Replaced "contains?" function with "key?" function.

25 files changed, 275 insertions, 134 deletions

diff --git a/stdlib/source/lux/data/collection/dictionary.lux b/stdlib/source/lux/data/collection/dictionary.lux
index efb99a8b4..8ca61b453 100644
--- a/stdlib/source/lux/data/collection/dictionary.lux
+++ b/stdlib/source/lux/data/collection/dictionary.lux
@@ -574,8 +574,8 @@
   (let [[Hash<k> node] dict]
     (get' root-level (\ Hash<k> hash key) key Hash<k> node)))
 
-(def: #export (contains? key dict)
-  (All [k v] (-> k (Dictionary k v) Bit))
+(def: #export (key? dict key)
+  (All [k v] (-> (Dictionary k v) k Bit))
   (case (get key dict)
     #.None     #0
     (#.Some _) #1))
diff --git a/stdlib/source/lux/data/collection/dictionary/ordered.lux b/stdlib/source/lux/data/collection/dictionary/ordered.lux
index b924a2e5d..c558a7669 100644
--- a/stdlib/source/lux/data/collection/dictionary/ordered.lux
+++ b/stdlib/source/lux/data/collection/dictionary/ordered.lux
@@ -75,8 +75,10 @@
                 (recur (get@ #right node))))
         ))))
 
-(def: #export (contains? key dict)
-  (All [k v] (-> k (Dictionary k v) Bit))
+## TODO: Doing inneficient access of Order functions due to compiler bug.
+## TODO: Must improve it as soon as bug is fixed.
+(def: #export (key? dict key)
+  (All [k v] (-> (Dictionary k v) k Bit))
   (let [## (^open "_\.") (get@ #&order dict)
         ]
     (loop [node (get@ #root dict)]
diff --git a/stdlib/source/lux/data/collection/set.lux b/stdlib/source/lux/data/collection/set.lux
index 80cdf89a6..b47c5761d 100644
--- a/stdlib/source/lux/data/collection/set.lux
+++ b/stdlib/source/lux/data/collection/set.lux
@@ -35,9 +35,9 @@
   (All [a] (-> a (Set a) (Set a)))
   //.remove)
 
-(def: #export (member? set elem)
+(def: #export member?
   (All [a] (-> (Set a) a Bit))
-  (//.contains? elem set))
+  //.key?)
 
 (def: #export to-list
   (All [a] (-> (Set a) (List a)))
diff --git a/stdlib/source/lux/data/collection/set/ordered.lux b/stdlib/source/lux/data/collection/set/ordered.lux
index d350c1e9c..7a2584227 100644
--- a/stdlib/source/lux/data/collection/set/ordered.lux
+++ b/stdlib/source/lux/data/collection/set/ordered.lux
@@ -20,7 +20,7 @@
 
   (def: #export (member? set elem)
     (All [a] (-> (Set a) a Bit))
-    (|> set :representation (/.contains? elem)))
+    (/.key? (:representation set) elem))
 
   (template [<type> <name> <alias>]
     [(def: #export <name>
diff --git a/stdlib/source/lux/data/number/i16.lux b/stdlib/source/lux/data/number/i16.lux
index 44fe0e988..4ca313730 100644
--- a/stdlib/source/lux/data/number/i16.lux
+++ b/stdlib/source/lux/data/number/i16.lux
@@ -15,6 +15,7 @@
                                 ..sub}
                                (I64 size)))
 
-(def: #export i16 (-> I64 I16) (get@ #i64.narrow ..sub))
-(def: #export i64 (-> I16 I64) (get@ #i64.wide ..sub))
-(def: #export equivalence (Equivalence I16) (get@ #i64.equivalence ..sub))
+(def: #export equivalence (Equivalence I16) (\ ..sub &equivalence))
+(def: #export width Nat (\ ..sub width))
+(def: #export i16 (-> I64 I16) (\ ..sub narrow))
+(def: #export i64 (-> I16 I64) (\ ..sub widen))
diff --git a/stdlib/source/lux/data/number/i32.lux b/stdlib/source/lux/data/number/i32.lux
index 560168f6f..35391519b 100644
--- a/stdlib/source/lux/data/number/i32.lux
+++ b/stdlib/source/lux/data/number/i32.lux
@@ -15,6 +15,7 @@
                                 ..sub}
                                (I64 size)))
 
-(def: #export i32 (-> I64 I32) (get@ #i64.narrow ..sub))
-(def: #export i64 (-> I32 I64) (get@ #i64.wide ..sub))
-(def: #export equivalence (Equivalence I32) (get@ #i64.equivalence ..sub))
+(def: #export equivalence (Equivalence I32) (\ ..sub &equivalence))
+(def: #export width Nat (\ ..sub width))
+(def: #export i32 (-> I64 I32) (\ ..sub narrow))
+(def: #export i64 (-> I32 I64) (\ ..sub widen))
diff --git a/stdlib/source/lux/data/number/i64.lux b/stdlib/source/lux/data/number/i64.lux
index 79bf7632d..249ae9046 100644
--- a/stdlib/source/lux/data/number/i64.lux
+++ b/stdlib/source/lux/data/number/i64.lux
@@ -143,25 +143,33 @@
   [conjunction ..true ..and]
   )
 
-(type: #export (Sub size)
-  {#narrow (-> I64 (I64 size))
-   #wide (-> (I64 size) I64)
-   #equivalence (Equivalence (I64 size))})
+(signature: #export (Sub size)
+  (: (Equivalence (I64 size))
+     &equivalence)
+  (: Nat
+     width)
+  (: (-> I64 (I64 size))
+     narrow)
+  (: (-> (I64 size) I64)
+     widen))
 
 (def: #export (sub width)
   (Ex [size] (-> Nat (Maybe (Sub size))))
   (if (.and (n.> 0 width)
             (n.< ..width width))
-    (let [top (dec width)
-          shift (n.- width ..width)
-          sign (..bit top)
-          number (..mask (dec width))]
-      (#.Some {#narrow (function (narrow value)
-                         (..or (|> value (..and ..sign) (..logic-right-shift shift))
-                               (|> value (..and number))))
-               #wide (function (wide value)
-                       (|> (..or (|> value (..and sign) (..left-shift shift))
-                                 (|> value (..clear top)))
-                           .i64))
-               #equivalence ..equivalence}))
+    (let [sign-shift (n.- width ..width)
+          sign (..bit (dec width))
+          mantissa (..mask (dec width))
+          co-mantissa (..xor (.i64 -1) mantissa)]
+      (#.Some (: Sub
+                 (structure
+                  (def: &equivalence ..equivalence)
+                  (def: width width)
+                  (def: (narrow value)
+                    (..or (|> value (..and ..sign) (..logic-right-shift sign-shift))
+                          (|> value (..and mantissa))))
+                  (def: (widen value)
+                    (.i64 (case (.nat (..and sign value))
+                            0 value
+                            _ (..or co-mantissa value))))))))
     #.None))
diff --git a/stdlib/source/lux/data/number/i8.lux b/stdlib/source/lux/data/number/i8.lux
index a6475eb15..49b9cca95 100644
--- a/stdlib/source/lux/data/number/i8.lux
+++ b/stdlib/source/lux/data/number/i8.lux
@@ -15,6 +15,7 @@
                                ..sub}
                               (I64 size)))
 
-(def: #export i8 (-> I64 I8) (get@ #i64.narrow ..sub))
-(def: #export i64 (-> I8 I64) (get@ #i64.wide ..sub))
-(def: #export equivalence (Equivalence I8) (get@ #i64.equivalence ..sub))
+(def: #export equivalence (Equivalence I8) (\ ..sub &equivalence))
+(def: #export width Nat (\ ..sub width))
+(def: #export i8 (-> I64 I8) (\ ..sub narrow))
+(def: #export i64 (-> I8 I64) (\ ..sub widen))
diff --git a/stdlib/source/lux/target/jvm/loader.lux b/stdlib/source/lux/target/jvm/loader.lux
index 74bfabc44..8f9f47e4f 100644
--- a/stdlib/source/lux/target/jvm/loader.lux
+++ b/stdlib/source/lux/target/jvm/loader.lux
@@ -130,7 +130,7 @@
   (-> Text Binary Library (IO (Try Any)))
   (do {! io.monad}
     [library' (atom.read library)]
-    (if (dictionary.contains? name library')
+    (if (dictionary.key? library' name)
       (wrap (exception.throw ..already-stored name))
       (do !
         [_ (atom.update (dictionary.put name bytecode) library)]
diff --git a/stdlib/source/lux/tool/compiler/version.lux b/stdlib/source/lux/tool/compiler/version.lux
index 3965b9b28..df405e75d 100644
--- a/stdlib/source/lux/tool/compiler/version.lux
+++ b/stdlib/source/lux/tool/compiler/version.lux
@@ -1,5 +1,50 @@
 (.module:
-  [lux #*])
+  [lux #*
+   [data
+    [number
+     ["n" nat]]
+    [text
+     ["%" format]]]])
 
 (type: #export Version
   Nat)
+
+(def: range 100)
+
+(def: level
+  (n.% ..range))
+
+(def: current
+  (-> Nat Nat)
+  (|>>))
+
+(def: next
+  (n./ ..range))
+
+(def: #export patch
+  (-> Version Nat)
+  (|>> ..current ..level))
+
+(def: #export minor
+  (-> Version Nat)
+  (|>> ..next ..level))
+
+(def: #export major
+  (-> Version Nat)
+  (|>> ..next ..next ..level))
+
+(def: separator ".")
+
+(def: (padded value)
+  (-> Nat Text)
+  (if (n.< 10 value)
+    (%.format "0" (%.nat value))
+    (%.nat value)))
+
+(def: #export (format version)
+  (%.Format Version)
+  (%.format (..padded (..major version))
+            ..separator
+            (..padded (..minor version))
+            ..separator
+            (..padded (..patch version))))
diff --git a/stdlib/source/lux/world/file/watch.lux b/stdlib/source/lux/world/file/watch.lux
index a1bb5a6de..5d995bbd4 100644
--- a/stdlib/source/lux/world/file/watch.lux
+++ b/stdlib/source/lux/world/file/watch.lux
@@ -147,8 +147,7 @@
   (do {! (try.with promise.monad)}
     [current-files (..poll-files directory file-tracker)
      #let [creations (if (..creation? concern)
-                       (list.filter (function (_ [path file last-modified])
-                                      (not (dictionary.contains? path file-tracker)))
+                       (list.filter (|>> product.left (dictionary.key? file-tracker) not)
                                     current-files)
                        (list))
            available (|> current-files
diff --git a/stdlib/source/program/aedifex.lux b/stdlib/source/program/aedifex.lux
index d876b5665..2478b4016 100644
--- a/stdlib/source/program/aedifex.lux
+++ b/stdlib/source/program/aedifex.lux
@@ -48,6 +48,7 @@
    ["#." dependency #_
     ["#" resolution (#+ Resolution)]]
    ["#." command (#+ Command)
+    ["#/." version]
     ["#/." clean]
     ["#/." pom]
     ["#/." install]
@@ -87,6 +88,10 @@
     (case ?profile
       (#try.Success profile)
       (case operation
+        #/cli.Version
+        (exec (/command/version.do! profile)
+          (wrap []))
+        
         #/cli.Clean
         (exec (/command/clean.do! (file.async file.default) profile)
           (wrap []))
diff --git a/stdlib/source/program/aedifex/cli.lux b/stdlib/source/program/aedifex/cli.lux
index d52bf4df6..7af7405a9 100644
--- a/stdlib/source/program/aedifex/cli.lux
+++ b/stdlib/source/program/aedifex/cli.lux
@@ -32,6 +32,7 @@
          (cli.this "test")))
 
 (type: #export Command
+  #Version
   #Clean
   #POM
   #Dependencies
@@ -43,6 +44,8 @@
 (def: #export equivalence
   (Equivalence Command)
   ($_ equivalence.sum
+      ## #Version
+      ..any-equivalence
       ## #Clean
       ..any-equivalence
       ## #POM
@@ -64,6 +67,7 @@
 (def: command'
   (Parser Command)
   ($_ <>.or
+      (cli.this "version")
       (cli.this "clean")
       (cli.this "pom")
       (cli.this "deps")
diff --git a/stdlib/source/program/aedifex/command/version.lux b/stdlib/source/program/aedifex/command/version.lux
new file mode 100644
index 000000000..8f26a7fb7
--- /dev/null
+++ b/stdlib/source/program/aedifex/command/version.lux
@@ -0,0 +1,16 @@
+(.module:
+  [lux #*
+   [tool
+    [compiler
+     ["." version]
+     ["." language #_
+      ["#/." lux #_
+       ["#" version]]]]]]
+  ["." /// #_
+   [command (#+ Command)]
+   ["#." action]])
+
+(def: #export (do! profile)
+  (Command Any)
+  (\ ///action.monad wrap
+     (log! (version.format language/lux.version))))
diff --git a/stdlib/source/test/aedifex.lux b/stdlib/source/test/aedifex.lux
index 02d2b8ed2..9166a4367 100644
--- a/stdlib/source/test/aedifex.lux
+++ b/stdlib/source/test/aedifex.lux
@@ -9,6 +9,7 @@
    ["#." artifact]
    ["#." input]
    ["#." command #_
+    ["#/." version]
     ["#/." clean]
     ["#/." pom]
     ["#/." install]
@@ -36,6 +37,7 @@
   ($_ _.and
       /artifact.test
       /input.test
+      /command/version.test
       /command/clean.test
       /command/pom.test
       /command/install.test
diff --git a/stdlib/source/test/aedifex/cli.lux b/stdlib/source/test/aedifex/cli.lux
index 805ccee03..c4c76f32f 100644
--- a/stdlib/source/test/aedifex/cli.lux
+++ b/stdlib/source/test/aedifex/cli.lux
@@ -29,6 +29,8 @@
 (def: command
   (Random /.Command)
   ($_ random.or
+      ## #Version
+      (random\wrap [])
       ## #Clean
       (random\wrap [])
       ## #POM
@@ -56,6 +58,7 @@
 (def: (format value)
   (-> /.Command (List Text))
   (case value
+    #/.Version (list "version")
     #/.Clean (list "clean")
     #/.POM (list "pom")
     #/.Dependencies (list "deps")
diff --git a/stdlib/source/test/aedifex/command/deps.lux b/stdlib/source/test/aedifex/command/deps.lux
index 42739a5ff..2f221a7ce 100644
--- a/stdlib/source/test/aedifex/command/deps.lux
+++ b/stdlib/source/test/aedifex/command/deps.lux
@@ -82,7 +82,7 @@
                                      (/.do! fs (list (///repository.mock ($///dependency/resolution.single depender-artifact depender-package) []))))]
                            (wrap (and (and (set.member? pre dependee-artifact)
                                            (not (set.member? pre depender-artifact)))
-                                      (and (dictionary.contains? dependee post)
-                                           (dictionary.contains? depender post)))))]
+                                      (and (dictionary.key? post dependee)
+                                           (dictionary.key? post depender)))))]
                 (_.cover' [/.do!]
                           (try.default false verdict)))))))
diff --git a/stdlib/source/test/aedifex/command/version.lux b/stdlib/source/test/aedifex/command/version.lux
new file mode 100644
index 000000000..f6196556d
--- /dev/null
+++ b/stdlib/source/test/aedifex/command/version.lux
@@ -0,0 +1,27 @@
+(.module:
+  [lux #*
+   ["_" test (#+ Test)]
+   [abstract
+    [monad (#+ do)]]
+   [control
+    ["." try]
+    [concurrency
+     ["." promise]]]
+   [math
+    ["." random]]]
+  [///
+   ["@." profile]]
+  {#program
+   ["." /]})
+
+(def: #export test
+  Test
+  (<| (_.covering /._)
+      (do random.monad
+        [profile @profile.random]
+        (wrap (do promise.monad
+                [verdict (do (try.with promise.monad)
+                           [_ (/.do! profile)]
+                           (wrap true))]
+                (_.cover' [/.do!]
+                          (try.default false verdict)))))))
diff --git a/stdlib/source/test/aedifex/dependency/resolution.lux b/stdlib/source/test/aedifex/dependency/resolution.lux
index b426a100d..0b3bf1634 100644
--- a/stdlib/source/test/aedifex/dependency/resolution.lux
+++ b/stdlib/source/test/aedifex/dependency/resolution.lux
@@ -346,9 +346,9 @@
            (_.cover' [/.all]
                      (case resolution
                        (#try.Success resolution)
-                       (and (dictionary.contains? depender resolution)
-                            (dictionary.contains? dependee resolution)
-                            (not (dictionary.contains? ignored resolution)))
+                       (and (dictionary.key? resolution depender)
+                            (dictionary.key? resolution dependee)
+                            (not (dictionary.key? resolution ignored)))
 
                        (#try.Failure error)
                        false))))
diff --git a/stdlib/source/test/lux/data/collection/dictionary.lux b/stdlib/source/test/lux/data/collection/dictionary.lux
index 718c9f0c9..b852f8dbf 100644
--- a/stdlib/source/test/lux/data/collection/dictionary.lux
+++ b/stdlib/source/test/lux/data/collection/dictionary.lux
@@ -2,6 +2,7 @@
   [lux #*
    ["_" test (#+ Test)]
    [abstract
+    [hash (#+ Hash)]
     [monad (#+ do)]
     ["." equivalence]
     {[0 #spec]
@@ -28,12 +29,14 @@
 
 (def: for-dictionaries
   Test
-  (do random.monad
+  (do {! random.monad}
     [#let [capped-nat (\ random.monad map (n.% 100) random.nat)]
      size capped-nat
      dict (random.dictionary n.hash size random.nat capped-nat)
-     non-key (|> random.nat (random.filter (function (_ key) (not (/.contains? key dict)))))
-     test-val (|> random.nat (random.filter (function (_ val) (not (list.member? n.equivalence (/.values dict) val)))))]
+     non-key (random.filter (|>> (/.key? dict) not)
+                            random.nat)
+     test-val (random.filter (|>> (list.member? n.equivalence (/.values dict)) not)
+                             random.nat)]
     ($_ _.and
         (_.cover [/.size]
                  (n.= size (/.size dict)))
@@ -47,6 +50,16 @@
                  (let [sample (/.new n.hash)]
                    (and (n.= 0 (/.size sample))
                         (/.empty? sample))))
+
+        (do !
+          [constant random.nat
+           #let [hash (: (Hash Nat)
+                         (structure
+                          (def: &equivalence n.equivalence)
+                          (def: (hash _)
+                            constant)))]]
+          (_.cover [/.key-hash]
+                   (is? hash (/.key-hash (/.new hash)))))
         
         (_.cover [/.entries /.keys /.values]
                  (\ (list.equivalence (equivalence.product n.equivalence n.equivalence)) =
@@ -82,11 +95,13 @@
     [#let [capped-nat (\ random.monad map (n.% 100) random.nat)]
      size capped-nat
      dict (random.dictionary n.hash size random.nat capped-nat)
-     non-key (|> random.nat (random.filter (function (_ key) (not (/.contains? key dict)))))
-     test-val (|> random.nat (random.filter (function (_ val) (not (list.member? n.equivalence (/.values dict) val)))))]
+     non-key (random.filter (|>> (/.key? dict) not)
+                            random.nat)
+     test-val (random.filter (|>> (list.member? n.equivalence (/.values dict)) not)
+                             random.nat)]
     ($_ _.and
-        (_.cover [/.contains?]
-                 (list.every? (function (_ key) (/.contains? key dict))
+        (_.cover [/.key?]
+                 (list.every? (/.key? dict)
                               (/.keys dict)))
         
         (_.cover [/.get]
@@ -130,8 +145,8 @@
         
         (_.cover [/.remove]
                  (and (let [base (/.put non-key test-val dict)]
-                        (and (/.contains? non-key base)
-                             (not (/.contains? non-key (/.remove non-key base)))))
+                        (and (/.key? base non-key)
+                             (not (/.key? (/.remove non-key base) non-key))))
                       (case (list.head (/.keys dict))
                         #.None
                         true
@@ -186,8 +201,8 @@
                      (let [first-key (|> dict /.keys list.head maybe.assume)
                            rebound (/.re-bind first-key non-key dict)]
                        (and (n.= (/.size dict) (/.size rebound))
-                            (/.contains? non-key rebound)
-                            (not (/.contains? first-key rebound))
+                            (/.key? rebound non-key)
+                            (not (/.key? rebound first-key))
                             (n.= (maybe.assume (/.get first-key dict))
                                  (maybe.assume (/.get non-key rebound)))))))
         )))
@@ -200,8 +215,10 @@
         [#let [capped-nat (\ random.monad map (n.% 100) random.nat)]
          size capped-nat
          dict (random.dictionary n.hash size random.nat capped-nat)
-         non-key (|> random.nat (random.filter (function (_ key) (not (/.contains? key dict)))))
-         test-val (|> random.nat (random.filter (function (_ val) (not (list.member? n.equivalence (/.values dict) val)))))]
+         non-key (random.filter (|>> (/.key? dict) not)
+                                random.nat)
+         test-val (random.filter (|>> (list.member? n.equivalence (/.values dict)) not)
+                                 random.nat)]
         ($_ _.and
             (_.with-cover [/.equivalence]
               ($equivalence.spec (/.equivalence n.equivalence)
diff --git a/stdlib/source/test/lux/data/collection/dictionary/ordered.lux b/stdlib/source/test/lux/data/collection/dictionary/ordered.lux
index c34f3e3cf..01920fa1c 100644
--- a/stdlib/source/test/lux/data/collection/dictionary/ordered.lux
+++ b/stdlib/source/test/lux/data/collection/dictionary/ordered.lux
@@ -32,8 +32,7 @@
     _
     (do random.monad
       [partial (dictionary order gen-key gen-value (dec size))
-       key (random.filter (function (_ candidate)
-                            (not (/.contains? candidate partial)))
+       key (random.filter (|>> (/.key? partial) not)
                           gen-key)
        value gen-value]
       (wrap (/.put key value partial)))))
@@ -103,14 +102,14 @@
                      (|> sample
                          /.entries (/.from-list n.order)
                          (/\= sample)))
-            (_.cover [/.contains?]
-                     (and (list.every? (function (_ key) (/.contains? key sample))
+            (_.cover [/.key?]
+                     (and (list.every? (/.key? sample)
                                        (/.keys sample))
-                          (not (/.contains? extra-key sample))))
+                          (not (/.key? sample extra-key))))
             (_.cover [/.put]
-                     (and (not (/.contains? extra-key sample))
+                     (and (not (/.key? sample extra-key))
                           (let [sample+ (/.put extra-key extra-value sample)]
-                            (and (/.contains? extra-key sample+)
+                            (and (/.key? sample+ extra-key)
                                  (n.= (inc (/.size sample))
                                       (/.size sample+))))))
             (_.cover [/.get]
diff --git a/stdlib/source/test/lux/data/number/frac.lux b/stdlib/source/test/lux/data/number/frac.lux
index ca3d4d21c..b9669756d 100644
--- a/stdlib/source/test/lux/data/number/frac.lux
+++ b/stdlib/source/test/lux/data/number/frac.lux
@@ -10,7 +10,9 @@
       ["$." monoid]
       ["$." codec]]}]
    [data
-    ["." bit ("#\." equivalence)]]
+    ["." bit ("#\." equivalence)]
+    [text
+     ["%" format (#+ format)]]]
    [math
     ["." random (#+ Random)]]]
   {1
@@ -32,14 +34,15 @@
             ($equivalence.spec /.equivalence random.safe-frac))
           (_.with-cover [/.order /.<]
             ($order.spec /.order random.safe-frac))
-          (~~ (template [<monoid> <compose>]
+          (~~ (template [<compose> <monoid>]
                 [(_.with-cover [<monoid> <compose>]
                    ($monoid.spec /.equivalence <monoid> ..random))]
 
-                [/.addition /.+]
-                [/.multiplication /.*]
-                [/.minimum /.min]
-                [/.maximum /.max]
+                [/.+ /.addition]
+                [/.* /.multiplication]
+
+                [/.min /.minimum]
+                [/.max /.maximum]
                 ))
           (~~ (template [<codec>]
                 [(_.with-cover [<codec>]
@@ -161,16 +164,21 @@
                                   (/.* (/.signum sample) sample)))))
               (do random.monad
                 [expected random.frac]
-                ($_ _.and
-                    (_.cover [/.to-bits /.from-bits]
-                             (let [actual (|> expected /.to-bits /.from-bits)]
-                               (or (/.= expected actual)
-                                   (and (/.not-a-number? expected)
-                                        (/.not-a-number? actual)))))
-                    (_.cover [/.negate]
-                             (and (/.= +0.0 (/.+ (/.negate expected) expected))
-                                  (|> expected /.negate /.negate (/.= expected))))
-                    ))
+                (_.cover [/.to-bits /.from-bits]
+                         (let [actual (|> expected /.to-bits /.from-bits)]
+                           (or (/.= expected actual)
+                               (and (/.not-a-number? expected)
+                                    (/.not-a-number? actual))))))
+              (do random.monad
+                [expected random.safe-frac]
+                (_.cover [/.negate]
+                         (let [subtraction!
+                               (/.= +0.0 (/.+ (/.negate expected) expected))
+
+                               inverse!
+                               (|> expected /.negate /.negate (/.= expected))]
+                           (and subtraction!
+                                inverse!))))
               
               ..signature
               ..constant
diff --git a/stdlib/source/test/lux/data/number/i16.lux b/stdlib/source/test/lux/data/number/i16.lux
index f3d8030c0..038d6d7f2 100644
--- a/stdlib/source/test/lux/data/number/i16.lux
+++ b/stdlib/source/test/lux/data/number/i16.lux
@@ -1,39 +1,40 @@
 (.module:
   [lux #*
    ["_" test (#+ Test)]
-   [data
-    ["." name]
-    ["%" text/format (#+ format)]]
    [abstract
     [monad (#+ do)]
     {[0 #spec]
      [/
       ["$." equivalence]]}]
+   [data
+    [number
+     ["i" int]]]
    [math
-    ["r" random (#+ Random)]]]
+    ["." random (#+ Random)]]]
   {1
    ["." /
     ["/#" // #_
-     ["#." i64 (#+ Mask)]]]})
+     ["#." i64]]]})
 
-(def: #export i16
+(def: #export random
   (Random /.I16)
-  (\ r.functor map /.i16 r.i64))
-
-(def: mask
-  Mask
-  (//i64.or //i64.sign
-            (//i64.mask 15)))
+  (\ random.functor map /.i16 random.i64))
 
 (def: #export test
   Test
-  (<| (_.context (name.module (name-of /._)))
-      (do {! r.monad}
-        [expected (\ ! map (|>> (//i64.and ..mask) (: I64)) r.i64)]
+  (<| (_.covering /._)
+      (_.with-cover [/.I16])
+      (do {! random.monad}
+        [#let [limit (|> (dec /.width)
+                         //i64.mask
+                         .int
+                         inc)]
+         expected (\ ! map (i.% limit) random.int)]
         ($_ _.and
-            ($equivalence.spec /.equivalence ..i16)
+            (_.with-cover [/.equivalence]
+              ($equivalence.spec /.equivalence ..random))
             
-            (_.test "Can convert between I64 and I16"
-                    (let [actual (|> expected /.i16 /.i64)]
-                      (\ //i64.equivalence = expected actual)))
+            (_.cover [/.i16 /.i64 /.width]
+                     (let [actual (|> expected .i64 /.i16 /.i64)]
+                       (\ //i64.equivalence = expected actual)))
             ))))
diff --git a/stdlib/source/test/lux/data/number/i32.lux b/stdlib/source/test/lux/data/number/i32.lux
index 1bf6bfee7..11dd6f3f9 100644
--- a/stdlib/source/test/lux/data/number/i32.lux
+++ b/stdlib/source/test/lux/data/number/i32.lux
@@ -1,39 +1,40 @@
 (.module:
   [lux #*
    ["_" test (#+ Test)]
-   [data
-    ["." name]
-    ["%" text/format (#+ format)]]
    [abstract
     [monad (#+ do)]
     {[0 #spec]
      [/
       ["$." equivalence]]}]
+   [data
+    [number
+     ["i" int]]]
    [math
-    ["r" random (#+ Random)]]]
+    ["." random (#+ Random)]]]
   {1
    ["." /
     ["/#" // #_
-     ["#." i64 (#+ Mask)]]]})
+     ["#." i64]]]})
 
-(def: #export i32
+(def: #export random
   (Random /.I32)
-  (\ r.functor map /.i32 r.i64))
-
-(def: mask
-  Mask
-  (//i64.or //i64.sign
-            (//i64.mask 31)))
+  (\ random.functor map /.i32 random.i64))
 
 (def: #export test
   Test
-  (<| (_.context (name.module (name-of /._)))
-      (do {! r.monad}
-        [expected (\ ! map (|>> (//i64.and ..mask) (: I64)) r.i64)]
+  (<| (_.covering /._)
+      (_.with-cover [/.I32])
+      (do {! random.monad}
+        [#let [limit (|> (dec /.width)
+                         //i64.mask
+                         .int
+                         inc)]
+         expected (\ ! map (i.% limit) random.int)]
         ($_ _.and
-            ($equivalence.spec /.equivalence ..i32)
+            (_.with-cover [/.equivalence]
+              ($equivalence.spec /.equivalence ..random))
             
-            (_.test "Can convert between I64 and I32"
-                    (let [actual (|> expected /.i32 /.i64)]
-                      (\ //i64.equivalence = expected actual)))
+            (_.cover [/.i32 /.i64 /.width]
+                     (let [actual (|> expected .i64 /.i32 /.i64)]
+                       (\ //i64.equivalence = expected actual)))
             ))))
diff --git a/stdlib/source/test/lux/data/number/i8.lux b/stdlib/source/test/lux/data/number/i8.lux
index 88f456bca..b855ac1e0 100644
--- a/stdlib/source/test/lux/data/number/i8.lux
+++ b/stdlib/source/test/lux/data/number/i8.lux
@@ -1,39 +1,40 @@
 (.module:
   [lux #*
    ["_" test (#+ Test)]
-   [data
-    ["." name]
-    ["%" text/format (#+ format)]]
    [abstract
     [monad (#+ do)]
     {[0 #spec]
      [/
       ["$." equivalence]]}]
+   [data
+    [number
+     ["i" int]]]
    [math
-    ["r" random (#+ Random)]]]
+    ["." random (#+ Random)]]]
   {1
    ["." /
     ["/#" // #_
-     ["#." i64 (#+ Mask)]]]})
+     ["#." i64]]]})
 
-(def: #export i8
+(def: #export random
   (Random /.I8)
-  (\ r.functor map /.i8 r.i64))
-
-(def: mask
-  Mask
-  (//i64.or //i64.sign
-            (//i64.mask 7)))
+  (\ random.functor map /.i8 random.i64))
 
 (def: #export test
   Test
-  (<| (_.context (name.module (name-of /._)))
-      (do {! r.monad}
-        [expected (\ ! map (|>> (//i64.and ..mask) (: I64)) r.i64)]
+  (<| (_.covering /._)
+      (_.with-cover [/.I8])
+      (do {! random.monad}
+        [#let [limit (|> (dec /.width)
+                         //i64.mask
+                         .int
+                         inc)]
+         expected (\ ! map (i.% limit) random.int)]
         ($_ _.and
-            ($equivalence.spec /.equivalence ..i8)
+            (_.with-cover [/.equivalence]
+              ($equivalence.spec /.equivalence ..random))
             
-            (_.test "Can convert between I64 and I8"
-                    (let [actual (|> expected /.i8 /.i64)]
-                      (\ //i64.equivalence = expected actual)))
+            (_.cover [/.i8 /.i64 /.width]
+                     (let [actual (|> expected .i64 /.i8 /.i64)]
+                       (\ //i64.equivalence = expected actual)))
             ))))