- I overdid the switch from null to lux.base/unit-tag, so I reversed the change on places where it was superfluous, to reduce the overhead of variable look-up during compilation.

11 files changed, 110 insertions, 110 deletions

diff --git a/src/lux/analyser/host.clj b/src/lux/analyser/host.clj
index 8dff15622..0bdb82d21 100644
--- a/src/lux/analyser/host.clj
+++ b/src/lux/analyser/host.clj
@@ -20,7 +20,7 @@
 
 ;; [Utils]
 (defn ^:private ensure-catching [exceptions]
-  "(-> (List Text) (Lux (,)))"
+  "(-> (List Text) (Lux Null))"
   (|do [class-loader &/loader]
     (fn [state]
       (let [exceptions (&/|map #(Class/forName % true class-loader) exceptions)
@@ -38,7 +38,7 @@
                                     nil
                                     exceptions)]
           (&/fail* (str "[Analyser Error] Unhandled exception: " missing-ex))
-          (&/return* state &/unit-tag)))
+          (&/return* state nil)))
       )))
 
 (defn ^:private with-catches [catches body]
@@ -629,7 +629,7 @@
     (&/flat-map% (partial &host/abstract-methods class-loader) supers)))
 
 (defn ^:private check-method-completion [supers methods]
-  "(-> (List SuperClassDecl) (List (, MethodDecl Analysis)) (Lux (,)))"
+  "(-> (List SuperClassDecl) (List (, MethodDecl Analysis)) (Lux Null))"
   (|do [abstract-methods (mandatory-methods supers)
         :let [methods-map (&/fold (fn [mmap mentry]
                                     (|case mentry
@@ -661,7 +661,7 @@
                                      nil
                                      abstract-methods)]]
     (if (nil? missing-method)
-      (return &/unit-tag)
+      (return nil)
       (|let [[am-name am-inputs] missing-method]
         (fail (str "[Analyser Error] Missing method: " am-name " " "(" (->> am-inputs (&/|interpose " ") (&/fold str "")) ")"))))))
 
diff --git a/src/lux/analyser/lux.clj b/src/lux/analyser/lux.clj
index 8d2736f9d..04f2c9828 100644
--- a/src/lux/analyser/lux.clj
+++ b/src/lux/analyser/lux.clj
@@ -263,7 +263,7 @@
   (|do [[[r-module r-name] [endo-type ?meta ?value]] (&&module/find-def module name)
         _ (if (and (clojure.lang.Util/identical &type/Type endo-type)
                    (clojure.lang.Util/identical &type/Type exo-type))
-            (return &/unit-tag)
+            (return nil)
             (&type/check exo-type endo-type))
         _cursor &/cursor]
     (return (&/|list (&&/|meta endo-type _cursor
@@ -520,7 +520,7 @@
   (|do [module-name &/get-module-name
         _ (if (= module-name path)
             (fail (str "[Analyser Error] Module can't import itself: " path))
-            (return &/unit-tag))]
+            (return nil))]
     (&/save-module
      (|do [already-compiled? (&&module/exists? path)
            active? (&/active-module? path)
@@ -528,7 +528,7 @@
            _ (&&module/add-import path)
            _ (if (not already-compiled?)
                (compile-module path)
-               (return &/unit-tag))]
+               (return nil))]
        (return &/Nil$)))))
 
 (defn analyse-alias [analyse compile-token ex-alias ex-module]
diff --git a/src/lux/analyser/module.clj b/src/lux/analyser/module.clj
index 4b6013d8e..69635d4ad 100644
--- a/src/lux/analyser/module.clj
+++ b/src/lux/analyser/module.clj
@@ -38,7 +38,7 @@
 
 ;; [Exports]
 (defn add-import [module]
-  "(-> Text (Lux (,)))"
+  "(-> Text (Lux Null))"
   (|do [current-module &/get-module-name]
     (fn [state]
       (return* (&/update$ &/$modules
@@ -47,10 +47,10 @@
                                        (fn [m] (&/update$ $imports (partial &/Cons$ module) m))
                                        ms))
                           state)
-               &/unit-tag))))
+               nil))))
 
 (defn set-imports [imports]
-  "(-> (List Text) (Lux (,)))"
+  "(-> (List Text) (Lux Null))"
   (|do [current-module &/get-module-name]
     (fn [state]
       (return* (&/update$ &/$modules
@@ -59,7 +59,7 @@
                                        (fn [m] (&/set$ $imports imports m))
                                        ms))
                           state)
-               &/unit-tag))))
+               nil))))
 
 (defn define [module name def-type def-meta def-value]
   (fn [state]
@@ -76,7 +76,7 @@
                                                          #(&/|put name (&/T [def-type def-meta def-value]) %)
                                                          m))
                                             ms))))
-               &/unit-tag)
+               nil)
       
       _
       (fail* (str "[Analyser Error] Can't create a new global definition outside of a global environment: " module ";" name)))))
@@ -132,7 +132,7 @@
                                                           (&/|put alias reference aliases))
                                                         %)
                                             ms))))
-               &/unit-tag))))
+               nil))))
 
 (defn find-def [module name]
   (|do [current-module &/get-module-name]
@@ -178,17 +178,17 @@
       (return* state (->> state (&/get$ &/$modules) (&/|get module) (&/get$ $imports))))))
 
 (defn create-module [name]
-  "(-> Text (Lux (,)))"
+  "(-> Text (Lux Null))"
   (fn [state]
-    (return* (&/update$ &/$modules #(&/|put name +init+ %) state) &/unit-tag)))
+    (return* (&/update$ &/$modules #(&/|put name +init+ %) state) nil)))
 
 (defn enter-module [name]
-  "(-> Text (Lux (,)))"
+  "(-> Text (Lux Null))"
   (fn [state]
     (return* (->> state
                   (&/update$ &/$modules #(&/|put name +init+ %))
                   (&/set$ &/$envs (&/|list (&/env name))))
-             &/unit-tag)))
+             nil)))
 
 (do-template [<name> <tag> <type>]
   (defn <name> [module]
@@ -208,18 +208,18 @@
         _ (&/map% (fn [tag]
                     (if (&/|get tag tags-table)
                       (fail (str "[Analyser Error] Can't re-declare tag: " (&/ident->text (&/T [module tag]))))
-                      (return &/unit-tag)))
+                      (return nil)))
                   tags)]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn ensure-undeclared-type [module name]
   (|do [types-table (types-by-module module)
         _ (&/assert! (nil? (&/|get name types-table))
                      (str "[Analyser Error] Can't re-declare type: " (&/ident->text (&/T [module name]))))]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn declare-tags [module tag-names type]
-  "(-> Text (List Text) Type (Lux (,)))"
+  "(-> Text (List Text) Type (Lux Null))"
   (|do [_ (ensure-undeclared-tags module tag-names)
         type-name (&type/type-name type)
         :let [[_module _name] type-name]
@@ -241,7 +241,7 @@
                                                  (&/update$ $types (partial &/|put _name (&/T [tags type]))))
                                            =modules))
                               state)
-                   &/unit-tag))
+                   nil))
         (fail* (str "[Lux Error] Unknown module: " module))))))
 
 (do-template [<name> <part> <doc>]
@@ -283,7 +283,7 @@
                            (fail (str "[Analyser Error] Can't tag as lux;" <desc> "? if it's not a " <desc> ": " (str module ";" name)))))
 
       _
-      (return &/unit-tag)))
+      (return nil)))
 
   test-type  &type/Type  &meta/type?-tag  "type"
   test-macro &type/Macro &meta/macro?-tag "macro"
diff --git a/src/lux/compiler.clj b/src/lux/compiler.clj
index d9b76b84b..31e0ca3a2 100644
--- a/src/lux/compiler.clj
+++ b/src/lux/compiler.clj
@@ -460,7 +460,7 @@
                               (.visitInsn Opcodes/RETURN)
                               (.visitMaxs 0 0)
                               (.visitEnd))]]
-                (return &/unit-tag)))
+                (return nil)))
           :let [bytecode (.toByteArray (doto =class
                                          .visitEnd))]
           _ (&&/save-class! (str id) bytecode)
@@ -494,8 +494,8 @@
                     _ (if (= "lux" name)
                         (|do [_ &&host/compile-Function-class
                               _ &&host/compile-LuxUtils-class]
-                          (return &/unit-tag))
-                        (return &/unit-tag))]
+                          (return nil))
+                        (return nil))]
                 (fn [state]
                   (|case ((&/with-writer =class
                             (&/exhaust% compiler-step))
diff --git a/src/lux/compiler/base.clj b/src/lux/compiler/base.clj
index 66e3d23f2..b046b237f 100644
--- a/src/lux/compiler/base.clj
+++ b/src/lux/compiler/base.clj
@@ -64,7 +64,7 @@
 
 (defn class-exists? [^String module ^String class-name]
   "(-> Text Text (IO Bool))"
-  (|do [_ (return &/unit-tag)
+  (|do [_ (return nil)
         :let [full-path (str output-dir "/" module "/" class-name ".class")
               exists? (.exists (File. full-path))]]
     (return exists?)))
@@ -84,7 +84,7 @@
               _ (when (not eval?)
                   (write-output module name bytecode))
               _ (load-class! loader real-name)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (do-template [<wrap-name> <unwrap-name> <class> <unwrap-method> <prim> <dup>]
   (do (defn <wrap-name> [^MethodVisitor writer]
diff --git a/src/lux/compiler/cache.clj b/src/lux/compiler/cache.clj
index efba55f1a..38592d16f 100644
--- a/src/lux/compiler/cache.clj
+++ b/src/lux/compiler/cache.clj
@@ -50,13 +50,13 @@
   (.exists (new File (str &&/output-dir "/" (&host/->module-class module) "/" module-class))))
 
 (defn delete [module]
-  "(-> Text (Lux Unit))"
+  "(-> Text (Lux Null))"
   (fn [state]
     (do (clean-file (new File (str &&/output-dir "/" (&host/->module-class module))))
-      (return* state &/unit-tag))))
+      (return* state nil))))
 
 (defn clean [state]
-  "(-> Compiler Unit)"
+  "(-> Compiler Null)"
   (let [needed-modules (->> state (&/get$ &/$modules) &/|keys &/->seq set)
         outdated? #(-> ^File % .getName (string/replace &host/module-separator "/") (->> (contains? needed-modules)) not)
         outdate-files (->> &&/output-dir (new File) .listFiles seq (filter outdated?))
@@ -65,7 +65,7 @@
       (.delete program-file))
     (doseq [f outdate-files]
       (clean-file f))
-    &/unit-tag))
+    nil))
 
 (let [->regex (fn [text] (re-pattern (java.util.regex.Pattern/quote text)))
       import-separator-re (->regex &&/import-separator)
diff --git a/src/lux/compiler/host.clj b/src/lux/compiler/host.clj
index eb67b5215..e7982a8ca 100644
--- a/src/lux/compiler/host.clj
+++ b/src/lux/compiler/host.clj
@@ -109,7 +109,7 @@
                 _ (doto *writer*
                     (.visitInsn <opcode>)
                     (<wrap>))]]
-      (return &/unit-tag)))
+      (return nil)))
 
   compile-jvm-iadd Opcodes/IADD "java.lang.Integer" "intValue"    "()I" &&/wrap-int
   compile-jvm-isub Opcodes/ISUB "java.lang.Integer" "intValue"    "()I" &&/wrap-int
@@ -157,7 +157,7 @@
                     (.visitLabel $then)
                     (.visitFieldInsn Opcodes/GETSTATIC (&host-generics/->bytecode-class-name "java.lang.Boolean") "FALSE" (&host-generics/->type-signature "java.lang.Boolean"))
                     (.visitLabel $end))]]
-      (return &/unit-tag)))
+      (return nil)))
 
   compile-jvm-ieq Opcodes/IF_ICMPEQ "java.lang.Integer" "intValue" "()I"
   compile-jvm-ilt Opcodes/IF_ICMPLT "java.lang.Integer" "intValue" "()I"
@@ -191,7 +191,7 @@
                     (.visitLabel $then)
                     (.visitFieldInsn Opcodes/GETSTATIC (&host-generics/->bytecode-class-name "java.lang.Boolean") "TRUE" (&host-generics/->type-signature "java.lang.Boolean"))
                     (.visitLabel $end))]]
-      (return &/unit-tag)))
+      (return nil)))
 
   compile-jvm-leq Opcodes/LCMP  0 "java.lang.Long"   "longValue"   "()J"
   compile-jvm-llt Opcodes/LCMP  1 "java.lang.Long"   "longValue"   "()J"
@@ -218,7 +218,7 @@
         :let [_ (doto *writer*
                   (.visitMethodInsn Opcodes/INVOKESTATIC (&host-generics/->bytecode-class-name (&host-type/as-obj ?class)) ?method method-sig)
                   (prepare-return! ?output-type))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (do-template [<name> <op>]
   (defn <name> [compile ?class ?method ?classes ?object ?args ?output-type]
@@ -237,7 +237,7 @@
           :let [_ (doto *writer*
                     (.visitMethodInsn <op> ?class* ?method method-sig)
                     (prepare-return! ?output-type))]]
-      (return &/unit-tag)))
+      (return nil)))
 
   compile-jvm-invokevirtual   Opcodes/INVOKEVIRTUAL
   compile-jvm-invokeinterface Opcodes/INVOKEINTERFACE
@@ -247,7 +247,7 @@
 (defn compile-jvm-null [compile]
   (|do [^MethodVisitor *writer* &/get-writer
         :let [_ (.visitInsn *writer* Opcodes/ACONST_NULL)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-null? [compile ?object]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -261,7 +261,7 @@
                   (.visitLabel $then)
                   (.visitFieldInsn Opcodes/GETSTATIC (&host-generics/->bytecode-class-name "java.lang.Boolean") "TRUE"  (&host-generics/->type-signature "java.lang.Boolean"))
                   (.visitLabel $end))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-new [compile ?class ?classes ?args]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -278,7 +278,7 @@
                   (&/zip2 ?classes ?args))
         :let [_ (doto *writer*
                   (.visitMethodInsn Opcodes/INVOKESPECIAL class* "<init>" init-sig))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (do-template [<prim-type> <array-type> <new-name> <load-name> <load-op> <store-name> <store-op> <wrapper> <unwrapper>]
   (do (defn <new-name> [compile ?length]
@@ -288,7 +288,7 @@
                         &&/unwrap-long
                         (.visitInsn Opcodes/L2I))]
               :let [_ (.visitIntInsn *writer* Opcodes/NEWARRAY <prim-type>)]]
-          (return &/unit-tag)))
+          (return nil)))
 
     (defn <load-name> [compile ?array ?idx]
       (|do [^MethodVisitor *writer* &/get-writer
@@ -301,7 +301,7 @@
             :let [_ (doto *writer*
                       (.visitInsn <load-op>)
                       <wrapper>)]]
-        (return &/unit-tag)))
+        (return nil)))
 
     (defn <store-name> [compile ?array ?idx ?elem]
       (|do [^MethodVisitor *writer* &/get-writer
@@ -316,7 +316,7 @@
             :let [_ (doto *writer*
                       <unwrapper>
                       (.visitInsn <store-op>))]]
-        (return &/unit-tag)))
+        (return nil)))
     )
 
   Opcodes/T_BOOLEAN "[Z" compile-jvm-znewarray compile-jvm-zaload Opcodes/BALOAD compile-jvm-zastore Opcodes/BASTORE &&/wrap-boolean &&/unwrap-boolean
@@ -336,7 +336,7 @@
                   &&/unwrap-long
                   (.visitInsn Opcodes/L2I))]
         :let [_ (.visitTypeInsn *writer* Opcodes/ANEWARRAY (&host-generics/gclass->bytecode-class-name* ?gclass type-env))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-aaload [compile ?array ?idx]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -348,7 +348,7 @@
                   &&/unwrap-long
                   (.visitInsn Opcodes/L2I))]
         :let [_ (.visitInsn *writer* Opcodes/AALOAD)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-aastore [compile ?array ?idx ?elem]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -362,7 +362,7 @@
                   (.visitInsn Opcodes/L2I))]
         _ (compile ?elem)
         :let [_ (.visitInsn *writer* Opcodes/AASTORE)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-arraylength [compile ?array]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -373,7 +373,7 @@
                   (.visitInsn Opcodes/ARRAYLENGTH)
                   (.visitInsn Opcodes/I2L)
                   &&/wrap-long)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-getstatic [compile ?class ?field ?output-type]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -381,7 +381,7 @@
         :let [_ (doto *writer*
                   (.visitFieldInsn Opcodes/GETSTATIC (&host-generics/->bytecode-class-name (&host-type/as-obj ?class)) ?field =output-type)
                   (prepare-return! ?output-type))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-getfield [compile ?class ?field ?object ?output-type]
   (|do [:let [class* (&host-generics/->bytecode-class-name (&host-type/as-obj ?class))]
@@ -392,7 +392,7 @@
                   (.visitTypeInsn Opcodes/CHECKCAST class*)
                   (.visitFieldInsn Opcodes/GETFIELD class* ?field =output-type)
                   (prepare-return! ?output-type))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-putstatic [compile ?class ?field ?value input-gclass ?input-type]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -402,7 +402,7 @@
                   (prepare-arg! (&host-generics/gclass->class-name input-gclass))
                   (.visitFieldInsn Opcodes/PUTSTATIC (&host-generics/->bytecode-class-name (&host-type/as-obj ?class)) ?field =input-sig)
                   (.visitInsn Opcodes/ACONST_NULL))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-putfield [compile ?class ?field ?object ?value input-gclass ?input-type]
   (|do [:let [class* (&host-generics/->bytecode-class-name (&host-type/as-obj ?class))]
@@ -415,7 +415,7 @@
                   (prepare-arg! (&host-generics/gclass->class-name input-gclass))
                   (.visitFieldInsn Opcodes/PUTFIELD class* ?field =input-sig)
                   (.visitInsn Opcodes/ACONST_NULL))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-instanceof [compile class object]
   (|do [:let [class* (&host-generics/->bytecode-class-name class)]
@@ -424,7 +424,7 @@
         :let [_ (doto *writer*
                   (.visitTypeInsn Opcodes/INSTANCEOF class*)
                   (&&/wrap-boolean))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn ^:private compile-annotation [writer ann]
   (doto ^AnnotationVisitor (.visitAnnotation writer (&host-generics/->bytecode-class-name (:name ann)) true)
@@ -432,7 +432,7 @@
             (->> (|let [[param-name param-value] param])
                  (doseq [param (&/->seq (:params ann))])))
         (.visitEnd))
-  &/unit-tag)
+  nil)
 
 (defn ^:private compile-field [^ClassWriter writer field]
   (|let [[=name =anns =type] field
@@ -441,7 +441,7 @@
                              (&host-generics/gclass->signature =type) nil)]
     (do (&/|map (partial compile-annotation =field) =anns)
       (.visitEnd =field)
-      &/unit-tag)))
+      nil)))
 
 (defn ^:private compile-method-return [^MethodVisitor writer output]
   (|case output
@@ -519,7 +519,7 @@
                         (compile-method-return ?output)
                         (.visitMaxs 0 0)
                         (.visitEnd))]]
-          (return &/unit-tag))))
+          (return nil))))
     
     (&/$VirtualMethodAnalysis ?name ?anns ?gvars ?exceptions ?inputs ?output ?body)
     (|let [=method-decl (&/T [?name ?anns ?gvars ?exceptions (&/|map &/|second ?inputs) ?output])
@@ -538,7 +538,7 @@
                         (compile-method-return ?output)
                         (.visitMaxs 0 0)
                         (.visitEnd))]]
-          (return &/unit-tag))))
+          (return nil))))
     
     (&/$OverridenMethodAnalysis ?class-decl ?name ?anns ?gvars ?exceptions ?inputs ?output ?body)
     (|let [=method-decl (&/T [?name ?anns ?gvars ?exceptions (&/|map &/|second ?inputs) ?output])
@@ -557,7 +557,7 @@
                         (compile-method-return ?output)
                         (.visitMaxs 0 0)
                         (.visitEnd))]]
-          (return &/unit-tag))))
+          (return nil))))
     ))
 
 (defn ^:private compile-method-decl [^ClassWriter class-writer =method-decl]
@@ -571,7 +571,7 @@
                                (->> =exceptions (&/|map &host-generics/gclass->class-name) &/->seq (into-array java.lang.String)))
          _ (&/|map (partial compile-annotation =method) =anns)
          _ (.visitEnd =method)]
-    &/unit-tag))
+    nil))
 
 (defn ^:private prepare-ctor-arg [^MethodVisitor writer type]
   (case type
@@ -621,7 +621,7 @@
                           (|let [[type term] type+term]
                             (|do [_ (compile term)
                                   :let [_ (prepare-ctor-arg =method type)]]
-                              (return &/unit-tag))))
+                              (return nil))))
                         ctor-args)
               :let [_ (doto =method
                         (.visitMethodInsn Opcodes/INVOKESPECIAL (&host-generics/->bytecode-class-name super-class-name) init-method (str "(" init-types ")" <init>-return))
@@ -635,7 +635,7 @@
                         (.visitInsn Opcodes/RETURN)
                         (.visitMaxs 0 0)
                         (.visitEnd))]]
-          (return &/unit-tag)))))
+          (return nil)))))
   )
 
 (defn compile-jvm-class [compile class-decl ?super-class ?interfaces ?anns ?fields ?methods env ??ctor-args]
@@ -658,7 +658,7 @@
             (add-anon-class-<init> =class compile full-name ?super-class env ctor-args)
 
             _
-            (return &/unit-tag))]
+            (return nil))]
     (&&/save-class! ?name (.toByteArray (doto =class .visitEnd)))))
 
 (defn compile-jvm-interface [compile interface-decl ?supers ?anns ?methods]
@@ -692,7 +692,7 @@
     (compile-jvm-interface nil interface-decl ?supers ?anns ?methods)))
 
 (def compile-LuxUtils-class
-  (|do [_ (return &/unit-tag)
+  (|do [_ (return nil)
         :let [full-name &&/lux-utils-class
               super-class (&host-generics/->bytecode-class-name "java.lang.Object")
               tag-sig (&host-generics/->type-signature "java.lang.String")
@@ -829,15 +829,15 @@
               $end (new Label)
               $catch-finally (new Label)
               compile-finally (|case ?finally
-                                (&/$Some ?finally*) (|do [_ (return &/unit-tag)
+                                (&/$Some ?finally*) (|do [_ (return nil)
                                                           _ (compile ?finally*)
                                                           :let [_ (doto *writer*
                                                                     (.visitInsn Opcodes/POP)
                                                                     (.visitJumpInsn Opcodes/GOTO $end))]]
-                                                      (return &/unit-tag))
-                                (&/$None) (|do [_ (return &/unit-tag)
+                                                      (return nil))
+                                (&/$None) (|do [_ (return nil)
                                                 :let [_ (.visitJumpInsn *writer* Opcodes/GOTO $end)]]
-                                            (return &/unit-tag)))
+                                            (return nil)))
               catch-boundaries (&/|map (fn [_catch_]
                                          (|let [[?ex-class ?ex-idx ?catch-body] _catch_]
                                            (&/T [?ex-class (new Label) (new Label)])))
@@ -868,19 +868,19 @@
             (&/$Some ?finally*) (|do [_ (compile ?finally*)
                                       :let [_ (.visitInsn *writer* Opcodes/POP)]
                                       :let [_ (.visitInsn *writer* Opcodes/ATHROW)]]
-                                  (return &/unit-tag))
-            (&/$None) (|do [_ (return &/unit-tag)
+                                  (return nil))
+            (&/$None) (|do [_ (return nil)
                             :let [_ (.visitInsn *writer* Opcodes/ATHROW)]]
-                        (return &/unit-tag)))
+                        (return nil)))
         :let [_ (.visitJumpInsn *writer* Opcodes/GOTO $end)]
         :let [_ (.visitLabel *writer* $end)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-jvm-throw [compile ?ex]
   (|do [^MethodVisitor *writer* &/get-writer
         _ (compile ?ex)
         :let [_ (.visitInsn *writer* Opcodes/ATHROW)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (do-template [<name> <op>]
   (defn <name> [compile ?monitor]
@@ -889,7 +889,7 @@
           :let [_ (doto *writer*
                     (.visitInsn <op>)
                     (.visitInsn Opcodes/ACONST_NULL))]]
-      (return &/unit-tag)))
+      (return nil)))
 
   compile-jvm-monitorenter Opcodes/MONITORENTER
   compile-jvm-monitorexit  Opcodes/MONITOREXIT
@@ -907,7 +907,7 @@
                     (.visitMethodInsn Opcodes/INVOKEVIRTUAL (&host-generics/->bytecode-class-name <from-class>) <from-method> <from-sig>)
                     (.visitInsn <op>)
                     (.visitMethodInsn Opcodes/INVOKESPECIAL (&host-generics/->bytecode-class-name <to-class>) init-method <to-sig>))]]
-      (return &/unit-tag)))
+      (return nil)))
 
   compile-jvm-d2f Opcodes/D2F "java.lang.Double"  "doubleValue" "()D" "java.lang.Float"     "(F)V"
   compile-jvm-d2i Opcodes/D2I "java.lang.Double"  "doubleValue" "()D" "java.lang.Integer"   "(I)V"
@@ -946,7 +946,7 @@
           :let [_ (doto *writer*
                     (.visitInsn <op>)
                     (.visitMethodInsn Opcodes/INVOKESPECIAL (&host-generics/->bytecode-class-name <to-class>) init-method <to-sig>))]]
-      (return &/unit-tag)))
+      (return nil)))
 
   compile-jvm-iand  Opcodes/IAND  "intValue"  "()I" "java.lang.Integer" "intValue"  "()I" "java.lang.Integer" "java.lang.Integer" "(I)V"
   compile-jvm-ior   Opcodes/IOR   "intValue"  "()I" "java.lang.Integer" "intValue"  "()I" "java.lang.Integer" "java.lang.Integer" "(I)V"
@@ -1049,4 +1049,4 @@
                       (.visitInsn Opcodes/RETURN)
                       (.visitMaxs 0 0)
                       (.visitEnd))]]
-        (return &/unit-tag)))))
+        (return nil)))))
diff --git a/src/lux/compiler/lambda.clj b/src/lux/compiler/lambda.clj
index 9767e93dc..83714517f 100644
--- a/src/lux/compiler/lambda.clj
+++ b/src/lux/compiler/lambda.clj
@@ -87,7 +87,7 @@
                       (compile ?source)))
                   closed-over)
         :let [_ (.visitMethodInsn *writer* Opcodes/INVOKESPECIAL lambda-class "<init>" init-signature)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 ;; [Exports]
 (let [lambda-flags (+ Opcodes/ACC_PUBLIC Opcodes/ACC_FINAL Opcodes/ACC_SUPER)
diff --git a/src/lux/compiler/lux.clj b/src/lux/compiler/lux.clj
index 14d34e6dc..3c09f6362 100644
--- a/src/lux/compiler/lux.clj
+++ b/src/lux/compiler/lux.clj
@@ -31,7 +31,7 @@
 (defn compile-bool [compile ?value]
   (|do [^MethodVisitor *writer* &/get-writer
         :let [_ (.visitFieldInsn *writer* Opcodes/GETSTATIC "java/lang/Boolean" (if ?value "TRUE" "FALSE") "Ljava/lang/Boolean;")]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (do-template [<name> <class> <sig> <caster>]
   (defn <name> [compile value]
@@ -41,7 +41,7 @@
                     (.visitInsn Opcodes/DUP)
                     (.visitLdcInsn (<caster> value))
                     (.visitMethodInsn Opcodes/INVOKESPECIAL <class> "<init>" <sig>))]]
-      (return &/unit-tag)))
+      (return nil)))
 
   compile-int  "java/lang/Long"      "(J)V" long
   compile-real "java/lang/Double"    "(D)V" double
@@ -51,7 +51,7 @@
 (defn compile-text [compile ?value]
   (|do [^MethodVisitor *writer* &/get-writer
         :let [_ (.visitLdcInsn *writer* ?value)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-tuple [compile ?elems]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -59,7 +59,7 @@
     (|case num-elems
       0
       (|do [:let [_ (.visitLdcInsn *writer* &/unit-tag)]]
-        (return &/unit-tag))
+        (return nil))
 
       1
       (compile (&/|head ?elems))
@@ -81,7 +81,7 @@
                       (.visitLdcInsn (int num-elems))
                       (.visitLdcInsn &/product-tag)
                       (.visitInsn Opcodes/AASTORE))]]
-        (return &/unit-tag)))))
+        (return nil)))))
 
 (defn compile-variant [compile ?tag tail? ?value]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -105,12 +105,12 @@
                   (.visitLdcInsn (int 3)))]
         _ (compile ?value)
         :let [_ (.visitInsn *writer* Opcodes/AASTORE)]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-local [compile ?idx]
   (|do [^MethodVisitor *writer* &/get-writer
         :let [_ (.visitVarInsn *writer* Opcodes/ALOAD (int ?idx))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-captured [compile ?scope ?captured-id ?source]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -120,12 +120,12 @@
                                    (str (&host/->module-class (&/|head ?scope)) "/" (&host/location (&/|tail ?scope)))
                                    (str &&/closure-prefix ?captured-id)
                                    "Ljava/lang/Object;"))]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-global [compile ?owner-class ?name]
   (|do [^MethodVisitor *writer* &/get-writer
         :let [_ (.visitFieldInsn *writer* Opcodes/GETSTATIC (str (&host/->module-class ?owner-class) "/" (&host/def-name ?name)) &/value-field "Ljava/lang/Object;")]]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn compile-apply [compile ?fn ?args]
   (|do [^MethodVisitor *writer* &/get-writer
@@ -135,7 +135,7 @@
                           :let [_ (.visitMethodInsn *writer* Opcodes/INVOKEINTERFACE &&/function-class "apply" &&/apply-signature)]]
                       (return =arg)))
                   ?args)]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn ^:private compile-def-type [compile ?body]
   (|do [:let [?def-type (|case ?body
@@ -167,7 +167,7 @@
                       def-meta ?meta
                       def-value (-> def-class (.getField &/value-field) (.get nil))]
                 _ (&a-module/define module-name ?name def-type def-meta def-value)]
-            (return &/unit-tag))
+            (return nil))
           (fail (str "[Compilation Error] Aliases cannot contain meta-data: " module-name ";" ?name)))
 
         (&/$Some _)
@@ -205,7 +205,7 @@
                                   (.visitInsn Opcodes/RETURN)
                                   (.visitMaxs 0 0)
                                   (.visitEnd))]]
-                    (return &/unit-tag)))
+                    (return nil)))
               :let [_ (.visitEnd *writer*)]
               _ (&&/save-class! def-name (.toByteArray =class))
               :let [def-class (&&/load-class! class-loader (&host-generics/->class-name current-class))
@@ -234,7 +234,7 @@
                                          (fail "[Compiler Error] Incorrect format for tags.")))
                                      tags*)
                         _ (&a-module/declare-tags module-name tags def-value)]
-                    (return &/unit-tag))
+                    (return nil))
 
                   [false (&/$Some _)]
                   (fail "[Compiler Error] Can't define tags for non-type.")
@@ -243,9 +243,9 @@
                   (fail "[Compiler Error] Incorrect format for tags.")
 
                   [_ (&/$None)]
-                  (return &/unit-tag))
+                  (return nil))
               :let [_ (println 'DEF (str module-name ";" ?name))]]
-          (return &/unit-tag))))))
+          (return nil))))))
 
 (defn compile-ann [compile ?value-ex ?type-ex ?value-type]
   (compile ?value-ex))
diff --git a/src/lux/type.clj b/src/lux/type.clj
index 7fbd3f39c..cae91e588 100644
--- a/src/lux/type.clj
+++ b/src/lux/type.clj
@@ -211,7 +211,7 @@
         (return* (&/update$ &/$type-vars (fn [ts] (&/update$ &/$mappings #(&/|put id (&/V &/$Some type) %)
                                                             ts))
                             state)
-                 &/unit-tag))
+                 nil))
       (fail* (str "[Type Error] <set-var> Unknown type-var: " id " | " (->> state (&/get$ &/$type-vars) (&/get$ &/$mappings) &/|length))))))
 
 ;; [Exports]
@@ -234,7 +234,7 @@
 (defn ^:private delete-var [id]
   (|do [? (bound? id)
         _ (if ?
-            (return &/unit-tag)
+            (return nil)
             (|do [ex existential]
               (set-var id ex)))]
     (fn [state]
@@ -261,7 +261,7 @@
          (fn [state]
            (return* (&/update$ &/$type-vars #(&/set$ &/$mappings (&/|remove id mappings*) %)
                                state)
-                    &/unit-tag)))
+                    nil)))
        state))))
 
 (defn with-var [k]
@@ -584,12 +584,12 @@
 
 (defn ^:private check* [class-loader fixpoints invariant?? expected actual]
   (if (clojure.lang.Util/identical expected actual)
-    (return (&/T [fixpoints &/unit-tag]))
+    (return (&/T [fixpoints nil]))
     (&/with-attempt
       (|case [expected actual]
         [(&/$VarT ?eid) (&/$VarT ?aid)]
         (if (.equals ^Object ?eid ?aid)
-          (return (&/T [fixpoints &/unit-tag]))
+          (return (&/T [fixpoints nil]))
           (|do [ebound (fn [state]
                          (|case ((deref ?eid) state)
                            (&/$Right state* ebound)
@@ -607,7 +607,7 @@
             (|case [ebound abound]
               [(&/$None _) (&/$None _)]
               (|do [_ (set-var ?eid actual)]
-                (return (&/T [fixpoints &/unit-tag])))
+                (return (&/T [fixpoints nil])))
               
               [(&/$Some etype) (&/$None _)]
               (check* class-loader fixpoints invariant?? etype actual)
@@ -622,7 +622,7 @@
         (fn [state]
           (|case ((set-var ?id actual) state)
             (&/$Right state* _)
-            (return* state* (&/T [fixpoints &/unit-tag]))
+            (return* state* (&/T [fixpoints nil]))
 
             (&/$Left _)
             ((|do [bound (deref ?id)]
@@ -633,7 +633,7 @@
         (fn [state]
           (|case ((set-var ?id expected) state)
             (&/$Right state* _)
-            (return* state* (&/T [fixpoints &/unit-tag]))
+            (return* state* (&/T [fixpoints nil]))
 
             (&/$Left _)
             ((|do [bound (deref ?id)]
@@ -658,7 +658,7 @@
                    e* (apply-type F2 A1)
                    a* (apply-type F2 A2)
                    [fixpoints** _] (check* class-loader fixpoints* invariant?? e* a*)]
-               (return (&/T [fixpoints** &/unit-tag])))
+               (return (&/T [fixpoints** nil])))
              state)))
         
         [(&/$AppT F1 A1) (&/$AppT (&/$VarT ?id) A2)]
@@ -674,7 +674,7 @@
                    e* (apply-type F1 A1)
                    a* (apply-type F1 A2)
                    [fixpoints** _] (check* class-loader fixpoints* invariant?? e* a*)]
-               (return (&/T [fixpoints** &/unit-tag])))
+               (return (&/T [fixpoints** nil])))
              state)))
         
         [(&/$AppT F A) _]
@@ -691,7 +691,7 @@
           (|case (fp-get fp-pair fixpoints)
             (&/$Some ?)
             (if ?
-              (return (&/T [fixpoints &/unit-tag]))
+              (return (&/T [fixpoints nil]))
               (check-error "" expected actual))
 
             (&/$None)
@@ -741,10 +741,10 @@
                                  a!data)
 
         [(&/$VoidT) (&/$VoidT)]
-        (return (&/T [fixpoints &/unit-tag]))
+        (return (&/T [fixpoints nil]))
         
         [(&/$UnitT) (&/$UnitT)]
-        (return (&/T [fixpoints &/unit-tag]))
+        (return (&/T [fixpoints nil]))
 
         [(&/$LambdaT eI eO) (&/$LambdaT aI aO)]
         (|do [[fixpoints* _] (check* class-loader fixpoints invariant?? aI eI)]
@@ -760,7 +760,7 @@
 
         [(&/$ExT e!id) (&/$ExT a!id)]
         (if (.equals ^Object e!id a!id)
-          (return (&/T [fixpoints &/unit-tag]))
+          (return (&/T [fixpoints nil]))
           (check-error "" expected actual))
 
         [(&/$NamedT ?ename ?etype) _]
@@ -777,7 +777,7 @@
 (defn check [expected actual]
   (|do [class-loader &/loader
         _ (check* class-loader init-fixpoints false expected actual)]
-    (return &/unit-tag)))
+    (return nil)))
 
 (defn actual-type [type]
   "(-> Type (Lux Type))"
diff --git a/src/lux/type/host.clj b/src/lux/type/host.clj
index 27afc1563..ae225db1f 100644
--- a/src/lux/type/host.clj
+++ b/src/lux/type/host.clj
@@ -215,16 +215,16 @@
   (|let [[e!name e!params] expected
          [a!name a!params] actual]
     (try (cond (= "java.lang.Object" e!name)
-               (return (&/T [fixpoints &/unit-tag]))
+               (return (&/T [fixpoints nil]))
 
                (= null-data-tag a!name)
                (if (not (primitive-type? e!name))
-                 (return (&/T [fixpoints &/unit-tag]))
+                 (return (&/T [fixpoints nil]))
                  (check-error "" (&/V &/$DataT expected) (&/V &/$DataT actual)))
 
                (= null-data-tag e!name)
                (if (= null-data-tag a!name)
-                 (return (&/T [fixpoints &/unit-tag]))
+                 (return (&/T [fixpoints nil]))
                  (check-error "" (&/V &/$DataT expected) (&/V &/$DataT actual)))
 
                (and (= array-data-tag e!name)
@@ -237,7 +237,7 @@
                  (cond (.equals ^Object e!name a!name)
                        (if (= (&/|length e!params) (&/|length a!params))
                          (|do [_ (&/map2% check e!params a!params)]
-                           (return (&/T [fixpoints &/unit-tag])))
+                           (return (&/T [fixpoints nil])))
                          (fail (str "[Type Error] Amounts of generic parameters don't match: " e!name "(" (&/|length e!params) ")" " vs " a!name "(" (&/|length a!params) ")")))
 
                        (not invariant??)