Implemented an optimization for getting fields/slots from records in the new compiler.

21 files changed, 482 insertions, 208 deletions

diff --git a/stdlib/source/lux/tool/compiler/language/lux/analysis.lux b/stdlib/source/lux/tool/compiler/language/lux/analysis.lux
index 27bc09652..c9bc95612 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/analysis.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/analysis.lux
@@ -1,6 +1,7 @@
 (.module:
   [lux (#- nat int rev)
    [abstract
+    [equivalence (#+ Equivalence)]
     [monad (#+ do)]]
    [control
     ["." function]
@@ -9,8 +10,12 @@
    [data
     ["." product]
     ["." maybe]
+    ["." bit ("#@." equivalence)]
     [number
-     ["n" nat]]
+     ["n" nat]
+     ["i" int]
+     ["r" rev]
+     ["f" frac]]
     ["." text ("#@." equivalence)
      ["%" format (#+ Format format)]]
     [collection
@@ -21,7 +26,8 @@
    [///
     [arity (#+ Arity)]
     [version (#+ Version)]
-    ["." reference (#+ Register Variable Reference)]
+    ["." reference (#+ Reference)
+     ["." variable (#+ Register Variable)]]
     ["." phase]]])
 
 (type: #export #rec Primitive
@@ -76,6 +82,103 @@
 (type: #export Match
   (Match' Analysis))
 
+(structure: primitive-equivalence
+  (Equivalence Primitive)
+
+  (def: (= reference sample)
+    (case [reference sample]
+      [#Unit #Unit]
+      true
+      
+      (^template [<tag> <=>]
+        [(<tag> reference) (<tag> sample)]
+        (<=> reference sample))
+      ([#Bit bit@=]
+       [#Nat n.=]
+       [#Int i.=]
+       [#Rev r.=]
+       [#Frac f.=]
+       [#Text text@=])
+      
+      _
+      false)))
+
+(structure: (composite-equivalence (^open "/@."))
+  (All [a] (-> (Equivalence a) (Equivalence (Composite a))))
+  
+  (def: (= reference sample)
+    (case [reference sample]
+      [(#Variant [reference-lefts reference-right? reference-value])
+       (#Variant [sample-lefts sample-right? sample-value])]
+      (and (n.= reference-lefts sample-lefts)
+           (bit@= reference-right? sample-right?)
+           (/@= reference-value sample-value))
+      
+      [(#Tuple reference) (#Tuple sample)]
+      (:: (list.equivalence /@=) = reference sample)
+
+      _
+      false)))
+
+(structure: pattern-equivalence
+  (Equivalence Pattern)
+
+  (def: (= reference sample)
+    (case [reference sample]
+      [(#Simple reference) (#Simple sample)]
+      (:: primitive-equivalence = reference sample)
+      
+      [(#Complex reference) (#Complex sample)]
+      (:: (composite-equivalence =) = reference sample)
+
+      [(#Bind reference) (#Bind sample)]
+      (n.= reference sample)
+
+      _
+      false)))
+
+(structure: (branch-equivalence equivalence)
+  (-> (Equivalence Analysis) (Equivalence Branch))
+
+  (def: (= [reference-pattern reference-body] [sample-pattern sample-body])
+    (and (:: pattern-equivalence = reference-pattern sample-pattern)
+         (:: equivalence = reference-body sample-body))))
+
+(structure: #export equivalence
+  (Equivalence Analysis)
+
+  (def: (= reference sample)
+    (case [reference sample]
+      [(#Primitive reference) (#Primitive sample)]
+      (:: primitive-equivalence = reference sample)
+
+      [(#Structure reference) (#Structure sample)]
+      (:: (composite-equivalence =) = reference sample)
+
+      [(#Reference reference) (#Reference sample)]
+      (:: reference.equivalence = reference sample)
+
+      [(#Case [reference-analysis reference-match])
+       (#Case [sample-analysis sample-match])]
+      (and (= reference-analysis sample-analysis)
+           (:: (list.equivalence (branch-equivalence =)) = (#.Cons reference-match) (#.Cons sample-match)))
+
+      [(#Function [reference-environment reference-analysis])
+       (#Function [sample-environment sample-analysis])]
+      (and (= reference-analysis sample-analysis)
+           (:: (list.equivalence variable.equivalence) = reference-environment sample-environment))
+
+      [(#Apply [reference-input reference-abstraction])
+       (#Apply [sample-input sample-abstraction])]
+      (and (= reference-input sample-input)
+           (= reference-abstraction sample-abstraction))
+
+      [(#Extension reference) (#Extension sample)]
+      (:: (extension.equivalence =) = reference sample)
+
+      _
+      false)))
+
 (template [<name> <tag>]
   [(template: #export (<name> content)
      (<tag> content))]
@@ -104,7 +207,7 @@
   (n.= (dec size) tag))
 
 (template: #export (no-op value)
-  (|> 1 #reference.Local #reference.Variable #..Reference
+  (|> 1 #variable.Local #reference.Variable #..Reference
       (#..Function (list))
       (#..Apply value)))
 
@@ -207,12 +310,7 @@
           (text.enclose ["[" "]"])))
     
     (#Reference reference)
-    (case reference
-      (#reference.Variable variable)
-      (reference.%variable variable)
-      
-      (#reference.Constant constant)
-      (%.name constant))
+    (reference.format reference)
     
     (#Case analysis match)
     "{?}"
@@ -221,7 +319,7 @@
     (|> (%analysis body)
         (format " ")
         (format (|> environment
-                    (list@map reference.%variable)
+                    (list@map variable.format)
                     (text.join-with " ")
                     (text.enclose ["[" "]"])))
         (text.enclose ["(" ")"]))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/scope.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/scope.lux
index d68d3fed7..ffa635109 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/scope.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/scope.lux
@@ -18,7 +18,8 @@
    [//
     ["/" analysis (#+ Operation Phase)]
     [///
-     ["." reference (#+ Register Variable)]
+     [reference
+      ["." variable (#+ Register Variable)]]
      ["#" phase]]]])
 
 (type: Local (Bindings Text [Type Register]))
@@ -36,7 +37,7 @@
       (get@ [#.locals #.mappings])
       (plist.get name)
       (maybe@map (function (_ [type value])
-                   [type (#reference.Local value)]))))
+                   [type (#variable.Local value)]))))
 
 (def: (captured? name scope)
   (-> Text Scope Bit)
@@ -51,7 +52,7 @@
     (case mappings
       (#.Cons [_name [_source-type _source-ref]] mappings')
       (if (text@= name _name)
-        (#.Some [_source-type (#reference.Foreign idx)])
+        (#.Some [_source-type (#variable.Foreign idx)])
         (recur (inc idx) mappings'))
 
       #.Nil
@@ -87,7 +88,7 @@
                                                   (..reference name top-outer))
                [ref inner'] (list@fold (: (-> Scope [Variable (List Scope)] [Variable (List Scope)])
                                           (function (_ scope ref+inner)
-                                            [(#reference.Foreign (get@ [#.captured #.counter] scope))
+                                            [(#variable.Foreign (get@ [#.captured #.counter] scope))
                                              (#.Cons (update@ #.captured
                                                               (: (-> Foreign Foreign)
                                                                  (|>> (update@ #.counter inc)
@@ -101,11 +102,8 @@
                      (#.Some [ref-type ref])]))
          )))))
 
-(exception: #export (cannot-create-local-binding-without-a-scope)
-  "")
-
-(exception: #export (invalid-scope-alteration)
-  "")
+(exception: #export cannot-create-local-binding-without-a-scope)
+(exception: #export invalid-scope-alteration)
 
 (def: #export (with-local [name type] action)
   (All [a] (-> [Text Type] (Operation a) (Operation a)))
@@ -195,10 +193,10 @@
   (-> Ref Variable)
   (case ref
     (#.Local register)
-    (#reference.Local register)
+    (#variable.Local register)
     
     (#.Captured register)
-    (#reference.Foreign register)))
+    (#variable.Foreign register)))
 
 (def: #export (environment scope)
   (-> Scope (List Variable))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension.lux
index 8498c0321..2cc5c42b8 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension.lux
@@ -1,6 +1,7 @@
 (.module:
   [lux (#- Name)
    [abstract
+    [equivalence (#+ Equivalence)]
     ["." monad (#+ do)]]
    [control
     ["." function]
@@ -19,8 +20,15 @@
 
 (type: #export Name Text)
 
-(type: #export (Extension i)
-  [Name (List i)])
+(type: #export (Extension a)
+  [Name (List a)])
+
+(structure: #export (equivalence input-equivalence)
+  (All [a] (-> (Equivalence a) (Equivalence (Extension a))))
+
+  (def: (= [reference-name reference-inputs] [sample-name sample-inputs])
+    (and (text@= reference-name sample-name)
+         (:: (list.equivalence input-equivalence) = reference-inputs sample-inputs))))
 
 (with-expansions [<Bundle> (as-is (Dictionary Name (Handler s i o)))]
   (type: #export (Handler s i o)
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/jvm/host.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/jvm/host.lux
index 026b31c70..005563f1a 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/jvm/host.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/jvm/host.lux
@@ -63,7 +63,8 @@
      ["#." generation]
      [///
       ["#" phase]
-      ["#." reference (#+ Variable)]
+      [reference (#+)
+       ["#." variable (#+ Variable)]]
       [meta
        ["." archive (#+ Archive)]]]]]])
 
@@ -897,6 +898,9 @@
       (^ (//////synthesis.branch/if [testS thenS elseS]))
       (//////synthesis.branch/if [(recur testS) (recur thenS) (recur elseS)])
 
+      (^ (//////synthesis.branch/get [path recordS]))
+      (//////synthesis.branch/get [path (recur recordS)])
+
       (^ (//////synthesis.loop/scope [offset initsS+ bodyS]))
       (//////synthesis.loop/scope [offset (list@map recur initsS+) (recur bodyS)])
 
@@ -1006,14 +1010,14 @@
                                      ## Combine them.
                                      list@join
                                      ## Remove duplicates.
-                                     (set.from-list //////reference.hash)
+                                     (set.from-list //////variable.hash)
                                      set.to-list)
                global-mapping (|> total-environment
                                   ## Give them names as "foreign" variables.
                                   list.enumerate
                                   (list@map (function (_ [id capture])
-                                              [capture (#//////reference.Foreign id)]))
-                                  (dictionary.from-list //////reference.hash))
+                                              [capture (#//////variable.Foreign id)]))
+                                  (dictionary.from-list //////variable.hash))
                normalized-methods (list@map (function (_ [environment
                                                           [ownerT name
                                                            strict-fp? annotations vars
@@ -1022,11 +1026,11 @@
                                               (let [local-mapping (|> environment
                                                                       list.enumerate
                                                                       (list@map (function (_ [foreign-id capture])
-                                                                                  [(#//////reference.Foreign foreign-id)
+                                                                                  [(#//////variable.Foreign foreign-id)
                                                                                    (|> global-mapping
                                                                                        (dictionary.get capture)
                                                                                        maybe.assume)]))
-                                                                      (dictionary.from-list //////reference.hash))]
+                                                                      (dictionary.from-list //////variable.hash))]
                                                 [ownerT name
                                                  strict-fp? annotations vars
                                                  self-name arguments returnT exceptionsT
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm.lux
index b552f16d5..5ede5f926 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm.lux
@@ -53,6 +53,9 @@
     (^ (synthesis.branch/if [conditionS thenS elseS]))
     (/case.if generate archive [conditionS thenS elseS])
 
+    (^ (synthesis.branch/get [path recordS]))
+    (/case.get generate archive [path recordS])
+
     (^ (synthesis.loop/scope scope))
     (/loop.scope generate archive scope)
 
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/case.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/case.lux
index 9abfe1f55..0d94ac026 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/case.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/case.lux
@@ -7,7 +7,9 @@
    [data
     [number
      ["." i32]
-     ["n" nat]]]
+     ["n" nat]]
+    [collection
+     ["." list ("#@." fold)]]]
    [target
     [jvm
      ["_" bytecode (#+ Label Bytecode) ("#@." monad)]
@@ -21,8 +23,9 @@
     ["." synthesis (#+ Path Synthesis)]
     ["." generation]
     [///
-     [reference (#+ Register)]
-     ["." phase ("operation@." monad)]]]])
+     ["." phase ("operation@." monad)]
+     [reference
+      [variable (#+ Register)]]]]])
 
 (def: equals-name
   "equals")
@@ -65,6 +68,25 @@
       (//runtime.get //runtime.stack-tail)
       (_.checkcast //type.stack)))
 
+(def: (left-projection lefts)
+  (-> Nat (Bytecode Any))
+  ($_ _.compose
+      (_.checkcast //type.tuple)
+      (..int lefts)
+      (.case lefts
+        0
+        _.aaload
+        
+        lefts
+        //runtime.left-projection)))
+
+(def: (right-projection lefts)
+  (-> Nat (Bytecode Any))
+  ($_ _.compose
+      (_.checkcast //type.tuple)
+      (..int lefts)
+      //runtime.right-projection))
+
 (def: (path' stack-depth @else @end phase archive path)
   (-> Nat Label Label (Generator Path))
   (.case path
@@ -138,25 +160,15 @@
      [synthesis.side/right //runtime.right-flag .inc])
 
     (^ (synthesis.member/left lefts))
-    (operation@wrap (.let [optimized-projection (.case lefts
-                                                  0
-                                                  _.aaload
-                                                  
-                                                  lefts
-                                                  //runtime.left-projection)]
-                      ($_ _.compose
-                          ..peek
-                          (_.checkcast //type.tuple)
-                          (..int lefts)
-                          optimized-projection
-                          //runtime.push)))
+    (operation@wrap ($_ _.compose
+                        ..peek
+                        (..left-projection lefts)
+                        //runtime.push))
 
     (^ (synthesis.member/right lefts))
     (operation@wrap ($_ _.compose
                         ..peek
-                        (_.checkcast //type.tuple)
-                        (..int lefts)
-                        //runtime.right-projection
+                        (..right-projection lefts)
                         //runtime.push))
     
     ## Extra optimization
@@ -253,6 +265,21 @@
               (_.astore register)
               bodyG))))
 
+(def: #export (get phase archive [path recordS])
+  (Generator [(List synthesis.Member) Synthesis])
+  (do phase.monad
+    [recordG (phase archive recordS)]
+    (wrap (list@fold (function (_ step so-far)
+                       (.let [next (.case step
+                                     (#.Left lefts)
+                                     (..left-projection lefts)
+                                     
+                                     (#.Right lefts)
+                                     (..right-projection lefts))]
+                         (_.compose so-far next)))
+                     recordG
+                     path))))
+
 (def: #export (case phase archive [valueS path])
   (Generator [Synthesis Path])
   (do phase.monad
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function.lux
index 788919379..4359d7815 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function.lux
@@ -52,9 +52,10 @@
      [synthesis (#+ Synthesis Abstraction Apply)]
      ["." generation]
      [///
-      [reference (#+ Register)]
       ["." arity (#+ Arity)]
-      ["." phase]]]]])
+      ["." phase]
+      [reference
+       [variable (#+ Register)]]]]]])
 
 (def: #export (with archive @begin class environment arity body)
   (-> Archive Label External Environment Arity (Bytecode Any)
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable.lux
index c491039b9..13865b17e 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable.lux
@@ -17,7 +17,8 @@
    ["#." type]
    ["#." reference]
    [//////
-    [reference (#+ Register)]]])
+    [reference
+     [variable (#+ Register)]]]])
 
 (def: #export type ////type.value)
 
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable/foreign.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable/foreign.lux
index b9e97ddfd..14b4f6cab 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable/foreign.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable/foreign.lux
@@ -18,7 +18,8 @@
     [////
      [analysis (#+ Environment)]
      [///
-      [reference (#+ Register)]]]]])
+      [reference
+       [variable (#+ Register)]]]]]])
 
 (def: #export (closure environment)
   (-> Environment (List (Type Value)))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable/partial.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable/partial.lux
index b44cb4102..57271de30 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable/partial.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/field/variable/partial.lux
@@ -25,8 +25,9 @@
      ["//#" /// #_
       ["#." reference]
       [//////
-       [reference (#+ Register)]
-       ["." arity (#+ Arity)]]]]]])
+       ["." arity (#+ Arity)]
+       [reference
+        [variable (#+ Register)]]]]]]])
 
 (def: #export (initial amount)
   (-> Nat (Bytecode Any))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/apply.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/apply.lux
index 592c798ec..cafb6ceeb 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/apply.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/apply.lux
@@ -42,7 +42,8 @@
       [analysis (#+ Environment)]
       [///
        [arity (#+ Arity)]
-       ["." reference (#+ Register)]]]]]])
+       [reference
+        [variable (#+ Register)]]]]]]])
 
 (def: (increment by)
   (-> Nat (Bytecode Any))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/init.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/init.lux
index 5c39bd145..cf1ad20df 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/init.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/init.lux
@@ -35,8 +35,9 @@
      [////
       [analysis (#+ Environment)]
       [///
-       [reference (#+ Register)]
-       ["." arity (#+ Arity)]]]]]])
+       ["." arity (#+ Arity)]
+       [reference
+        [variable (#+ Register)]]]]]]])
 
 (def: #export name "<init>")
 
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/loop.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/loop.lux
index 5e07ea35a..0f79b6e86 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/loop.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/loop.lux
@@ -20,8 +20,9 @@
     ["." synthesis (#+ Path Synthesis)]
     ["." generation]
     [///
-     [reference (#+ Register)]
-     ["." phase]]]])
+     ["." phase]
+     [reference
+      [variable (#+ Register)]]]]])
 
 (def: (invariant? register changeS)
   (-> Register Synthesis Bit)
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/reference.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/reference.lux
index 7bd43b8aa..b21c899e0 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/reference.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/reference.lux
@@ -20,7 +20,8 @@
      ["." generation]
      [///
       ["#" phase ("operation@." monad)]
-      ["." reference (#+ Register Variable)]
+      [reference
+       ["." variable (#+ Register Variable)]]
       [meta
        [archive (#+ Archive)]]]]]])
 
@@ -51,10 +52,10 @@
 (def: #export (variable archive variable)
   (-> Archive Variable (Operation (Bytecode Any)))
   (case variable
-    (#reference.Local variable)
+    (#variable.Local variable)
     (operation@wrap (_.aload variable))
     
-    (#reference.Foreign variable)
+    (#variable.Foreign variable)
     (..foreign archive variable)))
 
 (def: #export (constant archive name)
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/runtime.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/runtime.lux
index 304629c6f..41153f29c 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/runtime.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/runtime.lux
@@ -50,7 +50,8 @@
      [///
       ["#" phase]
       [arity (#+ Arity)]
-      [reference (#+ Register)]
+      [reference
+       [variable (#+ Register)]]
       ["." meta
        [io (#+ lux-context)]
        [archive (#+ Archive)]]]]]])
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/case.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/case.lux
index 149d3e69a..8d3b7b2d5 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/case.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/case.lux
@@ -20,8 +20,9 @@
     ["#." analysis (#+ Pattern Match Analysis)]
     ["/" synthesis (#+ Path Synthesis Operation Phase)]
     [///
-     ["#." reference (#+ Variable)]
      ["#" phase ("#@." monad)]
+     ["#." reference
+      ["#/." variable (#+ Register Variable)]]
      [meta
       [archive (#+ Archive)]]]]])
 
@@ -76,11 +77,11 @@
                  (list.reverse (list.enumerate tuple))))
     ))
 
-(def: #export (path archive synthesize pattern bodyA)
+(def: (path archive synthesize pattern bodyA)
   (-> Archive Phase Pattern Analysis (Operation Path))
   (path' pattern true (///@map (|>> #/.Then) (synthesize archive bodyA))))
 
-(def: #export (weave leftP rightP)
+(def: (weave leftP rightP)
   (-> Path Path Path)
   (with-expansions [<default> (as-is (#/.Alt leftP rightP))]
     (case [leftP rightP]
@@ -126,54 +127,127 @@
       _
       <default>)))
 
+(def: (get patterns @selection)
+  (-> (///analysis.Tuple ///analysis.Pattern) Register (List /.Member))
+  (loop [lefts 0
+         patterns patterns]
+    (with-expansions [<failure> (as-is (list))
+                      <continue> (as-is (recur (inc lefts)
+                                               tail))
+                      <member> (as-is (if (list.empty? tail)
+                                        (#.Right (dec lefts))
+                                        (#.Left lefts)))]
+      (case patterns
+        #.Nil
+        <failure>
+
+        (#.Cons head tail)
+        (case head
+          (#///analysis.Simple #///analysis.Unit)
+          <continue>
+          
+          (#///analysis.Bind register)
+          (if (n.= @selection register)
+            (list <member>)
+            <continue>)
+
+          (#///analysis.Complex (#///analysis.Tuple sub-patterns))
+          (case (get sub-patterns @selection)
+            #.Nil
+            <continue>
+
+            sub-members
+            (list& <member> sub-members))
+          
+          _
+          <failure>)))))
+
+(def: #export (synthesize-case synthesize archive input [headB tailB+])
+  (-> Phase Archive Synthesis Match (Operation Synthesis))
+  (let [[[lastP lastA] prevsPA] (|> (#.Cons headB tailB+)
+                                    list.reverse
+                                    (case> (#.Cons [lastP lastA] prevsPA)
+                                           [[lastP lastA] prevsPA]
+                                           
+                                           _
+                                           (undefined)))]
+    (do {@ ///.monad}
+      [lastSP (path archive synthesize lastP lastA)
+       prevsSP+ (monad.map @ (product.uncurry (path archive synthesize)) prevsPA)]
+      (wrap (/.branch/case [input (list@fold weave lastSP prevsSP+)])))))
+
+(template: (!masking <variable> <output>)
+  [[(#///analysis.Bind <variable>)
+    (#///analysis.Reference (///reference.local <output>))]
+   (list)])
+
+(def: #export (synthesize-masking synthesize archive input @variable @output)
+  (-> Phase Archive Synthesis Register Register (Operation Synthesis))
+  (if (n.= @variable @output)
+    (///@wrap input)
+    (..synthesize-case synthesize archive input (!masking @variable @output))))
+
+(def: #export (synthesize-let synthesize archive input @variable body)
+  (-> Phase Archive Synthesis Register Analysis (Operation Synthesis))
+  (do ///.monad
+    [body (/.with-new-local
+            (synthesize archive body))]
+    (wrap (/.branch/let [input @variable body]))))
+
+(def: #export (synthesize-if synthesize archive test then else)
+  (-> Phase Archive Synthesis Analysis Analysis (Operation Synthesis))
+  (do ///.monad
+    [then (synthesize archive then)
+     else (synthesize archive else)]
+    (wrap (/.branch/if [test then else]))))
+
+(template: (!get <patterns> <output>)
+  [[(///analysis.pattern/tuple <patterns>)
+    (#///analysis.Reference (///reference.local <output>))]
+   (.list)])
+
+(def: #export (synthesize-get synthesize archive input patterns @member)
+  (-> Phase Archive Synthesis (///analysis.Tuple ///analysis.Pattern) Register (Operation Synthesis))
+  (case (..get patterns @member)
+    #.Nil
+    (..synthesize-case synthesize archive input (!get patterns @member))
+
+    path
+    (case input
+      (^ (/.branch/get [sub-path sub-input]))
+      (///@wrap (/.branch/get [(list@compose path sub-path) sub-input]))
+
+      _
+      (///@wrap (/.branch/get [path input])))))
+
 (def: #export (synthesize synthesize^ [headB tailB+] archive inputA)
   (-> Phase Match Phase)
   (do {@ ///.monad}
     [inputS (synthesize^ archive inputA)]
-    (with-expansions [<unnecesary-let>
-                      (as-is (^multi (^ (#///analysis.Reference (///reference.local outputR)))
-                                     (n.= inputR outputR))
-                             (wrap inputS))
-
-                      <let>
-                      (as-is [[(#///analysis.Bind inputR) headB/bodyA]
-                              #.Nil]
-                             (case headB/bodyA
-                               <unnecesary-let>
-
-                               _
-                               (do @
-                                 [headB/bodyS (/.with-new-local
-                                                (synthesize^ archive headB/bodyA))]
-                                 (wrap (/.branch/let [inputS inputR headB/bodyS])))))
-
-                      <if>
-                      (as-is (^or (^ [[(///analysis.pattern/bit #1) thenA]
-                                      (list [(///analysis.pattern/bit #0) elseA])])
-                                  (^ [[(///analysis.pattern/bit #0) elseA]
-                                      (list [(///analysis.pattern/bit #1) thenA])]))
-                             (do @
-                               [thenS (synthesize^ archive thenA)
-                                elseS (synthesize^ archive elseA)]
-                               (wrap (/.branch/if [inputS thenS elseS]))))
-
-                      <case>
-                      (as-is _
-                             (let [[[lastP lastA] prevsPA] (|> (#.Cons headB tailB+)
-                                                               list.reverse
-                                                               (case> (#.Cons [lastP lastA] prevsPA)
-                                                                      [[lastP lastA] prevsPA]
-                                                                      
-                                                                      _
-                                                                      (undefined)))]
-                               (do @
-                                 [lastSP (path archive synthesize^ lastP lastA)
-                                  prevsSP+ (monad.map @ (product.uncurry (path archive synthesize^)) prevsPA)]
-                                 (wrap (/.branch/case [inputS (list@fold weave lastSP prevsSP+)])))))]
-      (case [headB tailB+]
-        <let>
-        <if>
-        <case>))))
+    (case [headB tailB+]
+      (^ (!masking @variable @output))
+      (..synthesize-masking synthesize^ archive inputS @variable @output)
+
+      [[(#///analysis.Bind @variable) body]
+       #.Nil]
+      (..synthesize-let synthesize^ archive inputS @variable body)
+      
+      (^or (^ [[(///analysis.pattern/bit #1) then]
+               (list [(///analysis.pattern/bit #0) else])])
+           (^ [[(///analysis.pattern/bit #1) then]
+               (list [(///analysis.pattern/unit) else])])
+
+           (^ [[(///analysis.pattern/bit #0) else]
+               (list [(///analysis.pattern/bit #1) then])])
+           (^ [[(///analysis.pattern/bit #0) else]
+               (list [(///analysis.pattern/unit) then])]))
+      (..synthesize-if synthesize^ archive inputS then else)
+      
+      (^ (!get patterns @member))
+      (..synthesize-get synthesize^ archive inputS patterns @member)
+      
+      match
+      (..synthesize-case synthesize^ archive inputS match))))
 
 (def: #export (count-pops path)
   (-> Path [Nat Path])
@@ -194,13 +268,13 @@
 
 (def: empty
   Storage
-  {#bindings (set.new ///reference.hash)
-   #dependencies (set.new ///reference.hash)})
+  {#bindings (set.new ///reference/variable.hash)
+   #dependencies (set.new ///reference/variable.hash)})
 
 ## TODO: Use this to declare all local variables at the beginning of
 ## script functions.
 ## That way, it should be possible to do cheap "let" expressions,
-## since the variable will exist before hand so no closure will need
+## since the variable will exist beforehand, so no closure will need
 ## to be created for it.
 ## Apply this trick to JS, Python et al.
 (def: #export (storage path)
@@ -210,7 +284,7 @@
      path-storage ..empty]
     (case path
       (^ (/.path/bind register))
-      (update@ #bindings (set.add (#///reference.Local register))
+      (update@ #bindings (set.add (#///reference/variable.Local register))
                path-storage)
 
       (^or (^ (/.path/seq left right))
@@ -245,7 +319,7 @@
 
           (^ (/.branch/let [inputS register exprS]))
           (list@fold for-synthesis
-                     (update@ #bindings (set.add (#///reference.Local register))
+                     (update@ #bindings (set.add (#///reference/variable.Local register))
                               synthesis-storage)
                      (list inputS exprS))
 
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/function.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/function.lux
index 02258a7b1..e34c78f71 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/function.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/function.lux
@@ -9,8 +9,7 @@
     ["." text
      ["%" format (#+ format)]]
     [collection
-     ["." list ("#@." functor monoid fold)]
-     ["dict" dictionary (#+ Dictionary)]]]]
+     ["." list ("#@." functor monoid fold)]]]]
   ["." // #_
    ["#." loop (#+ Transform)]
    ["//#" /// #_
@@ -18,13 +17,14 @@
     ["/" synthesis (#+ Path Synthesis Operation Phase)]
     [///
      [arity (#+ Arity)]
-     ["#." reference (#+ Register Variable)]
+     ["#." reference
+      ["#/." variable (#+ Register Variable)]]
      ["." phase ("#@." monad)]]]])
 
 (exception: #export (cannot-find-foreign-variable-in-environment {foreign Register} {environment Environment})
   (ex.report ["Foreign" (%.nat foreign)]
              ["Environment" (|> environment
-                                (list@map ////reference.%variable)
+                                (list@map ////reference/variable.format)
                                 (text.join-with " "))]))
 
 (def: arity-arguments
@@ -98,10 +98,10 @@
   (monad.map phase.monad
              (function (_ variable)
                (case variable
-                 (#////reference.Local register)
-                 (phase@wrap (#////reference.Local (inc register)))
+                 (#////reference/variable.Local register)
+                 (phase@wrap (#////reference/variable.Local (inc register)))
                  
-                 (#////reference.Foreign register)
+                 (#////reference/variable.Foreign register)
                  (find-foreign super register)))
              sub))
 
@@ -127,10 +127,10 @@
     (case reference
       (#////reference.Variable variable)
       (case variable
-        (#////reference.Local register)
+        (#////reference/variable.Local register)
         (phase@wrap (/.variable/local (inc register)))
         
-        (#////reference.Foreign register)
+        (#////reference/variable.Foreign register)
         (|> register
             (find-foreign environment)
             (phase@map (|>> /.variable))))
@@ -154,6 +154,11 @@
            thenS' (grow environment thenS)
            elseS' (grow environment elseS)]
           (wrap (/.branch/if [testS' thenS' elseS'])))
+
+        (#/.Get members inputS)
+        (do phase.monad
+          [inputS' (grow environment inputS)]
+          (wrap (/.branch/get [members inputS'])))
         
         (#/.Case [inputS pathS])
         (do phase.monad
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/loop.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/loop.lux
index f4cc28012..5aa644e18 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/loop.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/loop.lux
@@ -5,11 +5,11 @@
    [control
     ["p" parser]]
    [data
-    ["." maybe ("#;." monad)]
+    ["." maybe ("#@." monad)]
     [number
      ["n" nat]]
     [collection
-     ["." list ("#;." functor)]]]
+     ["." list ("#@." functor)]]]
    [macro
     ["." code]
     ["." syntax]]]
@@ -20,7 +20,8 @@
     ["#." analysis (#+ Environment)]
     ["/" synthesis (#+ Path Abstraction Synthesis)]
     [///
-     ["#." reference (#+ Register Variable)]]]])
+     ["#." reference
+      ["#/." variable (#+ Register Variable)]]]]])
 
 (type: #export (Transform a)
   (-> a (Maybe a)))
@@ -44,7 +45,7 @@
   (-> Synthesis Bit)
   (case exprS
     (^ (self))
-    improper
+    ..improper
 
     (#/.Structure structure)
     (case structure
@@ -69,7 +70,7 @@
                  (proper? bodyS)
                  
                  _
-                 proper)))
+                 ..proper)))
 
         (#/.Let inputS register bodyS)
         (and (proper? inputS)
@@ -78,7 +79,10 @@
         (#/.If inputS thenS elseS)
         (and (proper? inputS)
              (proper? thenS)
-             (proper? elseS)))
+             (proper? elseS))
+
+        (#/.Get members inputS)
+        (proper? inputS))
 
       (#/.Loop loopS)
       (case loopS
@@ -92,7 +96,7 @@
       (#/.Function functionS)
       (case functionS
         (#/.Abstraction environment arity bodyS)
-        (list.every? ///reference.self? environment)
+        (list.every? ///reference/variable.self? environment)
 
         (#/.Apply funcS argsS)
         (and (proper? funcS)
@@ -102,7 +106,7 @@
     (list.every? proper? argsS)
 
     _
-    proper))
+    ..proper))
 
 (def: (path-recursion synthesis-recursion)
   (-> (Transform Synthesis) (Transform Path))
@@ -118,10 +122,10 @@
           #.None))
       
       (#/.Seq leftS rightS)
-      (maybe;map (|>> (#/.Seq leftS)) (recur rightS))
+      (maybe@map (|>> (#/.Seq leftS)) (recur rightS))
 
       (#/.Then bodyS)
-      (maybe;map (|>> #/.Then) (synthesis-recursion bodyS))
+      (maybe@map (|>> #/.Then) (synthesis-recursion bodyS))
       
       _
       #.None)))
@@ -137,10 +141,10 @@
           (#/.Case inputS pathS)
           (|> pathS
               (path-recursion recur)
-              (maybe;map (|>> (#/.Case inputS) #/.Branch #/.Control)))
+              (maybe@map (|>> (#/.Case inputS) #/.Branch #/.Control)))
 
           (#/.Let inputS register bodyS)
-          (maybe;map (|>> (#/.Let inputS register) #/.Branch #/.Control)
+          (maybe@map (|>> (#/.Let inputS register) #/.Branch #/.Control)
                      (recur bodyS))
 
           (#/.If inputS thenS elseS)
@@ -152,7 +156,10 @@
                                  (maybe.default thenS thenS')
                                  (maybe.default elseS elseS'))
                           #/.Branch #/.Control))
-              #.None)))
+              #.None))
+
+          (#/.Get members inputS)
+          #.None)
 
         (^ (#/.Function (recursive-apply argsS)))
         (if (n.= arity (list.size argsS))
@@ -169,7 +176,7 @@
   (-> Environment (Transform Variable))
   (function (_ variable)
     (case variable
-      (#///reference.Foreign register)
+      (#///reference/variable.Foreign register)
       (list.nth register environment)
 
       _
@@ -191,7 +198,7 @@
       ([#/.Alt] [#/.Seq])
       
       (#/.Then bodyS)
-      (|> bodyS adjust-synthesis (maybe;map (|>> #/.Then)))
+      (|> bodyS adjust-synthesis (maybe@map (|>> #/.Then)))
 
       _
       (#.Some pathS))))
@@ -213,7 +220,7 @@
         (#///analysis.Tuple membersS+)
         (|> membersS+
             (monad.map maybe.monad recur)
-            (maybe;map (|>> #///analysis.Tuple #/.Structure))))
+            (maybe@map (|>> #///analysis.Tuple #/.Structure))))
 
       (#/.Reference reference)
       (case reference
@@ -226,7 +233,7 @@
         (^ (///reference.foreign register))
         (|> scope-environment
             (list.nth register)
-            (maybe;map (|>> #///reference.Variable #/.Reference))))
+            (maybe@map (|>> #///reference.Variable #/.Reference))))
 
       (^ (/.branch/case [inputS pathS]))
       (do maybe.monad
@@ -260,7 +267,7 @@
       (^ (/.loop/recur argsS))
       (|> argsS
           (monad.map maybe.monad recur)
-          (maybe;map (|>> /.loop/recur)))
+          (maybe@map (|>> /.loop/recur)))
       
 
       (^ (/.function/abstraction [environment arity bodyS]))
@@ -279,7 +286,7 @@
       (#/.Extension [name argsS])
       (|> argsS
           (monad.map maybe.monad recur)
-          (maybe;map (|>> [name] #/.Extension)))
+          (maybe@map (|>> [name] #/.Extension)))
 
       _
       (#.Some exprS))))
@@ -292,5 +299,5 @@
              (proper? bodyS))
       (|> bodyS
           (adjust environment num-locals)
-          (maybe;map (|>> [(inc num-locals) inits] /.loop/scope)))
+          (maybe@map (|>> [(inc num-locals) inits] /.loop/scope)))
       #.None)))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/synthesis.lux b/stdlib/source/lux/tool/compiler/language/lux/synthesis.lux
index 7519df0a2..a88d986fc 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/synthesis.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/synthesis.lux
@@ -6,15 +6,15 @@
    [control
     ["ex" exception (#+ exception:)]]
    [data
-    ["." bit ("#;." equivalence)]
-    ["." text ("#;." equivalence)
+    ["." bit ("#@." equivalence)]
+    ["." text ("#@." equivalence)
      ["%" format (#+ Format format)]]
     [number
      ["n" nat]
      ["i" int]
      ["f" frac]]
     [collection
-     ["." list ("#;." functor)]
+     ["." list ("#@." functor)]
      ["." dictionary (#+ Dictionary)]]]]
   ["." // #_
    ["#." analysis (#+ Environment Composite Analysis)]
@@ -22,7 +22,8 @@
     ["." extension (#+ Extension)]]
    [///
     [arity (#+ Arity)]
-    ["#." reference (#+ Register Variable Reference)]
+    ["#." reference (#+ Reference)
+     ["#/." variable (#+ Register Variable)]]
     ["#." phase]]])
 
 (type: #export Resolver (Dictionary Variable Variable))
@@ -32,7 +33,7 @@
 
 (def: #export fresh-resolver
   Resolver
-  (dictionary.new //reference.hash))
+  (dictionary.new //reference/variable.hash))
 
 (def: #export init
   State
@@ -75,6 +76,7 @@
 (type: #export (Branch s)
   (#Let s Register s)
   (#If s s s)
+  (#Get (List Member) s)
   (#Case s (Path' s)))
 
 (type: #export (Scope s)
@@ -246,6 +248,7 @@
   [branch/case          #..Branch   #..Case]
   [branch/let           #..Branch   #..Let]
   [branch/if            #..Branch   #..If]
+  [branch/get           #..Branch   #..Get]
 
   [loop/recur           #..Loop     #..Recur]
   [loop/scope           #..Loop     #..Scope]
@@ -331,12 +334,12 @@
       
       (#//analysis.Tuple members)
       (|> members
-          (list;map %synthesis)
+          (list@map %synthesis)
           (text.join-with " ")
           (text.enclose ["[" "]"])))
 
     (#Reference reference)
-    (//reference.%reference reference)
+    (//reference.format reference)
 
     (#Control control)
     (case control
@@ -346,14 +349,14 @@
         (|> (%synthesis body)
             (format (%.nat arity) " ")
             (format (|> environment
-                        (list;map //reference.%variable)
+                        (list@map //reference/variable.format)
                         (text.join-with " ")
                         (text.enclose ["[" "]"]))
                     " ")
             (text.enclose ["(" ")"]))
         
         (#Apply func args)
-        (|> (list;map %synthesis args)
+        (|> (list@map %synthesis args)
             (text.join-with " ")
             (format (%synthesis func) " ")
             (text.enclose ["(" ")"])))
@@ -367,6 +370,12 @@
         (#If test then else)
         (|> (format (%synthesis test) " " (%synthesis then) " " (%synthesis else))
             (text.enclose ["(#if " ")"]))
+
+        (#Get members record)
+        (|> (format (%.list (%path' %synthesis)
+                            (list@map (|>> #Member #Access) members))
+                    " " (%synthesis record))
+            (text.enclose ["(#get " ")"]))
         
         (#Case input path)
         (|> (format (%synthesis input) " " (%path' %synthesis path))
@@ -377,7 +386,7 @@
       "???")
 
     (#Extension [name args])
-    (|> (list;map %synthesis args)
+    (|> (list@map %synthesis args)
         (text.join-with " ")
         (format (%.text name))
         (text.enclose ["(" ")"]))))
@@ -392,9 +401,9 @@
       (^template [<tag> <eq> <format>]
         [(<tag> reference') (<tag> sample')]
         (<eq> reference' sample'))
-      ([#Bit  bit;=  %.bit]
+      ([#Bit  bit@=  %.bit]
        [#F64  f.=    %.frac]
-       [#Text text;= %.text])
+       [#Text text@= %.text])
 
       [(#I64 reference') (#I64 sample')]
       (i.= (.int reference') (.int sample'))
diff --git a/stdlib/source/lux/tool/compiler/reference.lux b/stdlib/source/lux/tool/compiler/reference.lux
index 79f6c921e..abcbe1162 100644
--- a/stdlib/source/lux/tool/compiler/reference.lux
+++ b/stdlib/source/lux/tool/compiler/reference.lux
@@ -1,46 +1,38 @@
 (.module:
   [lux #*
    [abstract
-    [equivalence (#+ Equivalence)]
-    [hash (#+ Hash)]]
+    [equivalence (#+ Equivalence)]]
    [control
-    pipe]
+    [pipe (#+ case>)]]
    [data
+    ["." name]
     [number
      ["n" nat]]
     [text
-     ["%" format (#+ Format format)]]]])
+     ["%" format (#+ Format)]]]]
+  ["." / #_
+   ["#." variable (#+ Variable)]])
 
-(type: #export Register Nat)
-
-(type: #export Variable
-  (#Local Register)
-  (#Foreign Register))
+(type: #export Constant
+  Name)
 
 (type: #export Reference
   (#Variable Variable)
-  (#Constant Name))
+  (#Constant Constant))
+
+(structure: #export equivalence
+  (Equivalence Reference)
 
-(structure: #export equivalence (Equivalence Variable)
   (def: (= reference sample)
     (case [reference sample]
-      (^template [<tag>]
-        [(<tag> reference') (<tag> sample')]
-        (n.= reference' sample'))
-      ([#Local] [#Foreign])
+      (^template [<tag> <equivalence>]
+        [(<tag> reference) (<tag> sample)]
+        (:: <equivalence> = reference sample))
+      ([#Variable /variable.equivalence]
+       [#Constant name.equivalence])
 
       _
-      #0)))
-
-(structure: #export hash (Hash Variable)
-  (def: &equivalence ..equivalence)
-  (def: (hash var)
-    (case var
-      (#Local register)
-      (n.* 1 register)
-      
-      (#Foreign register)
-      (n.* 2 register))))
+      false)))
 
 (template [<name> <family> <tag>]
   [(template: #export (<name> content)
@@ -48,8 +40,8 @@
          <tag>
          content))]
 
-  [local   #..Variable #..Local]
-  [foreign #..Variable #..Foreign]
+  [local   #..Variable #/variable.Local]
+  [foreign #..Variable #/variable.Foreign]
   )
 
 (template [<name> <tag>]
@@ -63,29 +55,10 @@
 
 (def: #export self Reference (..local 0))
 
-(def: #export self?
-  (-> Variable Bit)
-  (|>> ..variable
-       (case> (^ (..local 0))
-              #1
-
-              _
-              #0)))
-
-(def: #export (%variable variable)
-  (Format Variable)
-  (case variable
-    (#Local local)
-    (format "+" (%.nat local))
-    
-    (#Foreign foreign)
-    (format "-" (%.nat foreign))))
-
-(def: #export (%reference reference)
+(def: #export format
   (Format Reference)
-  (case reference
-    (#Variable variable)
-    (%variable variable)
-    
-    (#Constant constant)
-    (%.name constant)))
+  (|>> (case> (#Variable variable)
+              (/variable.format variable)
+              
+              (#Constant constant)
+              (%.name constant))))
diff --git a/stdlib/source/lux/tool/compiler/reference/variable.lux b/stdlib/source/lux/tool/compiler/reference/variable.lux
new file mode 100644
index 000000000..10c080c6e
--- /dev/null
+++ b/stdlib/source/lux/tool/compiler/reference/variable.lux
@@ -0,0 +1,59 @@
+(.module:
+  [lux #*
+   [abstract
+    [equivalence (#+ Equivalence)]
+    [hash (#+ Hash)]]
+   [control
+    [pipe (#+ case>)]]
+   [data
+    [number
+     ["n" nat]
+     ["i" int]]
+    [text
+     ["%" format (#+ Format)]]]])
+
+(type: #export Register Nat)
+
+(type: #export Variable
+  (#Local Register)
+  (#Foreign Register))
+
+(structure: #export equivalence
+  (Equivalence Variable)
+  
+  (def: (= reference sample)
+    (case [reference sample]
+      (^template [<tag>]
+        [(<tag> reference') (<tag> sample')]
+        (n.= reference' sample'))
+      ([#Local] [#Foreign])
+
+      _
+      #0)))
+
+(structure: #export hash
+  (Hash Variable)
+  
+  (def: &equivalence ..equivalence)
+  (def: hash
+    (|>> (case> (#Local register)
+                register
+                
+                (#Foreign register)
+                (|> register .int (i.* -1) .nat)))))
+
+(def: #export self?
+  (-> Variable Bit)
+  (|>> (case> (^ (#Local 0))
+              true
+
+              _
+              false)))
+
+(def: #export format
+  (Format Variable)
+  (|>> (case> (#Local local)
+              (%.format "+" (%.nat local))
+              
+              (#Foreign foreign)
+              (%.format "-" (%.nat foreign)))))