"signature:" -> "interface:" & "structure:" -> "implementation:"

"signature" & "structure" feel like very ML-specific terminology and might not be easy on programmers unfamiliar with it.

32 files changed, 244 insertions, 80 deletions

diff --git a/stdlib/source/test/aedifex.lux b/stdlib/source/test/aedifex.lux
index 477ae4d50..e3c2bd1eb 100644
--- a/stdlib/source/test/aedifex.lux
+++ b/stdlib/source/test/aedifex.lux
@@ -20,9 +20,8 @@
    ["#." pom]
    ["#." profile]
    ["#." project]
-   ## ["#." repository]
-   ## ["#." runtime]
-   ])
+   ["#." repository]
+   ["#." runtime]])
 
 (def: dependency
   Test
@@ -48,9 +47,8 @@
       /pom.test
       /profile.test
       /project.test
-      
-      ## /repository.test
-      ## /runtime.test
+      /repository.test
+      /runtime.test
       ))
 
 (program: args
diff --git a/stdlib/source/test/aedifex/command/build.lux b/stdlib/source/test/aedifex/command/build.lux
index 7fd8c3eb3..0e86ef946 100644
--- a/stdlib/source/test/aedifex/command/build.lux
+++ b/stdlib/source/test/aedifex/command/build.lux
@@ -43,7 +43,7 @@
    (function (_ [actual_environment actual_working_directory actual_command actual_arguments])
      (#try.Success
       (: (shell.Simulation [])
-         (structure
+         (implementation
           (def: (on_read state)
             (exception.throw shell.no_more_output []))
           (def: (on_error state)
@@ -61,7 +61,7 @@
    (function (_ [actual_environment actual_working_directory actual_command actual_arguments])
      (#try.Success
       (: (shell.Simulation [])
-         (structure
+         (implementation
           (def: (on_read state)
             (exception.throw shell.no_more_output []))
           (def: (on_error state)
diff --git a/stdlib/source/test/aedifex/command/test.lux b/stdlib/source/test/aedifex/command/test.lux
index 291b31863..cad06aa69 100644
--- a/stdlib/source/test/aedifex/command/test.lux
+++ b/stdlib/source/test/aedifex/command/test.lux
@@ -84,7 +84,7 @@
                                                    (function (_ [actual_environment actual_working_directory actual_command actual_arguments])
                                                      (#try.Success
                                                       (: (shell.Simulation [])
-                                                         (structure
+                                                         (implementation
                                                           (def: (on_read state)
                                                             (exception.throw shell.no_more_output []))
                                                           (def: (on_error state)
diff --git a/stdlib/source/test/aedifex/command/version.lux b/stdlib/source/test/aedifex/command/version.lux
index c7a9aa4ef..079b0fde4 100644
--- a/stdlib/source/test/aedifex/command/version.lux
+++ b/stdlib/source/test/aedifex/command/version.lux
@@ -31,7 +31,7 @@
 
 (exception: #export console_is_closed!)
 
-(structure: simulation
+(implementation: simulation
   (Simulation [Bit Text])
 
   (def: (on_read [open? state])
diff --git a/stdlib/source/test/aedifex/dependency/resolution.lux b/stdlib/source/test/aedifex/dependency/resolution.lux
index ae8c7699b..ebb32b790 100644
--- a/stdlib/source/test/aedifex/dependency/resolution.lux
+++ b/stdlib/source/test/aedifex/dependency/resolution.lux
@@ -59,7 +59,7 @@
 (def: #export (single artifact package)
   (-> Artifact Package (Simulation Any))
   (let [expected (///artifact.uri (get@ #///artifact.version artifact) artifact)]
-    (structure
+    (implementation
      (def: (on_download uri state)
        (if (text.contains? expected uri)
          (cond (text.ends_with? ///artifact/extension.lux_library uri)
@@ -122,7 +122,7 @@
 
 (def: (bad_sha-1 expected_artifact expected_package dummy_package)
   (-> Artifact Package Package (Simulation Any))
-  (structure
+  (implementation
    (def: (on_download uri state)
      (if (text.contains? (///artifact.uri (get@ #///artifact.version expected_artifact) expected_artifact) uri)
        (cond (text.ends_with? ///artifact/extension.lux_library uri)
@@ -173,7 +173,7 @@
 
 (def: (bad_md5 expected_artifact expected_package dummy_package)
   (-> Artifact Package Package (Simulation Any))
-  (structure
+  (implementation
    (def: (on_download uri state)
      (if (text.contains? (///artifact.uri (get@ #///artifact.version expected_artifact) expected_artifact) uri)
        (cond (text.ends_with? ///artifact/extension.lux_library uri)
diff --git a/stdlib/source/test/aedifex/repository.lux b/stdlib/source/test/aedifex/repository.lux
index df8db3e88..ed32f0ac3 100644
--- a/stdlib/source/test/aedifex/repository.lux
+++ b/stdlib/source/test/aedifex/repository.lux
@@ -30,6 +30,7 @@
    ["$." /]}
   {#program
    ["." /
+    ["#." remote]
     ["/#" // #_
      ["#." artifact (#+ Version Artifact)
       ["#/." extension (#+ Extension)]]]]})
@@ -42,6 +43,10 @@
   (exception.report
    ["URI" (%.text uri)]))
 
+(exception: (cannot_upload {uri URI})
+  (exception.report
+   ["URI" (%.text uri)]))
+
 (type: Store
   (Dictionary URI Binary))
 
@@ -49,27 +54,46 @@
   Store
   (dictionary.new text.hash))
 
-(structure: #export simulation
+(def: valid_version
+  Version
+  "1.2.3-YES")
+
+(def: invalid_version
+  Version
+  "4.5.6-NO")
+
+(implementation: #export simulation
   (/.Simulation Store)
 
   (def: (on_download uri state)
     (case (dictionary.get uri state)
       (#.Some content)
-      (exception.return [state content])
+      (case (binary.size content)
+        0 (exception.throw ..not_found [uri])
+        _ (exception.return [state content]))
       
       #.None
       (exception.throw ..not_found [uri])))
   (def: (on_upload uri content state)
-    (exception.return (dictionary.put uri content state))))
+    (if (dictionary.key? state uri)
+      (exception.throw ..cannot_upload [uri])
+      (exception.return (dictionary.put uri content state)))))
 
 (def: #export test
   Test
   (<| (_.covering /._)
       ($_ _.and
           (_.for [/.mock /.Simulation]
-                 ($/.spec (..artifact "1.2.3-YES")
-                          (..artifact "4.5.6-NO")
-                          (/.mock ..simulation ..empty)))
+                 (do random.monad
+                   [_ (wrap [])]
+                   ($/.spec (..artifact ..valid_version)
+                            (..artifact ..invalid_version)
+                            (/.mock ..simulation
+                                    (|> ..empty
+                                        (dictionary.put (/remote.uri ..invalid_version
+                                                                     (..artifact ..invalid_version)
+                                                                     //artifact/extension.lux_library)
+                                                        (binary.create 0)))))))
 
           /identity.test
           /origin.test
diff --git a/stdlib/source/test/aedifex/runtime.lux b/stdlib/source/test/aedifex/runtime.lux
index 17b3428d2..0143eaac8 100644
--- a/stdlib/source/test/aedifex/runtime.lux
+++ b/stdlib/source/test/aedifex/runtime.lux
@@ -18,8 +18,9 @@
         (`` ($_ _.and
                 (~~ (template [<command>]
                       [(_.cover [<command>]
-                                (let [command (<command> path)]
-                                  (and (text.starts_with? (<command> "") command)
+                                (let [command (text.join_with " " (#.Cons (<command> path)))
+                                      pure_command (text.join_with " " (#.Cons (<command> "")))]
+                                  (and (text.starts_with? pure_command command)
                                        (text.ends_with? path command))))]
 
                       [/.java]
diff --git a/stdlib/source/test/lux.lux b/stdlib/source/test/lux.lux
index b2929de58..bc7231470 100644
--- a/stdlib/source/test/lux.lux
+++ b/stdlib/source/test/lux.lux
@@ -37,6 +37,7 @@
      ["#." math]
      ["#." meta]
      ["#." program]
+     ["#." target]
      ["#." time]
      ## ["#." tool] ## TODO: Update & expand tests for this
      ["#." type]
@@ -222,6 +223,7 @@
                              /math.test
                              /meta.test
                              /program.test
+                             /target.test
                              /time.test
                              ## /tool.test
                              /type.test
diff --git a/stdlib/source/test/lux/abstract/codec.lux b/stdlib/source/test/lux/abstract/codec.lux
index 1bbbcf460..1ac81f9d2 100644
--- a/stdlib/source/test/lux/abstract/codec.lux
+++ b/stdlib/source/test/lux/abstract/codec.lux
@@ -19,7 +19,7 @@
 (def: json
   (Codec JSON Bit)
   (let [field "value"]
-    (structure
+    (implementation
      (def: encode
        (|>> #json.Boolean
             [field]
diff --git a/stdlib/source/test/lux/abstract/equivalence.lux b/stdlib/source/test/lux/abstract/equivalence.lux
index cceb75c42..cc6da47eb 100644
--- a/stdlib/source/test/lux/abstract/equivalence.lux
+++ b/stdlib/source/test/lux/abstract/equivalence.lux
@@ -27,7 +27,7 @@
      sample random.nat
      different (|> random.nat (random.filter (|>> (n.= sample) not)))
      #let [equivalence (: (Equivalence (Equivalence Nat))
-                          (structure
+                          (implementation
                            (def: (= left right)
                              (and (bit\= (\ left = leftN leftN)
                                          (\ right = leftN leftN))
@@ -42,7 +42,7 @@
             (_.cover [/.rec]
                      (let [equivalence (: (Equivalence (List Nat))
                                           (/.rec (function (_ equivalence)
-                                                   (structure
+                                                   (implementation
                                                     (def: (= left right)
                                                       (case [left right]
                                                         [#.Nil #.Nil]
diff --git a/stdlib/source/test/lux/abstract/hash.lux b/stdlib/source/test/lux/abstract/hash.lux
index c527fb9c9..d9ddadabe 100644
--- a/stdlib/source/test/lux/abstract/hash.lux
+++ b/stdlib/source/test/lux/abstract/hash.lux
@@ -24,7 +24,7 @@
     [leftN random.nat
      rightN random.nat
      #let [hash (: (Equivalence (/.Hash Nat))
-                   (structure
+                   (implementation
                     (def: (= (^open "left\.") (^open "right\."))
                       (and (bit\= (left\= (left\hash leftN) (left\hash leftN))
                                   (right\= (right\hash leftN) (right\hash leftN)))
diff --git a/stdlib/source/test/lux/abstract/order.lux b/stdlib/source/test/lux/abstract/order.lux
index e9121353a..495db63e8 100644
--- a/stdlib/source/test/lux/abstract/order.lux
+++ b/stdlib/source/test/lux/abstract/order.lux
@@ -25,7 +25,7 @@
         [left random.nat
          right (|> random.nat (random.filter (|>> (n.= left) not)))
          #let [equivalence (: (Equivalence (/.Order Nat))
-                              (structure
+                              (implementation
                                (def: (= leftO rightO)
                                  (and (bit\= (\ leftO < left left)
                                              (\ rightO < left left))
diff --git a/stdlib/source/test/lux/abstract/predicate.lux b/stdlib/source/test/lux/abstract/predicate.lux
index be2953aba..cf8ee5ad5 100644
--- a/stdlib/source/test/lux/abstract/predicate.lux
+++ b/stdlib/source/test/lux/abstract/predicate.lux
@@ -35,7 +35,7 @@
         [sample random.nat
          samples (random.list 10 random.nat)
          #let [equivalence (: (Equivalence (/.Predicate Nat))
-                              (structure
+                              (implementation
                                (def: (= left right)
                                  (bit\= (left sample)
                                         (right sample)))))]])
diff --git a/stdlib/source/test/lux/control/function.lux b/stdlib/source/test/lux/control/function.lux
index 354433cc8..f1730629c 100644
--- a/stdlib/source/test/lux/control/function.lux
+++ b/stdlib/source/test/lux/control/function.lux
@@ -32,7 +32,7 @@
     (<| (_.covering /._)
         ($_ _.and
             (let [equivalence (: (Equivalence (-> Nat Nat))
-                                 (structure
+                                 (implementation
                                   (def: (= left right)
                                     (n.= (left extra)
                                          (right extra)))))
diff --git a/stdlib/source/test/lux/control/function/mixin.lux b/stdlib/source/test/lux/control/function/mixin.lux
index 8ca196ba5..ed6ba8591 100644
--- a/stdlib/source/test/lux/control/function/mixin.lux
+++ b/stdlib/source/test/lux/control/function/mixin.lux
@@ -29,7 +29,7 @@
          dummy random.nat
          shift (|> random.nat (random.filter (|>> (n.= dummy) not)))
          #let [equivalence (: (Equivalence (/.Mixin Nat Nat))
-                              (structure
+                              (implementation
                                (def: (= left right)
                                  (n.= ((/.mixin left) input)
                                       ((/.mixin right) input)))))
diff --git a/stdlib/source/test/lux/control/parser/binary.lux b/stdlib/source/test/lux/control/parser/binary.lux
index 943b8b3d5..5311ccdb3 100644
--- a/stdlib/source/test/lux/control/parser/binary.lux
+++ b/stdlib/source/test/lux/control/parser/binary.lux
@@ -70,7 +70,7 @@
   (Random Name)
   (random.and ..random_text ..random_text))
 
-(structure: location_equivalence
+(implementation: location_equivalence
   (Equivalence Location)
 
   (def: (= [expected_module expected_line expected_column]
diff --git a/stdlib/source/test/lux/control/security/policy.lux b/stdlib/source/test/lux/control/security/policy.lux
index 9c72304d9..c4c0657e7 100644
--- a/stdlib/source/test/lux/control/security/policy.lux
+++ b/stdlib/source/test/lux/control/security/policy.lux
@@ -35,7 +35,7 @@
 
 (type: Password (Private Text))
 
-(signature: (Policy %)
+(interface: (Policy %)
   (: (Hash (Password %))
      &hash)
 
@@ -50,13 +50,14 @@
   (/.with_policy
     (: (Context Privacy Policy)
        (function (_ (^@ privilege (^open "%\.")))
-         (structure
+         (implementation
           (def: &hash
-            (structure
+            (implementation
              (def: &equivalence
-               (structure (def: (= reference sample)
-                            (text\= (!.use %\can_downgrade reference)
-                                    (!.use %\can_downgrade sample)))))
+               (implementation
+                (def: (= reference sample)
+                  (text\= (!.use %\can_downgrade reference)
+                          (!.use %\can_downgrade sample)))))
              (def: hash
                (|>> (!.use %\can_downgrade)
                     (\ text.hash hash)))))
diff --git a/stdlib/source/test/lux/data/collection/dictionary.lux b/stdlib/source/test/lux/data/collection/dictionary.lux
index 92705210b..d4ba74ed7 100644
--- a/stdlib/source/test/lux/data/collection/dictionary.lux
+++ b/stdlib/source/test/lux/data/collection/dictionary.lux
@@ -54,7 +54,7 @@
         (do !
           [constant random.nat
            #let [hash (: (Hash Nat)
-                         (structure
+                         (implementation
                           (def: &equivalence n.equivalence)
                           (def: (hash _)
                             constant)))]]
diff --git a/stdlib/source/test/lux/data/collection/sequence.lux b/stdlib/source/test/lux/data/collection/sequence.lux
index 013936731..d10ee90cc 100644
--- a/stdlib/source/test/lux/data/collection/sequence.lux
+++ b/stdlib/source/test/lux/data/collection/sequence.lux
@@ -21,7 +21,7 @@
   {1
    ["." /]})
 
-(structure: (equivalence super)
+(implementation: (equivalence super)
   (All [a] (-> (Equivalence a) (Equivalence (/.Sequence a))))
 
   (def: (= reference subject)
diff --git a/stdlib/source/test/lux/data/collection/set.lux b/stdlib/source/test/lux/data/collection/set.lux
index 282749f5e..a0d7e446b 100644
--- a/stdlib/source/test/lux/data/collection/set.lux
+++ b/stdlib/source/test/lux/data/collection/set.lux
@@ -54,7 +54,7 @@
                   (do !
                     [hash (\ ! map (function (_ constant)
                                      (: (Hash Nat)
-                                        (structure
+                                        (implementation
                                          (def: &equivalence n.equivalence)
                                          
                                          (def: (hash _)
diff --git a/stdlib/source/test/lux/data/color.lux b/stdlib/source/test/lux/data/color.lux
index a8119145b..50b1c1fd6 100644
--- a/stdlib/source/test/lux/data/color.lux
+++ b/stdlib/source/test/lux/data/color.lux
@@ -21,10 +21,10 @@
      ["f" frac]
      ["r" rev]]]]
   {1
-   ["." / (#+ Color)]})
+   ["." /]})
 
 (def: #export random
-  (Random Color)
+  (Random /.Color)
   (|> ($_ random.and random.nat random.nat random.nat)
       (\ random.monad map /.from_rgb)))
 
@@ -32,8 +32,13 @@
   (-> Nat Frac)
   (|>> .int int.frac))
 
-(def: square (-> Frac Frac) (math.pow +2.0))
-(def: square_root (-> Frac Frac) (math.pow +0.5))
+(def: square
+  (-> Frac Frac)
+  (math.pow +2.0))
+
+(def: square_root
+  (-> Frac Frac)
+  (math.pow +0.5))
 
 (def: (distance/1 from to)
   (-> Frac Frac Frac)
@@ -42,7 +47,7 @@
     (f.- from to))))
 
 (def: (distance/3 from to)
-  (-> Color Color Frac)
+  (-> /.Color /.Color Frac)
   (let [[fr fg fb] (/.to_rgb from)
         [tr tg tb] (/.to_rgb to)]
     (square_root
@@ -55,7 +60,7 @@
 
 (template [<field>]
   [(def: (<field> color)
-     (-> Color Frac)
+     (-> /.Color Frac)
      (let [[hue saturation luminance] (/.to_hsl color)]
        <field>))]
 
diff --git a/stdlib/source/test/lux/data/format/binary.lux b/stdlib/source/test/lux/data/format/binary.lux
index 6cc42d90d..c667c6070 100644
--- a/stdlib/source/test/lux/data/format/binary.lux
+++ b/stdlib/source/test/lux/data/format/binary.lux
@@ -14,7 +14,7 @@
   {1
    ["." /]})
 
-(structure: equivalence
+(implementation: equivalence
   (Equivalence /.Specification)
 
   (def: (= reference subject)
diff --git a/stdlib/source/test/lux/data/text/format.lux b/stdlib/source/test/lux/data/text/format.lux
index 8b1e9a700..1f0c2c9e6 100644
--- a/stdlib/source/test/lux/data/text/format.lux
+++ b/stdlib/source/test/lux/data/text/format.lux
@@ -50,7 +50,7 @@
   {1
    ["." /]})
 
-(structure: (equivalence example)
+(implementation: (equivalence example)
   (All [a] (-> a (Equivalence (/.Format a))))
 
   (def: (= reference subject)
diff --git a/stdlib/source/test/lux/ffi.jvm.lux b/stdlib/source/test/lux/ffi.jvm.lux
index 9edaecd0c..d2686f3ba 100644
--- a/stdlib/source/test/lux/ffi.jvm.lux
+++ b/stdlib/source/test/lux/ffi.jvm.lux
@@ -12,34 +12,34 @@
      ["i" int]]]
    ["_" test (#+ Test)]]
   {1
-   ["." / (#+ import: class: interface: object)]})
+   ["." /]})
 
-(import: (java/util/concurrent/Callable a))
+(/.import: (java/util/concurrent/Callable a))
 
-(import: java/lang/Long)
+(/.import: java/lang/Long)
 
-(import: java/lang/String)
+(/.import: java/lang/String)
 
-(import: java/lang/Exception
+(/.import: java/lang/Exception
   ["#::."
    (new [java/lang/String])])
 
-(import: java/lang/Object)
+(/.import: java/lang/Object)
 
-(import: (java/lang/Class a)
+(/.import: (java/lang/Class a)
   ["#::."
    (getName [] java/lang/String)])
 
-(import: java/lang/Runnable)
+(/.import: java/lang/Runnable)
 
-(import: java/lang/System
+(/.import: java/lang/System
   ["#::."
    (#static out java/io/PrintStream)
    (#static currentTimeMillis [] #io long)
    (#static getenv [java/lang/String] #io #? java/lang/String)])
 
-## TODO: Handle "class:" ASAP.
-## (class: #final (TestClass A) [java/lang/Runnable]
+## TODO: Handle "/.class:" ASAP.
+## (/.class: #final (TestClass A) [java/lang/Runnable]
 ##   ## Fields
 ##   (#private foo boolean)
 ##   (#private bar A)
@@ -58,20 +58,20 @@
 ##                       []))
 
 (def: test_runnable
-  (object [] [java/lang/Runnable]
+  (/.object [] [java/lang/Runnable]
     []
     (java/lang/Runnable
      [] (run self) void
      [])))
 
 (def: test_callable
-  (object [a] [(java/util/concurrent/Callable a)]
+  (/.object [a] [(java/util/concurrent/Callable a)]
     []
     ((java/util/concurrent/Callable a)
      [] (call self) a #throws [java/lang/Exception]
      (undefined))))
 
-## (interface: TestInterface
+## (/.interface: TestInterface
 ##   ([] foo [boolean java/lang/String] void #throws [java/lang/Exception]))
 
 (def: conversions
diff --git a/stdlib/source/test/lux/ffi.old.lux b/stdlib/source/test/lux/ffi.old.lux
index b14dac30d..37eb2c103 100644
--- a/stdlib/source/test/lux/ffi.old.lux
+++ b/stdlib/source/test/lux/ffi.old.lux
@@ -12,30 +12,30 @@
      ["i" int]]]
    ["_" test (#+ Test)]]
   {1
-   ["." / (#+ import: class: interface: object)]})
+   ["." /]})
 
-(import: (java/util/concurrent/Callable a))
+(/.import: (java/util/concurrent/Callable a))
 
-(import: java/lang/Object)
-(import: java/lang/String)
+(/.import: java/lang/Object)
+(/.import: java/lang/String)
 
-(import: java/lang/Exception
+(/.import: java/lang/Exception
   ["#::."
    (new [java/lang/String])])
 
-(import: java/lang/Runnable)
+(/.import: java/lang/Runnable)
 
-(import: (java/lang/Class a)
+(/.import: (java/lang/Class a)
   ["#::."
    (getName [] java/lang/String)])
 
-(import: java/lang/System
+(/.import: java/lang/System
   ["#::."
    (#static out java/io/PrintStream)
    (#static currentTimeMillis [] #io long)
    (#static getenv [java/lang/String] #io #? java/lang/String)])
 
-(class: #final (TestClass A) [java/lang/Runnable]
+(/.class: #final (TestClass A) [java/lang/Runnable]
   ## Fields
   (#private foo boolean)
   (#private bar A)
@@ -54,18 +54,18 @@
                       []))
 
 (def: test_runnable
-  (object [] [java/lang/Runnable]
+  (/.object [] [java/lang/Runnable]
     []
     (java/lang/Runnable [] (run self) void
                         [])))
 
 (def: test_callable
-  (object [a] [(java/util/concurrent/Callable a)]
+  (/.object [a] [(java/util/concurrent/Callable a)]
     []
     (java/util/concurrent/Callable [] (call self) a
                                    (undefined))))
 
-(interface: TestInterface
+(/.interface: TestInterface
   ([] foo [boolean java/lang/String] void #throws [java/lang/Exception]))
 
 (def: conversions
diff --git a/stdlib/source/test/lux/math/logic/fuzzy.lux b/stdlib/source/test/lux/math/logic/fuzzy.lux
index 58587ad95..bb2d7184c 100644
--- a/stdlib/source/test/lux/math/logic/fuzzy.lux
+++ b/stdlib/source/test/lux/math/logic/fuzzy.lux
@@ -340,7 +340,7 @@
         [sample random.rev
          [_ fuzzy] ..gradient
          #let [equivalence (: (Equivalence (/.Fuzzy Rev))
-                              (structure
+                              (implementation
                                (def: (= left right)
                                  (r.= (left sample)
                                       (right sample)))))]]
diff --git a/stdlib/source/test/lux/meta/annotation.lux b/stdlib/source/test/lux/meta/annotation.lux
index 51b33a70b..01f410b92 100644
--- a/stdlib/source/test/lux/meta/annotation.lux
+++ b/stdlib/source/test/lux/meta/annotation.lux
@@ -112,7 +112,7 @@
                                             (..annotation key)
                                             <definition>)))))]
 
-                  [/.structure? #.struct?]
+                  [/.implementation? #.implementation?]
                   [/.recursive_type? #.type-rec?]
                   [/.signature? #.sig?]
                   ))
diff --git a/stdlib/source/test/lux/target.lux b/stdlib/source/test/lux/target.lux
new file mode 100644
index 000000000..6f6050e1c
--- /dev/null
+++ b/stdlib/source/test/lux/target.lux
@@ -0,0 +1,45 @@
+(.module:
+  [lux #*
+   ["_" test (#+ Test)]
+   [data
+    ["." text]
+    [collection
+     ["." list]
+     ["." set (#+ Set)]]]
+   [math
+    [number
+     ["n" nat]]]]
+  {1
+   ["." /]})
+
+(with_expansions [<targets> (as_is /.old
+                                   /.js
+                                   /.jvm
+                                   /.lua
+                                   /.python
+                                   /.ruby
+                                   /.common_lisp
+                                   /.php
+                                   /.r
+                                   /.scheme)]
+  (def: all
+    (List /.Target)
+    (list <targets>))
+  
+  (def: unique
+    (Set /.Target)
+    (set.from_list text.hash ..all))
+
+  (def: verdict
+    (n.= (list.size ..all)
+         (set.size ..unique)))
+
+  (def: #export test
+    Test
+    (<| (_.covering /._)
+        (_.for [/.Target])
+        ($_ _.and
+            (_.cover [<targets>]
+                     ..verdict)
+            )))
+  )
diff --git a/stdlib/source/test/lux/world.lux b/stdlib/source/test/lux/world.lux
index 62e0fc397..47e4ceb27 100644
--- a/stdlib/source/test/lux/world.lux
+++ b/stdlib/source/test/lux/world.lux
@@ -10,7 +10,10 @@
     ["#/." keyboard]]
    ["#." output #_
     ["#/." video #_
-     ["#/." resolution]]]])
+     ["#/." resolution]]]
+   ["#." net #_
+    ["#/." http #_
+     ["#/." client]]]])
 
 (def: #export test
   Test
@@ -21,4 +24,5 @@
       /program.test
       /input/keyboard.test
       /output/video/resolution.test
+      /net/http/client.test
       ))
diff --git a/stdlib/source/test/lux/world/console.lux b/stdlib/source/test/lux/world/console.lux
index 6c71f913c..56e3902f0 100644
--- a/stdlib/source/test/lux/world/console.lux
+++ b/stdlib/source/test/lux/world/console.lux
@@ -23,7 +23,7 @@
 
 (def: simulation
   (/.Simulation [Bit Text])
-  (structure
+  (implementation
    (def: (on_read [dead? content])
      (do try.monad
        [char (try.from_maybe (text.nth 0 content))
diff --git a/stdlib/source/test/lux/world/net/http/client.lux b/stdlib/source/test/lux/world/net/http/client.lux
new file mode 100644
index 000000000..0ac51bad0
--- /dev/null
+++ b/stdlib/source/test/lux/world/net/http/client.lux
@@ -0,0 +1,84 @@
+(.module:
+  [lux #*
+   ["_" test (#+ Test)]
+   [abstract
+    [monad (#+ do)]]
+   [control
+    [pipe (#+ do>)]
+    ["." io (#+ IO)]
+    ["." try]
+    ["." function]]
+   [data
+    ["." binary]
+    ["." product]
+    [text
+     ["%" format (#+ format)]
+     [encoding
+      ["." utf8]]]]
+   [math
+    ["." random (#+ Random)]
+    [number
+     ["." nat]]]]
+  {1
+   ["." /
+    ["/#" //
+     ["#." status]]]})
+
+(def: #export test
+  Test
+  (<| (_.covering /._)
+      (_.for [/.Client])
+      (do random.monad
+        [on_post random.nat
+         on_get random.nat
+         on_put random.nat
+         on_patch random.nat
+         on_delete random.nat
+         on_head random.nat
+         on_connect random.nat
+         on_options random.nat
+         on_trace random.nat
+         #let [mock (: (/.Client IO)
+                       (implementation
+                        (def: (request method url headers data)
+                          (io.io (let [value (case method
+                                               #//.Post on_post
+                                               #//.Get on_get
+                                               #//.Put on_put
+                                               #//.Patch on_patch
+                                               #//.Delete on_delete
+                                               #//.Head on_head
+                                               #//.Connect on_connect
+                                               #//.Options on_options
+                                               #//.Trace on_trace)
+                                       data (|> value
+                                                (\ nat.decimal encode)
+                                                (\ utf8.codec encode))]
+                                   (#try.Success [//status.ok
+                                                  {#//.headers headers
+                                                   #//.body (function (_ ?wanted_bytes)
+                                                              (io.io (#try.Success [(binary.size data)
+                                                                                    data])))}]))))))]]
+        (`` ($_ _.and
+                (~~ (template [<definition> <expected>]
+                      [(_.cover [<definition>]
+                                (|> (<definition> "" //.empty #.None mock)
+                                    (do> try.monad
+                                         [io.run]
+                                         [product.right (get@ #//.body) (function.apply #.None) io.run]
+                                         [product.right (\ utf8.codec decode)]
+                                         [(\ nat.decimal decode)]
+                                         [(nat.= <expected>) wrap])
+                                    (try.default false)))]
+
+                      [/.post on_post]
+                      [/.get on_get]
+                      [/.put on_put]
+                      [/.patch on_patch]
+                      [/.delete on_delete]
+                      [/.head on_head]
+                      [/.connect on_connect]
+                      [/.options on_options]
+                      [/.trace on_trace]
+                      ))
+                )))))
diff --git a/stdlib/source/test/lux/world/shell.lux b/stdlib/source/test/lux/world/shell.lux
index fa7d77f22..334250a96 100644
--- a/stdlib/source/test/lux/world/shell.lux
+++ b/stdlib/source/test/lux/world/shell.lux
@@ -35,7 +35,7 @@
 (def: (simulation [environment working_directory command arguments])
   (-> [Environment Path /.Command (List /.Argument)]
       (/.Simulation Bit))
-  (structure
+  (implementation
    (def: (on_read dead?)
      (if dead?
        (exception.throw ..dead [])
@@ -65,14 +65,14 @@
 
 (def: (io_shell command oops input destruction exit)
   (-> /.Command Text Text Text /.Exit (/.Shell IO))
-  (structure
+  (implementation
    (def: execute
      ((debug.private /.can_execute)
       (function (_ [environment working_directory command arguments])
         (io.io
          (#try.Success
           (: (/.Process IO)
-             (structure
+             (implementation
               (def: read
                 ((debug.private /.can_read)
                  (function (_ _)