@@ -1078,6 +1125,21 @@
         "put"    (analyse-jvm-aastore analyse exo-type ?values)
         "remove" (analyse-array-remove analyse exo-type ?values)
         "size"   (analyse-jvm-arraylength analyse exo-type ?values))
+
+      "nat"
+      (case proc
+        "+" (analyse-nat-add analyse exo-type ?values)
+        "-" (analyse-nat-sub analyse exo-type ?values)
+        "*" (analyse-nat-mul analyse exo-type ?values)
+        "/" (analyse-nat-div analyse exo-type ?values)
+        "%" (analyse-nat-rem analyse exo-type ?values)
+        "=" (analyse-nat-eq analyse exo-type ?values)
+        "<" (analyse-nat-lt analyse exo-type ?values)
+        "encode" (analyse-nat-encode analyse exo-type ?values)
+        "decode" (analyse-nat-decode analyse exo-type ?values)
+        "min-value" (analyse-nat-min-value analyse exo-type ?values)
+        "max-value" (analyse-nat-max-value analyse exo-type ?values)
+        )
       
       "jvm"
       (case proc
diff --git a/src/lux/base.clj b/src/lux/base.clj
index 462bccd69..ba42f702d 100644
--- a/src/lux/base.clj
+++ b/src/lux/base.clj
@@ -70,6 +70,7 @@
 ;; AST
 (defvariant
   ("BoolS" 1)
+  ("NatS" 1)
   ("IntS" 1)
   ("RealS" 1)
   ("CharS" 1)
@@ -213,6 +214,7 @@
 ;; Meta-data
 (defvariant
   ("BoolM" 1)
+  ("NatM" 1)
   ("IntM" 1)
   ("RealM" 1)
   ("CharM" 1)
@@ -1044,6 +1046,9 @@
     [_ ($BoolS ?value)]
     (pr-str ?value)
 
+    [_ ($NatS ?value)]
+    (Long/toUnsignedString ?value)
+
     [_ ($IntS ?value)]
     (pr-str ?value)
 
diff --git a/src/lux/compiler.clj b/src/lux/compiler.clj
index 4548e71ab..19832d4e6 100644
--- a/src/lux/compiler.clj
+++ b/src/lux/compiler.clj
@@ -52,6 +52,9 @@
         (&o/$bool ?value)
         (&&lux/compile-bool ?value)
 
+        (&o/$nat ?value)
+        (&&lux/compile-nat ?value)
+
         (&o/$int ?value)
         (&&lux/compile-int ?value)
 
diff --git a/src/lux/compiler/host.clj b/src/lux/compiler/host.clj
index ae4b98f9f..cdfc7dc7e 100644
--- a/src/lux/compiler/host.clj
+++ b/src/lux/compiler/host.clj
@@ -779,26 +779,106 @@
                              (.visitInsn Opcodes/RETURN)
                              (.visitMaxs 0 0)
                              (.visitEnd))
+              _ (doto (.visitMethod =class (+ Opcodes/ACC_PUBLIC Opcodes/ACC_STATIC) "log" "(Ljava/lang/Object;)Ljava/lang/Object;" nil nil)
+                  (.visitCode)
+                  (.visitFieldInsn Opcodes/GETSTATIC "java/lang/System" "out" "Ljava/io/PrintStream;")
+                  (.visitLdcInsn "LOG: ")
+                  (.visitMethodInsn Opcodes/INVOKEVIRTUAL "java/io/PrintStream" "print" "(Ljava/lang/Object;)V")
+                  (.visitFieldInsn Opcodes/GETSTATIC "java/lang/System" "out" "Ljava/io/PrintStream;")
+                  (.visitVarInsn Opcodes/ALOAD 0)
+                  (.visitMethodInsn Opcodes/INVOKEVIRTUAL "java/io/PrintStream" "println" "(Ljava/lang/Object;)V")
+                  (.visitVarInsn Opcodes/ALOAD 0)
+                  (.visitInsn Opcodes/ARETURN)
+                  (.visitMaxs 0 0)
+                  (.visitEnd))
+              _ (doto (.visitMethod =class (+ Opcodes/ACC_PUBLIC Opcodes/ACC_STATIC) "make_none" "()Ljava/lang/Object;" nil nil)
+                  (.visitCode)
+                  (.visitLdcInsn (->> #'&/$None meta ::&/idx int)) ;; I
+                  (.visitInsn Opcodes/ACONST_NULL) ;; I?
+                  (.visitLdcInsn &/unit-tag) ;; I?U
+                  (.visitMethodInsn Opcodes/INVOKESTATIC "lux/LuxRT" "sum_make" "(ILjava/lang/Object;Ljava/lang/Object;)[Ljava/lang/Object;")
+                  (.visitInsn Opcodes/ARETURN)
+                  (.visitMaxs 0 0)
+                  (.visitEnd))
+              _ (doto (.visitMethod =class (+ Opcodes/ACC_PUBLIC Opcodes/ACC_STATIC) "make_some" "(Ljava/lang/Object;)Ljava/lang/Object;" nil nil)
+                  (.visitCode)
+                  (.visitLdcInsn (->> #'&/$Some meta ::&/idx int)) ;; I
+                  (.visitInsn Opcodes/ACONST_NULL) ;; I?
+                  (.visitVarInsn Opcodes/ALOAD 0) ;; I?O
+                  (.visitMethodInsn Opcodes/INVOKESTATIC "lux/LuxRT" "sum_make" "(ILjava/lang/Object;Ljava/lang/Object;)[Ljava/lang/Object;")
+                  (.visitInsn Opcodes/ARETURN)
+                  (.visitMaxs 0 0)
+                  (.visitEnd))
               _ (let [$end (new Label)
-                      $else (new Label)]
-                  (doto (.visitMethod =class (+ Opcodes/ACC_PUBLIC Opcodes/ACC_STATIC) "log" "(Ljava/lang/Object;)Ljava/lang/Object;" nil nil)
+                      ;; $then (new Label)
+                      $else (new Label)
+                      $from (new Label)
+                      $to (new Label)
+                      $handler (new Label)]
+                  (doto (.visitMethod =class (+ Opcodes/ACC_PUBLIC Opcodes/ACC_STATIC) "decode_nat" "(Ljava/lang/String;)Ljava/lang/Object;" nil nil)
                     (.visitCode)
-                    (.visitFieldInsn Opcodes/GETSTATIC "java/lang/System" "out" "Ljava/io/PrintStream;")
-                    (.visitLdcInsn "LOG: ")
-                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL "java/io/PrintStream" "print" "(Ljava/lang/Object;)V")
-                    (.visitFieldInsn Opcodes/GETSTATIC "java/lang/System" "out" "Ljava/io/PrintStream;")
                     (.visitVarInsn Opcodes/ALOAD 0)
-                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL "java/io/PrintStream" "println" "(Ljava/lang/Object;)V")
+                    (.visitLdcInsn "+")
+                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL "java/lang/String" "startsWith" "(Ljava/lang/String;)Z")
+                    (.visitJumpInsn Opcodes/IFEQ $else)
                     (.visitVarInsn Opcodes/ALOAD 0)
+                    (.visitLdcInsn (int 1))
+                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL "java/lang/String" "substring" "(I)Ljava/lang/String;")
+                    (.visitTryCatchBlock $from $to $handler "java/lang/Exception")
+                    (.visitLabel $from)
+                    (.visitMethodInsn Opcodes/INVOKESTATIC "java/lang/Long" "parseUnsignedLong" "(Ljava/lang/String;)J")
+                    (.visitLabel $to)
+                    ;; (.visitJumpInsn Opcodes/GOTO $then)
+                    ;; (.visitLabel $then)
+                    (&&/wrap-long)
+                    (.visitMethodInsn Opcodes/INVOKESTATIC "lux/LuxRT" "make_some" "(Ljava/lang/Object;)Ljava/lang/Object;")
+                    (.visitFrame Opcodes/F_NEW 1 (to-array ["java/lang/String"]) 1 (to-array ["java/lang/Object"]))
+                    (.visitJumpInsn Opcodes/GOTO $end)
+                    (.visitLabel $handler)
+                    (.visitFrame Opcodes/F_NEW 1 (to-array ["java/lang/String"]) 1 (to-array ["java/lang/Exception"]))
+                    (.visitInsn Opcodes/POP)
+                    (.visitMethodInsn Opcodes/INVOKESTATIC "lux/LuxRT" "make_none" "()Ljava/lang/Object;")
+                    (.visitFrame Opcodes/F_NEW 1 (to-array ["java/lang/String"]) 1 (to-array ["java/lang/Object"]))
+                    (.visitJumpInsn Opcodes/GOTO $end)
+                    (.visitLabel $else)
+                    (.visitFrame Opcodes/F_NEW 1 (to-array ["java/lang/String"]) 0 (to-array []))
+                    (.visitMethodInsn Opcodes/INVOKESTATIC "lux/LuxRT" "make_none" "()Ljava/lang/Object;")
+                    (.visitLabel $end)
+                    (.visitFrame Opcodes/F_NEW 1 (to-array ["java/lang/String"]) 1 (to-array ["java/lang/Object"]))
                     (.visitInsn Opcodes/ARETURN)
                     (.visitMaxs 0 0)
                     (.visitEnd)))
               _ (doto =class
-                  (compile-LuxRT-adt-methods)
-                  (compile-LuxRT-pm-methods))]]
+                  (compile-LuxRT-pm-methods)
+                  (compile-LuxRT-adt-methods))]]
     (&&/save-class! (second (string/split &&/lux-utils-class #"/"))
                     (.toByteArray (doto =class .visitEnd)))))
 
+(defn ^:private compile-jvm-try [compile ?values special-args]
+  (|do [:let [(&/$Cons ?body (&/$Cons ?catch (&/$Nil))) ?values
+              ;; (&/$Nil) special-args
+              ]
+        ^MethodVisitor *writer* &/get-writer
+        :let [$from (new Label)
+              $to (new Label)
+              $handler (new Label)
+              $end (new Label)]
+        :let [_ (doto *writer*
+                  (.visitTryCatchBlock $from $to $handler "java/lang/Exception")
+                  (.visitLabel $from))]
+        _ (compile ?body)
+        :let [_ (doto *writer*
+                  (.visitJumpInsn Opcodes/GOTO $end)
+                  (.visitLabel $to)
+                  (.visitLabel $handler))]
+        _ (compile ?catch)
+        :let [_ (doto *writer*
+                  (.visitTypeInsn Opcodes/CHECKCAST &&/function-class)
+                  (.visitInsn Opcodes/SWAP)
+                  (.visitMethodInsn Opcodes/INVOKEVIRTUAL &&/function-class &&/apply-method (&&/apply-signature 1)))]
+        :let [_ (.visitLabel *writer* $end)]]
+    (return nil)))
+
 (do-template [<name> <op> <from-class> <from-method> <from-sig> <to-class> <to-sig>]
   (defn <name> [compile _?value special-args]
     (|do [:let [(&/$Cons ?value (&/$Nil)) _?value]
@@ -1406,6 +1486,117 @@
                   (.visitLabel $end))]]
     (return nil)))
 
+(do-template [<name> <opcode> <wrapper-class> <value-method> <value-method-sig> <wrap>]
+  (defn <name> [compile ?values special-args]
+    (|do [:let [(&/$Cons ?x (&/$Cons ?y (&/$Nil))) ?values]
+          :let [+wrapper-class+ (&host-generics/->bytecode-class-name <wrapper-class>)]
+          ^MethodVisitor *writer* &/get-writer
+          _ (compile ?x)
+          :let [_ (doto *writer*
+                    (.visitTypeInsn Opcodes/CHECKCAST +wrapper-class+)
+                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL +wrapper-class+ <value-method> <value-method-sig>))]
+          _ (compile ?y)
+          :let [_ (doto *writer*
+                    (.visitTypeInsn Opcodes/CHECKCAST +wrapper-class+)
+                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL +wrapper-class+ <value-method> <value-method-sig>))
+                _ (doto *writer*
+                    (.visitInsn <opcode>)
+                    (<wrap>))]]
+      (return nil)))
+
+  ^:private compile-nat-add Opcodes/LADD "java.lang.Long"    "longValue"   "()J" &&/wrap-long
+  ^:private compile-nat-sub Opcodes/LSUB "java.lang.Long"    "longValue"   "()J" &&/wrap-long
+  ^:private compile-nat-mul Opcodes/LMUL "java.lang.Long"    "longValue"   "()J" &&/wrap-long
+  )
+
+(do-template [<name> <wrapper-class> <value-method> <value-method-sig> <wrap> <comp-method> <comp-sig>]
+  (defn <name> [compile ?values special-args]
+    (|do [:let [(&/$Cons ?x (&/$Cons ?y (&/$Nil))) ?values]
+          :let [+wrapper-class+ (&host-generics/->bytecode-class-name <wrapper-class>)]
+          ^MethodVisitor *writer* &/get-writer
+          _ (compile ?x)
+          :let [_ (doto *writer*
+                    (.visitTypeInsn Opcodes/CHECKCAST +wrapper-class+)
+                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL +wrapper-class+ <value-method> <value-method-sig>))]
+          _ (compile ?y)
+          :let [_ (doto *writer*
+                    (.visitTypeInsn Opcodes/CHECKCAST +wrapper-class+)
+                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL +wrapper-class+ <value-method> <value-method-sig>))
+                _ (doto *writer*
+                    (.visitMethodInsn Opcodes/INVOKESTATIC +wrapper-class+ <comp-method> <comp-sig>)
+                    (&&/wrap-long))]]
+      (return nil)))
+
+  ^:private compile-nat-div "java.lang.Long" "longValue" "()J" &&/wrap-long "divideUnsigned"    "(JJ)J"
+  ^:private compile-nat-rem "java.lang.Long" "longValue" "()J" &&/wrap-long "remainderUnsigned" "(JJ)J"
+  )
+
+(do-template [<name> <cmpcode> <cmp-output> <wrapper-class> <value-method> <value-method-sig> <comp-method> <comp-sig>]
+  (defn <name> [compile ?values special-args]
+    (|do [:let [(&/$Cons ?x (&/$Cons ?y (&/$Nil))) ?values]
+          :let [+wrapper-class+ (&host-generics/->bytecode-class-name <wrapper-class>)]
+          ^MethodVisitor *writer* &/get-writer
+          _ (compile ?x)
+          :let [_ (doto *writer*
+                    (.visitTypeInsn Opcodes/CHECKCAST +wrapper-class+)
+                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL +wrapper-class+ <value-method> <value-method-sig>))]
+          _ (compile ?y)
+          :let [_ (doto *writer*
+                    (.visitTypeInsn Opcodes/CHECKCAST +wrapper-class+)
+                    (.visitMethodInsn Opcodes/INVOKEVIRTUAL +wrapper-class+ <value-method> <value-method-sig>))
+                $then (new Label)
+                $end (new Label)
+                _ (doto *writer*
+                    (.visitMethodInsn Opcodes/INVOKESTATIC +wrapper-class+ "compareUnsigned" "(JJ)I")
+                    (.visitLdcInsn (int <cmp-output>))
+                    (.visitJumpInsn Opcodes/IF_ICMPEQ $then)
+                    (.visitFieldInsn Opcodes/GETSTATIC (&host-generics/->bytecode-class-name "java.lang.Boolean") "FALSE"  (&host-generics/->type-signature "java.lang.Boolean"))
+                    (.visitJumpInsn Opcodes/GOTO $end)
+                    (.visitLabel $then)
+                    (.visitFieldInsn Opcodes/GETSTATIC (&host-generics/->bytecode-class-name "java.lang.Boolean") "TRUE" (&host-generics/->type-signature "java.lang.Boolean"))
+                    (.visitLabel $end))]]
+      (return nil)))
+
+  ^:private compile-nat-eq Opcodes/LCMP   0 "java.lang.Long"   "longValue"   "()J" "compareUnsigned" "(JJ)I"
+  ^:private compile-nat-lt Opcodes/LCMP  -1 "java.lang.Long"   "longValue"   "()J" "compareUnsigned" "(JJ)I"
+  )
+
+(defn ^:private compile-nat-encode [compile ?values special-args]
+  (|do [:let [(&/$Cons ?x (&/$Nil)) ?values]
+        :let [+wrapper-class+ (&host-generics/->bytecode-class-name "java.lang.Long")]
+        ^MethodVisitor *writer* &/get-writer
+        _ (compile ?x)
+        :let [_ (doto *writer*
+                  (.visitTypeInsn Opcodes/CHECKCAST +wrapper-class+)
+                  (.visitMethodInsn Opcodes/INVOKEVIRTUAL +wrapper-class+ "longValue" "()J"))]
+        :let [_ (doto *writer*
+                  (.visitMethodInsn Opcodes/INVOKESTATIC +wrapper-class+ "toUnsignedString" "(J)Ljava/lang/String;"))]]
+    (return nil)))
+
+(defn ^:private compile-nat-decode [compile ?values special-args]
+  (|do [:let [(&/$Cons ?x (&/$Nil)) ?values]
+        :let [+wrapper-class+ (&host-generics/->bytecode-class-name "java.lang.String")]
+        ^MethodVisitor *writer* &/get-writer
+        _ (compile ?x)
+        :let [_ (doto *writer*
+                  (.visitTypeInsn Opcodes/CHECKCAST +wrapper-class+))]
+        :let [_ (doto *writer*
+                  (.visitMethodInsn Opcodes/INVOKESTATIC "lux/LuxRT" "decode_nat" "(Ljava/lang/String;)Ljava/lang/Object;"))]]
+    (return nil)))
+
+(do-template [<name> <instr> <wrapper>]
+  (defn <name> [compile ?values special-args]
+    (|do [:let [(&/$Nil) ?values]
+          ^MethodVisitor *writer* &/get-writer
+          :let [_ (doto *writer*
+                    <instr>
+                    <wrapper>)]]
+      (return nil)))
+
+  ^:private compile-nat-min-value (.visitLdcInsn 0)  &&/wrap-long
+  ^:private compile-nat-max-value (.visitLdcInsn -1) &&/wrap-long
+  )
+
 (defn compile-host [compile proc-category proc-name ?values special-args]
   (case proc-category
     "lux"
@@ -1425,6 +1616,21 @@
     "array"
     (case proc-name
       "get" (compile-array-get compile ?values special-args))
+
+    "nat"
+    (case proc-name
+      "add"       (compile-nat-add compile ?values special-args)
+      "sub"       (compile-nat-sub compile ?values special-args)
+      "mul"       (compile-nat-mul compile ?values special-args)
+      "div"       (compile-nat-div compile ?values special-args)
+      "rem"       (compile-nat-rem compile ?values special-args)
+      "eq"        (compile-nat-eq compile ?values special-args)
+      "lt"        (compile-nat-lt compile ?values special-args)
+      "encode"    (compile-nat-encode compile ?values special-args)
+      "decode"    (compile-nat-decode compile ?values special-args)
+      "max-value" (compile-nat-max-value compile ?values special-args)
+      "min-value" (compile-nat-min-value compile ?values special-args)
+      )
     
     "jvm"
     (case proc-name
diff --git a/src/lux/compiler/lux.clj b/src/lux/compiler/lux.clj
index 87113b538..83bb2ac44 100644
--- a/src/lux/compiler/lux.clj
+++ b/src/lux/compiler/lux.clj
@@ -45,6 +45,7 @@
                     (.visitMethodInsn Opcodes/INVOKESPECIAL <class> "<init>" <sig>))]]
       (return nil)))
 
+  compile-nat  "java/lang/Long"      "(J)V" long
   compile-int  "java/lang/Long"      "(J)V" long
   compile-real "java/lang/Double"    "(D)V" double
   compile-char "java/lang/Character" "(C)V" char
diff --git a/src/lux/compiler/type.clj b/src/lux/compiler/type.clj
index bf6ec5539..f51165ea3 100644
--- a/src/lux/compiler/type.clj
+++ b/src/lux/compiler/type.clj
@@ -30,6 +30,7 @@
               (<tag> value)))
 
   ^:private bool$ &a/$bool "(-> Bool Analysis)"
+  ^:private nat$  &a/$nat  "(-> Nat Analysis)"
   ^:private int$  &a/$int  "(-> Int Analysis)"
   ^:private real$ &a/$real "(-> Real Analysis)"
   ^:private char$ &a/$char "(-> Char Analysis)"
@@ -109,6 +110,9 @@
     (&/$BoolM value)
     (variant$ #'&/$BoolM (bool$ value))
     
+    (&/$NatM value)
+    (variant$ #'&/$NatM (nat$ value))
+
     (&/$IntM value)
     (variant$ #'&/$IntM (int$ value))
 
diff --git a/src/lux/lexer.clj b/src/lux/lexer.clj
index 9754456b9..690a25106 100644
--- a/src/lux/lexer.clj
+++ b/src/lux/lexer.clj
@@ -15,6 +15,7 @@
   ("White_Space" 1)
   ("Comment" 1)
   ("Bool" 1)
+  ("Nat" 1)
   ("Int" 1)
   ("Real" 1)
   ("Char" 1)
@@ -157,6 +158,7 @@
       (return (&/T [meta (<tag> token)]))))
 
   lex-bool  $Bool  #"^(true|false)"
+  lex-nat   $Nat   #"^\+(0|[1-9][0-9]*)"
   lex-int   $Int   #"^-?(0|[1-9][0-9]*)"
   lex-real  $Real  #"^-?(0\.[0-9]+|[1-9][0-9]*\.[0-9]+)(e-?[1-9][0-9]*)?"
   )
@@ -233,6 +235,7 @@
                         lex-comment
                         lex-bool
                         lex-real
+                        lex-nat
                         lex-int
                         lex-char
                         lex-text
diff --git a/src/lux/optimizer.clj b/src/lux/optimizer.clj
index c03515370..fd859d90d 100644
--- a/src/lux/optimizer.clj
+++ b/src/lux/optimizer.clj
@@ -10,6 +10,7 @@
 ;; [Tags]
 (defvariant
   ("bool" 1)
+  ("nat" 1)
   ("int" 1)
   ("real" 1)
   ("char" 1)
@@ -34,6 +35,7 @@
   ("PopPM" 0)
   ("BindPM" 1)
   ("BoolPM" 1)
+  ("NatPM" 1)
   ("IntPM" 1)
   ("RealPM" 1)
   ("CharPM" 1)
@@ -58,6 +60,10 @@
     (&/|list ($BoolPM _value)
              $PopPM)
 
+    (&a-case/$NatTestAC _value)
+    (&/|list ($NatPM _value)
+             $PopPM)
+
     (&a-case/$IntTestAC _value)
     (&/|list ($IntPM _value)
              $PopPM)
@@ -129,6 +135,11 @@
       ($BoolPM _pre-value)
       ($AltPM pre post))
 
+    [($NatPM _pre-value) ($NatPM _post-value)]
+    (if (= _pre-value _post-value)
+      ($NatPM _pre-value)
+      ($AltPM pre post))
+
     [($IntPM _pre-value) ($IntPM _post-value)]
     (if (= _pre-value _post-value)
       ($IntPM _pre-value)
@@ -342,6 +353,9 @@
         (&a/$bool value)
         (&/T [meta ($bool value)])
         
+        (&a/$nat value)
+        (&/T [meta ($nat value)])
+
         (&a/$int value)
         (&/T [meta ($int value)])
         
diff --git a/src/lux/parser.clj b/src/lux/parser.clj
index 5b0bfce57..d5b4a54cd 100644
--- a/src/lux/parser.clj
+++ b/src/lux/parser.clj
@@ -76,6 +76,9 @@
       (&lexer/$Bool ?value)
       (return (&/|list (&/T [meta (&/$BoolS (Boolean/parseBoolean ?value))])))
 
+      (&lexer/$Nat ?value)
+      (return (&/|list (&/T [meta (&/$NatS (Long/parseUnsignedLong ?value))])))
+
       (&lexer/$Int ?value)
       (return (&/|list (&/T [meta (&/$IntS (Long/parseLong ?value))])))
 
diff --git a/src/lux/type.clj b/src/lux/type.clj
index e79cfe46d..7ca4145a6 100644
--- a/src/lux/type.clj
+++ b/src/lux/type.clj
@@ -28,6 +28,7 @@
 (def empty-env &/$Nil)
 
 (def Bool (&/$NamedT (&/T ["lux" "Bool"]) (&/$HostT "java.lang.Boolean" &/$Nil)))
+(def Nat (&/$NamedT (&/T ["lux" "Nat"]) (&/$HostT "#Nat" &/$Nil)))
 (def Int (&/$NamedT (&/T ["lux" "Int"]) (&/$HostT "java.lang.Long" &/$Nil)))
 (def Real (&/$NamedT (&/T ["lux" "Real"]) (&/$HostT "java.lang.Double" &/$Nil)))
 (def Char (&/$NamedT (&/T ["lux" "Char"]) (&/$HostT "java.lang.Character" &/$Nil)))
@@ -120,25 +121,28 @@
                                    ;; BoolM
                                    Bool
                                    (&/$SumT
-                                    ;; IntM
-                                    Int
+                                    ;; NatM
+                                    Nat
                                     (&/$SumT
-                                     ;; RealM
-                                     Real
+                                     ;; IntM
+                                     Int
                                      (&/$SumT
-                                      ;; CharM
-                                      Char
+                                      ;; RealM
+                                      Real
                                       (&/$SumT
-                                       ;; TextM
-                                       Text
+                                       ;; CharM
+                                       Char
                                        (&/$SumT
-                                        ;; IdentM
-                                        Ident
+                                        ;; TextM
+                                        Text
                                         (&/$SumT
-                                         ;; ListM
-                                         (&/$AppT List DefMetaValue)
-                                         ;; DictM
-                                         (&/$AppT List (&/$ProdT Text DefMetaValue)))))))))
+                                         ;; IdentM
+                                         Ident
+                                         (&/$SumT
+                                          ;; ListM
+                                          (&/$AppT List DefMetaValue)
+                                          ;; DictM
+                                          (&/$AppT List (&/$ProdT Text DefMetaValue))))))))))
                                   )
                         &/$VoidT))))
 
diff --git a/src/lux/type/host.clj b/src/lux/type/host.clj
index b3858d2e5..a3252ddb7 100644
--- a/src/lux/type/host.clj
+++ b/src/lux/type/host.clj
@@ -16,6 +16,7 @@
 ;; [Exports]
 (def array-data-tag "#Array")
 (def null-data-tag "#Null")
+(def nat-data-tag "#Nat")
 
 ;; [Utils]
 (defn ^:private trace-lineage* [^Class super-class ^Class sub-class]
@@ -267,7 +268,12 @@
                (and (= array-data-tag e!name)
                     (not= array-data-tag a!name))
                (check-error "" (&/$HostT e!name e!params) (&/$HostT a!name a!params))
-               
+
+               (and (or (= nat-data-tag e!name)
+                        (= "java.lang.Long" e!name))
+                    (= nat-data-tag a!name))
+               (return fixpoints)
+
                :else
                (let [e!name (as-obj e!name)
                      a!name (as-obj a!name)]