Made labels (tags & slots) into a form of global binding.

25 files changed, 616 insertions, 390 deletions

diff --git a/stdlib/source/library/lux.lux b/stdlib/source/library/lux.lux
index 20614dc2f..804c27ee5 100644
--- a/stdlib/source/library/lux.lux
+++ b/stdlib/source/library/lux.lux
@@ -53,7 +53,7 @@
   (9 #1 (0 #1 [[dummy_location (7 #0 ["library/lux" "type_args"])]
                [dummy_location (9 #0 (0 #1 [dummy_location (5 #0 "a")] (0 #0)))]]
            (0 #0)))]
- ["End" "Item"]
+ ("End" "Item")
  #1)
 
 ("lux def" Bit
@@ -135,7 +135,7 @@
   (9 #1 (#Item [[dummy_location (7 #0 ["library/lux" "type_args"])]
                 [dummy_location (9 #0 (#Item [dummy_location (5 #0 "a")] #End))]]
                #End))]
- ["None" "Some"]
+ ("None" "Some")
  #1)
 
 ... (type: .public Type
@@ -196,7 +196,7 @@
      ("lux type check type" (9 #0 (4 #0 1) (4 #0 0)))))
  [dummy_location
   (9 #1 #End)]
- ["Primitive" "Sum" "Product" "Function" "Parameter" "Var" "Ex" "UnivQ" "ExQ" "Apply" "Named"]
+ ("Primitive" "Sum" "Product" "Function" "Parameter" "Var" "Ex" "UnivQ" "ExQ" "Apply" "Named")
  #1)
 
 ... (type: .public Location
@@ -276,7 +276,7 @@
   (9 #1 (#Item [[dummy_location (7 #0 ["library/lux" "type_args"])]
                 [dummy_location (9 #0 (#Item [dummy_location (5 #0 "w")] #End))]]
                #End))]
- ["Bit" "Nat" "Int" "Rev" "Frac" "Text" "Identifier" "Tag" "Form" "Tuple" "Record"]
+ ("Bit" "Nat" "Int" "Rev" "Frac" "Text" "Identifier" "Tag" "Form" "Tuple" "Record")
  #1)
 
 ... (type: .public Code
@@ -420,15 +420,33 @@
  (record$ #End)
  .public)
 
+... (type: .public Label
+...   [Bit Type (List Text) Nat])
+("lux def" Label
+ ("lux type check type"
+  (#Named ["library/lux" "Label"]
+          (#Product Bit (#Product Type (#Product (#Apply Text List) Nat)))))
+ (record$ #End)
+ .public)
+
 ... (type: .public Global
-...   (#Alias Alias)
-...   (#Definition Definition))
+...   (Variant
+...    (#Definition Definition)
+...    (#Type [Bit Type (Either [Text (List Text)] [Text (List Text)])])
+...    (#Tag Label)
+...    (#Slot Label)
+...    (#Alias Alias)))
 ("lux def type tagged" Global
  (#Named ["library/lux" "Global"]
-         (#Sum Alias
-               Definition))
+         (#Sum Definition
+               (#Sum ({labels
+                       (#Product Bit (#Product Type (#Sum labels labels)))}
+                      (#Product Text (#Apply Text List)))
+                     (#Sum Label
+                           (#Sum Label
+                                 Alias)))))
  (record$ #End)
- ["Alias" "Definition"]
+ ("Definition" "Type" "Label" "Slot" "Alias")
  .public)
 
 ... (type: .public (Bindings k v)
@@ -460,7 +478,7 @@
           ... Captured
           Nat))
  (record$ #End)
- ["Local" "Captured"]
+ ("Local" "Captured")
  .public)
 
 ... (type: .public Scope
@@ -502,7 +520,7 @@
  (record$ (#Item [(tag$ ["library/lux" "type_args"])
                   (tuple$ (#Item (text$ "l") (#Item (text$ "r") #End)))]
                  #End))
- ["Left" "Right"]
+ ("Left" "Right")
  .public)
 
 ... (type: .public Source
@@ -529,47 +547,39 @@
            ... #Cached
            Any)))
  (record$ #End)
- ["Active" "Compiled" "Cached"]
+ ("Active" "Compiled" "Cached")
  .public)
 
 ... (type: .public Module
-...   {#module_hash        Nat
-...    #module_aliases     (List [Text Text])
-...    #definitions        (List [Text Global])
-...    #imports            (List Text)
-...    #tags               (List [Text [Nat (List Name) Bit Type]])
-...    #types              (List [Text [(List Name) Bit Type]])
-...    #module_annotations (Maybe Code)
-...    #module_state       Module_State})
+...   (Record
+...    {#module_hash        Nat
+...     #module_aliases     (List [Text Text])
+...     #definitions        (List [Text Global])
+...     #imports            (List Text)
+...     #module_annotations (Maybe Code)
+...     #module_state       Module_State}))
 ("lux def type tagged" Module
  (#Named ["library/lux" "Module"]
-         (#Product ... "lux.module_hash"
+         (#Product
+          ... "lux.module_hash"
           Nat
-          (#Product ... "lux.module_aliases"
+          (#Product
+           ... "lux.module_aliases"
            (#Apply (#Product Text Text) List)
-           (#Product ... "lux.definitions"
+           (#Product
+            ... "lux.definitions"
             (#Apply (#Product Text Global) List)
-            (#Product ... "lux.imports"
+            (#Product
+             ... "lux.imports"
              (#Apply Text List)
-             (#Product ... "lux.tags"
-              (#Apply (#Product Text
-                                (#Product Nat
-                                          (#Product (#Apply Name List)
-                                                    (#Product Bit
-                                                              Type))))
-                      List)
-              (#Product ... "lux.types"
-               (#Apply (#Product Text
-                                 (#Product (#Apply Name List)
-                                           (#Product Bit
-                                                     Type)))
-                       List)
-               (#Product ... "lux.module_annotations"
-                (#Apply Code Maybe)
-                Module_State))
-              ))))))
+             (#Product
+              ... "lux.module_annotations"
+              (#Apply Code Maybe)
+              ... module_state
+              Module_State)
+             )))))
  (record$ #End)
- ["module_hash" "module_aliases" "definitions" "imports" "tags" "types" "module_annotations" "module_state"]
+ ["module_hash" "module_aliases" "definitions" "imports" "module_annotations" "module_state"]
  .public)
 
 ... (type: .public Type_Context
@@ -602,7 +612,7 @@
            ... Interpreter
            Any)))
  (record$ #End)
- ["Build" "Eval" "Interpreter"]
+ ("Build" "Eval" "Interpreter")
  .public)
 
 ... (type: .public Info
@@ -1668,13 +1678,22 @@
                  #scopes scopes #type_context types    #host    host
                  #seed seed #expected  expected #location  location #extensions extensions
                  #scope_type_vars scope_type_vars #eval _eval} state]
-               ({(#Some {#module_hash _ #module_aliases _ #definitions definitions #imports _ #tags tags #types types #module_annotations _ #module_state _})
+               ({(#Some {#module_hash _ #module_aliases _ #definitions definitions #imports _ #module_annotations _ #module_state _})
                  ({(#Some constant)
-                   ({(#Left real_name)
+                   ({(#Alias real_name)
                      (#Right [state real_name])
                      
-                     (#Right [exported? def_type def_meta def_value])
-                     (#Right [state full_name])}
+                     (#Definition [exported? def_type def_meta def_value])
+                     (#Right [state full_name])
+
+                     (#Type [exported? type labels])
+                     (#Right [state full_name])
+
+                     (#Label _)
+                     (#Left ($_ text\composite "Unknown definition: " (name\encoded full_name)))
+
+                     (#Slot _)
+                     (#Left ($_ text\composite "Unknown definition: " (name\encoded full_name)))}
                     constant)
 
                    #None
@@ -2189,26 +2208,35 @@
            #0}
           type))
 
-(def:''' .private (macro' modules current_module module name)
+(def:''' .private (macro'' modules current_module module name)
          #End
          (-> ($' List (Tuple Text Module))
              Text Text Text
              ($' Maybe Macro))
          (do maybe_monad
            [$module (plist\value module modules)
-            gdef (let' [{#module_hash _ #module_aliases _ #definitions bindings #imports _ #tags tags #types types #module_annotations _ #module_state _} ("lux type check" Module $module)]
+            gdef (let' [{#module_hash _ #module_aliases _ #definitions bindings #imports _ #module_annotations _ #module_state _} ("lux type check" Module $module)]
                        (plist\value name bindings))]
-           ({(#Left [r_module r_name])
-             (macro' modules current_module r_module r_name)
+           ({(#Alias [r_module r_name])
+             (macro'' modules current_module r_module r_name)
 
-             (#Right [exported? def_type def_meta def_value])
+             (#Definition [exported? def_type def_meta def_value])
              (if (macro_type? def_type)
                (if exported?
                  (#Some ("lux type as" Macro def_value))
                  (if (text\= module current_module)
                    (#Some ("lux type as" Macro def_value))
                    #None))
-               #None)}
+               #None)
+
+             (#Type [exported? type labels])
+             #None
+
+             (#Label _)
+             #None
+
+             (#Slot _)
+             #None}
             ("lux type check" Global gdef))))
 
 (def:''' .private (normal name)
@@ -2223,7 +2251,7 @@
            (in_meta name)}
           name))
 
-(def:''' .private (macro full_name)
+(def:''' .private (macro' full_name)
          #End
          (-> Name ($' Meta ($' Maybe Macro)))
          (do meta_monad
@@ -2235,7 +2263,7 @@
                                #seed   seed #expected expected
                                #location location #extensions extensions
                                #scope_type_vars scope_type_vars #eval _eval}
-                              (#Right state (macro' modules current_module module name))}
+                              (#Right state (macro'' modules current_module module name))}
                              state)))))
 
 (def:''' .private (macro? name)
@@ -2243,7 +2271,7 @@
          (-> Name ($' Meta Bit))
          (do meta_monad
            [name (normal name)
-            output (macro name)]
+            output (macro' name)]
            (in ({(#Some _) #1
                  #None     #0}
                 output))))
@@ -2268,7 +2296,7 @@
          ({[_ (#Form (#Item [_ (#Identifier name)] args))]
            (do meta_monad
              [name' (normal name)
-              ?macro (macro name')]
+              ?macro (macro' name')]
              ({(#Some macro)
                (("lux type as" Macro' macro) args)
                
@@ -2286,7 +2314,7 @@
          ({[_ (#Form (#Item [_ (#Identifier name)] args))]
            (do meta_monad
              [name' (normal name)
-              ?macro (macro name')]
+              ?macro (macro' name')]
              ({(#Some macro)
                (do meta_monad
                  [top_level_expansion (("lux type as" Macro' macro) args)
@@ -2307,7 +2335,7 @@
          ({[_ (#Form (#Item [_ (#Identifier name)] args))]
            (do meta_monad
              [name' (normal name)
-              ?macro (macro name')]
+              ?macro (macro' name')]
              ({(#Some macro)
                (do meta_monad
                  [expansion (("lux type as" Macro' macro) args)
@@ -3270,17 +3298,22 @@
         _
         (#Left ($_ text\composite "Unknown module: " name))))))
 
-(def: (type_tag [module name])
+(def: (type_slot [module name])
   (-> Name (Meta [Nat (List Name) Bit Type]))
   (do meta_monad
     [=module (..module module)
-     .let [{#module_hash _ #module_aliases _ #definitions bindings #imports _ #tags tags_table #types types #module_annotations _ #module_state _} =module]]
-    (case (plist\value name tags_table)
-      (#Some output)
-      (in_meta output)
+     .let [{#module_hash _ #module_aliases _ #definitions definitions #imports _ #module_annotations _ #module_state _} =module]]
+    (case (plist\value (text\composite "#" name) definitions)
+      (#Some (#Slot [exported type group index]))
+      (in_meta [index
+                (list\each (function (_ slot)
+                             [module slot])
+                           group)
+                exported
+                type])
 
       _
-      (failure (text\composite "Unknown tag: " (name\encoded [module name]))))))
+      (failure (text\composite "Unknown slot: " (name\encoded [module name]))))))
 
 (def: (record_slots type)
   (-> Type (Meta (Maybe [(List Name) (List Type)])))
@@ -3297,12 +3330,14 @@
     (#Named [module name] unnamed)
     (do meta_monad
       [=module (..module module)
-       .let [{#module_hash _ #module_aliases _ #definitions bindings #imports _ #tags tags #types types #module_annotations _ #module_state _} =module]]
-      (case (plist\value name types)
-        (#Some [tags exported? (#Named _ _type)])
+       .let [{#module_hash _ #module_aliases _ #definitions definitions #imports _ #module_annotations _ #module_state _} =module]]
+      (case (plist\value name definitions)
+        (#Some (#Type [exported? (#Named _ _type) (#Right slots)]))
         (case (interface_methods _type)
           (#Some members)
-          (in_meta (#Some [tags members]))
+          (in_meta (#Some [(list\each (function (_ slot) [module slot])
+                                      (#Item slots))
+                           members]))
 
           _
           (in_meta #None))
@@ -3520,9 +3555,9 @@
   (case (everyP caseP tokens)
     (#Some cases)
     (in_meta (list (` (..Union (~+ (list\each product\right cases))))
-                   (tuple$ (list\each (function (_ case)
-                                        (text$ (product\left case)))
-                                      cases))))
+                   (form$ (list\each (function (_ case)
+                                       (text$ (product\left case)))
+                                     cases))))
     
     #None
     (failure "Wrong syntax for Variant")))
@@ -3616,15 +3651,23 @@
     #None))
 
 (def: (type_declaration it)
-  (-> Code (Meta (Tuple Code (Maybe (List Text)))))
+  (-> Code (Meta (Tuple Code (Maybe (Either (List Text) (List Text))))))
   ({[_ (#Form (#Item [_ (#Identifier declarer)] parameters))]
     (do meta_monad
       [declaration (single_expansion (form$ (list& (identifier$ declarer) parameters)))]
       (case declaration
-        (^ (list type [_ (#Tuple tags)]))
+        (^ (list type [_ (#Form tags)]))
         (case (everyP textP tags)
           (#Some tags)
-          (in_meta [type (#Some tags)])
+          (in_meta [type (#Some (#Left tags))])
+          
+          #None
+          (failure "Improper type-definition syntax"))
+
+        (^ (list type [_ (#Tuple slots)]))
+        (case (everyP textP slots)
+          (#Some slots)
+          (in_meta [type (#Some (#Right slots))])
           
           #None
           (failure "Improper type-definition syntax"))
@@ -3643,10 +3686,10 @@
   (case (typeP tokens)
     (#Some [export_policy name args meta type_codes])
     (do meta_monad
-      [type+tags?? (..type_declaration type_codes)
+      [type+labels?? (..type_declaration type_codes)
        module_name current_module_name
        .let' [type_name (local_identifier$ name)
-              [type tags??] type+tags??
+              [type labels??] type+labels??
               type' (: (Maybe Code)
                        (case args
                          #End
@@ -3663,13 +3706,22 @@
         (let [typeC (` (#.Named [(~ (text$ module_name))
                                  (~ (text$ name))]
                                 (.type (~ type''))))]
-          (in_meta (list (case tags??
-                           (#Some tags)
-                           (` ("lux def type tagged" (~ type_name)
-                               (~ typeC)
-                               (~ total_meta)
-                               [(~+ (list\each text$ tags))]
-                               (~ export_policy)))
+          (in_meta (list (case labels??
+                           (#Some labels)
+                           (case labels
+                             (#Left tags)
+                             (` ("lux def type tagged" (~ type_name)
+                                 (~ typeC)
+                                 (~ total_meta)
+                                 ((~+ (list\each text$ tags)))
+                                 (~ export_policy)))
+                             
+                             (#Right slots)
+                             (` ("lux def type tagged" (~ type_name)
+                                 (~ typeC)
+                                 (~ total_meta)
+                                 [(~+ (list\each text$ slots))]
+                                 (~ export_policy))))
                            
                            _
                            (` ("lux def" (~ type_name)
@@ -3980,14 +4032,25 @@
                                        (List Text))
                                    (function (_ [name definition])
                                      (case definition
-                                       (#Left _)
+                                       (#Alias _)
                                        (list)
 
-                                       (#Right [exported? def_type def_meta def_value])
+                                       (#Definition [exported? def_type def_meta def_value])
+                                       (if exported?
+                                         (list name)
+                                         (list))
+
+                                       (#Type [exported? type labels])
                                        (if exported?
                                          (list name)
-                                         (list)))))
-                                (let [{#module_hash _ #module_aliases _ #definitions definitions #imports _ #tags tags #types types #module_annotations _ #module_state _} =module]
+                                         (list))
+
+                                       (#Label _)
+                                       (list)
+
+                                       (#Slot _)
+                                       (list))))
+                                (let [{#module_hash _ #module_aliases _ #definitions definitions #imports _ #module_annotations _ #module_state _} =module]
                                   definitions))]
         (#Right state (list\conjoint to_alias)))
       
@@ -4069,18 +4132,27 @@
       #None
       #None
 
-      (#Some {#definitions definitions #module_hash _ #module_aliases _ #imports _ #tags tags #types types #module_annotations _ #module_state _})
+      (#Some {#definitions definitions #module_hash _ #module_aliases _ #imports _ #module_annotations _ #module_state _})
       (case (plist\value v_name definitions)
         #None
         #None
 
         (#Some definition)
         (case definition
-          (#Left real_name)
+          (#Alias real_name)
           (definition_type real_name state)
           
-          (#Right [exported? def_type def_meta def_value])
-          (#Some def_type))))))
+          (#Definition [exported? def_type def_meta def_value])
+          (#Some def_type)
+
+          (#Type [exported? type labels])
+          (#Some ..Type)
+
+          (#Label _)
+          #None
+
+          (#Slot _)
+          #None)))))
 
 (def: (definition_value name state)
   (-> Name (Meta [Type Any]))
@@ -4093,18 +4165,27 @@
       #None
       (#Left (text\composite "Unknown definition: " (name\encoded name)))
 
-      (#Some {#definitions definitions #module_hash _ #module_aliases _ #imports _ #tags tags #types types #module_annotations _ #module_state _})
+      (#Some {#definitions definitions #module_hash _ #module_aliases _ #imports _ #module_annotations _ #module_state _})
       (case (plist\value v_name definitions)
         #None
         (#Left (text\composite "Unknown definition: " (name\encoded name)))
 
         (#Some definition)
         (case definition
-          (#Left real_name)
+          (#Alias real_name)
           (definition_value real_name state)
           
-          (#Right [exported? def_type def_meta def_value])
-          (#Right [state [def_type def_value]]))))))
+          (#Definition [exported? def_type def_meta def_value])
+          (#Right [state [def_type def_value]])
+
+          (#Type [exported? type labels])
+          (#Right [state [..Type type]])
+
+          (#Label _)
+          (#Left (text\composite "Unknown definition: " (name\encoded name)))
+
+          (#Slot _)
+          (#Left (text\composite "Unknown definition: " (name\encoded name))))))))
 
 (def: (type_variable idx bindings)
   (-> Nat (List [Nat (Maybe Type)]) (Maybe Type))
@@ -4254,7 +4335,7 @@
     (^ (list [_ (#Tag slot')] record))
     (do meta_monad
       [slot (normal slot')
-       output (..type_tag slot)
+       output (..type_slot slot)
        .let [[idx tags exported? type] output]
        g!_ (..identifier "_")
        g!output (..identifier "")]
@@ -4366,7 +4447,7 @@
   (-> Text Text (Meta Bit))
   (do meta_monad
     [module (module module_name)
-     .let [{#module_hash _ #module_aliases _ #definitions _ #imports imports #tags _ #types _ #module_annotations _ #module_state _} module]]
+     .let [{#module_hash _ #module_aliases _ #definitions _ #imports imports #module_annotations _ #module_state _} module]]
     (in (is_member? imports import_name))))
 
 (def: (referrals module_name options)
@@ -4514,7 +4595,7 @@
     (^ (list [_ (#Tag slot')] value record))
     (do meta_monad
       [slot (normal slot')
-       output (..type_tag slot)
+       output (..type_slot slot)
        .let [[idx tags exported? type] output]]
       (case (interface_methods type)
         (#Some members)
@@ -4593,7 +4674,7 @@
     (^ (list [_ (#Tag slot')] fun record))
     (do meta_monad
       [slot (normal slot')
-       output (..type_tag slot)
+       output (..type_slot slot)
        .let [[idx tags exported? type] output]]
       (case (interface_methods type)
         (#Some members)
@@ -4798,7 +4879,7 @@
        .let [[hslot tslots] slots]
        hslot (..normal hslot)
        tslots (monad\each meta_monad ..normal tslots)
-       output (..type_tag hslot)
+       output (..type_slot hslot)
        g!_ (..identifier "_")
        .let [[idx tags exported? type] output
              slot_pairings (list\each (: (-> Name [Text Code])
@@ -5520,3 +5601,7 @@
 
     _
     (failure "Wrong syntax for Rec")))
+
+(def: .public macro
+  (-> Macro Macro')
+  (|>> (:as Macro')))
diff --git a/stdlib/source/library/lux/control/function/mutual.lux b/stdlib/source/library/lux/control/function/mutual.lux
index 3d26dedd1..5ef853829 100644
--- a/stdlib/source/library/lux/control/function/mutual.lux
+++ b/stdlib/source/library/lux/control/function/mutual.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- Definition let def:)
+   [lux (#- Definition let def: macro)
     ["." meta]
     [abstract
      ["." monad (#+ do)]]
diff --git a/stdlib/source/library/lux/control/parser/binary.lux b/stdlib/source/library/lux/control/parser/binary.lux
index 409d2a872..6c0f82a06 100644
--- a/stdlib/source/library/lux/control/parser/binary.lux
+++ b/stdlib/source/library/lux/control/parser/binary.lux
@@ -110,16 +110,28 @@
   [(do {! //.monad}
      [flag (: (Parser Nat)
               ..bits/8)]
-     (`` (case flag
-           (^template [<number> <tag> <parser>]
-             [<number> (\ ! each (|>> <tag>) <parser>)])
-           ((~~ (template.spliced <case>+)))
-           _ (//.lifted (exception.except ..invalid_tag [(~~ (template.amount <case>+)) flag])))))])
+     (with_expansions [<case>+' (template.spliced <case>+)]
+       (case flag
+         (^template [<number> <tag> <parser>]
+           [<number> (`` (\ ! each (|>> ((~~ (template.spliced <tag>)))) <parser>))])
+         (<case>+')
+         
+         _ (//.lifted (exception.except ..invalid_tag [(template.amount [<case>+]) flag])))))])
 
 (def: .public (or left right)
   (All (_ l r) (-> (Parser l) (Parser r) (Parser (Or l r))))
-  (!variant [[0 #.Left left]
-             [1 #.Right right]]))
+  (!variant [[0 [#.Left] left]
+             [1 [#.Right] right]]))
+
+(def: .public (or/5 p/0 p/1 p/2 p/3 p/4)
+  (All (_ p/0 p/1 p/2 p/3 p/4)
+    (-> (Parser p/0) (Parser p/1) (Parser p/2) (Parser p/3) (Parser p/4)
+        (Parser (Or p/0 p/1 p/2 p/3 p/4))))
+  (!variant [[0 [0 #0] p/0]
+             [1 [1 #0] p/1]
+             [2 [2 #0] p/2]
+             [3 [3 #0] p/3]
+             [4 [3 #1] p/4]]))
 
 (def: .public (rec body)
   (All (_ a) (-> (-> (Parser a) (Parser a)) (Parser a)))
@@ -242,17 +254,17 @@
      (let [pair (//.and type type)
            indexed ..nat
            quantified (//.and (..list type) type)]
-       (!variant [[0 #.Primitive (//.and ..text (..list type))]
-                  [1 #.Sum pair]
-                  [2 #.Product pair]
-                  [3 #.Function pair]
-                  [4 #.Parameter indexed]
-                  [5 #.Var indexed]
-                  [6 #.Ex indexed]
-                  [7 #.UnivQ quantified]
-                  [8 #.ExQ quantified]
-                  [9 #.Apply pair]
-                  [10 #.Named (//.and ..name type)]])))))
+       (!variant [[0 [#.Primitive] (//.and ..text (..list type))]
+                  [1 [#.Sum] pair]
+                  [2 [#.Product] pair]
+                  [3 [#.Function] pair]
+                  [4 [#.Parameter] indexed]
+                  [5 [#.Var] indexed]
+                  [6 [#.Ex] indexed]
+                  [7 [#.UnivQ] quantified]
+                  [8 [#.ExQ] quantified]
+                  [9 [#.Apply] pair]
+                  [10 [#.Named] (//.and ..name type)]])))))
 
 (def: .public location
   (Parser Location)
@@ -264,14 +276,14 @@
    (function (_ recur)
      (let [sequence (..list recur)]
        (//.and ..location
-               (!variant [[0 #.Bit ..bit]
-                          [1 #.Nat ..nat]
-                          [2 #.Int ..int]
-                          [3 #.Rev ..rev]
-                          [4 #.Frac ..frac]
-                          [5 #.Text ..text]
-                          [6 #.Identifier ..name]
-                          [7 #.Tag ..name]
-                          [8 #.Form sequence]
-                          [9 #.Tuple sequence]
-                          [10 #.Record (..list (//.and recur recur))]]))))))
+               (!variant [[0 [#.Bit] ..bit]
+                          [1 [#.Nat] ..nat]
+                          [2 [#.Int] ..int]
+                          [3 [#.Rev] ..rev]
+                          [4 [#.Frac] ..frac]
+                          [5 [#.Text] ..text]
+                          [6 [#.Identifier] ..name]
+                          [7 [#.Tag] ..name]
+                          [8 [#.Form] sequence]
+                          [9 [#.Tuple] sequence]
+                          [10 [#.Record] (..list (//.and recur recur))]]))))))
diff --git a/stdlib/source/library/lux/data/format/binary.lux b/stdlib/source/library/lux/data/format/binary.lux
index 109b1c19d..8ffed2724 100644
--- a/stdlib/source/library/lux/data/format/binary.lux
+++ b/stdlib/source/library/lux/data/format/binary.lux
@@ -98,6 +98,29 @@
        [1 #.Right right])
       )))
 
+(def: .public (or/5 w/0 w/1 w/2 w/3 w/4)
+  (All (_ w/0 w/1 w/2 w/3 w/4)
+    (-> (Writer w/0) (Writer w/1) (Writer w/2) (Writer w/3) (Writer w/4)
+        (Writer (Or w/0 w/1 w/2 w/3 w/4))))
+  (function (_ altV)
+    (case altV
+      (^template [<number> <tag> <right?> <writer>]
+        [(<tag> <right?> caseV)
+         (let [[caseS caseT] (<writer> caseV)]
+           [(.++ caseS)
+            (function (_ [offset binary])
+              (|> binary
+                  (binary.write/8! offset <number>)
+                  try.trusted
+                  [(.++ offset)]
+                  caseT))])])
+      ([0 0 #0 w/0]
+       [1 1 #0 w/1]
+       [2 2 #0 w/2]
+       [3 3 #0 w/3]
+       [4 3 #1 w/4])
+      )))
+
 (def: .public (and pre post)
   (All (_ a b) (-> (Writer a) (Writer b) (Writer [a b])))
   (function (_ [preV postV])
diff --git a/stdlib/source/library/lux/macro/template.lux b/stdlib/source/library/lux/macro/template.lux
index 65b4f96ba..3c18f9f9e 100644
--- a/stdlib/source/library/lux/macro/template.lux
+++ b/stdlib/source/library/lux/macro/template.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- let local)
+   [lux (#- let local macro)
     ["." meta]
     [abstract
      ["." monad (#+ do)]]
diff --git a/stdlib/source/library/lux/meta.lux b/stdlib/source/library/lux/meta.lux
index 208663367..f19bc2964 100644
--- a/stdlib/source/library/lux/meta.lux
+++ b/stdlib/source/library/lux/meta.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- type)
+   [lux (#- type macro)
     [abstract
      [functor (#+ Functor)]
      [apply (#+ Apply)]
@@ -189,7 +189,16 @@
                                   (#.Definition [exported? def_type def_anns def_value])
                                   (if (macro_type? def_type)
                                     (#.Some (:as Macro def_value))
-                                    #.None))))))])))))
+                                    #.None)
+
+                                  (#.Type [exported? type labels])
+                                  #.None
+
+                                  (#.Label _)
+                                  #.None
+
+                                  (#.Slot _)
+                                  #.None)))))])))))
 
 (def: .public seed
   (Meta Nat)
@@ -315,13 +324,20 @@
                                                                     (value@ #.definitions)
                                                                     (list.all (function (_ [def_name global])
                                                                                 (case global
-                                                                                  (#.Definition [exported? _ _ _])
+                                                                                  (^or (#.Definition [exported? _])
+                                                                                       (#.Type [exported? _]))
                                                                                   (if (and exported?
                                                                                            (text\= normal_short def_name))
                                                                                     (#.Some (name\encoded [module_name def_name]))
                                                                                     #.None)
 
                                                                                   (#.Alias _)
+                                                                                  #.None
+
+                                                                                  (#.Label _)
+                                                                                  #.None
+
+                                                                                  (#.Slot _)
                                                                                   #.None))))))
                                                    list.together
                                                    (list.sorted text\<)
@@ -348,27 +364,55 @@
   (do ..monad
     [definition (..definition name)]
     (case definition
-      (#.Left de_aliased)
-      (failure ($_ text\composite
-                   "Aliases are not considered exports: "
-                   (name\encoded name)))
-      
-      (#.Right definition)
+      (#.Definition definition)
       (let [[exported? def_type def_data def_value] definition]
         (if exported?
           (in definition)
-          (failure ($_ text\composite "Definition is not an export: " (name\encoded name))))))))
+          (failure ($_ text\composite "Definition is not an export: " (name\encoded name)))))
+
+      (#.Type [exported? type labels])
+      (if exported?
+        (in [exported? .Type (' {}) type])
+        (failure ($_ text\composite "Type is not an export: " (name\encoded name))))
+
+      (#.Alias de_aliased)
+      (failure ($_ text\composite
+                   "Aliases are not considered exports: "
+                   (name\encoded name)))
+
+      (#.Label _)
+      (failure ($_ text\composite
+                   "Tags are not considered exports: "
+                   (name\encoded name)))
+
+      (#.Slot _)
+      (failure ($_ text\composite
+                   "Slots are not considered exports: "
+                   (name\encoded name))))))
 
 (def: .public (definition_type name)
   (-> Name (Meta Type))
   (do ..monad
     [definition (definition name)]
     (case definition
-      (#.Left de_aliased)
+      (#.Alias de_aliased)
       (definition_type de_aliased)
       
-      (#.Right [exported? def_type def_data def_value])
-      (clean_type def_type))))
+      (#.Definition [exported? def_type def_data def_value])
+      (clean_type def_type)
+
+      (#.Type [exported? type labels])
+      (in .Type)
+
+      (#.Label _)
+      (failure ($_ text\composite
+                   "Tags have no type: "
+                   (name\encoded name)))
+
+      (#.Slot _)
+      (failure ($_ text\composite
+                   "Slots have no type: "
+                   (name\encoded name))))))
 
 (def: .public (type name)
   (-> Name (Meta Type))
@@ -385,17 +429,26 @@
   (do ..monad
     [definition (definition name)]
     (case definition
-      (#.Left de_aliased)
+      (#.Alias de_aliased)
       (type_definition de_aliased)
       
-      (#.Right [exported? def_type def_data def_value])
+      (#.Definition [exported? def_type def_data def_value])
       (let [type_code (`` ("lux in-module" (~~ (static .prelude_module)) .type_code))]
         (if (or (same? .Type def_type)
                 (\ code.equivalence =
                    (type_code .Type)
                    (type_code def_type)))
           (in (:as Type def_value))
-          (..failure ($_ text\composite "Definition is not a type: " (name\encoded name))))))))
+          (..failure ($_ text\composite "Definition is not a type: " (name\encoded name)))))
+
+      (#.Type [exported? type labels])
+      (in type)
+
+      (#.Label _)
+      (..failure ($_ text\composite "Tag is not a type: " (name\encoded name)))
+
+      (#.Slot _)
+      (..failure ($_ text\composite "Slot is not a type: " (name\encoded name))))))
 
 (def: .public (globals module)
   (-> Text (Meta (List [Text Global])))
@@ -412,11 +465,20 @@
   (\ ..monad each
      (list.all (function (_ [name global])
                  (case global
-                   (#.Left de_aliased)
+                   (#.Alias de_aliased)
                    #.None
                    
-                   (#.Right definition)
-                   (#.Some [name definition]))))
+                   (#.Definition definition)
+                   (#.Some [name definition])
+
+                   (#.Type [exported? type labels])
+                   (#.Some [name [exported? .Type (' {}) type]])
+
+                   (#.Label _)
+                   #.None
+
+                   (#.Slot _)
+                   #.None)))
      (..globals module)))
 
 (def: .public (exports module_name)
@@ -440,11 +502,12 @@
 (def: .public (tags_of type_name)
   (-> Name (Meta (Maybe (List Name))))
   (do ..monad
-    [.let [[module name] type_name]
-     module (..module module)]
-    (case (plist.value name (value@ #.types module))
-      (#.Some [tags _])
-      (in (#.Some tags))
+    [.let [[module_name name] type_name]
+     module (..module module_name)]
+    (case (plist.value name (value@ #.definitions module))
+      (#.Some (#.Type [exported? type (#.Right slots)]))
+      (in (#.Some (list\each (|>> [module_name])
+                             (#.Item slots))))
 
       _
       (in #.None))))
@@ -489,33 +552,41 @@
      =module (..module module)
      this_module_name ..current_module_name
      imported! (..imported? module)]
-    (case (plist.value name (value@ #.tags =module))
-      (#.Some [idx tag_list exported? type])
+    (case (plist.value (text\composite "#" name) (value@ #.definitions =module))
+      (^or (#.Some (#.Label [exported? type group idx]))
+           (#.Some (#.Slot [exported? type group idx])))
       (if (or (text\= this_module_name module)
               (and imported! exported?))
-        (in [idx tag_list type])
+        (in [idx (list\each (|>> [module]) group) type])
         (..failure ($_ text\composite "Cannot access tag: " (name\encoded tag_name) " from module " this_module_name)))
 
       _
       (..failure ($_ text\composite
-                     "Unknown tag: " (name\encoded tag_name) text.new_line
-                     " Known tags: " (|> =module
-                                         (value@ #.tags)
-                                         (list\each (|>> product.left [module] name\encoded (text.prefix text.new_line)))
-                                         text.together)
-                     )))))
+                     "Unknown tag: " (name\encoded tag_name))))))
 
 (def: .public (tag_lists module)
   (-> Text (Meta (List [(List Name) Type])))
   (do ..monad
     [=module (..module module)
      this_module_name ..current_module_name]
-    (in (|> (value@ #.types =module)
-            (list.only (function (_ [type_name [tag_list exported? type]])
-                         (or exported?
-                             (text\= this_module_name module))))
-            (list\each (function (_ [type_name [tag_list exported? type]])
-                         [tag_list type]))))))
+    (in (list.all (function (_ [short global])
+                    (case global
+                      (#.Type [exported? type labels])
+                      (if (or exported?
+                              (text\= this_module_name module))
+                        (#.Some [(list\each (|>> [module])
+                                            (case labels
+                                              (#.Left tags)
+                                              (#.Item tags)
+                                              
+                                              (#.Right slots)
+                                              (#.Item slots)))
+                                 type])
+                        #.None)
+
+                      _
+                      #.None))
+                  (value@ #.definitions =module)))))
 
 (def: .public locals
   (Meta (List (List [Text Type])))
@@ -536,10 +607,19 @@
   (do ..monad
     [constant (..definition def_name)]
     (in (case constant
-          (#.Left real_def_name)
+          (#.Alias real_def_name)
           real_def_name
 
-          (#.Right _)
+          (#.Definition _)
+          def_name
+
+          (#.Type _)
+          def_name
+
+          (#.Label _)
+          def_name
+
+          (#.Slot _)
           def_name))))
 
 (def: .public compiler_state
diff --git a/stdlib/source/library/lux/target/js.lux b/stdlib/source/library/lux/target/js.lux
index 07318b451..62ce204c5 100644
--- a/stdlib/source/library/lux/target/js.lux
+++ b/stdlib/source/library/lux/target/js.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- Location Code or and function if cond undefined for comment not int try ++ --)
+   [lux (#- Location Code Label or and function if cond undefined for comment not int try ++ --)
     [control
      [pipe (#+ case>)]]
     [data
diff --git a/stdlib/source/library/lux/target/jvm.lux b/stdlib/source/library/lux/target/jvm.lux
index ce273f401..50543961c 100644
--- a/stdlib/source/library/lux/target/jvm.lux
+++ b/stdlib/source/library/lux/target/jvm.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- Type)
+   [lux (#- Type Label)
     [data
      [collection
       [row (#+ Row)]]]
diff --git a/stdlib/source/library/lux/target/jvm/bytecode.lux b/stdlib/source/library/lux/target/jvm/bytecode.lux
index 9c106e442..53886c7b5 100644
--- a/stdlib/source/library/lux/target/jvm/bytecode.lux
+++ b/stdlib/source/library/lux/target/jvm/bytecode.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- Type int try)
+   [lux (#- Type Label int try)
     ["." ffi (#+ import:)]
     [abstract
      [monoid (#+ Monoid)]
diff --git a/stdlib/source/library/lux/target/jvm/reflection.lux b/stdlib/source/library/lux/target/jvm/reflection.lux
index 3fdf491bc..55316e26f 100644
--- a/stdlib/source/library/lux/target/jvm/reflection.lux
+++ b/stdlib/source/library/lux/target/jvm/reflection.lux
@@ -174,7 +174,7 @@
             (do {! try.monad}
               [paramsT (|> reflection
                            java/lang/reflect/ParameterizedType::getActualTypeArguments
-                           array.list
+                           (array.list #.None)
                            (monad.each ! parameter))]
               (in (/.class (|> raw
                                (:as (java/lang/Class java/lang/Object))
@@ -297,7 +297,7 @@
   (case type
     (#.Primitive name params)
     (let [class_name (java/lang/Class::getName class)
-          class_params (array.list (java/lang/Class::getTypeParameters class))
+          class_params (array.list #.None (java/lang/Class::getTypeParameters class))
           num_class_params (list.size class_params)
           num_type_params (list.size params)]
       (if (text\= class_name name)
@@ -360,7 +360,7 @@
 
 (def: .public deprecated?
   (-> (array.Array java/lang/annotation/Annotation) Bit)
-  (|>> array.list
+  (|>> (array.list #.None)
        (list.all (|>> (ffi.check java/lang/Deprecated)))
        list.empty?
        not))
diff --git a/stdlib/source/library/lux/target/lua.lux b/stdlib/source/library/lux/target/lua.lux
index 42d8d60e5..faac1b184 100644
--- a/stdlib/source/library/lux/target/lua.lux
+++ b/stdlib/source/library/lux/target/lua.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- Location Code int if cond function or and not let ^ local)
+   [lux (#- Location Code Label int if cond function or and not let ^ local)
     ["@" target]
     [abstract
      [equivalence (#+ Equivalence)]
diff --git a/stdlib/source/library/lux/target/php.lux b/stdlib/source/library/lux/target/php.lux
index 0e228dc57..a14b3e0ce 100644
--- a/stdlib/source/library/lux/target/php.lux
+++ b/stdlib/source/library/lux/target/php.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- Location Code Global static int if cond or and not comment for try global)
+   [lux (#- Location Code Global Label static int if cond or and not comment for try global)
     ["@" target]
     [abstract
      [equivalence (#+ Equivalence)]
diff --git a/stdlib/source/library/lux/target/python.lux b/stdlib/source/library/lux/target/python.lux
index 8a41d3ae8..6b24b6ae2 100644
--- a/stdlib/source/library/lux/target/python.lux
+++ b/stdlib/source/library/lux/target/python.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- Location Code not or and list if cond int comment exec try)
+   [lux (#- Location Code Label not or and list if cond int comment exec try)
     ["@" target]
     ["." ffi]
     [abstract
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux.lux b/stdlib/source/library/lux/tool/compiler/language/lux.lux
index e86bd51aa..5bb42e533 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux.lux
@@ -24,24 +24,23 @@
   (Writer .Module)
   (let [definition (: (Writer Definition)
                       ($_ _.and _.bit _.type _.code _.any))
+        labels (: (Writer [Text (List Text)])
+                  (_.and _.text (_.list _.text)))
+        global_type (: (Writer [Bit Type (Either [Text (List Text)]
+                                                 [Text (List Text)])])
+                       ($_ _.and _.bit _.type (_.or labels labels)))
+        global_label (: (Writer .Label)
+                        ($_ _.and _.bit _.type (_.list _.text) _.nat))
         name (: (Writer Name)
                 (_.and _.text _.text))
         alias (: (Writer Alias)
                  (_.and _.text _.text))
         global (: (Writer Global)
-                  (_.or alias
-                        definition))
-        tag (: (Writer [Nat (List Name) Bit Type])
-               ($_ _.and
-                   _.nat
-                   (_.list name)
-                   _.bit
-                   _.type))
-        type (: (Writer [(List Name) Bit Type])
-                ($_ _.and
-                    (_.list name)
-                    _.bit
-                    _.type))]
+                  (_.or/5 definition
+                          global_type
+                          global_label
+                          global_label
+                          alias))]
     ($_ _.and
         ... #module_hash
         _.nat
@@ -51,10 +50,6 @@
         (_.list (_.and _.text global))
         ... #imports
         (_.list _.text)
-        ... #tags
-        (_.list (_.and _.text tag))
-        ... #types
-        (_.list (_.and _.text type))
         ... #module_annotations
         (_.maybe _.code)
         ... #module_state
@@ -64,24 +59,23 @@
   (Parser .Module)
   (let [definition (: (Parser Definition)
                       ($_ <>.and <b>.bit <b>.type <b>.code <b>.any))
+        labels (: (Parser [Text (List Text)])
+                  (<>.and <b>.text (<b>.list <b>.text)))
+        global_type (: (Parser [Bit Type (Either [Text (List Text)]
+                                                 [Text (List Text)])])
+                       ($_ <>.and <b>.bit <b>.type (<b>.or labels labels)))
+        global_label (: (Parser .Label)
+                        ($_ <>.and <b>.bit <b>.type (<b>.list <b>.text) <b>.nat))
         name (: (Parser Name)
                 (<>.and <b>.text <b>.text))
         alias (: (Parser Alias)
                  (<>.and <b>.text <b>.text))
         global (: (Parser Global)
-                  (<b>.or alias
-                          definition))
-        tag (: (Parser [Nat (List Name) Bit Type])
-               ($_ <>.and
-                   <b>.nat
-                   (<b>.list name)
-                   <b>.bit
-                   <b>.type))
-        type (: (Parser [(List Name) Bit Type])
-                ($_ <>.and
-                    (<b>.list name)
-                    <b>.bit
-                    <b>.type))]
+                  (<b>.or/5 definition
+                            global_type
+                            global_label
+                            global_label
+                            alias))]
     ($_ <>.and
         ... #module_hash
         <b>.nat
@@ -91,10 +85,6 @@
         (<b>.list (<>.and <b>.text global))
         ... #imports
         (<b>.list <b>.text)
-        ... #tags
-        (<b>.list (<>.and <b>.text tag))
-        ... #types
-        (<b>.list (<>.and <b>.text type))
         ... #module_annotations
         (<b>.maybe <b>.code)
         ... #module_state
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/module.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/module.lux
index 42dc67db6..b6817b6c8 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/module.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/module.lux
@@ -28,11 +28,6 @@
   (exception.report
    ["Module" module]))
 
-(exception: .public (cannot_declare_tag_twice {module Text} {tag Text})
-  (exception.report
-   ["Module" module]
-   ["Tag" tag]))
-
 (template [<name>]
   [(exception: .public (<name> {tags (List Text)} {owner Type})
      (exception.report
@@ -51,7 +46,16 @@
                  (format "alias " (%.name alias))
                  
                  (#.Definition definition)
-                 (format "definition " (%.name name)))]))
+                 (format "definition " (%.name name))
+
+                 (#.Type _)
+                 (format "type " (%.name name))
+
+                 (#.Label _)
+                 (format "tag " (%.name name))
+
+                 (#.Slot _)
+                 (format "slot " (%.name name)))]))
 
 (exception: .public (can_only_change_state_of_active_module {module Text} {state Module_State})
   (exception.report
@@ -73,8 +77,6 @@
    #.module_aliases     (list)
    #.definitions        (list)
    #.imports            (list)
-   #.tags               (list)
-   #.types              (list)
    #.module_annotations #.None
    #.module_state       #.Active})
 
@@ -211,41 +213,20 @@
   [set_cached   cached?   #.Cached]
   )
 
-(template [<name> <tag> <type>]
-  [(def: (<name> module_name)
-     (-> Text (Operation <type>))
-     (///extension.lifted
-      (function (_ state)
-        (case (|> state (value@ #.modules) (plist.value module_name))
-          (#.Some module)
-          (#try.Success [state (value@ <tag> module)])
-
-          #.None
-          ((/.except' unknown_module module_name) state)))))]
+(def: (hash module_name)
+  (-> Text (Operation Nat))
+  (///extension.lifted
+   (function (_ state)
+     (case (|> state (value@ #.modules) (plist.value module_name))
+       (#.Some module)
+       (#try.Success [state (value@ #.module_hash module)])
 
-  [tags  #.tags        (List [Text [Nat (List Name) Bit Type]])]
-  [types #.types       (List [Text [(List Name) Bit Type]])]
-  [hash  #.module_hash Nat]
-  )
+       #.None
+       ((/.except' unknown_module module_name) state)))))
 
-(def: (ensure_undeclared_tags module_name tags)
-  (-> Text (List Tag) (Operation Any))
+(def: .public (declare_tags record? tags exported? type)
+  (-> Bit (List Tag) Bit Type (Operation Any))
   (do {! ///.monad}
-    [bindings (..tags module_name)
-     _ (monad.each !
-                   (function (_ tag)
-                     (case (plist.value tag bindings)
-                       #.None
-                       (in [])
-
-                       (#.Some _)
-                       (/.except ..cannot_declare_tag_twice [module_name tag])))
-                   tags)]
-    (in [])))
-
-(def: .public (declare_tags tags exported? type)
-  (-> (List Tag) Bit Type (Operation Any))
-  (do ///.monad
     [self_name (///extension.lifted meta.current_module_name)
      [type_module type_name] (case type
                                (#.Named type_name _)
@@ -253,23 +234,11 @@
 
                                _
                                (/.except ..cannot_declare_tags_for_unnamed_type [tags type]))
-     _ (ensure_undeclared_tags self_name tags)
      _ (///.assertion cannot_declare_tags_for_foreign_type [tags type]
                       (text\= self_name type_module))]
-    (///extension.lifted
-     (function (_ state)
-       (case (|> state (value@ #.modules) (plist.value self_name))
-         (#.Some module)
-         (let [namespaced_tags (list\each (|>> [self_name]) tags)]
-           (#try.Success [(revised@ #.modules
-                                    (plist.revised self_name
-                                                   (|>> (revised@ #.tags (function (_ tag_bindings)
-                                                                           (list\mix (function (_ [idx tag] table)
-                                                                                       (plist.has tag [idx namespaced_tags exported? type] table))
-                                                                                     tag_bindings
-                                                                                     (list.enumeration tags))))
-                                                        (revised@ #.types (plist.has type_name [namespaced_tags exported? type]))))
-                                    state)
-                          []]))
-         #.None
-         ((/.except' unknown_module self_name) state))))))
+    (monad.each ! (function (_ [index short])
+                    (..define (format "#" short)
+                              (if record?
+                                (#.Slot [exported? type tags index])
+                                (#.Label [exported? type tags index]))))
+                (list.enumeration tags))))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/reference.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/reference.lux
index 92a7a8f9c..d7d19e802 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/reference.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/reference.lux
@@ -29,16 +29,20 @@
   (exception.report
    ["Definition" (%.name definition)]))
 
+(exception: .public (labels_are_not_definitions {definition Name})
+  (exception.report
+   ["Label" (%.name definition)]))
+
 (def: (definition def_name)
   (-> Name (Operation Analysis))
   (with_expansions [<return> (in (|> def_name ///reference.constant #/.Reference))]
     (do {! ///.monad}
       [constant (///extension.lifted (meta.definition def_name))]
       (case constant
-        (#.Left real_def_name)
+        (#.Alias real_def_name)
         (definition real_def_name)
         
-        (#.Right [exported? actualT def_anns _])
+        (#.Definition [exported? actualT def_anns _])
         (do !
           [_ (//type.infer actualT)
            (^@ def_name [::module ::name]) (///extension.lifted (meta.normal def_name))
@@ -51,7 +55,28 @@
                 (if imported!
                   <return>
                   (/.except foreign_module_has_not_been_imported [current ::module])))
-              (/.except definition_has_not_been_exported def_name))))))))
+              (/.except definition_has_not_been_exported def_name))))
+
+        (#.Type [exported? value labels])
+        (do !
+          [_ (//type.infer .Type)
+           (^@ def_name [::module ::name]) (///extension.lifted (meta.normal def_name))
+           current (///extension.lifted meta.current_module_name)]
+          (if (text\= current ::module)
+            <return>
+            (if exported?
+              (do !
+                [imported! (///extension.lifted (meta.imported_by? ::module current))]
+                (if imported!
+                  <return>
+                  (/.except foreign_module_has_not_been_imported [current ::module])))
+              (/.except definition_has_not_been_exported def_name))))
+
+        (#.Label _)
+        (/.except labels_are_not_definitions [def_name])
+        
+        (#.Slot _)
+        (/.except labels_are_not_definitions [def_name])))))
 
 (def: (variable var_name)
   (-> Text (Operation (Maybe Analysis)))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux
index d3384588e..30da17c13 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux
@@ -876,13 +876,13 @@
                     (in [[super_name superT] (java/lang/Class::isAssignableFrom super_class target_class)])))
                 (case (java/lang/Class::getGenericSuperclass source_class)
                   (#.Some super)
-                  (list& super (array.list (java/lang/Class::getGenericInterfaces source_class)))
+                  (list& super (array.list #.None (java/lang/Class::getGenericInterfaces source_class)))
 
                   #.None
                   (if (java/lang/reflect/Modifier::isInterface (java/lang/Class::getModifiers source_class))
                     (#.Item (:as java/lang/reflect/Type (ffi.class_for java/lang/Object))
-                            (array.list (java/lang/Class::getGenericInterfaces source_class)))
-                    (array.list (java/lang/Class::getGenericInterfaces source_class)))))))
+                            (array.list #.None (java/lang/Class::getGenericInterfaces source_class)))
+                    (array.list #.None (java/lang/Class::getGenericInterfaces source_class)))))))
 
 (def: (inheritance_candidate_parents class_loader fromT target_class toT fromC)
   (-> java/lang/ClassLoader .Type (java/lang/Class java/lang/Object) .Type Code (Operation (List [[Text .Type] Bit])))
@@ -1092,7 +1092,7 @@
   (-> Aliasing (java/lang/Class java/lang/Object) Text Method_Style (List (Type Value)) java/lang/reflect/Method (Operation Bit))
   (do phase.monad
     [parameters (|> (java/lang/reflect/Method::getGenericParameterTypes method)
-                    array.list
+                    (array.list #.None)
                     (monad.each try.monad reflection!.type)
                     phase.lifted)
      .let [modifiers (java/lang/reflect/Method::getModifiers method)
@@ -1138,7 +1138,7 @@
   (-> Aliasing (java/lang/Class java/lang/Object) (List (Type Value)) (java/lang/reflect/Constructor java/lang/Object) (Operation Bit))
   (do phase.monad
     [parameters (|> (java/lang/reflect/Constructor::getGenericParameterTypes constructor)
-                    array.list
+                    (array.list #.None)
                     (monad.each try.monad reflection!.type)
                     phase.lifted)]
     (in (and (java/lang/Object::equals class (java/lang/reflect/Constructor::getDeclaringClass constructor))
@@ -1183,15 +1183,15 @@
 
                       _
                       (|> (java/lang/Class::getTypeParameters owner)
-                          array.list
+                          (array.list #.None)
                           (list\each (|>> java/lang/reflect/TypeVariable::getName))))
         method_tvars (|> (java/lang/reflect/Method::getTypeParameters method)
-                         array.list
+                         (array.list #.None)
                          (list\each (|>> java/lang/reflect/TypeVariable::getName)))
         [owner_tvarsT mapping] (jvm_type_var_mapping owner_tvars method_tvars)]
     (do {! phase.monad}
       [inputsT (|> (java/lang/reflect/Method::getGenericParameterTypes method)
-                   array.list
+                   (array.list #.None)
                    (monad.each ! (|>> reflection!.type phase.lifted))
                    (phase\each (monad.each ! (..reflection_type mapping)))
                    phase\conjoint)
@@ -1202,7 +1202,7 @@
                    (phase\each (..reflection_return mapping))
                    phase\conjoint)
        exceptionsT (|> (java/lang/reflect/Method::getGenericExceptionTypes method)
-                       array.list
+                       (array.list #.None)
                        (monad.each ! (|>> reflection!.type phase.lifted))
                        (phase\each (monad.each ! (..reflection_type mapping)))
                        phase\conjoint)
@@ -1223,20 +1223,20 @@
   (-> (java/lang/reflect/Constructor java/lang/Object) (Operation Method_Signature))
   (let [owner (java/lang/reflect/Constructor::getDeclaringClass constructor)
         owner_tvars (|> (java/lang/Class::getTypeParameters owner)
-                        array.list
+                        (array.list #.None)
                         (list\each (|>> java/lang/reflect/TypeVariable::getName)))
         method_tvars (|> (java/lang/reflect/Constructor::getTypeParameters constructor)
-                         array.list
+                         (array.list #.None)
                          (list\each (|>> java/lang/reflect/TypeVariable::getName)))
         [owner_tvarsT mapping] (jvm_type_var_mapping owner_tvars method_tvars)]
     (do {! phase.monad}
       [inputsT (|> (java/lang/reflect/Constructor::getGenericParameterTypes constructor)
-                   array.list
+                   (array.list #.None)
                    (monad.each ! (|>> reflection!.type phase.lifted))
                    (phase\each (monad.each ! (reflection_type mapping)))
                    phase\conjoint)
        exceptionsT (|> (java/lang/reflect/Constructor::getGenericExceptionTypes constructor)
-                       array.list
+                       (array.list #.None)
                        (monad.each ! (|>> reflection!.type phase.lifted))
                        (phase\each (monad.each ! (reflection_type mapping)))
                        phase\conjoint)
@@ -1270,7 +1270,7 @@
   [(def: <name>
      (-> <type> (List (Type Var)))
      (|>> <method>
-          array.list
+          (array.list #.None)
           (list\each (|>> java/lang/reflect/TypeVariable::getName jvm.var))))]
 
   [class_type_variables (java/lang/Class java/lang/Object) java/lang/Class::getTypeParameters]
@@ -1291,7 +1291,7 @@
      .let [expected_class_tvars (class_type_variables class)]
      candidates (|> class
                     java/lang/Class::getDeclaredMethods
-                    array.list
+                    (array.list #.None)
                     (list.only (|>> java/lang/reflect/Method::getName (text\= method_name)))
                     (monad.each ! (: (-> java/lang/reflect/Method (Operation Evaluation))
                                      (function (_ method)
@@ -1324,7 +1324,7 @@
      .let [expected_class_tvars (class_type_variables class)]
      candidates (|> class
                     java/lang/Class::getConstructors
-                    array.list
+                    (array.list #.None)
                     (monad.each ! (function (_ constructor)
                                     (do !
                                       [.let [expected_method_tvars (constructor_type_variables constructor)
@@ -1549,23 +1549,23 @@
      (-> (java/lang/Class java/lang/Object)
          (Try (List [Text (Type Method)])))
      (|>> java/lang/Class::getDeclaredMethods
-          array.list
+          (array.list #.None)
           <only>
           (monad.each try.monad
                       (function (_ method)
                         (do {! try.monad}
                           [.let [type_variables (|> (java/lang/reflect/Method::getTypeParameters method)
-                                                    array.list
+                                                    (array.list #.None)
                                                     (list\each (|>> java/lang/reflect/TypeVariable::getName
                                                                     jvm.var)))]
                            inputs (|> (java/lang/reflect/Method::getGenericParameterTypes method)
-                                      array.list
+                                      (array.list #.None)
                                       (monad.each ! reflection!.type))
                            return (|> method
                                       java/lang/reflect/Method::getGenericReturnType
                                       reflection!.return)
                            exceptions (|> (java/lang/reflect/Method::getGenericExceptionTypes method)
-                                          array.list
+                                          (array.list #.None)
                                           (monad.each ! reflection!.class))]
                           (in [(java/lang/reflect/Method::getName method)
                                (jvm.method [type_variables inputs return exceptions])]))))))]
@@ -2066,7 +2066,7 @@
     [.let [[name actual_parameters] (jvm_parser.read_class class)]
      class (phase.lifted (reflection!.load class_loader name))
      .let [expected_parameters (|> (java/lang/Class::getTypeParameters class)
-                                   array.list
+                                   (array.list #.None)
                                    (list\each (|>> java/lang/reflect/TypeVariable::getName)))]
      _ (phase.assertion ..class_parameter_mismatch [expected_parameters actual_parameters]
                         (n.= (list.size expected_parameters)
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/lux.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/lux.lux
index 7952434ee..278447d11 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/lux.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/lux.lux
@@ -199,6 +199,10 @@
         (typeA.with_type input
           (phase archive valueC))))]))
 
+(exception: .public (not_a_type {symbol Name})
+  (exception.report
+   ["Symbol" (%.name symbol)]))
+
 (def: lux::macro
   Handler
   (..custom
@@ -210,9 +214,14 @@
                       (do !
                         [input_type (///.lifted (meta.definition (name_of .Macro')))]
                         (case input_type
-                          (#.Definition [exported? def_type def_data def_value])
+                          (^or (#.Definition [exported? def_type def_data def_value])
+                               (#.Type [exported? def_value labels]))
                           (in (:as Type def_value))
 
+                          (^or (#.Label _)
+                               (#.Slot _))
+                          (////.failure (exception.error ..not_a_type [(name_of .Macro')]))
+
                           (#.Alias real_name)
                           (recur real_name))))]
         (typeA.with_type input_type
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/directive/lux.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/directive/lux.lux
index c805124dd..f2ffaccae 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/directive/lux.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/directive/lux.lux
@@ -228,7 +228,7 @@
          [_ _ exported?] (evaluate! archive Bit exported?C)
          [_ _ annotations] (evaluate! archive Code annotationsC)
          _ (/////directive.lifted_analysis
-            (module.define short_name (#.Right [(:as Bit exported?) type (:as Code annotations) value])))
+            (module.define short_name (#.Definition [(:as Bit exported?) type (:as Code annotations) value])))
          _ (..refresh expander host_analysis)
          _ (..announce_definition! short_name type)]
         (in /////directive.no_requirements))
@@ -236,7 +236,7 @@
       _
       (phase.except ///.invalid_syntax [extension_name %.code inputsC+]))))
 
-(def: (announce_tags! tags owner)
+(def: (announce_labels! tags owner)
   (All (_ anchor expression directive)
     (-> (List Text) Type (Operation anchor expression directive (List Any))))
   (/////directive.lifted_generation
@@ -247,8 +247,11 @@
 (def: (def::type_tagged expander host_analysis)
   (-> Expander /////analysis.Bundle Handler)
   (..custom
-   [($_ <>.and <code>.local_identifier <code>.any <code>.any (<code>.tuple (<>.some <code>.text)) <code>.any)
-    (function (_ extension_name phase archive [short_name valueC annotationsC tags exported?C])
+   [($_ <>.and <code>.local_identifier <code>.any <code>.any
+        (<>.or (<code>.form (<>.some <code>.text))
+               (<code>.tuple (<>.some <code>.text)))
+        <code>.any)
+    (function (_ extension_name phase archive [short_name valueC annotationsC labels exported?C])
       (do phase.monad
         [current_module (/////directive.lifted_analysis
                          (///.lifted meta.current_module_name))
@@ -258,13 +261,27 @@
          .let [exported? (:as Bit exported?)
                annotations (:as Code annotations)]
          [type valueT value] (..definition archive full_name (#.Some .Type) valueC)
-         _ (/////directive.lifted_analysis
-            (do phase.monad
-              [_ (module.define short_name (#.Right [exported? type annotations value]))]
-              (module.declare_tags tags exported? (:as Type value))))
+         labels (/////directive.lifted_analysis
+                 (do phase.monad
+                   [.let [[record? labels] (case labels
+                                             (#.Left tags)
+                                             [false tags]
+                                             
+                                             (#.Right slots)
+                                             [true slots])]
+                    _ (case labels
+                        #.End
+                        (module.define short_name (#.Definition [exported? type annotations value]))
+
+                        (#.Item labels)
+                        (module.define short_name (#.Type [exported? (:as .Type value) (if record?
+                                                                                         (#.Right labels)
+                                                                                         (#.Left labels))])))
+                    _ (module.declare_tags record? labels exported? (:as .Type value))]
+                   (in labels)))
          _ (..refresh expander host_analysis)
          _ (..announce_definition! short_name type)
-         _ (..announce_tags! tags (:as Type value))]
+         _ (..announce_labels! labels (:as Type value))]
         (in /////directive.no_requirements)))]))
 
 (def: imports
@@ -300,17 +317,27 @@
    ["Foreign alias" (%.name foreign)]
    ["Target definition" (%.name target)]))
 
+(exception: .public (cannot_alias_a_label {local Alias} {foreign Alias})
+  (exception.report
+   ["Alias" (%.name local)]
+   ["Label" (%.name foreign)]))
+
 (def: (define_alias alias original)
   (-> Text Name (/////analysis.Operation Any))
   (do phase.monad
     [current_module (///.lifted meta.current_module_name)
      constant (///.lifted (meta.definition original))]
     (case constant
-      (#.Left de_aliased)
+      (#.Alias de_aliased)
       (phase.except ..cannot_alias_an_alias [[current_module alias] original de_aliased])
       
-      (#.Right [exported? original_type original_annotations original_value])
-      (module.define alias (#.Left original)))))
+      (^or (#.Definition _)
+           (#.Type _))
+      (module.define alias (#.Alias original))
+
+      (^or (#.Label _)
+           (#.Slot _))
+      (phase.except ..cannot_alias_a_label [[current_module alias] original]))))
 
 (def: def::alias
   Handler
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/jvm/runtime.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/jvm/runtime.lux
index d99cfca3d..54c3ac8ba 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/jvm/runtime.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/jvm/runtime.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- Type Definition case false true try)
+   [lux (#- Type Definition Label case false true try)
     [abstract
      ["." monad (#+ do)]
      ["." enum]]
diff --git a/stdlib/source/library/lux/tool/compiler/meta/io/archive.lux b/stdlib/source/library/lux/tool/compiler/meta/io/archive.lux
index 25b9ec0b4..a2b2908b3 100644
--- a/stdlib/source/library/lux/tool/compiler/meta/io/archive.lux
+++ b/stdlib/source/library/lux/tool/compiler/meta/io/archive.lux
@@ -323,8 +323,12 @@
      content (document.read $.key document)
      definitions (monad.each ! (function (_ [def_name def_global])
                                  (case def_global
-                                   (#.Alias alias)
-                                   (in [def_name (#.Alias alias)])
+                                   (^template [<tag>]
+                                     [(<tag> payload)
+                                      (in [def_name (<tag> payload)])])
+                                   ([#.Alias]
+                                    [#.Label]
+                                    [#.Slot])
                                    
                                    (#.Definition [exported? type annotations _])
                                    (|> definitions
@@ -332,7 +336,14 @@
                                        try.of_maybe
                                        (\ ! each (|>> [exported? type annotations]
                                                       #.Definition
-                                                      [def_name])))))
+                                                      [def_name])))
+
+                                   (#.Type [exported? _ labels])
+                                   (|> definitions
+                                       (dictionary.value def_name)
+                                       try.of_maybe
+                                       (\ ! each (function (_ def_value)
+                                                   [def_name (#.Type [exported? (:as .Type def_value) labels])])))))
                              (value@ #.definitions content))]
     (in [(document.write $.key (with@ #.definitions definitions content))
          bundles])))
diff --git a/stdlib/source/library/lux/type/abstract.lux b/stdlib/source/library/lux/type/abstract.lux
index 837f6ba11..9a0edab98 100644
--- a/stdlib/source/library/lux/type/abstract.lux
+++ b/stdlib/source/library/lux/type/abstract.lux
@@ -60,11 +60,14 @@
   (-> Text (List [Text Global]) (Stack Frame))
   (!peek source reference
          (case head
-           (#.Left _)
-           (undefined)
+           (#.Definition [exported? frame_type frame_anns frame_value])
+           (:as (Stack Frame) frame_value)
 
-           (#.Right [exported? frame_type frame_anns frame_value])
-           (:as (Stack Frame) frame_value))))
+           (^or (#.Type _)
+                (#.Alias _)
+                (#.Label _)
+                (#.Slot _))
+           (undefined))))
 
 (def: (peek_frames reference definition_reference source)
   (-> Text Text (List [Text Module]) (Stack Frame))
@@ -117,14 +120,17 @@
   (-> Text Frame (List [Text Global]) (List [Text Global]))
   (!push source reference
          (case head
-           (#.Left _)
-           (undefined)
-
-           (#.Right [exported? frames_type frames_anns frames_value])
-           (#.Right [exported?
-                     frames_type
-                     frames_anns
-                     (..push frame (:as (Stack Frame) frames_value))]))))
+           (#.Definition [exported? frames_type frames_anns frames_value])
+           (#.Definition [exported?
+                          frames_type
+                          frames_anns
+                          (..push frame (:as (Stack Frame) frames_value))])
+
+           (^or (#.Type _)
+                (#.Alias _)
+                (#.Label _)
+                (#.Slot _))
+           (undefined))))
 
 (def: (push_frame [module_reference definition_reference] frame source)
   (-> Name Frame (List [Text Module]) (List [Text Module]))
@@ -143,20 +149,23 @@
   (-> Text (List [Text Global]) (List [Text Global]))
   (!push source reference
          (case head
-           (#.Left _)
-           (undefined)
-
-           (#.Right [exported? frames_type frames_anns frames_value])
-           (#.Right [exported?
-                     frames_type
-                     frames_anns
-                     (let [current_frames (:as (Stack Frame) frames_value)]
-                       (case (..pop current_frames)
-                         (#.Some current_frames')
-                         current_frames'
-
-                         #.None
-                         current_frames))]))))
+           (#.Definition [exported? frames_type frames_anns frames_value])
+           (#.Definition [exported?
+                          frames_type
+                          frames_anns
+                          (let [current_frames (:as (Stack Frame) frames_value)]
+                            (case (..pop current_frames)
+                              (#.Some current_frames')
+                              current_frames'
+
+                              #.None
+                              current_frames))])
+
+           (^or (#.Type _)
+                (#.Alias _)
+                (#.Label _)
+                (#.Slot _))
+           (undefined))))
 
 (def: (pop_frame [module_reference definition_reference] source)
   (-> Name (List [Text Module]) (List [Text Module]))
diff --git a/stdlib/source/test/lux/macro.lux b/stdlib/source/test/lux/macro.lux
index 2e8c199b4..fa117e96b 100644
--- a/stdlib/source/test/lux/macro.lux
+++ b/stdlib/source/test/lux/macro.lux
@@ -79,8 +79,6 @@
                                                                   (!global /.log_expansion!)
                                                                   (!global /.log_full_expansion!)))
                                     #.imports            (list)
-                                    #.tags               (list)
-                                    #.types              (list)
                                     #.module_annotations #.None
                                     #.module_state       #.Active}]
                                   [current_module
@@ -91,8 +89,6 @@
                                                                   (!global ..pow/4)
                                                                   (!global ..repeated)))
                                     #.imports            (list)
-                                    #.tags               (list)
-                                    #.types              (list)
                                     #.module_annotations #.None
                                     #.module_state       #.Active}])
           #.scopes          (list)
diff --git a/stdlib/source/test/lux/meta.lux b/stdlib/source/test/lux/meta.lux
index 7d397e5d5..9e0175947 100644
--- a/stdlib/source/test/lux/meta.lux
+++ b/stdlib/source/test/lux/meta.lux
@@ -183,16 +183,12 @@
                             #.module_aliases     (list)
                             #.definitions        (list)
                             #.imports            (list)
-                            #.tags               (list)
-                            #.types              (list)
                             #.module_annotations #.None
                             #.module_state       #.Active}
            expected_module {#.module_hash        0
                             #.module_aliases     (list)
                             #.definitions        (list)
                             #.imports            (list imported_module_name)
-                            #.tags               (list)
-                            #.types              (list)
                             #.module_annotations #.None
                             #.module_state       #.Active}
            expected_modules (list [expected_current_module
@@ -384,8 +380,6 @@
                                               #.module_aliases     (list)
                                               #.definitions        current_globals
                                               #.imports            (list)
-                                              #.tags               (list)
-                                              #.types              (list)
                                               #.module_annotations #.None
                                               #.module_state       #.Active}]
                                             [expected_macro_module
@@ -393,8 +387,6 @@
                                               #.module_aliases     (list)
                                               #.definitions        macro_globals
                                               #.imports            (list)
-                                              #.tags               (list)
-                                              #.types              (list)
                                               #.module_annotations #.None
                                               #.module_state       #.Active}])
                     #.scopes          (list)
@@ -506,8 +498,6 @@
                                               #.module_aliases     (list)
                                               #.definitions        current_globals
                                               #.imports            (list)
-                                              #.tags               (list)
-                                              #.types              (list)
                                               #.module_annotations #.None
                                               #.module_state       #.Active}]
                                             [expected_macro_module
@@ -515,8 +505,6 @@
                                               #.module_aliases     (list)
                                               #.definitions        macro_globals
                                               #.imports            (list)
-                                              #.tags               (list)
-                                              #.types              (list)
                                               #.module_annotations #.None
                                               #.module_state       #.Active}])
                     #.scopes          (list)
@@ -655,19 +643,22 @@
                          (random.ascii/upper 1))
      
      .let [random_tag (\ ! each (|>> [tag_module])
-                         (random.ascii/upper 1))]
-     all_tags (|> random_tag
-                  (random.set name.hash 10)
-                  (\ ! each set.list))
-     .let [tags_0 (list.first 5 all_tags)
-           tags_1 (list.after 5 all_tags)
-
-           type_0 (#.Primitive name_0 (list))
+                         (random.ascii/upper 1))
+           random_labels (: (Random [Text (List Text)])
+                            (do !
+                              [head (random.ascii/lower 5)]
+                              (|> (random.ascii/lower 5)
+                                  (random.only (|>> (text\= head) not))
+                                  (random.set text.hash 3)
+                                  (\ ! each set.list)
+                                  (random.and (in head)))))]
+     tags_0 random_labels
+     tags_1 (let [set/0 (set.of_list text.hash (#.Item tags_0))]
+              (random.only (|>> #.Item (list.any? (set.member? set/0))not)
+                           random_labels))
+     .let [type_0 (#.Primitive name_0 (list))
            type_1 (#.Primitive name_1 (list))
            
-           entry_0 [name_0 [tags_0 false type_0]]
-           entry_1 [name_1 [tags_1 true type_1]]
-
            expected_lux
            (: Lux
               {#.info            {#.target  ""
@@ -681,24 +672,23 @@
                                          #.module_aliases     (list)
                                          #.definitions        (list)
                                          #.imports            (list tag_module)
-                                         #.tags               (list)
-                                         #.types              (list)
                                          #.module_annotations #.None
                                          #.module_state       #.Active}]
                                        [tag_module
                                         {#.module_hash        0
                                          #.module_aliases     (list)
-                                         #.definitions        (list)
+                                         #.definitions        (list& [name_0 (#.Type [false type_0 (#.Left tags_0)])]
+                                                                     [name_1 (#.Type [true type_1 (#.Right tags_1)])]
+                                                                     ($_ list\composite
+                                                                         (|> (#.Item tags_0)
+                                                                             list.enumeration
+                                                                             (list\each (function (_ [index short])
+                                                                                          [(format "#" short) (#.Label [false type_0 (#.Item tags_0) index])])))
+                                                                         (|> (#.Item tags_1)
+                                                                             list.enumeration
+                                                                             (list\each (function (_ [index short])
+                                                                                          [(format "#" short) (#.Slot [true type_1 (#.Item tags_1) index])])))))
                                          #.imports            (list)
-                                         #.tags               (list\composite (|> tags_0
-                                                                                  list.enumeration
-                                                                                  (list\each (function (_ [index [_ short]])
-                                                                                               [short [index tags_0 false type_0]])))
-                                                                              (|> tags_1
-                                                                                  list.enumeration
-                                                                                  (list\each (function (_ [index [_ short]])
-                                                                                               [short [index tags_1 true type_1]]))))
-                                         #.types              (list entry_0 entry_1)
                                          #.module_annotations #.None
                                          #.module_state       #.Active}])
                #.scopes          (list)
@@ -719,28 +709,29 @@
                                      type.equivalence))]
                    (|> (/.tag_lists tag_module)
                        (/.result expected_lux)
-                       (try\each (\ equivalence = (list [tags_1 type_1])))
+                       (try\each (\ equivalence = (list [(list\each (|>> [tag_module]) (#.Item tags_1))
+                                                         type_1])))
                        (try.else false))))
         (_.cover [/.tags_of]
                  (|> (/.tags_of [tag_module name_1])
                      (/.result expected_lux)
-                     (try\each (\ (maybe.equivalence (list.equivalence name.equivalence)) = (#.Some tags_1)))
+                     (try\each (\ (maybe.equivalence (list.equivalence name.equivalence)) = (#.Some (list\each (|>> [tag_module]) (#.Item tags_1)))))
                      (try.else false)))
         (_.cover [/.tag]
-                 (|> tags_1
+                 (|> (#.Item tags_1)
                      list.enumeration
                      (list.every? (function (_ [expected_index tag])
-                                    (|> tag
+                                    (|> [tag_module tag]
                                         /.tag
                                         (/.result expected_lux)
-                                        (!expect (^multi (^ (#try.Success [actual_index actual_tags actual_type]))
+                                        (!expect (^multi (#try.Success [actual_index actual_tags actual_type])
                                                          (let [correct_index!
                                                                (n.= expected_index
                                                                     actual_index)
 
                                                                correct_tags!
                                                                (\ (list.equivalence name.equivalence) =
-                                                                  tags_1
+                                                                  (list\each (|>> [tag_module]) (#.Item tags_1))
                                                                   actual_tags)
 
                                                                correct_type!
@@ -748,7 +739,8 @@
                                                                        actual_type)]
                                                            (and correct_index!
                                                                 correct_tags!
-                                                                correct_type!)))))))))
+                                                                correct_type!))))
+                                        )))))
         )))
 
 (def: locals_related
@@ -807,8 +799,6 @@
                                          #.module_aliases     (list)
                                          #.definitions        globals
                                          #.imports            (list)
-                                         #.tags               (list)
-                                         #.types              (list)
                                          #.module_annotations #.None
                                          #.module_state       #.Active}])
                #.scopes          scopes
diff --git a/stdlib/source/test/lux/target/jvm.lux b/stdlib/source/test/lux/target/jvm.lux
index 9494096f2..6dd299f2c 100644
--- a/stdlib/source/test/lux/target/jvm.lux
+++ b/stdlib/source/test/lux/target/jvm.lux
@@ -1,6 +1,6 @@
 (.module:
   [library
-   [lux (#- Type type primitive int)
+   [lux (#- Type Label type primitive int)
     ["." ffi (#+ import:)]
     ["@" target]
     [abstract