Easy to use Rev constants.

86 files changed, 829 insertions, 649 deletions

diff --git a/stdlib/source/lux/control/parser.lux b/stdlib/source/lux/control/parser.lux
index ac01d0735..259748caa 100644
--- a/stdlib/source/lux/control/parser.lux
+++ b/stdlib/source/lux/control/parser.lux
@@ -110,9 +110,9 @@
   {#.doc "1-or-more combinator."}
   (All [s a]
     (-> (Parser s a) (Parser s (List a))))
-  (do {@ ..monad}
+  (do {! ..monad}
     [head parser]
-    (:: @ map (|>> (list& head))
+    (:: ! map (|>> (list& head))
         (some parser))))
 
 (def: #export (and p1 p2)
@@ -199,14 +199,14 @@
 (def: #export (sep-by sep p)
   {#.doc "Parsers instances of 'p' that are separated by instances of 'sep'."}
   (All [s a b] (-> (Parser s b) (Parser s a) (Parser s (List a))))
-  (do {@ ..monad}
+  (do {! ..monad}
     [?x (maybe p)]
     (case ?x
       #.None
       (wrap #.Nil)
       
       (#.Some x)
-      (do @
+      (do !
         [xs' (some (..and sep p))]
         (wrap (#.Cons x (list@map product.right xs'))))
       )))
diff --git a/stdlib/source/lux/control/region.lux b/stdlib/source/lux/control/region.lux
index 332546685..9965aee3e 100644
--- a/stdlib/source/lux/control/region.lux
+++ b/stdlib/source/lux/control/region.lux
@@ -54,9 +54,9 @@
   (All [m a]
     (-> (Monad m) (All [r] (Region r m a))
         (m (Try a))))
-  (do {@ Monad<m>}
+  (do {! Monad<m>}
     [[cleaners output] (computation [[] (list)])
-     results (monad.map @ (function (_ cleaner) (cleaner []))
+     results (monad.map ! (function (_ cleaner) (cleaner []))
                         cleaners)]
     (wrap (list@fold combine-outcomes output results))))
 
diff --git a/stdlib/source/lux/control/state.lux b/stdlib/source/lux/control/state.lux
index d42408984..d4aae98a6 100644
--- a/stdlib/source/lux/control/state.lux
+++ b/stdlib/source/lux/control/state.lux
@@ -80,10 +80,10 @@
 
 (def: #export (while condition body)
   (All [s] (-> (State s Bit) (State s Any) (State s Any)))
-  (do {@ ..monad}
+  (do {! ..monad}
     [execute? condition]
     (if execute?
-      (do @
+      (do !
         [_ body]
         (while condition body))
       (wrap []))))
diff --git a/stdlib/source/lux/data/number/rev.lux b/stdlib/source/lux/data/number/rev.lux
index 578f6f955..6345cf02d 100644
--- a/stdlib/source/lux/data/number/rev.lux
+++ b/stdlib/source/lux/data/number/rev.lux
@@ -446,3 +446,22 @@
   
   (def: &equivalence ..equivalence)
   (def: hash .nat))
+
+(template [<power> <name>]
+  [(def: #export <name>
+     Rev
+     (.rev (//i64.left-shift (//nat.- <power> 64) 1)))]
+
+  [01 /2]
+  [02 /4]
+  [03 /8]
+  [04 /16]
+  [05 /32]
+  [06 /64]
+  [07 /128]
+  [08 /256]
+  [09 /512]
+  [10 /1024]
+  [11 /2048]
+  [12 /4096]
+  )
diff --git a/stdlib/source/lux/test.lux b/stdlib/source/lux/test.lux
index aace53f25..dd00517d0 100644
--- a/stdlib/source/lux/test.lux
+++ b/stdlib/source/lux/test.lux
@@ -1,8 +1,9 @@
 (.module: {#.doc "Tools for unit & property-based/generative testing."}
   [lux (#- and)
    [abstract
-    ["." monad (#+ Monad do)]]
+    ["." monad (#+ do)]]
    [control
+    ["." try]
     ["." exception (#+ exception:)]
     ["." io]
     [concurrency
@@ -140,12 +141,12 @@
   (format documentation ..separator ..separator
           "Failed with this seed: " (%.nat seed)))
 
-(exception: #export (must-try-test-at-least-once) "")
+(exception: #export must-try-test-at-least-once)
 
 (def: #export (times amount test)
   (-> Nat Test Test)
   (cond (n.= 0 amount)
-        (fail (exception.construct must-try-test-at-least-once []))
+        (fail (exception.construct ..must-try-test-at-least-once []))
 
         (n.= 1 amount)
         test
@@ -321,6 +322,10 @@
                     (~ (code.text coverage))
                     (~ test)))))))
 
+(exception: #export (error-during-execution {error Text})
+  (exception.report
+   ["Error" (%.text error)]))
+
 (def: #export (in-parallel tests)
   (-> (List Test) Test)
   (do random.monad
@@ -328,14 +333,21 @@
      #let [prng (random.pcg-32 [..pcg-32-magic-inc seed])
            run! (: (-> Test Assertion)
                    (function (_ test)
-                     (|> test
-                         (random.run prng)
-                         product.right
+                     (|> (case (|> test
+                                   (random.run prng)
+                                   product.right
+                                   io.io
+                                   "lux try")
+                           (#try.Success output)
+                           output
+                           
+                           (#try.Failure error)
+                           (..assert (exception.construct ..error-during-execution [error]) false))
                          io.io
                          promise.future
                          promise@join)))]]
-    (wrap (do {@ promise.monad}
-            [assertions (monad.seq @ (list@map run! tests))]
+    (wrap (do {! promise.monad}
+            [assertions (monad.seq ! (list@map run! tests))]
             (wrap [(|> assertions
                        (list@map product.left)
                        (list@fold ..add-counters ..start))
diff --git a/stdlib/source/lux/tool/compiler/default/init.lux b/stdlib/source/lux/tool/compiler/default/init.lux
index f30f9f8db..a3eaa03e3 100644
--- a/stdlib/source/lux/tool/compiler/default/init.lux
+++ b/stdlib/source/lux/tool/compiler/default/init.lux
@@ -116,9 +116,9 @@
     [#let [module (get@ #///.module input)]
      _ (///directive.set-current-module module)]
     (///directive.lift-analysis
-     (do {@ ///phase.monad}
+     (do {! ///phase.monad}
        [_ (module.create hash module)
-        _ (monad.map @ module.import dependencies)
+        _ (monad.map ! module.import dependencies)
         #let [source (///analysis.source (get@ #///.module input) (get@ #///.code input))]
         _ (///analysis.set-source-code source)]
        (wrap [source [///generation.empty-buffer
@@ -225,18 +225,18 @@
       (let [dependencies (default-dependencies prelude input)]
         {#///.dependencies dependencies
          #///.process (function (_ state archive)
-                        (do {@ try.monad}
+                        (do {! try.monad}
                           [#let [hash (text@hash (get@ #///.code input))]
                            [state [source buffer]] (<| (///phase.run' state)
                                                        (..begin dependencies hash input))
                            #let [module (get@ #///.module input)]]
                           (loop [iteration (<| (///phase.run' state)
                                                (..iterate archive expander module source buffer ///syntax.no-aliases))]
-                            (do @
+                            (do !
                               [[state ?source&requirements&temporary-payload] iteration]
                               (case ?source&requirements&temporary-payload
                                 #.None
-                                (do @
+                                (do !
                                   [[state [analysis-module [final-buffer final-registry]]] (///phase.run' state (..end module))
                                    #let [descriptor {#descriptor.hash hash
                                                      #descriptor.name module
@@ -258,7 +258,7 @@
                                                                         (list@map product.left))
                                                   #///.process (function (_ state archive)
                                                                  (recur (<| (///phase.run' state)
-                                                                            (do {@ ///phase.monad}
+                                                                            (do {! ///phase.monad}
                                                                               [analysis-module (<| (: (Operation .Module))
                                                                                                    ///directive.lift-analysis
                                                                                                    extension.lift
@@ -269,7 +269,7 @@
                                                                                   (///generation.set-registry temporary-registry))
                                                                                _ (|> requirements
                                                                                      (get@ #///directive.referrals)
-                                                                                     (monad.map @ (execute! archive)))
+                                                                                     (monad.map ! (execute! archive)))
                                                                                temporary-payload (..get-current-payload temporary-payload)]
                                                                               (..iterate archive expander module source temporary-payload (..module-aliases analysis-module))))))})]))
                                 )))))}))))
diff --git a/stdlib/source/lux/tool/compiler/default/platform.lux b/stdlib/source/lux/tool/compiler/default/platform.lux
index d15bec236..5e3ad19f9 100644
--- a/stdlib/source/lux/tool/compiler/default/platform.lux
+++ b/stdlib/source/lux/tool/compiler/default/platform.lux
@@ -345,7 +345,7 @@
                           (stm.var ..independence))]
         (function (_ compile)
           (function (import! importer module)
-            (do {@ promise.monad}
+            (do {! promise.monad}
               [[return signal] (:share [<type-vars>]
                                        {<Context>
                                         initial}
@@ -354,10 +354,10 @@
                                                                    <Signal>])])
                                         (:assume
                                          (stm.commit
-                                          (do {@ stm.monad}
+                                          (do {! stm.monad}
                                             [dependence (if (text@= archive.runtime-module importer)
                                                           (stm.read dependence)
-                                                          (do @
+                                                          (do !
                                                             [[_ dependence] (stm.update (..depend importer module) dependence)]
                                                             (wrap dependence)))]
                                             (case (..verify-dependencies importer module dependence)
@@ -366,12 +366,12 @@
                                                      #.None])
 
                                               (#try.Success _)
-                                              (do @
+                                              (do !
                                                 [[archive state] (stm.read current)]
                                                 (if (archive.archived? archive module)
                                                   (wrap [(promise@wrap (#try.Success [archive state]))
                                                          #.None])
-                                                  (do @
+                                                  (do !
                                                     [@pending (stm.read pending)]
                                                     (case (dictionary.get module @pending)
                                                       (#.Some [return signal])
@@ -385,7 +385,7 @@
                                                                 (wrap [module-id archive]))
                                                               (archive.reserve module archive))
                                                         (#try.Success [module-id archive])
-                                                        (do @
+                                                        (do !
                                                           [_ (stm.write [archive state] current)
                                                            #let [[return signal] (:share [<type-vars>]
                                                                                          {<Context>
@@ -406,7 +406,7 @@
                    (wrap [])
                    
                    (#.Some [context module-id resolver])
-                   (do @
+                   (do !
                      [result (compile import! module-id context module)
                       result (case result
                                (#try.Failure error)
@@ -427,9 +427,9 @@
     (def: (updated-state archive state)
       (All [<type-vars>]
         (-> Archive <State+> (Try <State+>)))
-      (do {@ try.monad}
-        [modules (monad.map @ (function (_ module)
-                                (do @
+      (do {! try.monad}
+        [modules (monad.map ! (function (_ module)
+                                (do !
                                   [[descriptor document] (archive.find module archive)
                                    lux-module (document.read $.key document)]
                                   (wrap [module lux-module])))
@@ -474,7 +474,7 @@
             compiler (..parallel
                       context
                       (function (_ import! module-id [archive state] module)
-                        (do {@ (try.with promise.monad)}
+                        (do {! (try.with promise.monad)}
                           [#let [state (..set-current-module module state)]
                            input (context.read (get@ #&file-system platform)
                                                import
@@ -494,13 +494,13 @@
                                                          (Action [Archive <State+>]))
                                                      (:assume
                                                       recur)})]
-                              (do @
+                              (do !
                                 [[archive state] (case new-dependencies
                                                    #.Nil
                                                    (wrap [archive state])
 
                                                    (#.Cons _)
-                                                   (do @
+                                                   (do !
                                                      [archive,document+ (|> new-dependencies
                                                                             (list@map (import! module))
                                                                             (monad.seq ..monad))
@@ -523,7 +523,7 @@
                                     (continue! [archive state] more all-dependencies)
 
                                     (#.Right [[descriptor document] output])
-                                    (do @
+                                    (do !
                                       [#let [_ (log! (..module-compilation-log state))
                                              descriptor (set@ #descriptor.references (set.from-list text.hash all-dependencies) descriptor)]
                                        _ (..cache-module static platform module-id [[descriptor document] output])]
@@ -536,7 +536,7 @@
                                         (promise@wrap (#try.Failure error)))))
 
                                   (#try.Failure error)
-                                  (do @
+                                  (do !
                                     [_ (ioW.freeze (get@ #&file-system platform) static archive)]
                                     (promise@wrap (#try.Failure error))))))))))]
         (compiler archive.runtime-module compilation-module)))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis.lux
index 41c99534a..2d3b61280 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis.lux
@@ -109,16 +109,16 @@
     (/function.function compile function-name arg-name archive body)
 
     (^ (#.Form (list& functionC argsC+)))
-    (do {@ //.monad}
+    (do {! //.monad}
       [[functionT functionA] (/type.with-inference
                                (compile archive functionC))]
       (case functionA
         (#/.Reference (#reference.Constant def-name))
-        (do @
+        (do !
           [?macro (//extension.lift (meta.find-macro def-name))]
           (case ?macro
             (#.Some macro)
-            (do @
+            (do !
               [expansion (//extension.lift (/macro.expand-one expander def-name macro argsC+))]
               (compile archive expansion))
 
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/case.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/case.lux
index c9443b43f..2996ed6d0 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/case.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/case.lux
@@ -184,7 +184,7 @@
     
     [location (#.Tuple sub-patterns)]
     (/.with-location location
-      (do {@ ///.monad}
+      (do {! ///.monad}
         [inputT' (simplify-case inputT)]
         (.case inputT'
           (#.Product _)
@@ -202,17 +202,17 @@
                               
                               ## (n.= num-subs num-sub-patterns)
                               (list.zip/2 subs sub-patterns))]
-            (do @
+            (do !
               [[memberP+ thenA] (list@fold (: (All [a]
                                                 (-> [Type Code] (Operation [(List Pattern) a])
                                                     (Operation [(List Pattern) a])))
                                               (function (_ [memberT memberC] then)
-                                                (do @
+                                                (do !
                                                   [[memberP [memberP+ thenA]] ((:coerce (All [a] (-> (Maybe Nat) Type Code (Operation a) (Operation [Pattern a])))
                                                                                         analyse-pattern)
                                                                                #.None memberT memberC then)]
                                                   (wrap [(list& memberP memberP+) thenA]))))
-                                           (do @
+                                           (do !
                                              [nextA next]
                                              (wrap [(list) nextA]))
                                            (list.reverse matches))]
@@ -297,16 +297,16 @@
   (-> Phase (List [Code Code]) Phase)
   (.case branches
     (#.Cons [patternH bodyH] branchesT)
-    (do {@ ///.monad}
+    (do {! ///.monad}
       [[inputT inputA] (//type.with-inference
                          (analyse archive inputC))
        outputH (analyse-pattern #.None inputT patternH (analyse archive bodyH))
-       outputT (monad.map @
+       outputT (monad.map !
                           (function (_ [patternT bodyT])
                             (analyse-pattern #.None inputT patternT (analyse archive bodyT)))
                           branchesT)
        outputHC (|> outputH product.left /coverage.determine)
-       outputTC (monad.map @ (|>> product.left /coverage.determine) outputT)
+       outputTC (monad.map ! (|>> product.left /coverage.determine) outputT)
        _ (.case (monad.fold try.monad /coverage.merge outputHC outputTC)
            (#try.Success coverage)
            (///.assert non-exhaustive-pattern-matching [inputC branches coverage]
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/case/coverage.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/case/coverage.lux
index bb9eef8cb..792a779ab 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/case/coverage.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/case/coverage.lux
@@ -238,12 +238,12 @@
             (ex.throw redundant-pattern [so-far addition])
 
             ## else
-            (do {@ try.monad}
-              [casesM (monad.fold @
+            (do {! try.monad}
+              [casesM (monad.fold !
                                   (function (_ [tagA coverageA] casesSF')
                                     (case (dictionary.get tagA casesSF')
                                       (#.Some coverageSF)
-                                      (do @
+                                      (do !
                                         [coverageM (merge coverageA coverageSF)]
                                         (wrap (dictionary.put tagA coverageM casesSF')))
 
@@ -319,7 +319,7 @@
     ## This process must be repeated until no further productive
     ## merges can be done.
     [_ (#Alt leftS rightS)]
-    (do {@ try.monad}
+    (do {! try.monad}
       [#let [fuse-once (: (-> Coverage (List Coverage)
                               (Try [(Maybe Coverage)
                                     (List Coverage)]))
@@ -334,7 +334,7 @@
                                   (#try.Success altMSF)
                                   (case altMSF
                                     (#Alt _)
-                                    (do @
+                                    (do !
                                       [[success altsSF+] (recur altsSF')]
                                       (wrap [success (#.Cons altSF altsSF+)]))
 
@@ -349,7 +349,7 @@
              possibilitiesSF possibilitiesSF]
         (case successA
           (#.Some coverageA')
-          (do @
+          (do !
             [[successA' possibilitiesSF'] (fuse-once coverageA' possibilitiesSF)]
             (recur successA' possibilitiesSF'))
           
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/function.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/function.lux
index 2430ce82f..e06265806 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/function.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/function.lux
@@ -43,7 +43,7 @@
 
 (def: #export (function analyse function-name arg-name archive body)
   (-> Phase Text Text Phase)
-  (do {@ ///.monad}
+  (do {! ///.monad}
     [functionT (///extension.lift meta.expected-type)]
     (loop [expectedT functionT]
       (/.with-stack ..cannot-analyse [expectedT function-name arg-name body]
@@ -61,14 +61,14 @@
 
           (^template [<tag> <instancer>]
             (<tag> _)
-            (do @
+            (do !
               [[_ instanceT] (//type.with-env <instancer>)]
               (recur (maybe.assume (type.apply (list instanceT) expectedT)))))
           ([#.UnivQ check.existential]
            [#.ExQ check.var])
           
           (#.Var id)
-          (do @
+          (do !
             [?expectedT' (//type.with-env
                            (check.read id))]
             (case ?expectedT'
@@ -77,7 +77,7 @@
 
               ## Inference
               _
-              (do @
+              (do !
                 [[input-id inputT] (//type.with-env check.var)
                  [output-id outputT] (//type.with-env check.var)
                  #let [functionT (#.Function inputT outputT)]
@@ -88,7 +88,7 @@
               ))
 
           (#.Function inputT outputT)
-          (<| (:: @ map (.function (_ [scope bodyA])
+          (<| (:: ! map (.function (_ [scope bodyA])
                           (#/.Function (list@map (|>> /.variable)
                                                  (//scope.environment scope))
                                        bodyA)))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/inference.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/inference.lux
index 5f06a02cf..839fe1617 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/inference.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/inference.lux
@@ -124,7 +124,7 @@
         (general archive analyse (maybe.assume (type.apply (list varT) inferT)) args))
 
       (#.ExQ _)
-      (do {@ ///.monad}
+      (do {! ///.monad}
         [[var-id varT] (//type.with-env check.var)
          output (general archive analyse
                          (maybe.assume (type.apply (list varT) inferT))
@@ -133,7 +133,7 @@
                   (check.bound? var-id))
          _ (if bound?
              (wrap [])
-             (do @
+             (do !
                [newT new-named-type]
                (//type.with-env
                  (check.check varT newT))))]
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/module.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/module.lux
index 06b0c41c6..b04c02674 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/module.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/module.lux
@@ -223,9 +223,9 @@
 
 (def: (ensure-undeclared-tags module-name tags)
   (-> Text (List Tag) (Operation Any))
-  (do {@ ///.monad}
+  (do {! ///.monad}
     [bindings (..tags module-name)
-     _ (monad.map @
+     _ (monad.map !
                   (function (_ tag)
                     (case (plist.get tag bindings)
                       #.None
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/reference.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/reference.lux
index 827e36a2e..72e47e33d 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/reference.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/reference.lux
@@ -31,21 +31,21 @@
 (def: (definition def-name)
   (-> Name (Operation Analysis))
   (with-expansions [<return> (wrap (|> def-name ///reference.constant #/.Reference))]
-    (do {@ ///.monad}
+    (do {! ///.monad}
       [constant (///extension.lift (meta.find-def def-name))]
       (case constant
         (#.Left real-def-name)
         (definition real-def-name)
         
         (#.Right [exported? actualT def-anns _])
-        (do @
+        (do !
           [_ (//type.infer actualT)
            (^@ def-name [::module ::name]) (///extension.lift (meta.normalize def-name))
            current (///extension.lift meta.current-module-name)]
           (if (text@= current ::module)
             <return>
             (if exported?
-              (do @
+              (do !
                 [imported! (///extension.lift (meta.imported-by? ::module current))]
                 (if imported!
                   <return>
@@ -54,11 +54,11 @@
 
 (def: (variable var-name)
   (-> Text (Operation (Maybe Analysis)))
-  (do {@ ///.monad}
+  (do {! ///.monad}
     [?var (//scope.find var-name)]
     (case ?var
       (#.Some [actualT ref])
-      (do @
+      (do !
         [_ (//type.infer actualT)]
         (wrap (#.Some (|> ref ///reference.variable #/.Reference))))
 
@@ -69,14 +69,14 @@
   (-> Name (Operation Analysis))
   (case reference
     ["" simple-name]
-    (do {@ ///.monad}
+    (do {! ///.monad}
       [?var (variable simple-name)]
       (case ?var
         (#.Some varA)
         (wrap varA)
 
         #.None
-        (do @
+        (do !
           [this-module (///extension.lift meta.current-module-name)]
           (definition [this-module simple-name]))))
 
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/structure.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/structure.lux
index fd0b58449..3f8f023aa 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/structure.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/analysis/structure.lux
@@ -92,7 +92,7 @@
   (-> Phase Nat Bit Phase)
   (let [tag (/.tag lefts right?)]
     (function (recur valueC)
-      (do {@ ///.monad}
+      (do {! ///.monad}
         [expectedT (///extension.lift meta.expected-type)
          expectedT' (//type.with-env
                       (check.clean expectedT))]
@@ -102,7 +102,7 @@
             (let [flat (type.flatten-variant expectedT)]
               (case (list.nth tag flat)
                 (#.Some variant-type)
-                (do @
+                (do !
                   [valueA (//type.with-type variant-type
                             (analyse archive valueC))]
                   (wrap (/.variant [lefts right? valueA])))
@@ -115,7 +115,7 @@
               (recur valueC))
 
             (#.Var id)
-            (do @
+            (do !
               [?expectedT' (//type.with-env
                              (check.read id))]
               (case ?expectedT'
@@ -131,7 +131,7 @@
 
             (^template [<tag> <instancer>]
               (<tag> _)
-              (do @
+              (do !
                 [[instance-id instanceT] (//type.with-env <instancer>)]
                 (//type.with-type (maybe.assume (type.apply (list instanceT) expectedT))
                   (recur valueC))))
@@ -141,7 +141,7 @@
             (#.Apply inputT funT)
             (case funT
               (#.Var funT-id)
-              (do @
+              (do !
                 [?funT' (//type.with-env (check.read funT-id))]
                 (case ?funT'
                   (#.Some funT')
@@ -165,7 +165,7 @@
 
 (def: (typed-product archive analyse members)
   (-> Archive Phase (List Code) (Operation Analysis))
-  (do {@ ///.monad}
+  (do {! ///.monad}
     [expectedT (///extension.lift meta.expected-type)
      membersA+ (: (Operation (List Analysis))
                   (loop [membersT+ (type.flatten-tuple expectedT)
@@ -173,14 +173,14 @@
                     (case [membersT+ membersC+]
                       [(#.Cons memberT #.Nil) _]
                       (//type.with-type memberT
-                        (:: @ map (|>> list) (analyse archive (code.tuple membersC+))))
+                        (:: ! map (|>> list) (analyse archive (code.tuple membersC+))))
                       
                       [_ (#.Cons memberC #.Nil)]
                       (//type.with-type (type.tuple membersT+)
-                        (:: @ map (|>> list) (analyse archive memberC)))
+                        (:: ! map (|>> list) (analyse archive memberC)))
                       
                       [(#.Cons memberT membersT+') (#.Cons memberC membersC+')]
-                      (do @
+                      (do !
                         [memberA (//type.with-type memberT
                                    (analyse archive memberC))
                          memberA+ (recur membersT+' membersC+')]
@@ -192,7 +192,7 @@
 
 (def: #export (product archive analyse membersC)
   (-> Archive Phase (List Code) (Operation Analysis))
-  (do {@ ///.monad}
+  (do {! ///.monad}
     [expectedT (///extension.lift meta.expected-type)]
     (/.with-stack ..cannot-analyse-tuple [expectedT membersC]
       (case expectedT
@@ -204,7 +204,7 @@
           (product archive analyse membersC))
 
         (#.Var id)
-        (do @
+        (do !
           [?expectedT' (//type.with-env
                          (check.read id))]
           (case ?expectedT'
@@ -214,8 +214,8 @@
 
             _
             ## Must do inference...
-            (do @
-              [membersTA (monad.map @ (|>> (analyse archive) //type.with-inference)
+            (do !
+              [membersTA (monad.map ! (|>> (analyse archive) //type.with-inference)
                                     membersC)
                _ (//type.with-env
                    (check.check expectedT
@@ -224,7 +224,7 @@
 
         (^template [<tag> <instancer>]
           (<tag> _)
-          (do @
+          (do !
             [[instance-id instanceT] (//type.with-env <instancer>)]
             (//type.with-type (maybe.assume (type.apply (list instanceT) expectedT))
               (product archive analyse membersC))))
@@ -234,7 +234,7 @@
         (#.Apply inputT funT)
         (case funT
           (#.Var funT-id)
-          (do @
+          (do !
             [?funT' (//type.with-env (check.read funT-id))]
             (case ?funT'
               (#.Some funT')
@@ -259,7 +259,7 @@
 
 (def: #export (tagged-sum analyse tag archive valueC)
   (-> Phase Name Phase)
-  (do {@ ///.monad}
+  (do {! ///.monad}
     [tag (///extension.lift (meta.normalize tag))
      [idx group variantT] (///extension.lift (meta.resolve-tag tag))
      #let [case-size (list.size group)
@@ -267,7 +267,7 @@
      expectedT (///extension.lift meta.expected-type)]
     (case expectedT
       (#.Var _)
-      (do @
+      (do !
         [inferenceT (//inference.variant idx case-size variantT)
          [inferredT valueA+] (//inference.general archive analyse inferenceT (list valueC))]
         (wrap (/.variant [lefts right? (|> valueA+ list.head maybe.assume)])))
@@ -304,7 +304,7 @@
     (:: ///.monad wrap [(list) Any])
 
     (#.Cons [head-k head-v] _)
-    (do {@ ///.monad}
+    (do {! ///.monad}
       [head-k (///extension.lift (meta.normalize head-k))
        [_ tag-set recordT] (///extension.lift (meta.resolve-tag head-k))
        #let [size-record (list.size record)
@@ -314,9 +314,9 @@
            (/.throw ..record-size-mismatch [size-ts size-record recordT record]))
        #let [tuple-range (list.indices size-ts)
              tag->idx (dictionary.from-list name.hash (list.zip/2 tag-set tuple-range))]
-       idx->val (monad.fold @
+       idx->val (monad.fold !
                             (function (_ [key val] idx->val)
-                              (do @
+                              (do !
                                 [key (///extension.lift (meta.normalize key))]
                                 (case (dictionary.get key tag->idx)
                                   (#.Some idx)
@@ -344,13 +344,13 @@
     (analyse archive singletonC)
 
     _
-    (do {@ ///.monad}
+    (do {! ///.monad}
       [members (normalize members)
        [membersC recordT] (order members)
        expectedT (///extension.lift meta.expected-type)]
       (case expectedT
         (#.Var _)
-        (do @
+        (do !
           [inferenceT (//inference.record recordT)
            [inferredT membersA] (//inference.general archive analyse inferenceT membersC)]
           (wrap (/.tuple membersA)))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/directive.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/directive.lux
index a58a3f323..855d1cf9f 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/directive.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/directive.lux
@@ -44,14 +44,14 @@
           (//extension.apply archive recur [name inputs])
 
           (^ [_ (#.Form (list& macro inputs))])
-          (do {@ //.monad}
+          (do {! //.monad}
             [expansion (/.lift-analysis
-                        (do @
+                        (do !
                           [macroA (//analysis/type.with-type Macro
                                     (analyze archive macro))]
                           (case macroA
                             (^ (///analysis.constant macro-name))
-                            (do @
+                            (do !
                               [?macro (//extension.lift (meta.find-macro macro-name))
                                macro (case ?macro
                                        (#.Some macro)
@@ -66,12 +66,12 @@
             (case expansion
               (^ (list& <lux_def_module> referrals))
               (|> (recur archive <lux_def_module>)
-                  (:: @ map (update@ #/.referrals (list@compose referrals))))
+                  (:: ! map (update@ #/.referrals (list@compose referrals))))
 
               _
               (|> expansion
-                  (monad.map @ (recur archive))
-                  (:: @ map (list@fold /.merge-requirements /.no-requirements)))))
+                  (monad.map ! (recur archive))
+                  (:: ! map (list@fold /.merge-requirements /.no-requirements)))))
 
           _
           (//.throw ..not-a-directive code))))))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/js.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/js.lux
index b195a11a2..708b93ddd 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/js.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/js.lux
@@ -111,10 +111,10 @@
   (custom
    [($_ <>.and <c>.any (<c>.tuple (<>.some <c>.any)))
     (function (_ extension phase archive [constructorC inputsC])
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [constructorA (type.with-type Any
                         (phase archive constructorC))
-         inputsA (monad.map @ (|>> (phase archive) (type.with-type Any)) inputsC)
+         inputsA (monad.map ! (|>> (phase archive) (type.with-type Any)) inputsC)
          _ (type.infer .Any)]
         (wrap (#analysis.Extension extension (list& constructorA inputsA)))))]))
 
@@ -135,10 +135,10 @@
   (custom
    [($_ <>.and <c>.text <c>.any (<c>.tuple (<>.some <c>.any)))
     (function (_ extension phase archive [methodC objectC inputsC])
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [objectA (type.with-type Any
                    (phase archive objectC))
-         inputsA (monad.map @ (|>> (phase archive) (type.with-type Any)) inputsC)
+         inputsA (monad.map ! (|>> (phase archive) (type.with-type Any)) inputsC)
          _ (type.infer .Any)]
         (wrap (#analysis.Extension extension (list& (analysis.text methodC)
                                                     objectA
@@ -171,10 +171,10 @@
   (custom
    [($_ <>.and <c>.any (<>.some <c>.any))
     (function (_ extension phase archive [abstractionC inputsC])
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [abstractionA (type.with-type Any
                         (phase archive abstractionC))
-         inputsA (monad.map @ (|>> (phase archive) (type.with-type Any)) inputsC)
+         inputsA (monad.map ! (|>> (phase archive) (type.with-type Any)) inputsC)
          _ (type.infer Any)]
         (wrap (#analysis.Extension extension (list& abstractionA inputsA)))))]))
 
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux
index 9900c6764..cd8784056 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux
@@ -288,9 +288,9 @@
         (/////analysis.throw ..primitives-cannot-have-type-parameters class))
 
       #.None
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [parametersJT (: (Operation (List (Type Parameter)))
-                         (monad.map @
+                         (monad.map !
                                     (function (_ parameterT)
                                       (do phase.monad
                                         [parameterJT (jvm-type parameterT)]
@@ -485,8 +485,8 @@
         (phase@map jvm.array))
     
     (#.Primitive name parameters)
-    (do {@ phase.monad}
-      [parameters (monad.map @ check-parameter parameters)]
+    (do {! phase.monad}
+      [parameters (monad.map ! check-parameter parameters)]
       (phase@wrap (jvm.class name parameters)))
 
     (#.Named name anonymous)
@@ -511,8 +511,8 @@
 
 (def: (check-object objectT)
   (-> .Type (Operation External))
-  (do {@ phase.monad}
-    [name (:: @ map ..reflection (check-jvm objectT))]
+  (do {! phase.monad}
+    [name (:: ! map ..reflection (check-jvm objectT))]
     (if (dictionary.contains? name ..boxes)
       (/////analysis.throw ..primitives-are-not-objects [name])
       (phase@wrap name))))
@@ -815,12 +815,12 @@
 
 (def: (class-candidate-parents from-name fromT to-name to-class)
   (-> External .Type External (java/lang/Class java/lang/Object) (Operation (List [[Text .Type] Bit])))
-  (do {@ phase.monad}
+  (do {! phase.monad}
     [from-class (phase.lift (reflection!.load from-name))
      mapping (phase.lift (reflection!.correspond from-class fromT))]
-    (monad.map @
+    (monad.map !
                (function (_ superJT)
-                 (do @
+                 (do !
                    [superJT (phase.lift (reflection!.type superJT))
                     #let [super-name (|> superJT ..reflection)]
                     super-class (phase.lift (reflection!.load super-name))
@@ -842,8 +842,8 @@
     (^ (#.Primitive _ (list& self-classT super-classT super-interfacesT+)))
     (monad.map phase.monad
                (function (_ superT)
-                 (do {@ phase.monad}
-                   [super-name (:: @ map ..reflection (check-jvm superT))
+                 (do {! phase.monad}
+                   [super-name (:: ! map ..reflection (check-jvm superT))
                     super-class (phase.lift (reflection!.load super-name))]
                    (wrap [[super-name superT]
                           (java/lang/Class::isAssignableFrom super-class to-class)])))
@@ -857,12 +857,12 @@
   (function (_ extension-name analyse archive args)
     (case args
       (^ (list fromC))
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [toT (///.lift meta.expected-type)
-         to-name (:: @ map ..reflection (check-jvm toT))
+         to-name (:: ! map ..reflection (check-jvm toT))
          [fromT fromA] (typeA.with-inference
                          (analyse archive fromC))
-         from-name (:: @ map ..reflection (check-jvm fromT))
+         from-name (:: ! map ..reflection (check-jvm fromT))
          can-cast? (: (Operation Bit)
                       (`` (cond (~~ (template [<primitive> <object>]
                                       [(let [=primitive (reflection.reflection <primitive>)]
@@ -883,7 +883,7 @@
                                       [reflection.char    box.char]))
 
                                 ## else
-                                (do @
+                                (do !
                                   [_ (phase.assert ..primitives-are-not-objects [from-name]
                                                    (not (dictionary.contains? from-name ..boxes)))
                                    _ (phase.assert ..primitives-are-not-objects [to-name]
@@ -891,14 +891,14 @@
                                    to-class (phase.lift (reflection!.load to-name))
                                    _ (if (text@= ..inheritance-relationship-type-name from-name)
                                        (wrap [])
-                                       (do @
+                                       (do !
                                          [from-class (phase.lift (reflection!.load from-name))]
                                          (phase.assert cannot-cast [fromT toT fromC]
                                                        (java/lang/Class::isAssignableFrom from-class to-class))))]
                                   (loop [[current-name currentT] [from-name fromT]]
                                     (if (text@= to-name current-name)
                                       (wrap true)
-                                      (do @
+                                      (do !
                                         [candidate-parents (: (Operation (List [[Text .Type] Bit]))
                                                               (if (text@= ..inheritance-relationship-type-name current-name)
                                                                 (inheritance-candidate-parents currentT to-class toT fromC)
@@ -1128,11 +1128,11 @@
                          array.to-list
                          (list@map (|>> java/lang/reflect/TypeVariable::getName)))
         [owner-tvarsT mapping] (jvm-type-var-mapping owner-tvars method-tvars)]
-    (do {@ phase.monad}
+    (do {! phase.monad}
       [inputsT (|> (java/lang/reflect/Method::getGenericParameterTypes method)
                    array.to-list
-                   (monad.map @ (|>> reflection!.type phase.lift))
-                   (phase@map (monad.map @ (..reflection-type mapping)))
+                   (monad.map ! (|>> reflection!.type phase.lift))
+                   (phase@map (monad.map ! (..reflection-type mapping)))
                    phase@join)
        outputT (|> method
                    java/lang/reflect/Method::getGenericReturnType
@@ -1142,8 +1142,8 @@
                    phase@join)
        exceptionsT (|> (java/lang/reflect/Method::getGenericExceptionTypes method)
                        array.to-list
-                       (monad.map @ (|>> reflection!.type phase.lift))
-                       (phase@map (monad.map @ (..reflection-type mapping)))
+                       (monad.map ! (|>> reflection!.type phase.lift))
+                       (phase@map (monad.map ! (..reflection-type mapping)))
                        phase@join)
        #let [methodT (<| (type.univ-q (dictionary.size mapping))
                          (type.function (case method-style
@@ -1166,16 +1166,16 @@
                          array.to-list
                          (list@map (|>> java/lang/reflect/TypeVariable::getName)))
         [owner-tvarsT mapping] (jvm-type-var-mapping owner-tvars method-tvars)]
-    (do {@ phase.monad}
+    (do {! phase.monad}
       [inputsT (|> (java/lang/reflect/Constructor::getGenericParameterTypes constructor)
                    array.to-list
-                   (monad.map @ (|>> reflection!.type phase.lift))
-                   (phase@map (monad.map @ (reflection-type mapping)))
+                   (monad.map ! (|>> reflection!.type phase.lift))
+                   (phase@map (monad.map ! (reflection-type mapping)))
                    phase@join)
        exceptionsT (|> (java/lang/reflect/Constructor::getGenericExceptionTypes constructor)
                        array.to-list
-                       (monad.map @ (|>> reflection!.type phase.lift))
-                       (phase@map (monad.map @ (reflection-type mapping)))
+                       (monad.map ! (|>> reflection!.type phase.lift))
+                       (phase@map (monad.map ! (reflection-type mapping)))
                        phase@join)
        #let [objectT (#.Primitive (java/lang/Class::getName owner) owner-tvarsT)
              constructorT (<| (type.univ-q (dictionary.size mapping))
@@ -1220,21 +1220,21 @@
 
 (def: (method-candidate actual-class-tvars class-name actual-method-tvars method-name method-style inputsJT)
   (-> (List (Type Var)) External (List (Type Var)) Text Method-Style (List (Type Value)) (Operation Method-Signature))
-  (do {@ phase.monad}
+  (do {! phase.monad}
     [class (phase.lift (reflection!.load class-name))
      #let [expected-class-tvars (class-type-variables class)]
      candidates (|> class
                     java/lang/Class::getDeclaredMethods
                     array.to-list
                     (list.filter (|>> java/lang/reflect/Method::getName (text@= method-name)))
-                    (monad.map @ (: (-> java/lang/reflect/Method (Operation Evaluation))
+                    (monad.map ! (: (-> java/lang/reflect/Method (Operation Evaluation))
                                     (function (_ method)
-                                      (do @
+                                      (do !
                                         [#let [expected-method-tvars (method-type-variables method)
                                                aliasing (dictionary.merge (..aliasing expected-class-tvars actual-class-tvars)
                                                                           (..aliasing expected-method-tvars actual-method-tvars))]
                                          passes? (check-method aliasing class method-name method-style inputsJT method)]
-                                        (:: @ map (if passes?
+                                        (:: ! map (if passes?
                                                     (|>> #Pass)
                                                     (|>> #Hint))
                                             (method-signature method-style method)))))))]
@@ -1252,19 +1252,19 @@
 
 (def: (constructor-candidate actual-class-tvars class-name actual-method-tvars inputsJT)
   (-> (List (Type Var)) External (List (Type Var)) (List (Type Value)) (Operation Method-Signature))
-  (do {@ phase.monad}
+  (do {! phase.monad}
     [class (phase.lift (reflection!.load class-name))
      #let [expected-class-tvars (class-type-variables class)]
      candidates (|> class
                     java/lang/Class::getConstructors
                     array.to-list
-                    (monad.map @ (function (_ constructor)
-                                   (do @
+                    (monad.map ! (function (_ constructor)
+                                   (do !
                                      [#let [expected-method-tvars (constructor-type-variables constructor)
                                             aliasing (dictionary.merge (..aliasing expected-class-tvars actual-class-tvars)
                                                                        (..aliasing expected-method-tvars actual-method-tvars))]
                                       passes? (check-constructor aliasing class inputsJT constructor)]
-                                     (:: @ map
+                                     (:: ! map
                                          (if passes? (|>> #Pass) (|>> #Hint))
                                          (constructor-signature constructor))))))]
     (case (list.all pass! candidates)
@@ -1469,16 +1469,16 @@
           <filter>
           (monad.map try.monad
                      (function (_ method)
-                       (do {@ try.monad}
+                       (do {! try.monad}
                          [inputs (|> (java/lang/reflect/Method::getGenericParameterTypes method)
                                      array.to-list
-                                     (monad.map @ reflection!.type))
+                                     (monad.map ! reflection!.type))
                           return (|> method
                                      java/lang/reflect/Method::getGenericReturnType
                                      reflection!.return)
                           exceptions (|> (java/lang/reflect/Method::getGenericExceptionTypes method)
                                          array.to-list
-                                         (monad.map @ reflection!.class))]
+                                         (monad.map ! reflection!.class))]
                          (wrap [(java/lang/reflect/Method::getName method)
                                 (jvm.method [inputs return exceptions])]))))))]
 
@@ -1575,26 +1575,26 @@
   (let [[visibility strict-fp?
          annotations vars exceptions
          self-name arguments super-arguments body] method]
-    (do {@ phase.monad}
-      [annotationsA (monad.map @ (function (_ [name parameters])
-                                   (do @
-                                     [parametersA (monad.map @ (function (_ [name value])
-                                                                 (do @
+    (do {! phase.monad}
+      [annotationsA (monad.map ! (function (_ [name parameters])
+                                   (do !
+                                     [parametersA (monad.map ! (function (_ [name value])
+                                                                 (do !
                                                                    [valueA (analyse archive value)]
                                                                    (wrap [name valueA])))
                                                              parameters)]
                                      (wrap [name parametersA])))
                                annotations)
-       super-arguments (monad.map @ (function (_ [jvmT super-argC])
-                                      (do @
+       super-arguments (monad.map ! (function (_ [jvmT super-argC])
+                                      (do !
                                         [luxT (reflection-type mapping jvmT)
                                          super-argA (typeA.with-type luxT
                                                       (analyse archive super-argC))]
                                         (wrap [jvmT super-argA])))
                                   super-arguments)
-       arguments' (monad.map @
+       arguments' (monad.map !
                              (function (_ [name jvmT])
-                               (do @
+                               (do !
                                  [luxT (reflection-type mapping jvmT)]
                                  (wrap [name luxT])))
                              arguments)
@@ -1657,20 +1657,20 @@
          final? strict-fp? annotations vars
          self-name arguments return exceptions
          body] method]
-    (do {@ phase.monad}
-      [annotationsA (monad.map @ (function (_ [name parameters])
-                                   (do @
-                                     [parametersA (monad.map @ (function (_ [name value])
-                                                                 (do @
+    (do {! phase.monad}
+      [annotationsA (monad.map ! (function (_ [name parameters])
+                                   (do !
+                                     [parametersA (monad.map ! (function (_ [name value])
+                                                                 (do !
                                                                    [valueA (analyse archive value)]
                                                                    (wrap [name valueA])))
                                                              parameters)]
                                      (wrap [name parametersA])))
                                annotations)
        returnT (reflection-return mapping return)
-       arguments' (monad.map @
+       arguments' (monad.map !
                              (function (_ [name jvmT])
-                               (do @
+                               (do !
                                  [luxT (reflection-type mapping jvmT)]
                                  (wrap [name luxT])))
                              arguments)
@@ -1731,20 +1731,20 @@
          strict-fp? annotations vars exceptions
          arguments return
          body] method]
-    (do {@ phase.monad}
-      [annotationsA (monad.map @ (function (_ [name parameters])
-                                   (do @
-                                     [parametersA (monad.map @ (function (_ [name value])
-                                                                 (do @
+    (do {! phase.monad}
+      [annotationsA (monad.map ! (function (_ [name parameters])
+                                   (do !
+                                     [parametersA (monad.map ! (function (_ [name value])
+                                                                 (do !
                                                                    [valueA (analyse archive value)]
                                                                    (wrap [name valueA])))
                                                              parameters)]
                                      (wrap [name parametersA])))
                                annotations)
        returnT (reflection-return mapping return)
-       arguments' (monad.map @
+       arguments' (monad.map !
                              (function (_ [name jvmT])
-                               (do @
+                               (do !
                                  [luxT (reflection-type mapping jvmT)]
                                  (wrap [name luxT])))
                              arguments)
@@ -1806,20 +1806,20 @@
          strict-fp? annotations vars
          self-name arguments return exceptions
          body] method]
-    (do {@ phase.monad}
-      [annotationsA (monad.map @ (function (_ [name parameters])
-                                   (do @
-                                     [parametersA (monad.map @ (function (_ [name value])
-                                                                 (do @
+    (do {! phase.monad}
+      [annotationsA (monad.map ! (function (_ [name parameters])
+                                   (do !
+                                     [parametersA (monad.map ! (function (_ [name value])
+                                                                 (do !
                                                                    [valueA (analyse archive value)]
                                                                    (wrap [name valueA])))
                                                              parameters)]
                                      (wrap [name parametersA])))
                                annotations)
        returnT (reflection-return mapping return)
-       arguments' (monad.map @
+       arguments' (monad.map !
                              (function (_ [name jvmT])
-                               (do @
+                               (do !
                                  [luxT (reflection-type mapping jvmT)]
                                  (wrap [name luxT])))
                              arguments)
@@ -1920,7 +1920,7 @@
                                                  super-interfaces
                                                  constructor-args
                                                  methods])
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [parameters (typeA.with-env
                       (..parameter-types parameters))
          #let [mapping (list@fold (function (_ [parameterJ parameterT] mapping)
@@ -1942,21 +1942,21 @@
                                                                 super-classT
                                                                 super-interfaceT+))))
          _ (typeA.infer selfT)
-         constructor-argsA+ (monad.map @ (function (_ [type term])
-                                           (do @
+         constructor-argsA+ (monad.map ! (function (_ [type term])
+                                           (do !
                                              [argT (reflection-type mapping type)
                                               termA (typeA.with-type argT
                                                       (analyse archive term))]
                                              (wrap [type termA])))
                                        constructor-args)
-         methodsA (monad.map @ (analyse-overriden-method analyse archive selfT mapping) methods)
+         methodsA (monad.map ! (analyse-overriden-method analyse archive selfT mapping) methods)
          required-abstract-methods (phase.lift (all-abstract-methods (list& super-class super-interfaces)))
          available-methods (phase.lift (all-methods (list& super-class super-interfaces)))
-         overriden-methods (monad.map @ (function (_ [parent-type method-name
+         overriden-methods (monad.map ! (function (_ [parent-type method-name
                                                       strict-fp? annotations vars
                                                       self-name arguments return exceptions
                                                       body])
-                                          (do @
+                                          (do !
                                             [aliasing (super-aliasing parent-type)]
                                             (wrap [method-name (|> (jvm.method [(list@map product.right arguments)
                                                                                 return
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/lux.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/lux.lux
index 1e3a18cba..0e6d9ba7d 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/lux.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/analysis/lux.lux
@@ -52,9 +52,9 @@
     (function (_ extension-name analyse archive args)
       (let [num-actual (list.size args)]
         (if (n.= num-expected num-actual)
-          (do {@ ////.monad}
+          (do {! ////.monad}
             [_ (typeA.infer outputT)
-             argsA (monad.map @
+             argsA (monad.map !
                               (function (_ [argT argC])
                                 (typeA.with-type argT
                                   (analyse archive argC)))
@@ -100,12 +100,12 @@
                                      <c>.any)))
          <c>.any)
      (function (_ extension-name phase archive [input conditionals else])
-       (do {@ ////.monad}
+       (do {! ////.monad}
          [input (typeA.with-type text.Char
                   (phase archive input))
           expectedT (///.lift meta.expected-type)
-          conditionals (monad.map @ (function (_ [cases branch])
-                                      (do @
+          conditionals (monad.map ! (function (_ [cases branch])
+                                      (do !
                                         [branch (typeA.with-type expectedT
                                                   (phase archive branch))]
                                         (wrap [cases branch])))
@@ -162,9 +162,9 @@
   (function (_ extension-name analyse archive args)
     (case args
       (^ (list typeC valueC))
-      (do {@ ////.monad}
+      (do {! ////.monad}
         [count (///.lift meta.count)
-         actualT (:: @ map (|>> (:coerce Type))
+         actualT (:: ! map (|>> (:coerce Type))
                      (eval archive count Type typeC))
          _ (typeA.infer actualT)]
         (typeA.with-type actualT
@@ -178,9 +178,9 @@
   (function (_ extension-name analyse archive args)
     (case args
       (^ (list typeC valueC))
-      (do {@ ////.monad}
+      (do {! ////.monad}
         [count (///.lift meta.count)
-         actualT (:: @ map (|>> (:coerce Type))
+         actualT (:: ! map (|>> (:coerce Type))
                      (eval archive count Type typeC))
          _ (typeA.infer actualT)
          [valueT valueA] (typeA.with-inference
@@ -195,7 +195,7 @@
   (..custom
    [<c>.any
     (function (_ extension-name phase archive valueC)
-      (do {@ ////.monad}
+      (do {! ////.monad}
         [_ (typeA.infer output)]
         (typeA.with-type input
           (phase archive valueC))))]))
@@ -205,10 +205,10 @@
   (..custom
    [<c>.any
     (function (_ extension-name phase archive valueC)
-      (do {@ ////.monad}
+      (do {! ////.monad}
         [_ (typeA.infer .Macro)
          input-type (loop [input-name (name-of .Macro')]
-                      (do @
+                      (do !
                         [input-type (///.lift (meta.find-def (name-of .Macro')))]
                         (case input-type
                           (#.Definition [exported? def-type def-data def-value])
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/directive/jvm.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/directive/jvm.lux
index 5a2770b70..b86c2488c 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/directive/jvm.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/directive/jvm.lux
@@ -257,7 +257,7 @@
                   annotations
                   fields
                   methods])
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [parameters (directive.lift-analysis
                      (typeA.with-env
                        (jvm.parameter-types parameters)))
@@ -280,7 +280,7 @@
          #let [analyse (get@ [#directive.analysis #directive.phase] state)
                synthesize (get@ [#directive.synthesis #directive.phase] state)
                generate (get@ [#directive.generation #directive.phase] state)]
-         methods (monad.map @ (..method-definition [mapping selfT] [analyse synthesize generate])
+         methods (monad.map ! (..method-definition [mapping selfT] [analyse synthesize generate])
                             methods)
          ## _ (directive.lift-generation
          ##    (generation.save! true ["" name]
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/directive/lux.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/directive/lux.lux
index 391c13cb1..d8d6ed817 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/directive/lux.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/directive/lux.lux
@@ -120,7 +120,7 @@
   (All [anchor expression directive]
     (-> Archive Name (Maybe Type) Code
         (Operation anchor expression directive [Type expression Any])))
-  (do {@ phase.monad}
+  (do {! phase.monad}
     [state (///.lift phase.get-state)
      #let [analyse (get@ [#/////directive.analysis #/////directive.phase] state)
            synthesize (get@ [#/////directive.synthesis #/////directive.phase] state)
@@ -130,7 +130,7 @@
                              (typeA.with-fresh-env
                                (case expected
                                  #.None
-                                 (do @
+                                 (do !
                                    [[code//type codeA] (typeA.with-inference
                                                          (analyse archive codeC))
                                     code//type (typeA.with-env
@@ -138,7 +138,7 @@
                                    (wrap [code//type codeA]))
 
                                  (#.Some expected)
-                                 (do @
+                                 (do !
                                    [codeA (typeA.with-type expected
                                             (analyse archive codeC))]
                                    (wrap [expected codeA]))))))
@@ -265,13 +265,13 @@
   (..custom
    [($_ p.and s.any ..imports)
     (function (_ extension-name phase archive [annotationsC imports])
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [[_ annotationsT annotationsV] (evaluate! archive Code annotationsC)
          #let [annotationsV (:coerce Code annotationsV)]
          _ (/////directive.lift-analysis
-            (do @
-              [_ (monad.map @ (function (_ [module alias])
-                                (do @
+            (do !
+              [_ (monad.map ! (function (_ [module alias])
+                                (do !
                                   [_ (module.import module)]
                                   (case alias
                                     "" (wrap [])
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/js/common.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/js/common.lux
index 546477aac..13d67f8fa 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/js/common.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/js/common.lux
@@ -155,13 +155,13 @@
                                          (<s>.tuple (<>.many <s>.i64))
                                          <s>.any))))
              (function (_ extension-name phase archive [input else conditionals])
-               (do {@ /////.monad}
+               (do {! /////.monad}
                  [inputG (phase archive input)
                   elseG (phase archive else)
                   conditionalsG (: (Operation (List [(List Literal)
                                                      Statement]))
-                                   (monad.map @ (function (_ [chars branch])
-                                                  (do @
+                                   (monad.map ! (function (_ [chars branch])
+                                                  (do !
                                                     [branchG (phase archive branch)]
                                                     (wrap [(list@map (|>> .int _.int) chars)
                                                            (_.return branchG)])))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/js/host.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/js/host.lux
index d9b52e450..f7cc747ff 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/js/host.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/js/host.lux
@@ -65,9 +65,9 @@
   (custom
    [($_ <>.and <s>.any (<>.some <s>.any))
     (function (_ extension phase archive [constructorS inputsS])
-      (do {@ ////////phase.monad}
+      (do {! ////////phase.monad}
         [constructorG (phase archive constructorS)
-         inputsG (monad.map @ (phase archive) inputsS)]
+         inputsG (monad.map ! (phase archive) inputsS)]
         (wrap (_.new constructorG inputsG))))]))
 
 (def: object::get
@@ -84,9 +84,9 @@
   (custom
    [($_ <>.and <s>.text <s>.any (<>.some <s>.any))
     (function (_ extension phase archive [methodS objectS inputsS])
-      (do {@ ////////phase.monad}
+      (do {! ////////phase.monad}
         [objectG (phase archive objectS)
-         inputsG (monad.map @ (phase archive) inputsS)]
+         inputsG (monad.map ! (phase archive) inputsS)]
         (wrap (_.do methodS inputsG objectG))))]))
 
 (template [<!> <?> <unit>]
@@ -122,21 +122,21 @@
   (custom
    [($_ <>.and <s>.any (<>.some <s>.any))
     (function (_ extension phase archive [abstractionS inputsS])
-      (do {@ ////////phase.monad}
+      (do {! ////////phase.monad}
         [abstractionG (phase archive abstractionS)
-         inputsG (monad.map @ (phase archive) inputsS)]
+         inputsG (monad.map ! (phase archive) inputsS)]
         (wrap (_.apply/* abstractionG inputsG))))]))
 
 (def: js::function
   (custom
    [($_ <>.and <s>.i64 <s>.any)
     (function (_ extension phase archive [arity abstractionS])
-      (do {@ ////////phase.monad}
+      (do {! ////////phase.monad}
         [abstractionG (phase archive abstractionS)
          #let [variable (: (-> Text (Operation Var))
                            (|>> generation.gensym
-                                (:: @ map _.var)))]
-         g!inputs (monad.map @ (function (_ _) (variable "input"))
+                                (:: ! map _.var)))]
+         g!inputs (monad.map ! (function (_ _) (variable "input"))
                              (list.repeat (.nat arity) []))
          g!abstraction (variable "abstraction")]
         (wrap (_.closure g!inputs
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/jvm/common.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/jvm/common.lux
index 313620611..68c69d153 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/jvm/common.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/extension/generation/jvm/common.lux
@@ -105,14 +105,14 @@
                                          (<s>.tuple (<>.many <s>.i64))
                                          <s>.any))))
              (function (_ extension-name phase archive [inputS elseS conditionalsS])
-               (do {@ /////.monad}
+               (do {! /////.monad}
                  [@end ///runtime.forge-label
                   inputG (phase archive inputS)
                   elseG (phase archive elseS)
                   conditionalsG+ (: (Operation (List [(List [S4 Label])
                                                       (Bytecode Any)]))
-                                    (monad.map @ (function (_ [chars branch])
-                                                   (do @
+                                    (monad.map ! (function (_ [chars branch])
+                                                   (do !
                                                      [branchG (phase archive branch)
                                                       @branch ///runtime.forge-label]
                                                      (wrap [(list@map (function (_ char)
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 7c4d09936..f0f2fa635 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
@@ -750,8 +750,8 @@
   (..custom
    [($_ <>.and ..class <s>.text ..return (<>.some ..input))
     (function (_ extension-name generate archive [class method outputT inputsTS])
-      (do {@ //////.monad}
-        [inputsTG (monad.map @ (generate-input generate archive) inputsTS)]
+      (do {! //////.monad}
+        [inputsTG (monad.map ! (generate-input generate archive) inputsTS)]
         (wrap ($_ _.compose
                   (monad.map _.monad product.right inputsTG)
                   (_.invokestatic class method (type.method [(list@map product.left inputsTG) outputT (list)]))
@@ -763,9 +763,9 @@
      (..custom
       [($_ <>.and ..class <s>.text ..return <s>.any (<>.some ..input))
        (function (_ extension-name generate archive [class method outputT objectS inputsTS])
-         (do {@ //////.monad}
+         (do {! //////.monad}
            [objectG (generate archive objectS)
-            inputsTG (monad.map @ (generate-input generate archive) inputsTS)]
+            inputsTG (monad.map ! (generate-input generate archive) inputsTS)]
            (wrap ($_ _.compose
                      objectG
                      (_.checkcast class)
@@ -783,8 +783,8 @@
   (..custom
    [($_ <>.and ..class (<>.some ..input))
     (function (_ extension-name generate archive [class inputsTS])
-      (do {@ //////.monad}
-        [inputsTG (monad.map @ (generate-input generate archive) inputsTS)]
+      (do {! //////.monad}
+        [inputsTG (monad.map ! (generate-input generate archive) inputsTS)]
         (wrap ($_ _.compose
                   (_.new class)
                   _.dup
@@ -959,8 +959,8 @@
 
 (def: (anonymous-instance generate archive class env)
   (-> Phase Archive (Type category.Class) (Environment Synthesis) (Operation (Bytecode Any)))
-  (do {@ //////.monad}
-    [captureG+ (monad.map @ (generate archive) env)]
+  (do {! //////.monad}
+    [captureG+ (monad.map ! (generate archive) env)]
     (wrap ($_ _.compose
               (_.new class)
               _.dup
@@ -1008,7 +1008,7 @@
     (function (_ extension-name generate archive [super-class super-interfaces
                                                   inputsTS
                                                   overriden-methods])
-      (do {@ //////.monad}
+      (do {! //////.monad}
         [[context _] (//////generation.with-new-context archive (wrap []))
          #let [[module-id artifact-id] context
                anonymous-class-name (///runtime.class-name context)
@@ -1045,12 +1045,12 @@
                                                  self-name arguments returnT exceptionsT
                                                  (normalize-method-body local-mapping body)]))
                                             overriden-methods)]
-         inputsTI (monad.map @ (generate-input generate archive) inputsTS)
-         method-definitions (monad.map @ (function (_ [ownerT name
+         inputsTI (monad.map ! (generate-input generate archive) inputsTS)
+         method-definitions (monad.map ! (function (_ [ownerT name
                                                        strict-fp? annotations vars
                                                        self-name arguments returnT exceptionsT
                                                        bodyS])
-                                           (do @
+                                           (do !
                                              [bodyG (//////generation.with-context artifact-id
                                                       (generate archive bodyS))]
                                              (wrap (method.method ($_ modifier@compose
@@ -1068,7 +1068,7 @@
                                                                               bodyG
                                                                               (returnG returnT)))))))
                                        normalized-methods)
-         bytecode (<| (:: @ map (format.run class.writer))
+         bytecode (<| (:: ! map (format.run class.writer))
                       //////.lift
                       (class.class version.v6_0 ($_ modifier@compose class.public class.final)
                                    (name.internal anonymous-class-name)
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/common-lisp/function.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/common-lisp/function.lux
index 36c082daf..196938917 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/common-lisp/function.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/common-lisp/function.lux
@@ -25,9 +25,9 @@
 
 (def: #export (apply generate [functionS argsS+])
   (-> Phase (Application Synthesis) (Operation (Expression Any)))
-  (do {@ ////.monad}
+  (do {! ////.monad}
     [functionG (generate functionS)
-     argsG+ (monad.map @ generate argsS+)]
+     argsG+ (monad.map ! generate argsS+)]
     (wrap (_.funcall/+ [functionG argsG+]))))
 
 (def: #export capture
@@ -40,8 +40,8 @@
     (:: ////.monad wrap function-definition)
 
     _
-    (do {@ ////.monad}
-      [@closure (:: @ map _.var (///.gensym "closure"))]
+    (do {! ////.monad}
+      [@closure (:: ! map _.var (///.gensym "closure"))]
       (wrap (_.labels (list [@closure [(|> (list.enumeration inits)
                                            (list@map (|>> product.left ..capture))
                                            _.args)
@@ -53,14 +53,14 @@
 
 (def: #export (function generate [environment arity bodyS])
   (-> Phase (Abstraction Synthesis) (Operation (Expression Any)))
-  (do {@ ////.monad}
+  (do {! ////.monad}
     [[function-name bodyG] (///.with-context
-                             (do @
+                             (do !
                                [function-name ///.context]
                                (///.with-anchor (_.var function-name)
                                  (generate bodyS))))
      closureG+ (: (Operation (List (Expression Any)))
-                  (monad.map @ (:: //reference.system variable) environment))
+                  (monad.map ! (:: //reference.system variable) environment))
      #let [@curried (_.var "curried")
            @missing (_.var "missing")
            arityG (|> arity .int _.int)
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/common-lisp/loop.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/common-lisp/loop.lux
index b5de4353e..3c3232e64 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/common-lisp/loop.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/common-lisp/loop.lux
@@ -22,9 +22,9 @@
 
 (def: #export (scope generate [start initsS+ bodyS])
   (-> Phase (Scope Synthesis) (Operation (Expression Any)))
-  (do {@ ////.monad}
-    [@scope (:: @ map (|>> %.nat (format "scope") _.var) ///.next)
-     initsG+ (monad.map @ generate initsS+)
+  (do {! ////.monad}
+    [@scope (:: ! map (|>> %.nat (format "scope") _.var) ///.next)
+     initsG+ (monad.map ! generate initsS+)
      bodyG (///.with-anchor @scope
              (generate bodyS))]
     (wrap (_.labels (list [@scope {#_.input (|> initsS+
@@ -36,7 +36,7 @@
 
 (def: #export (recur generate argsS+)
   (-> Phase (List Synthesis) (Operation (Expression Any)))
-  (do {@ ////.monad}
+  (do {! ////.monad}
     [@scope ///.anchor
-     argsO+ (monad.map @ generate argsS+)]
+     argsO+ (monad.map ! generate argsS+)]
     (wrap (_.call/* @scope argsO+))))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/extension.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/extension.lux
index 64720073a..499ec7d37 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/extension.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/extension.lux
@@ -31,8 +31,8 @@
 
 (syntax: (arity: {arity s.nat} {name s.local-identifier} type)
   (with-gensyms [g!_ g!extension g!name g!phase g!archive g!inputs g!of g!anchor g!expression g!directive]
-    (do {@ meta.monad}
-      [g!input+ (monad.seq @ (list.repeat arity (meta.gensym "input")))]
+    (do {! meta.monad}
+      [g!input+ (monad.seq ! (list.repeat arity (meta.gensym "input")))]
       (wrap (list (` (def: #export ((~ (code.local-identifier name)) (~ g!extension))
                        (All [(~ g!anchor) (~ g!expression) (~ g!directive)]
                          (-> ((~ type) (~ g!expression))
@@ -60,6 +60,6 @@
     (-> (Variadic expression) (generation.Handler anchor expression directive)))
   (function (_ extension-name)
     (function (_ phase archive inputsS)
-      (do {@ ///.monad}
-        [inputsI (monad.map @ (phase archive) inputsS)]
+      (do {! ///.monad}
+        [inputsI (monad.map ! (phase archive) inputsS)]
         (wrap (extension inputsI))))))
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 99a6c247e..a2c46f8fd 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
@@ -117,9 +117,9 @@
 
 (def: #export (apply generate archive [abstractionS inputsS])
   (Generator Apply)
-  (do {@ phase.monad}
+  (do {! phase.monad}
     [abstractionG (generate archive abstractionS)
-     inputsG (monad.map @ (generate archive) inputsS)]
+     inputsG (monad.map ! (generate archive) inputsS)]
     (wrap ($_ _.compose
               abstractionG
               (|> inputsG
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/new.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/new.lux
index a36289d05..1800064a2 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/new.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/function/method/new.lux
@@ -53,8 +53,8 @@
 
 (def: #export (instance generate archive class environment arity)
   (-> Phase Archive (Type Class) (Environment Synthesis) Arity (Operation (Bytecode Any)))
-  (do {@ phase.monad}
-    [foreign* (monad.map @ (generate archive) environment)]
+  (do {! phase.monad}
+    [foreign* (monad.map ! (generate archive) environment)]
     (wrap (instance' foreign* class environment arity))))
 
 (def: #export (method class environment arity)
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/host.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/host.lux
index cdf03d7b0..d5ebb3fdc 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/host.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/host.lux
@@ -111,8 +111,8 @@
                                                         (_.putstatic (type.class bytecode-name (list)) ..value::field ..value::type)
                                                         _.return))))
                               (row.row))]
-    (io.run (do {@ (try.with io.monad)}
-              [bytecode (:: @ map (format.run class.writer)
+    (io.run (do {! (try.with io.monad)}
+              [bytecode (:: ! map (format.run class.writer)
                             (io.io bytecode))
                _ (loader.store eval-class bytecode library)
                class (loader.load eval-class loader)
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 cea8fda10..8eaafb3a5 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
@@ -38,17 +38,17 @@
 
 (def: #export (recur translate archive updatesS)
   (Generator (List Synthesis))
-  (do {@ phase.monad}
+  (do {! phase.monad}
     [[@begin offset] generation.anchor
      updatesG (|> updatesS
                   list.enumeration
                   (list@map (function (_ [index updateS])
                               [(n.+ offset index) updateS]))
-                  (monad.map @ (function (_ [register updateS])
+                  (monad.map ! (function (_ [register updateS])
                                  (if (invariant? register updateS)
                                    (wrap [..no-op
                                           ..no-op])
-                                   (do @
+                                   (do !
                                      [fetchG (translate archive updateS)
                                       #let [storeG (_.astore register)]]
                                      (wrap [fetchG storeG]))))))]
@@ -72,9 +72,9 @@
 
 (def: #export (scope translate archive [offset initsS+ iterationS])
   (Generator [Nat (List Synthesis) Synthesis])
-  (do {@ phase.monad}
+  (do {! phase.monad}
     [@begin //runtime.forge-label
-     initsI+ (monad.map @ (translate archive) initsS+)
+     initsI+ (monad.map ! (translate archive) initsS+)
      iterationG (generation.with-anchor [@begin offset]
                   (translate archive iterationS))
      #let [initializationG (|> (list.enumeration initsI+)
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 b21c899e0..1d99c2736 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
@@ -40,8 +40,8 @@
 
 (def: (foreign archive variable)
   (-> Archive Register (Operation (Bytecode Any)))
-  (do {@ ////.monad}
-    [bytecode-name (:: @ map //runtime.class-name
+  (do {! ////.monad}
+    [bytecode-name (:: ! map //runtime.class-name
                        (generation.context archive))]
     (wrap ($_ _.compose
               ..this
@@ -60,7 +60,7 @@
 
 (def: #export (constant archive name)
   (-> Archive Name (Operation (Bytecode Any)))
-  (do {@ ////.monad}
-    [bytecode-name (:: @ map //runtime.class-name
+  (do {! ////.monad}
+    [bytecode-name (:: ! map //runtime.class-name
                        (generation.remember archive name))]
     (wrap (_.getstatic (type.class bytecode-name (list)) //value.field //type.value))))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/structure.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/structure.lux
index eb786662c..bbf8f252c 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/structure.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/jvm/structure.lux
@@ -35,21 +35,21 @@
     (generate archive singletonS)
 
     _
-    (do {@ phase.monad}
+    (do {! phase.monad}
       [membersI (|> membersS
                     list.enumeration
-                    (monad.map @ (function (_ [idx member])
-                                   (do @
+                    (monad.map ! (function (_ [idx member])
+                                   (do !
                                      [memberI (generate archive member)]
                                      (wrap (do _.monad
                                              [_ _.dup
                                               _ (_.int (.i64 idx))
                                               _ memberI]
                                              _.aastore))))))]
-      (wrap (do {@ _.monad}
+      (wrap (do {! _.monad}
               [_ (_.int (.i64 (list.size membersS)))
                _ (_.anewarray $Object)]
-              (monad.seq @ membersI))))))
+              (monad.seq ! membersI))))))
 
 (def: #export (tag lefts right?)
   (-> Nat Bit (Bytecode Any))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/extension/common.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/extension/common.lux
index d5da7253a..b13bc5834 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/extension/common.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/extension/common.lux
@@ -39,8 +39,8 @@
 
 (syntax: (arity: {name s.local-identifier} {arity s.nat})
   (with-gensyms [g!_ g!extension g!name g!phase g!inputs]
-    (do {@ macro.monad}
-      [g!input+ (monad.seq @ (list.repeat arity (macro.gensym "input")))]
+    (do {! macro.monad}
+      [g!input+ (monad.seq ! (list.repeat arity (macro.gensym "input")))]
       (wrap (list (` (def: #export ((~ (code.local-identifier name)) (~ g!extension))
                        (-> (-> (..Vector (~ (code.nat arity)) Expression) Computation)
                            Handler)
@@ -66,8 +66,8 @@
   (-> Variadic Handler)
   (function (_ extension-name)
     (function (_ phase inputsS)
-      (do {@ /////.monad}
-        [inputsI (monad.map @ phase inputsS)]
+      (do {! /////.monad}
+        [inputsI (monad.map ! phase inputsS)]
         (wrap (extension inputsI))))))
 
 (def: bundle::lux
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/function.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/function.lux
index ba48ab2ec..2bf25cec9 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/function.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/function.lux
@@ -27,9 +27,9 @@
 
 (def: #export (apply generate [functionS argsS+])
   (-> Phase (Application Synthesis) (Operation Computation))
-  (do {@ ////.monad}
+  (do {! ////.monad}
     [functionO (generate functionS)
-     argsO+ (monad.map @ generate argsS+)]
+     argsO+ (monad.map ! generate argsS+)]
     (wrap (_.apply/* functionO argsO+))))
 
 (def: #export capture
@@ -59,14 +59,14 @@
 
 (def: #export (function generate [environment arity bodyS])
   (-> Phase (Abstraction Synthesis) (Operation Computation))
-  (do {@ ////.monad}
+  (do {! ////.monad}
     [[function-name bodyO] (///.with-context
-                             (do @
+                             (do !
                                [function-name ///.context]
                                (///.with-anchor (_.var function-name)
                                  (generate bodyS))))
      closureO+ (: (Operation (List Expression))
-                  (monad.map @ (:: //reference.system variable) environment))
+                  (monad.map ! (:: //reference.system variable) environment))
      #let [arityO (|> arity .int _.int)
            apply-poly (.function (_ args func)
                         (_.apply/2 (_.global "apply") func args))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/loop.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/loop.lux
index aac83a7dc..b4a9943ec 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/loop.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/generation/scheme/loop.lux
@@ -23,8 +23,8 @@
 
 (def: #export (scope generate [start initsS+ bodyS])
   (-> Phase (Scope Synthesis) (Operation Computation))
-  (do {@ ////.monad}
-    [initsO+ (monad.map @ generate initsS+)
+  (do {! ////.monad}
+    [initsO+ (monad.map ! generate initsS+)
      bodyO (///.with-anchor @scope
              (generate bodyS))]
     (wrap (_.letrec (list [@scope (_.lambda [(|> initsS+
@@ -36,7 +36,7 @@
 
 (def: #export (recur generate argsS+)
   (-> Phase (List Synthesis) (Operation Computation))
-  (do {@ ////.monad}
+  (do {! ////.monad}
     [@scope ///.anchor
-     argsO+ (monad.map @ generate argsS+)]
+     argsO+ (monad.map ! generate argsS+)]
     (wrap (_.apply/* @scope argsO+))))
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 32db39342..268937c12 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
@@ -223,9 +223,9 @@
 
 (def: #export (synthesize-case synthesize archive input [[headP headA] tailPA+])
   (-> Phase Archive Synthesis Match (Operation Synthesis))
-  (do {@ ///.monad}
+  (do {! ///.monad}
     [headSP (path archive synthesize headP headA)
-     tailSP+ (monad.map @ (product.uncurry (path archive synthesize)) tailPA+)]
+     tailSP+ (monad.map ! (product.uncurry (path archive synthesize)) tailPA+)]
     (wrap (/.branch/case [input (list@fold weave headSP tailSP+)]))))
 
 (template: (!masking <variable> <output>)
@@ -274,7 +274,7 @@
 
 (def: #export (synthesize synthesize^ [headB tailB+] archive inputA)
   (-> Phase Match Phase)
-  (do {@ ///.monad}
+  (do {! ///.monad}
     [inputS (synthesize^ archive inputA)]
     (case [headB tailB+]
       (^ (!masking @variable @output))
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 4f510e1b6..6c70612b4 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
@@ -47,15 +47,15 @@
   (-> Phase Phase)
   (function (_ archive exprA)
     (let [[funcA argsA] (////analysis.application exprA)]
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [funcS (phase archive funcA)
-         argsS (monad.map @ (phase archive) argsA)]
+         argsS (monad.map ! (phase archive) argsA)]
         (with-expansions [<apply> (as-is (/.function/apply [funcS argsS]))]
           (case funcS
             (^ (/.function/abstraction functionS))
             (if (n.= (get@ #/.arity functionS)
                      (list.size argsS))
-              (do @
+              (do !
                 [locals /.locals]
                 (wrap (|> functionS
                           (//loop.optimization true locals argsS)
@@ -103,11 +103,11 @@
     ([#/.Alt] [#/.Seq])
 
     (#/.Bit-Fork when then else)
-    (do {@ phase.monad}
+    (do {! phase.monad}
       [then (grow-path grow then)
        else (case else
               (#.Some else)
-              (:: @ map (|>> #.Some) (grow-path grow else))
+              (:: ! map (|>> #.Some) (grow-path grow else))
 
               #.None
               (wrap #.None))]
@@ -115,10 +115,10 @@
     
     (^template [<tag>]
       (<tag> [[test then] elses])
-      (do {@ phase.monad}
+      (do {! phase.monad}
         [then (grow-path grow then)
-         elses (monad.map @ (function (_ [else-test else-then])
-                              (do @
+         elses (monad.map ! (function (_ [else-test else-then])
+                              (do !
                                 [else-then (grow-path grow else-then)]
                                 (wrap [else-test else-then])))
                           elses)]
@@ -197,8 +197,8 @@
       (#/.Loop loop)
       (case loop
         (#/.Scope [start initsS+ iterationS])
-        (do {@ phase.monad}
-          [initsS+' (monad.map @ (grow environment) initsS+)
+        (do {! phase.monad}
+          [initsS+' (monad.map ! (grow environment) initsS+)
            iterationS' (grow environment iterationS)]
           (wrap (/.loop/scope [(inc start) initsS+' iterationS'])))
         
@@ -210,8 +210,8 @@
       (#/.Function function)
       (case function
         (#/.Abstraction [_env _arity _body])
-        (do {@ phase.monad}
-          [_env' (monad.map @
+        (do {! phase.monad}
+          [_env' (monad.map !
                             (|>> (case> (#/.Reference (#////reference.Variable (#////reference/variable.Foreign register)))
                                         (..find-foreign environment register)
 
@@ -221,9 +221,9 @@
           (wrap (/.function/abstraction [_env' _arity _body])))
         
         (#/.Apply funcS argsS+)
-        (do {@ phase.monad}
+        (do {! phase.monad}
           [funcS (grow environment funcS)
-           argsS+ (monad.map @ (grow environment) argsS+)]
+           argsS+ (monad.map ! (grow environment) argsS+)]
           (wrap (/.function/apply (case funcS
                                     (^ (/.function/apply [(..self-reference) pre-argsS+]))
                                     [(..self-reference)
@@ -243,9 +243,9 @@
 
 (def: #export (abstraction phase environment archive bodyA)
   (-> Phase (Environment Analysis) Phase)
-  (do {@ phase.monad}
+  (do {! phase.monad}
     [currying? /.currying?
-     environment (monad.map @ (phase archive) environment)
+     environment (monad.map ! (phase archive) environment)
      bodyS (/.with-currying? true
              (/.with-locals 2
                (phase archive bodyA)))
@@ -254,7 +254,7 @@
                       (^ (/.function/abstraction [env' down-arity' bodyS']))
                       (|> bodyS'
                           (grow env')
-                          (:: @ map (function (_ body)
+                          (:: ! map (function (_ body)
                                       {#/.environment environment
                                        #/.arity (inc down-arity')
                                        #/.body body})))
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 064aca2a7..eca662b25 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
@@ -39,11 +39,11 @@
       ([#/.Alt] [#/.Seq])
 
       (#/.Bit-Fork when then else)
-      (do {@ maybe.monad}
+      (do {! maybe.monad}
         [then (recur then)
          else (case else
                 (#.Some else)
-                (:: @ map (|>> #.Some) (recur else))
+                (:: ! map (|>> #.Some) (recur else))
 
                 #.None
                 (wrap #.None))]
@@ -51,10 +51,10 @@
       
       (^template [<tag>]
         (<tag> [[test then] elses])
-        (do {@ maybe.monad}
+        (do {! maybe.monad}
           [then (recur then)
-           elses (monad.map @ (function (_ [else-test else-then])
-                                (do @
+           elses (monad.map ! (function (_ [else-test else-then])
+                                (do !
                                   [else-then (recur else-then)]
                                   (wrap [else-test else-then])))
                             elses)]
@@ -136,10 +136,10 @@
         (wrap (/.branch/get [path record])))
 
       (^ (/.loop/scope scope))
-      (do {@ maybe.monad}
+      (do {! maybe.monad}
         [inits' (|> scope
                     (get@ #/.inits)
-                    (monad.map @ (recur false)))
+                    (monad.map ! (recur false)))
          iteration' (recur return? (get@ #/.iteration scope))]
         (wrap (/.loop/scope {#/.start (|> scope (get@ #/.start) (register-optimization offset))
                              #/.inits inits'
@@ -151,8 +151,8 @@
           (maybe@map (|>> /.loop/recur)))
 
       (^ (/.function/abstraction [environment arity body]))
-      (do {@ maybe.monad}
-        [environment' (monad.map @ (recur false) environment)]
+      (do {! maybe.monad}
+        [environment' (monad.map ! (recur false) environment)]
         (wrap (/.function/abstraction [environment' arity body])))
       
       (^ (/.function/apply [abstraction arguments]))
diff --git a/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/variable.lux b/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/variable.lux
index 6b67ba5aa..ab0858583 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/variable.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/phase/synthesis/variable.lux
@@ -251,11 +251,11 @@
                      path])
 
       (#/.Bit-Fork when then else)
-      (do {@ try.monad}
+      (do {! try.monad}
         [[redundancy then] (recur [redundancy then])
          [redundancy else] (case else
                              (#.Some else)
-                             (:: @ map
+                             (:: ! map
                                  (function (_ [redundancy else])
                                    [redundancy (#.Some else)])
                                  (recur [redundancy else]))
@@ -266,11 +266,11 @@
       
       (^template [<tag> <type>]
         (<tag> [[test then] elses])
-        (do {@ try.monad}
+        (do {! try.monad}
           [[redundancy then] (recur [redundancy then])
            [redundancy elses] (..list-optimization (: (Optimization [<type> Path])
                                                       (function (_ [redundancy [else-test else-then]])
-                                                        (do @
+                                                        (do !
                                                           [[redundancy else-then] (recur [redundancy else-then])]
                                                           (wrap [redundancy [else-test else-then]]))))
                                                    [redundancy elses])]
@@ -415,7 +415,7 @@
         (#/.Function function)
         (case function
           (#/.Abstraction [environment arity body])
-          (do {@ try.monad}
+          (do {! try.monad}
             [[redundancy environment] (..list-optimization optimization' [redundancy environment])
              [_ body] (optimization' [(..default arity) body])]
             (wrap [redundancy
diff --git a/stdlib/source/lux/tool/compiler/language/lux/program.lux b/stdlib/source/lux/tool/compiler/language/lux/program.lux
index aef6fdab6..85cb03670 100644
--- a/stdlib/source/lux/tool/compiler/language/lux/program.lux
+++ b/stdlib/source/lux/tool/compiler/language/lux/program.lux
@@ -33,12 +33,12 @@
 
 (def: #export (context archive)
   (-> Archive (Try Context))
-  (do {@ try.monad}
+  (do {! try.monad}
     [registries (|> archive
                     archive.archived
-                    (monad.map @
+                    (monad.map !
                                (function (_ module)
-                                 (do @
+                                 (do !
                                    [id (archive.id module archive)
                                     [descriptor document] (archive.find module archive)]
                                    (wrap [[module id] (get@ #descriptor.registry descriptor)])))))]
diff --git a/stdlib/source/lux/tool/compiler/meta/io/archive.lux b/stdlib/source/lux/tool/compiler/meta/io/archive.lux
index 9e83cc367..1533816fc 100644
--- a/stdlib/source/lux/tool/compiler/meta/io/archive.lux
+++ b/stdlib/source/lux/tool/compiler/meta/io/archive.lux
@@ -91,14 +91,14 @@
 
 (def: #export (prepare system static module-id)
   (-> (file.System Promise) Static archive.ID (Promise (Try Any)))
-  (do {@ promise.monad}
+  (do {! promise.monad}
     [#let [module (..module system static module-id)]
      module-exists? (file.exists? promise.monad system module)]
     (if module-exists?
       (wrap (#try.Success []))
-      (do @
-        [_ (file.get-directory @ system (..unversioned-lux-archive system static))
-         _ (file.get-directory @ system (..versioned-lux-archive system static))
+      (do !
+        [_ (file.get-directory ! system (..unversioned-lux-archive system static))
+         _ (file.get-directory ! system (..versioned-lux-archive system static))
          outcome (!.use (:: system create-directory) module)]
         (case outcome
           (#try.Success output)
@@ -175,10 +175,10 @@
 
 (def: (analysis-state host archive)
   (-> Host Archive (Try .Lux))
-  (do {@ try.monad}
+  (do {! try.monad}
     [modules (: (Try (List [Module .Module]))
-                (monad.map @ (function (_ module)
-                               (do @
+                (monad.map ! (function (_ module)
+                               (do !
                                  [[descriptor document] (archive.find module archive)
                                   content (document.read $.key document)]
                                  (wrap [module content])))
@@ -187,7 +187,7 @@
 
 (def: (cached-artifacts system static module-id)
   (-> (file.System Promise) Static archive.ID (Promise (Try (Dictionary Text Binary))))
-  (do {@ (try.with promise.monad)}
+  (do {! (try.with promise.monad)}
     [module-dir (!.use (:: system directory) (..module system static module-id))
      cached-files (!.use (:: module-dir files) [])]
     (|> cached-files
@@ -195,14 +195,14 @@
                     [(!.use (:: file name) [])
                      (!.use (:: file path) [])]))
         (list.filter (|>> product.left (text@= ..module-descriptor-file) not))
-        (monad.map @ (function (_ [name path])
-                       (do @
+        (monad.map ! (function (_ [name path])
+                       (do !
                          [file (: (Promise (Try (File Promise)))
                                   (!.use (:: system file) path))
                           data (: (Promise (Try Binary))
                                   (!.use (:: file content) []))]
                          (wrap [name data]))))
-        (:: @ map (dictionary.from-list text.hash)))))
+        (:: ! map (dictionary.from-list text.hash)))))
 
 (type: Definitions (Dictionary Text Any))
 (type: Analysers (Dictionary Text analysis.Handler))
@@ -227,7 +227,7 @@
   (All [expression directive]
     (-> Text (generation.Host expression directive) archive.ID (Row Artifact) (Dictionary Text Binary) (Document .Module)
         (Try [(Document .Module) Bundles])))
-  (do {@ try.monad}
+  (do {! try.monad}
     [[definitions bundles] (: (Try [Definitions Bundles])
                               (loop [input (row.to-list expected)
                                      definitions (: Definitions
@@ -236,13 +236,13 @@
                                 (let [[analysers synthesizers generators directives] bundles]
                                   (case input
                                     (#.Cons [[artifact-id artifact-category] input'])
-                                    (case (do @
+                                    (case (do !
                                             [data (try.from-maybe (dictionary.get (format (%.nat artifact-id) extension) actual))
                                              #let [context [module-id artifact-id]
                                                    directive (:: host ingest context data)]]
                                             (case artifact-category
                                               #artifact.Anonymous
-                                              (do @
+                                              (do !
                                                 [_ (:: host re-learn context directive)]
                                                 (wrap [definitions
                                                        [analysers
@@ -257,7 +257,7 @@
                                                         synthesizers
                                                         generators
                                                         directives]])
-                                                (do @
+                                                (do !
                                                   [value (:: host re-load context directive)]
                                                   (wrap [(dictionary.put name value definitions)
                                                          [analysers
@@ -266,7 +266,7 @@
                                                           directives]])))
 
                                               (#artifact.Analyser extension)
-                                              (do @
+                                              (do !
                                                 [value (:: host re-load context directive)]
                                                 (wrap [definitions
                                                        [(dictionary.put extension (:coerce analysis.Handler value) analysers)
@@ -275,7 +275,7 @@
                                                         directives]]))
 
                                               (#artifact.Synthesizer extension)
-                                              (do @
+                                              (do !
                                                 [value (:: host re-load context directive)]
                                                 (wrap [definitions
                                                        [analysers
@@ -284,7 +284,7 @@
                                                         directives]]))
 
                                               (#artifact.Generator extension)
-                                              (do @
+                                              (do !
                                                 [value (:: host re-load context directive)]
                                                 (wrap [definitions
                                                        [analysers
@@ -293,7 +293,7 @@
                                                         directives]]))
 
                                               (#artifact.Directive extension)
-                                              (do @
+                                              (do !
                                                 [value (:: host re-load context directive)]
                                                 (wrap [definitions
                                                        [analysers
@@ -309,13 +309,13 @@
                                     #.None
                                     (#try.Success [definitions bundles])))))
      content (document.read $.key document)
-     definitions (monad.map @ (function (_ [def-name def-global])
+     definitions (monad.map ! (function (_ [def-name def-global])
                                 (case def-global
                                   (#.Alias alias)
                                   (wrap [def-name (#.Alias alias)])
                                   
                                   (#.Definition [exported? type annotations _])
-                                  (do @
+                                  (do !
                                     [value (try.from-maybe (dictionary.get def-name definitions))]
                                     (wrap [def-name (#.Definition [exported? type annotations value])]))))
                             (get@ #.definitions content))]
@@ -336,10 +336,10 @@
 
 (def: (purge! system static [module-name module-id])
   (-> (file.System Promise) Static [Module archive.ID] (Promise (Try Any)))
-  (do {@ (try.with promise.monad)}
+  (do {! (try.with promise.monad)}
     [cache (!.use (:: system directory) [(..module system static module-id)])
      artifacts (!.use (:: cache files) [])
-     _ (monad.map @ (function (_ artifact)
+     _ (monad.map ! (function (_ artifact)
                       (!.use (:: artifact delete) []))
                   artifacts)]
     (!.use (:: cache discard) [])))
@@ -388,17 +388,17 @@
   (All [expression directive]
     (-> (generation.Host expression directive) (file.System Promise) Static Import (List Context) Archive
         (Promise (Try [Archive .Lux Bundles]))))
-  (do {@ (try.with promise.monad)}
+  (do {! (try.with promise.monad)}
     [pre-loaded-caches (|> archive
                            archive.reservations
-                           (monad.map @ (function (_ [module-name module-id])
-                                          (do @
+                           (monad.map ! (function (_ [module-name module-id])
+                                          (do !
                                             [data (..read-module-descriptor system static module-id)
                                              [descriptor document] (promise@wrap (<b>.run ..parser data))]
                                             (if (text@= archive.runtime-module module-name)
                                               (wrap [true
                                                      [module-name [module-id [descriptor document]]]])
-                                              (do @
+                                              (do !
                                                 [input (//context.read system import contexts (get@ #static.host-module-extension static) module-name)]
                                                 (wrap [(..valid-cache? descriptor input)
                                                        [module-name [module-id [descriptor document]]]])))))))
@@ -414,18 +414,18 @@
      #let [purge (..full-purge pre-loaded-caches load-order)]
      _ (|> purge
            dictionary.entries
-           (monad.map @ (..purge! system static)))
+           (monad.map ! (..purge! system static)))
      loaded-caches (|> load-order
                        (list.filter (function (_ [module-name [module-id [descriptor document]]])
                                       (not (dictionary.contains? module-name purge))))
-                       (monad.map @ (function (_ [module-name [module-id descriptor,document]])
-                                      (do @
+                       (monad.map ! (function (_ [module-name [module-id descriptor,document]])
+                                      (do !
                                         [[descriptor,document bundles] (..load-definitions system static module-id host-environment descriptor,document)]
                                         (wrap [[module-name descriptor,document]
                                                bundles])))))]
     (promise@wrap
-     (do {@ try.monad}
-       [archive (monad.fold @
+     (do {! try.monad}
+       [archive (monad.fold !
                             (function (_ [[module descriptor,document] _bundle] archive)
                               (archive.add module descriptor,document archive))
                             archive
diff --git a/stdlib/source/lux/tool/compiler/meta/io/context.lux b/stdlib/source/lux/tool/compiler/meta/io/context.lux
index 7d6a56b63..c524f605f 100644
--- a/stdlib/source/lux/tool/compiler/meta/io/context.lux
+++ b/stdlib/source/lux/tool/compiler/meta/io/context.lux
@@ -78,16 +78,16 @@
       (Promise (Try [Path Binary])))
   ## Preference is explicitly being given to Lux files that have a host extension.
   ## Normal Lux files (i.e. without a host extension) are then picked as fallback files.
-  (do {@ promise.monad}
+  (do {! promise.monad}
     [outcome (..find-source-file system contexts module (..full-host-extension partial-host-extension))]
     (case outcome
       (#try.Success [path file])
-      (do (try.with @)
+      (do (try.with !)
         [data (!.use (:: file content) [])]
         (wrap [path data]))
 
       (#try.Failure _)
-      (do (try.with @)
+      (do (try.with !)
         [[path file] (..find-source-file system contexts module ..lux-extension)
          data (!.use (:: file content) [])]
         (wrap [path data])))))
@@ -113,7 +113,7 @@
       (Promise (Try [Path Binary])))
   ## Preference is explicitly being given to Lux files that have a host extension.
   ## Normal Lux files (i.e. without a host extension) are then picked as fallback files.
-  (do {@ promise.monad}
+  (do {! promise.monad}
     [outcome (find-local-source-file system import contexts partial-host-extension module)]
     (case outcome
       (#try.Success [path data])
@@ -157,16 +157,16 @@
 
 (def: (enumerate-context system context enumeration)
   (-> (file.System Promise) Context Enumeration (Promise (Try Enumeration)))
-  (do {@ (try.with promise.monad)}
+  (do {! (try.with promise.monad)}
     [directory (!.use (:: system directory) [context])]
     (loop [directory directory
            enumeration enumeration]
-      (do @
+      (do !
         [files (!.use (:: directory files) [])
-         enumeration (monad.fold @ (function (_ file enumeration)
+         enumeration (monad.fold ! (function (_ file enumeration)
                                      (let [path (!.use (:: file path) [])]
                                        (if (text.ends-with? ..lux-extension path)
-                                         (do @
+                                         (do !
                                            [path (promise@wrap (..clean-path system context path))
                                             source-code (!.use (:: file content) [])]
                                            (promise@wrap
@@ -175,7 +175,7 @@
                                  enumeration
                                  files)
          directories (!.use (:: directory directories) [])]
-        (monad.fold @ recur enumeration directories)))))
+        (monad.fold ! recur enumeration directories)))))
 
 (def: Action
   (type (All [a] (Promise (Try a)))))
diff --git a/stdlib/source/lux/tool/interpreter.lux b/stdlib/source/lux/tool/interpreter.lux
index 5a1b30d06..efff99be8 100644
--- a/stdlib/source/lux/tool/interpreter.lux
+++ b/stdlib/source/lux/tool/interpreter.lux
@@ -95,7 +95,7 @@
   (def: (interpret-expression code)
     (All [anchor expression directive]
       (-> Code <Interpretation>))
-    (do {@ phase.monad}
+    (do {! phase.monad}
       [state (extension.lift phase.get-state)
        #let [analyse (get@ [#directive.analysis #directive.phase] state)
              synthesize (get@ [#directive.synthesis #directive.phase] state)
@@ -103,7 +103,7 @@
        [_ codeT codeA] (directive.lift-analysis
                         (analysis.with-scope
                           (type.with-fresh-env
-                            (do @
+                            (do !
                               [[codeT codeA] (type.with-inference
                                                (analyse code))
                                codeT (type.with-env
@@ -113,7 +113,7 @@
               (synthesize codeA))]
       (directive.lift-generation
        (generation.with-buffer
-         (do @
+         (do !
            [codeH (generate codeS)
             count generation.next
             codeV (generation.evaluate! (format "interpretation_" (%.nat count)) codeH)]
@@ -193,13 +193,13 @@
         Configuration
         (generation.Bundle anchor expression directive)
         (! Any)))
-  (do {@ Monad<!>}
+  (do {! Monad<!>}
     [state (initialize Monad<!> Console<!> platform configuration)]
     (loop [context {#configuration configuration
                     #state state
                     #source ..fresh-source}
            multi-line? #0]
-      (do @
+      (do !
         [_ (if multi-line?
              (:: Console<!> write "  ")
              (:: Console<!> write "> "))
@@ -209,7 +209,7 @@
           (:: Console<!> write ..farewell-message)
           (case (read-eval-print (update@ #source (add-line line) context))
             (#try.Success [context' representation])
-            (do @
+            (do !
               [_ (:: Console<!> write representation)]
               (recur context' #0))
 
diff --git a/stdlib/source/poly/lux/abstract/equivalence.lux b/stdlib/source/poly/lux/abstract/equivalence.lux
index 69c2d24fb..8826b9ed9 100644
--- a/stdlib/source/poly/lux/abstract/equivalence.lux
+++ b/stdlib/source/poly/lux/abstract/equivalence.lux
@@ -42,7 +42,7 @@
    ["." /]})
 
 (poly: #export equivalence
-  (`` (do {@ p.monad}
+  (`` (do {! p.monad}
         [#let [g!_ (code.local-identifier "_____________")]
          *env* <type>.env
          inputT <type>.peek
@@ -52,7 +52,7 @@
         ($_ p.either
             ## Basic types
             (~~ (template [<matcher> <eq>]
-                  [(do @
+                  [(do !
                      [_ <matcher>]
                      (wrap (` (: (~ (@Equivalence inputT))
                                  <eq>))))]
@@ -66,7 +66,7 @@
                   [(<type>.sub Text)    (~! text.equivalence)]))
             ## Composite types
             (~~ (template [<name> <eq>]
-                  [(do @
+                  [(do !
                      [[_ argC] (<type>.apply (p.and (<type>.exactly <name>)
                                                     equivalence))]
                      (wrap (` (: (~ (@Equivalence inputT))
@@ -80,7 +80,7 @@
                   [set.Set     (~! set.equivalence)]
                   [tree.Tree   (~! tree.equivalence)]
                   ))
-            (do @
+            (do !
               [[_ _ valC] (<type>.apply ($_ p.and
                                             (<type>.exactly dictionary.Dictionary)
                                             <type>.any
@@ -89,7 +89,7 @@
                           ((~! dictionary.equivalence) (~ valC))))))
             ## Models
             (~~ (template [<type> <eq>]
-                  [(do @
+                  [(do !
                      [_ (<type>.exactly <type>)]
                      (wrap (` (: (~ (@Equivalence inputT))
                                  <eq>))))]
@@ -100,13 +100,13 @@
                   [day.Day day.equivalence]
                   [month.Month month.equivalence]
                   ))
-            (do @
+            (do !
               [_ (<type>.apply (p.and (<type>.exactly unit.Qty)
                                       <type>.any))]
               (wrap (` (: (~ (@Equivalence inputT))
                           unit.equivalence))))
             ## Variants
-            (do @
+            (do !
               [members (<type>.variant (p.many equivalence))
                #let [last (dec (list.size members))
                      g!_ (code.local-identifier "_____________")
@@ -127,7 +127,7 @@
                               (~ g!_)
                               #0))))))
             ## Tuples
-            (do @
+            (do !
               [g!eqs (<type>.tuple (p.many equivalence))
                #let [g!_ (code.local-identifier "_____________")
                      indices (list.indices (list.size g!eqs))
@@ -139,7 +139,7 @@
                                          (list@map (function (_ [g!eq g!left g!right])
                                                      (` ((~ g!eq) (~ g!left) (~ g!right)))))))))))))
             ## Type recursion
-            (do @
+            (do !
               [[g!self bodyC] (<type>.recursive equivalence)
                #let [g!_ (code.local-identifier "_____________")]]
               (wrap (` (: (~ (@Equivalence inputT))
@@ -147,13 +147,13 @@
                                         (~ bodyC)))))))
             <type>.recursive-self
             ## Type applications
-            (do @
+            (do !
               [[funcC argsC] (<type>.apply (p.and equivalence (p.many equivalence)))]
               (wrap (` ((~ funcC) (~+ argsC)))))
             ## Parameters
             <type>.parameter
             ## Polymorphism
-            (do @
+            (do !
               [[funcC varsC bodyC] (<type>.polymorphic equivalence)]
               (wrap (` (: (All [(~+ varsC)]
                             (-> (~+ (list@map (|>> (~) ((~! /.Equivalence)) (`)) varsC))
@@ -163,6 +163,6 @@
             <type>.recursive-call
             ## If all else fails...
             (|> <type>.any
-                (:: @ map (|>> %.type (format "Cannot create Equivalence for: ") p.fail))
-                (:: @ join))
+                (:: ! map (|>> %.type (format "Cannot create Equivalence for: ") p.fail))
+                (:: ! join))
             ))))
diff --git a/stdlib/source/poly/lux/abstract/functor.lux b/stdlib/source/poly/lux/abstract/functor.lux
index d1219bf87..da14b2b6c 100644
--- a/stdlib/source/poly/lux/abstract/functor.lux
+++ b/stdlib/source/poly/lux/abstract/functor.lux
@@ -24,7 +24,7 @@
    ["." /]})
 
 (poly: #export functor
-  (do {@ p.monad}
+  (do {! p.monad}
     [#let [type-funcC (code.local-identifier "____________type-funcC")
            funcC (code.local-identifier "____________funcC")
            inputC (code.local-identifier "____________inputC")]
@@ -49,7 +49,7 @@
                               _ (<type>.parameter! varI)]
                              (wrap (` ((~ funcC) (~ valueC)))))
                            ## Variants
-                           (do @
+                           (do !
                              [_ (wrap [])
                               membersC (<type>.variant (p.many (Arg<?> valueC)))
                               #let [last (dec (list.size membersC))]]
@@ -68,7 +68,7 @@
                                                               pairsCC (: (List [Code Code])
                                                                          (list))]
                                                          (p.either (let [slotC (|> idx %.nat (format "____________slot") code.local-identifier)]
-                                                                     (do @
+                                                                     (do !
                                                                        [_ (wrap [])
                                                                         memberC (Arg<?> slotC)]
                                                                        (recur (inc idx)
@@ -78,7 +78,7 @@
                                         [(~+ (list;map product.left pairsCC))]
                                         [(~+ (list;map product.right pairsCC))]))))
                            ## Functions
-                           (do @
+                           (do !
                              [_ (wrap [])
                               #let [g! (code.local-identifier "____________")
                                     outL (code.local-identifier "____________outL")]
diff --git a/stdlib/source/poly/lux/data/format/json.lux b/stdlib/source/poly/lux/data/format/json.lux
index 1921ecd3a..9cc39c994 100644
--- a/stdlib/source/poly/lux/data/format/json.lux
+++ b/stdlib/source/poly/lux/data/format/json.lux
@@ -99,7 +99,7 @@
 (poly: #export codec//encode
   (with-expansions
     [<basic> (template [<matcher> <encoder>]
-               [(do @
+               [(do !
                   [#let [g!_ (code.local-identifier "_______")]
                    _ <matcher>]
                   (wrap (` (: (~ (@JSON//encode inputT))
@@ -112,7 +112,7 @@
                [(<type>.sub Frac)    (|>> #/.Number)]
                [(<type>.sub Text)    (|>> #/.String)])
      <time> (template [<type> <codec>]
-              [(do @
+              [(do !
                  [_ (<type>.exactly <type>)]
                  (wrap (` (: (~ (@JSON//encode inputT))
                              (|>> (:: (~! <codec>) (~' encode)) #/.String)))))]
@@ -122,7 +122,7 @@
               [date.Date date.codec]
               [day.Day day.codec]
               [month.Month month.codec])]
-    (do {@ p.monad}
+    (do {! p.monad}
       [*env* <type>.env
        #let [@JSON//encode (: (-> Type Code)
                               (function (_ type)
@@ -131,12 +131,12 @@
       ($_ p.either
           <basic>
           <time>
-          (do @
+          (do !
             [unitT (<type>.apply (p.after (<type>.exactly unit.Qty)
                                           <type>.any))]
             (wrap (` (: (~ (@JSON//encode inputT))
                         (:: (~! qty-codec) (~' encode))))))
-          (do @
+          (do !
             [#let [g!_ (code.local-identifier "_______")
                    g!key (code.local-identifier "_______key")
                    g!val (code.local-identifier "_______val")]
@@ -150,19 +150,19 @@
                                               [(~ g!key) ((~ =val=) (~ g!val))]))
                              ((~! d.from-list) (~! text.hash))
                              #/.Object)))))
-          (do @
+          (do !
             [[_ =sub=] (<type>.apply ($_ p.and
                                          (<type>.exactly .Maybe)
                                          codec//encode))]
             (wrap (` (: (~ (@JSON//encode inputT))
                         ((~! ..nullable) (~ =sub=))))))
-          (do @
+          (do !
             [[_ =sub=] (<type>.apply ($_ p.and
                                          (<type>.exactly .List)
                                          codec//encode))]
             (wrap (` (: (~ (@JSON//encode inputT))
                         (|>> ((~! list@map) (~ =sub=)) ((~! row.from-list)) #/.Array)))))
-          (do @
+          (do !
             [#let [g!_ (code.local-identifier "_______")
                    g!input (code.local-identifier "_______input")]
              members (<type>.variant (p.many codec//encode))
@@ -181,7 +181,7 @@
                                                                                 #0
                                                                                 ((~ g!encode) (~ g!input))])))))
                                                      (list.enumeration members))))))))))
-          (do @
+          (do !
             [g!encoders (<type>.tuple (p.many codec//encode))
              #let [g!_ (code.local-identifier "_______")
                    g!members (|> (list.size g!encoders)
@@ -193,7 +193,7 @@
                                                         (` ((~ g!encode) (~ g!member))))
                                                       (list.zip/2 g!members g!encoders)))]))))))
           ## Type recursion
-          (do @
+          (do !
             [[selfC non-recC] (<type>.recursive codec//encode)
              #let [g! (code.local-identifier "____________")]]
             (wrap (` (: (~ (@JSON//encode inputT))
@@ -201,11 +201,11 @@
                                              (~ non-recC)))))))
           <type>.recursive-self
           ## Type applications
-          (do @
+          (do !
             [partsC (<type>.apply (p.many codec//encode))]
             (wrap (` ((~+ partsC)))))
           ## Polymorphism
-          (do @
+          (do !
             [[funcC varsC bodyC] (<type>.polymorphic codec//encode)]
             (wrap (` (: (All [(~+ varsC)]
                           (-> (~+ (list@map (function (_ varC) (` (-> (~ varC) /.JSON)))
@@ -223,7 +223,7 @@
 (poly: #export codec//decode
   (with-expansions
     [<basic> (template [<matcher> <decoder>]
-               [(do @
+               [(do !
                   [_ <matcher>]
                   (wrap (` (: (~ (@JSON//decode inputT))
                               (~! <decoder>)))))]
@@ -235,7 +235,7 @@
                [(<type>.sub Frac)     </>.number]
                [(<type>.sub Text)     </>.string])
      <time> (template [<type> <codec>]
-              [(do @
+              [(do !
                  [_ (<type>.exactly <type>)]
                  (wrap (` (: (~ (@JSON//decode inputT))
                              ((~! p.codec) (~! <codec>) (~! </>.string))))))]
@@ -245,7 +245,7 @@
               [date.Date date.codec]
               [day.Day day.codec]
               [month.Month month.codec])]
-    (do {@ p.monad}
+    (do {! p.monad}
       [*env* <type>.env
        #let [@JSON//decode (: (-> Type Code)
                               (function (_ type)
@@ -254,29 +254,29 @@
       ($_ p.either
           <basic>
           <time>
-          (do @
+          (do !
             [unitT (<type>.apply (p.after (<type>.exactly unit.Qty)
                                           <type>.any))]
             (wrap (` (: (~ (@JSON//decode inputT))
                         ((~! p.codec) (~! qty-codec) (~! </>.any))))))
-          (do @
+          (do !
             [[_ _ valC] (<type>.apply ($_ p.and
                                           (<type>.exactly d.Dictionary)
                                           (<type>.exactly .Text)
                                           codec//decode))]
             (wrap (` (: (~ (@JSON//decode inputT))
                         ((~! </>.dictionary) (~ valC))))))
-          (do @
+          (do !
             [[_ subC] (<type>.apply (p.and (<type>.exactly .Maybe)
                                            codec//decode))]
             (wrap (` (: (~ (@JSON//decode inputT))
                         ((~! </>.nullable) (~ subC))))))
-          (do @
+          (do !
             [[_ subC] (<type>.apply (p.and (<type>.exactly .List)
                                            codec//decode))]
             (wrap (` (: (~ (@JSON//decode inputT))
                         ((~! </>.array) ((~! p.some) (~ subC)))))))
-          (do @
+          (do !
             [members (<type>.variant (p.many codec//decode))
              #let [last (dec (list.size members))]]
             (wrap (` (: (~ (@JSON//decode inputT))
@@ -292,12 +292,12 @@
                                                      ((~! p.after) ((~! </>.number!) (~ (code.frac (..tag tag)))))
                                                      ((~! </>.array))))))
                                           (list.enumeration members))))))))
-          (do @
+          (do !
             [g!decoders (<type>.tuple (p.many codec//decode))]
             (wrap (` (: (~ (@JSON//decode inputT))
                         ((~! </>.array) ($_ ((~! p.and)) (~+ g!decoders)))))))
           ## Type recursion
-          (do @
+          (do !
             [[selfC bodyC] (<type>.recursive codec//decode)
              #let [g! (code.local-identifier "____________")]]
             (wrap (` (: (~ (@JSON//decode inputT))
@@ -305,11 +305,11 @@
                                       (~ bodyC)))))))
           <type>.recursive-self
           ## Type applications
-          (do @
+          (do !
             [[funcC argsC] (<type>.apply (p.and codec//decode (p.many codec//decode)))]
             (wrap (` ((~ funcC) (~+ argsC)))))
           ## Polymorphism
-          (do @
+          (do !
             [[funcC varsC bodyC] (<type>.polymorphic codec//decode)]
             (wrap (` (: (All [(~+ varsC)]
                           (-> (~+ (list@map (|>> (~) </>.Parser (`)) varsC))
diff --git a/stdlib/source/program/aedifex.lux b/stdlib/source/program/aedifex.lux
index 485277d88..d8d855bd0 100644
--- a/stdlib/source/program/aedifex.lux
+++ b/stdlib/source/program/aedifex.lux
@@ -81,7 +81,7 @@
                           error))))))
 
 (program: [{[profile operation] /cli.command}]
-  (do {@ io.monad}
+  (do {! io.monad}
     [?profile (/input.read io.monad file.default profile)]
     (case ?profile
       (#try.Success profile)
diff --git a/stdlib/source/program/aedifex/artifact.lux b/stdlib/source/program/aedifex/artifact.lux
index dc0892eb1..c29cc7b2d 100644
--- a/stdlib/source/program/aedifex/artifact.lux
+++ b/stdlib/source/program/aedifex/artifact.lux
@@ -9,8 +9,9 @@
     [collection
      ["." list ("#@." monoid)]]]
    [world
+    ["." file (#+ Path)]
     [net
-     ["." uri]]]])
+     ["." uri (#+ URI)]]]])
 
 (type: #export Group
   Text)
@@ -64,20 +65,28 @@
             ..identity-separator
             (..identity value)))
 
-(def: #export (path artifact)
-  (-> Artifact Text)
+(def: (address separator artifact)
+  (-> Text Artifact Text)
   (let [directory (%.format (|> artifact
                                 (get@ #group)
                                 (text.split-all-with ..group-separator)
-                                (text.join-with uri.separator))
-                            uri.separator
+                                (text.join-with separator))
+                            separator
                             (get@ #name artifact)
-                            uri.separator
+                            separator
                             (get@ #version artifact))]
     (%.format directory
-              uri.separator
+              separator
               (..identity artifact))))
 
+(def: #export uri
+  (-> Artifact URI)
+  (..address uri.separator))
+
+(def: #export (path system)
+  (All [!] (-> (file.System !) Artifact Path))
+  (..address (:: system separator)))
+
 (def: #export (local artifact)
   (-> Artifact (List Text))
   (list@compose (|> artifact
diff --git a/stdlib/source/program/aedifex/command/auto.lux b/stdlib/source/program/aedifex/command/auto.lux
index 738cae467..8150fa1f6 100644
--- a/stdlib/source/program/aedifex/command/auto.lux
+++ b/stdlib/source/program/aedifex/command/auto.lux
@@ -64,17 +64,17 @@
   (promise.future
    (loop [path path]
      (let [file (java/io/File::new path)]
-       (do {@ (try.with io.monad)}
+       (do {! (try.with io.monad)}
          [exists? (java/io/File::exists file)
           directory? (java/io/File::isDirectory file)]
          (if (and exists?
                   directory?)
-           (do @
+           (do !
              [children (java/io/File::listFiles file)
               children (|> children
                            array.to-list
-                           (monad.map @ (|>> java/io/File::getAbsolutePath)))
-              descendants (monad.map @ recur children)]
+                           (monad.map ! (|>> java/io/File::getAbsolutePath)))
+              descendants (monad.map ! recur children)]
              (wrap (#.Cons path (list.concat descendants))))
            (wrap (list))))))))
 
@@ -118,22 +118,22 @@
 
 (def: #export (do! command profile)
   (All [a] (-> (Command a) (Command Any)))
-  (do {@ ///action.monad}
+  (do {! ///action.monad}
     [#let [fs (java/nio/file/FileSystems::getDefault)]
      watcher (promise.future (java/nio/file/FileSystem::newWatchService fs))
      targets (|> profile
                  (get@ #///.sources)
                  set.to-list
-                 (monad.map @ ..targets)
-                 (:: @ map list.concat))
-     _ (monad.map @ (..watch! watcher) targets)
+                 (monad.map ! ..targets)
+                 (:: ! map list.concat))
+     _ (monad.map ! (..watch! watcher) targets)
      _ (command profile)]
     (loop [_ []]
-      (do @
+      (do !
         [?key (..poll! watcher)
          _ (case ?key
              (#.Some key)
-             (do @
+             (do !
                [_ (promise.future (..drain! watcher))
                 _ (command profile)]
                (wrap []))
diff --git a/stdlib/source/program/aedifex/command/deploy.lux b/stdlib/source/program/aedifex/command/deploy.lux
index b8ac5c97c..25b1a15aa 100644
--- a/stdlib/source/program/aedifex/command/deploy.lux
+++ b/stdlib/source/program/aedifex/command/deploy.lux
@@ -63,8 +63,8 @@
                                    {#///dependency.artifact identity
                                     #///dependency.type type}
                                    content))))]
-      (do {@ ///action.monad}
-        [library (:: @ map (binary.run tar.writer)
+      (do {! ///action.monad}
+        [library (:: ! map (binary.run tar.writer)
                      (export.library (file.async file.default)
                                      (set.to-list (get@ #/.sources profile))))
          pom (promise@wrap (///pom.write profile))
diff --git a/stdlib/source/program/aedifex/dependency/resolution.lux b/stdlib/source/program/aedifex/dependency/resolution.lux
index 57df92d2a..46d32a4f7 100644
--- a/stdlib/source/program/aedifex/dependency/resolution.lux
+++ b/stdlib/source/program/aedifex/dependency/resolution.lux
@@ -56,21 +56,21 @@
 
 (def: (download url)
   (-> URL (IO (Try Binary)))
-  (do {@ (try.with io.monad)}
+  (do {! (try.with io.monad)}
     [input (|> (java/net/URL::new url)
                java/net/URL::openStream
-               (:: @ map (|>> java/io/BufferedInputStream::new)))
+               (:: ! map (|>> java/io/BufferedInputStream::new)))
      #let [buffer (binary.create ..buffer-size)]]
     (loop [output (:: binary.monoid identity)]
-      (do @
+      (do !
         [bytes-read (java/io/BufferedInputStream::read buffer +0 (.int ..buffer-size) input)]
         (case bytes-read
-          -1 (do @
+          -1 (do !
                [_ (java/lang/AutoCloseable::close input)]
                (wrap output))
           _ (if (n.= ..buffer-size bytes-read)
               (recur (:: binary.monoid compose output buffer))
-              (do @
+              (do !
                 [chunk (:: io.monad wrap (binary.slice 0 (.nat bytes-read) buffer))]
                 (recur (:: binary.monoid compose output chunk)))))))))
 
@@ -116,7 +116,7 @@
 (def: #export (resolve repository dependency)
   (-> Repository Dependency (IO (Try Package)))
   (let [[artifact type] dependency
-        prefix (format repository uri.separator (///artifact.path artifact))]
+        prefix (format repository uri.separator (///artifact.uri artifact))]
     (do (try.with io.monad)
       [library (..download (format prefix (///artifact/extension.extension type)))
        sha1 (..verified-hash dependency library (format prefix ///artifact/extension.sha1) ///hash.sha1 ///hash.sha1-codec ..sha1-does-not-match)
diff --git a/stdlib/source/program/aedifex/local.lux b/stdlib/source/program/aedifex/local.lux
index 674d99f04..7a4cf070e 100644
--- a/stdlib/source/program/aedifex/local.lux
+++ b/stdlib/source/program/aedifex/local.lux
@@ -14,7 +14,7 @@
      ["<.>" xml]]]
    [data
     [binary (#+ Binary)]
-    ["." text
+    [text
      ["%" format (#+ format)]
      ["." encoding]]
     [collection
@@ -26,9 +26,7 @@
      ["." tar]
      ["." xml]]]
    [world
-    ["." file (#+ Path File Directory)]
-    [net
-     ["." uri]]]]
+    ["." file (#+ Path File Directory)]]]
   [program
    [compositor
     ["." export]]]
@@ -42,7 +40,7 @@
    ["#." dependency (#+ Dependency)
     ["#/." resolution (#+ Package Resolution)]]])
 
-(def: (repository system)
+(def: #export (repository system)
   (All [a] (-> (file.System a) Path))
   (let [/ (:: system separator)]
     (format "~" / ".m2" / "repository")))
@@ -51,8 +49,7 @@
   (All [a] (-> (file.System a) Artifact Path))
   (format (..repository system)
           (:: system separator)
-          (text.replace-all uri.separator (:: system separator)
-                            (//artifact.path artifact))))
+          (//artifact.path system artifact)))
 
 (def: (save! system content file)
   (-> (file.System Promise) Binary Path (Promise (Try Any)))
@@ -103,8 +100,8 @@
 
 (def: #export (cache-all system resolution)
   (-> (file.System Promise) Resolution (Promise (Try Any)))
-  (do {@ (try.with promise.monad)}
-    [_ (monad.map @ (function (_ [dependency package])
+  (do {! (try.with promise.monad)}
+    [_ (monad.map ! (function (_ [dependency package])
                       (..cache system dependency package))
                   (dictionary.entries resolution))]
     (wrap [])))
diff --git a/stdlib/source/program/aedifex/parser.lux b/stdlib/source/program/aedifex/parser.lux
index 867b3b81f..4fa6612c0 100644
--- a/stdlib/source/program/aedifex/parser.lux
+++ b/stdlib/source/program/aedifex/parser.lux
@@ -77,8 +77,8 @@
 
 (def: license
   (Parser /.License)
-  (do {@ <>.monad}
-    [input (:: @ map
+  (do {! <>.monad}
+    [input (:: ! map
                (dictionary.from-list text.hash)
                (<c>.record (<>.some (<>.and <c>.local-tag
                                             <c>.any))))]
@@ -92,8 +92,8 @@
 
 (def: organization
   (Parser /.Organization)
-  (do {@ <>.monad}
-    [input (:: @ map
+  (do {! <>.monad}
+    [input (:: ! map
                (dictionary.from-list text.hash)
                (<c>.record (<>.some (<>.and <c>.local-tag
                                             <c>.any))))]
@@ -103,8 +103,8 @@
 
 (def: developer
   (Parser /.Developer)
-  (do {@ <>.monad}
-    [input (:: @ map
+  (do {! <>.monad}
+    [input (:: ! map
                (dictionary.from-list text.hash)
                (<c>.record (<>.some (<>.and <c>.local-tag
                                             <c>.any))))]
@@ -120,8 +120,8 @@
 
 (def: info
   (Parser /.Info)
-  (do {@ <>.monad}
-    [input (:: @ map
+  (do {! <>.monad}
+    [input (:: ! map
                (dictionary.from-list text.hash)
                (<c>.record (<>.some (<>.and <c>.local-tag
                                             <c>.any))))]
@@ -171,8 +171,8 @@
 
 (def: profile
   (Parser /.Profile)
-  (do {@ <>.monad}
-    [input (:: @ map
+  (do {! <>.monad}
+    [input (:: ! map
                (dictionary.from-list text.hash)
                (<c>.record (<>.some (<>.and <c>.local-tag
                                             <c>.any))))
@@ -187,15 +187,15 @@
                      (..singular input "info" ..info)))
            ^repositories (: (Parser (Set //dependency.Repository))
                             (|> (..plural input "repositories" ..repository)
-                                (:: @ map (set.from-list text.hash))
+                                (:: ! map (set.from-list text.hash))
                                 (<>.default (set.new text.hash))))
            ^dependencies (: (Parser (Set //dependency.Dependency))
                             (|> (..plural input "dependencies" ..dependency)
-                                (:: @ map (set.from-list //dependency.hash))
+                                (:: ! map (set.from-list //dependency.hash))
                                 (<>.default (set.new //dependency.hash))))
            ^sources (: (Parser (Set /.Source))
                        (|> (..plural input "sources" ..source)
-                           (:: @ map (set.from-list text.hash))
+                           (:: ! map (set.from-list text.hash))
                            (<>.default (set.from-list text.hash (list /.default-source)))))
            ^target (: (Parser (Maybe /.Target))
                       (<>.maybe
@@ -207,7 +207,7 @@
                     (<>.maybe
                      (..singular input "test" ..module)))
            ^deploy-repositories (: (Parser (Dictionary Text //dependency.Repository))
-                                   (<| (:: @ map (dictionary.from-list text.hash))
+                                   (<| (:: ! map (dictionary.from-list text.hash))
                                        (<>.default (list))
                                        (..singular input "deploy-repositories" ..deploy-repository)))]]
     ($_ <>.and
diff --git a/stdlib/source/program/aedifex/pom.lux b/stdlib/source/program/aedifex/pom.lux
index 4f7d8a4fd..259a3f769 100644
--- a/stdlib/source/program/aedifex/pom.lux
+++ b/stdlib/source/program/aedifex/pom.lux
@@ -150,8 +150,8 @@
 
 (def: parse-dependency
   (Parser Dependency)
-  (do {@ <>.monad}
-    [properties (:: @ map (dictionary.from-list name.hash)
+  (do {! <>.monad}
+    [properties (:: ! map (dictionary.from-list name.hash)
                     (<xml>.children (<>.some ..parse-property)))]
     (<| <>.lift
         try.from-maybe
@@ -168,16 +168,16 @@
 
 (def: parse-dependencies
   (Parser (List Dependency))
-  (do {@ <>.monad}
+  (do {! <>.monad}
     [_ (<xml>.node ["" ..dependencies-tag])]
     (<xml>.children (<>.some ..parse-dependency))))
 
 (def: #export parser
   (Parser /.Profile)
-  (do {@ <>.monad}
+  (do {! <>.monad}
     [_ (<xml>.node ["" ..project-tag])]
     (<xml>.children
-     (do @
+     (do !
        [dependencies (<xml>.somewhere ..parse-dependencies)
         _ (<>.some <xml>.ignore)]
        (wrap (|> (:: /.monoid identity)
diff --git a/stdlib/source/program/aedifex/project.lux b/stdlib/source/program/aedifex/project.lux
index 9bc80c462..b084e0a3d 100644
--- a/stdlib/source/program/aedifex/project.lux
+++ b/stdlib/source/program/aedifex/project.lux
@@ -59,8 +59,8 @@
       (exception.throw ..circular-dependency [ouroboros name])
       
       #.None
-      (do {@ try.monad}
-        [parents (monad.map @ (profile' (set.add name lineage) project)
+      (do {! try.monad}
+        [parents (monad.map ! (profile' (set.add name lineage) project)
                             (get@ #//.parents profile))]
         (wrap (list@fold (function (_ parent child)
                            (:: //.monoid compose child parent))
diff --git a/stdlib/source/program/aedifex/shell.lux b/stdlib/source/program/aedifex/shell.lux
index 72150a016..5ef30cf91 100644
--- a/stdlib/source/program/aedifex/shell.lux
+++ b/stdlib/source/program/aedifex/shell.lux
@@ -82,12 +82,12 @@
 (def: #export (execute command working-directory)
   (-> Text Path (Action Any))
   (promise.future
-   (do {@ io.monad}
+   (do {! io.monad}
      [runtime (java/lang/Runtime::getRuntime)
       ?process (java/lang/Runtime::exec command #.None (java/io/File::new working-directory) runtime)]
      (case ?process
        (#try.Success process)
-       (do @
+       (do !
          [_ (..consume-stream working-directory command (java/lang/Process::getInputStream process))
           _ (..consume-stream working-directory command (java/lang/Process::getErrorStream process))
           ?exit-code (java/lang/Process::waitFor process)]
diff --git a/stdlib/source/program/aedifex/upload.lux b/stdlib/source/program/aedifex/upload.lux
index c4572de9d..f5834fa61 100644
--- a/stdlib/source/program/aedifex/upload.lux
+++ b/stdlib/source/program/aedifex/upload.lux
@@ -38,7 +38,7 @@
   (-> Repository Dependency URL)
   (format repository
           uri.separator
-          (//artifact.path (get@ #//dependency.artifact dependency))
+          (//artifact.uri (get@ #//dependency.artifact dependency))
           "."
           (get@ #//dependency.type dependency)))
 
@@ -82,7 +82,7 @@
 (def: #export (upload repository user password dependency content)
   (-> Repository User Password Dependency Binary
       (Action Any))
-  (do {@ ..monad}
+  (do {! ..monad}
     [connection (|> (..url repository dependency)
                     java/net/URL::new
                     java/net/URL::openConnection)
diff --git a/stdlib/source/program/compositor.lux b/stdlib/source/program/compositor.lux
index 3bc870f9b..e7884bf70 100644
--- a/stdlib/source/program/compositor.lux
+++ b/stdlib/source/program/compositor.lux
@@ -120,7 +120,7 @@
           Service
           [Packager Path]
           (Promise Any)))
-    (do {@ promise.monad}
+    (do {! promise.monad}
       [platform (promise.future platform)]
       (case service
         (#/cli.Compilation compilation)
@@ -156,9 +156,9 @@
         ## TODO: Fix the interpreter...
         (undefined)
         ## (<| (or-crash! "Interpretation failed:")
-        ##     (do {@ promise.monad}
+        ##     (do {! promise.monad}
         ##       [console (|> console.default
         ##                    promise.future
-        ##                    (:: @ map (|>> try.assume console.async)))]
+        ##                    (:: ! map (|>> try.assume console.async)))]
         ##       (interpreter.run (try.with promise.monad) console platform interpretation generation-bundle)))
         ))))
diff --git a/stdlib/source/program/compositor/import.lux b/stdlib/source/program/compositor/import.lux
index 2e53e0976..d69915cbb 100644
--- a/stdlib/source/program/compositor/import.lux
+++ b/stdlib/source/program/compositor/import.lux
@@ -39,9 +39,9 @@
                 (!.use (:: system file) [library]))
      binary (!.use (:: library content) [])]
     (promise@wrap
-     (do {@ try.monad}
+     (do {! try.monad}
        [tar (<b>.run tar.parser binary)]
-       (monad.fold @ (function (_ entry import)
+       (monad.fold ! (function (_ entry import)
                        (case entry
                          (#tar.Normal [path instant mode ownership content])
                          (dictionary.try-put (tar.from-path path)
diff --git a/stdlib/source/program/scriptum.lux b/stdlib/source/program/scriptum.lux
index 1cb0ee21a..9ad2c59a4 100644
--- a/stdlib/source/program/scriptum.lux
+++ b/stdlib/source/program/scriptum.lux
@@ -376,8 +376,8 @@
 
 (def: (document-types module types)
   (-> Text (List Value) (Meta (Markdown Block)))
-  (do {@ macro.monad}
-    [type-docs (monad.map @
+  (do {! macro.monad}
+    [type-docs (monad.map !
                           (: (-> Value (Meta (Markdown Block)))
                              (function (_ [name def-annotations type])
                                (do macro.monad
@@ -499,16 +499,16 @@
         (wrap [])))))
 
 (macro: (gen-documentation! _)
-  (do {@ macro.monad}
+  (do {! macro.monad}
     [all-modules macro.modules
      #let [lux-modules (|> all-modules
                            (list.filter (function.compose lux-module? product.left))
                            (list.sort name-sort))]
-     lux-exports (monad.map @ (function.compose macro.exports product.left)
+     lux-exports (monad.map ! (function.compose macro.exports product.left)
                             lux-modules)
      module-documentation (|> (list@map organize-definitions lux-exports)
                               (list.zip/2 lux-modules)
-                              (monad.map @ document-module))
+                              (monad.map ! document-module))
      #let [_ (io.run (monad.map io.monad save-documentation! module-documentation))]]
     (wrap (list))))
 
diff --git a/stdlib/source/spec/compositor/generation/case.lux b/stdlib/source/spec/compositor/generation/case.lux
index b4fa47b99..764d7351b 100644
--- a/stdlib/source/spec/compositor/generation/case.lux
+++ b/stdlib/source/spec/compositor/generation/case.lux
@@ -64,9 +64,9 @@
                     [r.i64         synthesis.i64  synthesis.path/i64]
                     [r.frac        synthesis.f64  synthesis.path/f64]
                     [(r.unicode 5) synthesis.text synthesis.path/text]))
-              (do {@ r.monad}
+              (do {! r.monad}
                 [size ..size
-                 idx (|> r.nat (:: @ map (n.% size)))
+                 idx (|> r.nat (:: ! map (n.% size)))
                  [subS subP] case
                  #let [unitS (synthesis.text synthesis.unit)
                        caseS (synthesis.tuple
@@ -79,9 +79,9 @@
                                    (synthesis.member/left idx))
                                  subP)]]
                 (wrap [caseS caseP]))
-              (do {@ r.monad}
+              (do {! r.monad}
                 [size ..size
-                 idx (|> r.nat (:: @ map (n.% size)))
+                 idx (|> r.nat (:: ! map (n.% size)))
                  [subS subP] case
                  #let [right? (tail? size idx)
                        caseS (synthesis.variant
diff --git a/stdlib/source/spec/compositor/generation/common.lux b/stdlib/source/spec/compositor/generation/common.lux
index 5868191c4..9060675f6 100644
--- a/stdlib/source/spec/compositor/generation/common.lux
+++ b/stdlib/source/spec/compositor/generation/common.lux
@@ -174,13 +174,13 @@
 
 (def: (text run)
   (-> Runner Test)
-  (do {@ r.monad}
-    [sample-size (|> r.nat (:: @ map (|>> (n.% 10) (n.max 1))))
+  (do {! r.monad}
+    [sample-size (|> r.nat (:: ! map (|>> (n.% 10) (n.max 1))))
      sample-lower (r.ascii/lower-alpha sample-size)
      sample-upper (r.ascii/upper-alpha sample-size)
      sample-alpha (|> (r.ascii/alpha sample-size)
                       (r.filter (|>> (text@= sample-upper) not)))
-     char-idx (|> r.nat (:: @ map (n.% sample-size)))
+     char-idx (|> r.nat (:: ! map (n.% sample-size)))
      #let [sample-lowerS (synthesis.text sample-lower)
            sample-upperS (synthesis.text sample-upper)
            sample-alphaS (synthesis.text sample-alpha)
diff --git a/stdlib/source/spec/compositor/generation/function.lux b/stdlib/source/spec/compositor/generation/function.lux
index e3112d799..fefe039f7 100644
--- a/stdlib/source/spec/compositor/generation/function.lux
+++ b/stdlib/source/spec/compositor/generation/function.lux
@@ -47,9 +47,9 @@
 
 (def: #export (spec run)
   (-> Runner Test)
-  (do {@ r.monad}
+  (do {! r.monad}
     [[arity local functionS] ..function
-     partial-arity (|> r.nat (:: @ map (|>> (n.% arity) (n.max 1))))
+     partial-arity (|> r.nat (:: ! map (|>> (n.% arity) (n.max 1))))
      inputs (r.list arity r.safe-frac)
      #let [expectation (maybe.assume (list.nth (dec local) inputs))
            inputsS (list@map (|>> synthesis.f64) inputs)]]
diff --git a/stdlib/source/spec/compositor/generation/reference.lux b/stdlib/source/spec/compositor/generation/reference.lux
index 8c53db6c6..f1e12ff96 100644
--- a/stdlib/source/spec/compositor/generation/reference.lux
+++ b/stdlib/source/spec/compositor/generation/reference.lux
@@ -39,8 +39,8 @@
 
 (def: (variable run)
   (-> Runner Test)
-  (do {@ r.monad}
-    [register (|> r.nat (:: @ map (n.% 100)))
+  (do {! r.monad}
+    [register (|> r.nat (:: ! map (n.% 100)))
      expected r.safe-frac]
     (_.test "Local variables."
             (|> (synthesis.branch/let [(synthesis.f64 expected)
diff --git a/stdlib/source/spec/compositor/generation/structure.lux b/stdlib/source/spec/compositor/generation/structure.lux
index c0539a975..cd790c6d2 100644
--- a/stdlib/source/spec/compositor/generation/structure.lux
+++ b/stdlib/source/spec/compositor/generation/structure.lux
@@ -30,9 +30,9 @@
 
 (def: (variant run)
   (-> Runner Test)
-  (do {@ r.monad}
-    [num-tags (|> r.nat (:: @ map (|>> (n.% 10) (n.max 2))))
-     tag-in (|> r.nat (:: @ map (n.% num-tags)))
+  (do {! r.monad}
+    [num-tags (|> r.nat (:: ! map (|>> (n.% 10) (n.max 2))))
+     tag-in (|> r.nat (:: ! map (n.% num-tags)))
      #let [last?-in (|> num-tags dec (n.= tag-in))]
      value-in r.i64]
     (_.test (%.name (name-of synthesis.variant))
@@ -65,8 +65,8 @@
 
 (def: (tuple run)
   (-> Runner Test)
-  (do {@ r.monad}
-    [size (|> r.nat (:: @ map (|>> (n.% 10) (n.max 2))))
+  (do {! r.monad}
+    [size (|> r.nat (:: ! map (|>> (n.% 10) (n.max 2))))
      tuple-in (r.list size r.i64)]
     (_.test (%.name (name-of synthesis.tuple))
             (|> (synthesis.tuple (list@map (|>> synthesis.i64) tuple-in))
diff --git a/stdlib/source/spec/lux/abstract/apply.lux b/stdlib/source/spec/lux/abstract/apply.lux
index 4220de34c..a9925b928 100644
--- a/stdlib/source/spec/lux/abstract/apply.lux
+++ b/stdlib/source/spec/lux/abstract/apply.lux
@@ -17,8 +17,8 @@
 
 (def: (identity injection comparison (^open "_@."))
   (All [f] (-> (Injection f) (Comparison f) (Apply f) Test))
-  (do {@ random.monad}
-    [sample (:: @ map injection random.nat)]
+  (do {! random.monad}
+    [sample (:: ! map injection random.nat)]
     (_.test "Identity."
             ((comparison n.=)
              (_@apply (injection function.identity) sample)
@@ -26,9 +26,9 @@
 
 (def: (homomorphism injection comparison (^open "_@."))
   (All [f] (-> (Injection f) (Comparison f) (Apply f) Test))
-  (do {@ random.monad}
+  (do {! random.monad}
     [sample random.nat
-     increase (:: @ map n.+ random.nat)]
+     increase (:: ! map n.+ random.nat)]
     (_.test "Homomorphism."
             ((comparison n.=)
              (_@apply (injection increase) (injection sample))
@@ -36,9 +36,9 @@
 
 (def: (interchange injection comparison (^open "_@."))
   (All [f] (-> (Injection f) (Comparison f) (Apply f) Test))
-  (do {@ random.monad}
+  (do {! random.monad}
     [sample random.nat
-     increase (:: @ map n.+ random.nat)]
+     increase (:: ! map n.+ random.nat)]
     (_.test "Interchange."
             ((comparison n.=)
              (_@apply (injection increase) (injection sample))
@@ -46,10 +46,10 @@
 
 (def: (composition injection comparison (^open "_@."))
   (All [f] (-> (Injection f) (Comparison f) (Apply f) Test))
-  (do {@ random.monad}
+  (do {! random.monad}
     [sample random.nat
-     increase (:: @ map n.+ random.nat)
-     decrease (:: @ map n.- random.nat)]
+     increase (:: ! map n.+ random.nat)
+     decrease (:: ! map n.- random.nat)]
     (_.test "Composition."
             ((comparison n.=)
              (_$ _@apply
diff --git a/stdlib/source/spec/lux/abstract/comonad.lux b/stdlib/source/spec/lux/abstract/comonad.lux
index e434f6ab1..b69581037 100644
--- a/stdlib/source/spec/lux/abstract/comonad.lux
+++ b/stdlib/source/spec/lux/abstract/comonad.lux
@@ -15,9 +15,9 @@
 
 (def: (left-identity injection (^open "_@."))
   (All [f] (-> (Injection f) (CoMonad f) Test))
-  (do {@ random.monad}
+  (do {! random.monad}
     [sample random.nat
-     morphism (:: @ map (function (_ diff)
+     morphism (:: ! map (function (_ diff)
                           (|>> _@unwrap (n.+ diff)))
                   random.nat)
      #let [start (injection sample)]]
@@ -37,12 +37,12 @@
 
 (def: (associativity injection comparison (^open "_@."))
   (All [f] (-> (Injection f) (Comparison f) (CoMonad f) Test))
-  (do {@ random.monad}
+  (do {! random.monad}
     [sample random.nat
-     increase (:: @ map (function (_ diff)
+     increase (:: ! map (function (_ diff)
                           (|>> _@unwrap (n.+ diff)))
                   random.nat)
-     decrease (:: @ map (function (_ diff)
+     decrease (:: ! map (function (_ diff)
                           (|>> _@unwrap(n.- diff)))
                   random.nat)
      #let [start (injection sample)
diff --git a/stdlib/source/spec/lux/abstract/functor.lux b/stdlib/source/spec/lux/abstract/functor.lux
index 2cb086b7a..d40ded1a2 100644
--- a/stdlib/source/spec/lux/abstract/functor.lux
+++ b/stdlib/source/spec/lux/abstract/functor.lux
@@ -24,8 +24,8 @@
 
 (def: (identity injection comparison (^open "/@."))
   (All [f] (-> (Injection f) (Comparison f) (Functor f) Test))
-  (do {@ random.monad}
-    [sample (:: @ map injection random.nat)]
+  (do {! random.monad}
+    [sample (:: ! map injection random.nat)]
     (_.test "Identity."
             ((comparison n.=)
              (/@map function.identity sample)
@@ -33,9 +33,9 @@
 
 (def: (homomorphism injection comparison (^open "/@."))
   (All [f] (-> (Injection f) (Comparison f) (Functor f) Test))
-  (do {@ random.monad}
+  (do {! random.monad}
     [sample random.nat
-     increase (:: @ map n.+ random.nat)]
+     increase (:: ! map n.+ random.nat)]
     (_.test "Homomorphism."
             ((comparison n.=)
              (/@map increase (injection sample))
@@ -43,10 +43,10 @@
 
 (def: (composition injection comparison (^open "/@."))
   (All [f] (-> (Injection f) (Comparison f) (Functor f) Test))
-  (do {@ random.monad}
-    [sample (:: @ map injection random.nat)
-     increase (:: @ map n.+ random.nat)
-     decrease (:: @ map n.- random.nat)]
+  (do {! random.monad}
+    [sample (:: ! map injection random.nat)
+     increase (:: ! map n.+ random.nat)
+     decrease (:: ! map n.- random.nat)]
     (_.test "Composition."
             ((comparison n.=)
              (|> sample (/@map increase) (/@map decrease))
diff --git a/stdlib/source/spec/lux/abstract/monad.lux b/stdlib/source/spec/lux/abstract/monad.lux
index d2eac535f..c9abf9b25 100644
--- a/stdlib/source/spec/lux/abstract/monad.lux
+++ b/stdlib/source/spec/lux/abstract/monad.lux
@@ -13,9 +13,9 @@
 
 (def: (left-identity injection comparison (^open "_@."))
   (All [f] (-> (Injection f) (Comparison f) (Monad f) Test))
-  (do {@ random.monad}
+  (do {! random.monad}
     [sample random.nat
-     morphism (:: @ map (function (_ diff)
+     morphism (:: ! map (function (_ diff)
                           (|>> (n.+ diff) _@wrap))
                   random.nat)]
     (_.test "Left identity."
@@ -34,12 +34,12 @@
 
 (def: (associativity injection comparison (^open "_@."))
   (All [f] (-> (Injection f) (Comparison f) (Monad f) Test))
-  (do {@ random.monad}
+  (do {! random.monad}
     [sample random.nat
-     increase (:: @ map (function (_ diff)
+     increase (:: ! map (function (_ diff)
                           (|>> (n.+ diff) _@wrap))
                   random.nat)
-     decrease (:: @ map (function (_ diff)
+     decrease (:: ! map (function (_ diff)
                           (|>> (n.- diff) _@wrap))
                   random.nat)]
     (_.test "Associativity."
diff --git a/stdlib/source/test/aedifex.lux b/stdlib/source/test/aedifex.lux
index fd92d9b40..c40939b47 100644
--- a/stdlib/source/test/aedifex.lux
+++ b/stdlib/source/test/aedifex.lux
@@ -10,6 +10,7 @@
    ["#." input]
    ["#." command #_
     ["#/." pom]]
+   ["#." local]
    ["#." dependency]
    ["#." profile]
    ["#." project]
@@ -24,6 +25,7 @@
       /artifact.test
       /input.test
       /command/pom.test
+      /local.test
       /dependency.test
       /profile.test
       /project.test
diff --git a/stdlib/source/test/aedifex/artifact.lux b/stdlib/source/test/aedifex/artifact.lux
index 376f26717..9a4607306 100644
--- a/stdlib/source/test/aedifex/artifact.lux
+++ b/stdlib/source/test/aedifex/artifact.lux
@@ -7,8 +7,17 @@
     {[0 #spec]
      [/
       ["$." equivalence]]}]
+   [control
+    [concurrency
+     [promise (#+ Promise)]]]
+   [data
+    ["." text ("#@." equivalence)]]
    [math
-    ["." random (#+ Random)]]]
+    ["." random (#+ Random)]]
+   [world
+    ["." file]
+    [net
+     ["." uri]]]]
   ["." / #_
    ["#." type]
    ["#." extension]]
@@ -31,6 +40,15 @@
             (_.with-cover [/.equivalence]
               ($equivalence.spec /.equivalence ..random))
 
+            (do random.monad
+              [sample ..random
+               #let [fs (: (file.System Promise)
+                           (file.mock (:: file.default separator)))]]
+              (_.cover [/.uri /.path]
+                       (|> (/.path fs sample)
+                           (text.replace-all uri.separator (:: fs separator))
+                           (text@= (/.uri sample)))))
+            
             /type.test
             /extension.test
             ))))
diff --git a/stdlib/source/test/aedifex/local.lux b/stdlib/source/test/aedifex/local.lux
new file mode 100644
index 000000000..a883f565e
--- /dev/null
+++ b/stdlib/source/test/aedifex/local.lux
@@ -0,0 +1,36 @@
+(.module:
+  [lux #*
+   ["_" test (#+ Test)]
+   [abstract
+    [monad (#+ do)]]
+   [control
+    [concurrency
+     [promise (#+ Promise)]]]
+   [data
+    ["." text]]
+   [math
+    ["." random (#+ Random)]]
+   [world
+    ["." file]]]
+  [//
+   ["@." artifact]]
+  {#program
+   ["." /
+    ["/#" // #_
+     ["#." artifact]]]})
+
+(def: #export test
+  Test
+  (<| (_.covering /._)
+      (do {@ random.monad}
+        [sample @artifact.random
+         #let [fs (: (file.System Promise)
+                     (file.mock (:: file.default separator)))]]
+        ($_ _.and
+            (_.cover [/.repository /.path]
+                     (let [path (/.path fs sample)]
+                       (and (text.starts-with? (/.repository fs)
+                                               path)
+                            (text.ends-with? (//artifact.path fs sample)
+                                             path))))
+            ))))
diff --git a/stdlib/source/test/lux/data/collection/set.lux b/stdlib/source/test/lux/data/collection/set.lux
index 993082e79..93549712f 100644
--- a/stdlib/source/test/lux/data/collection/set.lux
+++ b/stdlib/source/test/lux/data/collection/set.lux
@@ -9,66 +9,108 @@
       ["$." equivalence]
       ["$." monoid]]}]
    [data
+    ["." bit ("#@." equivalence)]
     [number
      ["n" nat]]
     [collection
      ["." list]]]
    [math
-    ["r" random]]]
+    ["." random (#+ Random)]]]
   {1
    ["." /]})
 
 (def: gen-nat
-  (r.Random Nat)
-  (|> r.nat
-      (:: r.monad map (n.% 100))))
+  (Random Nat)
+  (:: random.monad map (n.% 100)
+      random.nat))
 
 (def: #export test
   Test
-  (<| (_.context (%.name (name-of /.Set)))
-      (do r.monad
-        [size gen-nat]
+  (<| (_.covering /._)
+      (_.with-cover [/.Set])
+      (let [(^open "/@.") /.equivalence])
+      (do random.monad
+        [size ..gen-nat]
         ($_ _.and
-            ($equivalence.spec /.equivalence (r.set n.hash size r.nat))
-            ($monoid.spec /.equivalence (/.monoid n.hash) (r.set n.hash size r.nat))
+            (_.with-cover [/.equivalence]
+              ($equivalence.spec /.equivalence (random.set n.hash size random.nat)))
+            (_.with-cover [/.monoid]
+              ($monoid.spec /.equivalence (/.monoid n.hash) (random.set n.hash size random.nat)))
 
-            (do r.monad
-              [sizeL gen-nat
-               sizeR gen-nat
-               setL (r.set n.hash sizeL gen-nat)
-               setR (r.set n.hash sizeR gen-nat)
-               non-member (|> gen-nat
-                              (r.filter (|>> (/.member? setL) not)))
-               #let [(^open "/@.") /.equivalence]]
+            (do random.monad
+              [sizeL ..gen-nat
+               sizeR ..gen-nat
+               setL (random.set n.hash sizeL random.nat)
+               setR (random.set n.hash sizeR random.nat)
+               non-memberL (random.filter (|>> (/.member? setL) not)
+                                          random.nat)]
               ($_ _.and
-                  (_.test "I can query the size of a set."
-                          (and (n.= sizeL (/.size setL))
-                               (n.= sizeR (/.size setR))))
-                  (_.test "Converting sets to/from lists can't change their values."
-                          (|> setL
-                              /.to-list (/.from-list n.hash)
-                              (/@= setL)))
-                  (_.test "Every set is a sub-set of the union of itself with another."
-                          (let [setLR (/.union setL setR)]
-                            (and (/.sub? setLR setL)
-                                 (/.sub? setLR setR))))
-                  (_.test "Every set is a super-set of the intersection of itself with another."
-                          (let [setLR (/.intersection setL setR)]
-                            (and (/.super? setLR setL)
-                                 (/.super? setLR setR))))
-                  (_.test "Union with the empty set leaves a set unchanged."
-                          (/@= setL
-                               (/.union (/.new n.hash)
-                                        setL)))
-                  (_.test "Intersection with the empty set results in the empty set."
-                          (let [empty-set (/.new n.hash)]
-                            (/@= empty-set
-                                 (/.intersection empty-set setL))))
-                  (_.test "After substracting a set A from another B, no member of A can be a member of B."
-                          (let [sub (/.difference setR setL)]
-                            (not (list.any? (/.member? sub) (/.to-list setR)))))
-                  (_.test "Every member of a set must be identifiable."
-                          (and (not (/.member? setL non-member))
-                               (/.member? (/.add non-member setL) non-member)
-                               (not (/.member? (/.remove non-member (/.add non-member setL)) non-member))))
+                  (_.cover [/.size]
+                           (n.= sizeL (/.size setL)))
+                  (_.cover [/.empty?]
+                           (bit@= (/.empty? setL)
+                                  (n.= 0 (/.size setL))))
+                  (_.cover [/.to-list /.from-list]
+                           (|> setL /.to-list (/.from-list n.hash) (/@= setL)))
+                  (_.cover [/.member?]
+                           (and (list.every? (/.member? setL) (/.to-list setL))
+                                (not (/.member? setL non-memberL))))
+                  (_.cover [/.add]
+                           (let [before-addition!
+                                 (not (/.member? setL non-memberL))
+
+                                 after-addition!
+                                 (/.member? (/.add non-memberL setL) non-memberL)
+
+                                 size-increase!
+                                 (n.= (inc (/.size setL))
+                                      (/.size (/.add non-memberL setL)))]
+                             (and before-addition!
+                                  after-addition!)))
+                  (_.cover [/.remove]
+                           (let [symmetry!
+                                 (|> setL
+                                     (/.add non-memberL)
+                                     (/.remove non-memberL)
+                                     (/@= setL))
+
+                                 idempotency!
+                                 (|> setL
+                                     (/.remove non-memberL)
+                                     (/@= setL))]
+                             (and symmetry!
+                                  idempotency!)))
+                  (_.cover [/.union /.sub?]
+                           (let [setLR (/.union setL setR)
+                                 
+                                 sets-are-subs-of-their-unions!
+                                 (and (/.sub? setLR setL)
+                                      (/.sub? setLR setR))
+
+                                 union-with-empty-set!
+                                 (|> setL
+                                     (/.union (/.new n.hash))
+                                     (/@= setL))]
+                             (and sets-are-subs-of-their-unions!
+                                  union-with-empty-set!)))
+                  (_.cover [/.intersection /.super?]
+                           (let [setLR (/.intersection setL setR)
+                                 
+                                 sets-are-supers-of-their-intersections!
+                                 (and (/.super? setLR setL)
+                                      (/.super? setLR setR))
+
+                                 intersection-with-empty-set!
+                                 (|> setL
+                                     (/.intersection (/.new n.hash))
+                                     /.empty?)]
+                             (and sets-are-supers-of-their-intersections!
+                                  intersection-with-empty-set!)))
+                  (_.cover [/.difference]
+                           (let [setL+R (/.union setR setL)
+                                 setL-R (/.difference setR setL+R)]
+                             (and (list.every? (/.member? setL+R) (/.to-list setR))
+                                  (not (list.any? (/.member? setL-R) (/.to-list setR))))))
+                  (_.cover [/.predicate]
+                           (list.every? (/.predicate setL) (/.to-list setL)))
                   ))))))
diff --git a/stdlib/source/test/lux/data/format/json.lux b/stdlib/source/test/lux/data/format/json.lux
index 548dbebdd..c1341aae0 100644
--- a/stdlib/source/test/lux/data/format/json.lux
+++ b/stdlib/source/test/lux/data/format/json.lux
@@ -47,10 +47,10 @@
 (def: #export json
   (Random JSON)
   (r.rec (function (_ recur)
-           (do {@ r.monad}
-             [size (:: @ map (n.% 2) r.nat)]
+           (do {! r.monad}
+             [size (:: ! map (n.% 2) r.nat)]
              ($_ r.or
-                 (:: @ wrap [])
+                 (:: ! wrap [])
                  r.bit
                  r.safe-frac
                  (r.unicode size)
diff --git a/stdlib/source/test/lux/data/format/tar.lux b/stdlib/source/test/lux/data/format/tar.lux
index 17f18e005..0e274a6e6 100644
--- a/stdlib/source/test/lux/data/format/tar.lux
+++ b/stdlib/source/test/lux/data/format/tar.lux
@@ -35,7 +35,7 @@
 (def: path
   Test
   (_.with-cover [/.Path]
-    (do {@ random.monad}
+    (do {! random.monad}
       [expected (random.ascii/lower-alpha /.path-size)
        invalid (random.ascii/lower-alpha (inc /.path-size))
        not-ascii (random.text (random.char (unicode.set [unicode.katakana (list)]))
@@ -68,7 +68,7 @@
 (def: name
   Test
   (_.with-cover [/.Name]
-    (do {@ random.monad}
+    (do {! random.monad}
       [expected (random.ascii/lower-alpha /.name-size)
        invalid (random.ascii/lower-alpha (inc /.name-size))
        not-ascii (random.text (random.char (unicode.set [unicode.katakana (list)]))
@@ -101,9 +101,9 @@
 (def: small
   Test
   (_.with-cover [/.Small]
-    (do {@ random.monad}
-      [expected (|> random.nat (:: @ map (n.% /.small-limit)))
-       invalid (|> random.nat (:: @ map (n.max /.small-limit)))]
+    (do {! random.monad}
+      [expected (|> random.nat (:: ! map (n.% /.small-limit)))
+       invalid (|> random.nat (:: ! map (n.max /.small-limit)))]
       (`` ($_ _.and
               (_.cover [/.small /.from-small]
                        (case (/.small expected)
@@ -125,9 +125,9 @@
 (def: big
   Test
   (_.with-cover [/.Big]
-    (do {@ random.monad}
-      [expected (|> random.nat (:: @ map (n.% /.big-limit)))
-       invalid (|> random.nat (:: @ map (n.max /.big-limit)))]
+    (do {! random.monad}
+      [expected (|> random.nat (:: ! map (n.% /.big-limit)))
+       invalid (|> random.nat (:: ! map (n.max /.big-limit)))]
       (`` ($_ _.and
               (_.cover [/.big /.from-big]
                        (case (/.big expected)
@@ -150,12 +150,12 @@
 
 (def: entry
   Test
-  (do {@ random.monad}
+  (do {! random.monad}
     [expected-path (random.ascii/lower-alpha (dec /.path-size))
-     expected-moment (:: @ map (|>> (n.% 1,0,00,00,00,00,000) .int instant.from-millis)
+     expected-moment (:: ! map (|>> (n.% 1,0,00,00,00,00,000) .int instant.from-millis)
                          random.nat)
      chunk (random.ascii/lower-alpha chunk-size)
-     chunks (:: @ map (n.% 100) random.nat)
+     chunks (:: ! map (n.% 100) random.nat)
      #let [content (|> chunk
                        (list.repeat chunks)
                        (text.join-with "")
@@ -218,7 +218,7 @@
 
 (def: random-mode
   (Random /.Mode)
-  (do {@ random.monad}
+  (do {! random.monad}
     []
     (random.either (random.either (random.either (wrap /.execute-by-other)
                                                  (wrap /.write-by-other))
@@ -236,7 +236,7 @@
 (def: mode
   Test
   (_.with-cover [/.Mode /.mode]
-    (do {@ random.monad}
+    (do {! random.monad}
       [path (random.ascii/lower-alpha 10)
        modes (random.list 4 ..random-mode)
        #let [expected-mode (list@fold /.and /.none modes)]]
@@ -308,7 +308,7 @@
 
 (def: ownership
   Test
-  (do {@ random.monad}
+  (do {! random.monad}
     [path (random.ascii/lower-alpha /.path-size)
      expected (random.ascii/lower-alpha /.name-size)
      invalid (random.ascii/lower-alpha (inc /.name-size))
diff --git a/stdlib/source/test/lux/data/format/xml.lux b/stdlib/source/test/lux/data/format/xml.lux
index 6cf842827..e0a1a5c05 100644
--- a/stdlib/source/test/lux/data/format/xml.lux
+++ b/stdlib/source/test/lux/data/format/xml.lux
@@ -35,8 +35,8 @@
 
 (def: char
   (Random Nat)
-  (do {@ r.monad}
-    [idx (|> r.nat (:: @ map (n.% (text.size char-range))))]
+  (do {! r.monad}
+    [idx (|> r.nat (:: ! map (n.% (text.size char-range))))]
     (wrap (maybe.assume (text.nth idx char-range)))))
 
 (def: (size bottom top)
@@ -73,9 +73,9 @@
           ($equivalence.spec /.equivalence ..xml)
           ($codec.spec /.equivalence /.codec ..xml)
 
-          (do {@ r.monad}
+          (do {! r.monad}
             [text (..text 1 10)
-             num-children (|> r.nat (:: @ map (n.% 5)))
+             num-children (|> r.nat (:: ! map (n.% 5)))
              children (r.list num-children (..text 1 10))
              tag xml-identifier^
              attribute xml-identifier^
diff --git a/stdlib/source/test/lux/data/name.lux b/stdlib/source/test/lux/data/name.lux
index 836f75aa1..bf5c6e876 100644
--- a/stdlib/source/test/lux/data/name.lux
+++ b/stdlib/source/test/lux/data/name.lux
@@ -32,14 +32,14 @@
 (def: #export test
   Test
   (<| (_.covering /._)
-      (do {@ random.monad}
+      (do {! random.monad}
         [## First Name
-         sizeM1 (|> random.nat (:: @ map (n.% 100)))
-         sizeS1 (|> random.nat (:: @ map (|>> (n.% 100) (n.max 1))))
+         sizeM1 (|> random.nat (:: ! map (n.% 100)))
+         sizeS1 (|> random.nat (:: ! map (|>> (n.% 100) (n.max 1))))
          (^@ name1 [module1 short1]) (..name sizeM1 sizeS1)
          ## Second Name
-         sizeM2 (|> random.nat (:: @ map (n.% 100)))
-         sizeS2 (|> random.nat (:: @ map (|>> (n.% 100) (n.max 1))))
+         sizeM2 (|> random.nat (:: ! map (n.% 100)))
+         sizeS2 (|> random.nat (:: ! map (|>> (n.% 100) (n.max 1))))
          (^@ name2 [module2 short2]) (..name sizeM2 sizeS2)]
         (_.with-cover [.Name]
           ($_ _.and
diff --git a/stdlib/source/test/lux/data/number.lux b/stdlib/source/test/lux/data/number.lux
index 876cf4c4d..d8b0ad3bf 100644
--- a/stdlib/source/test/lux/data/number.lux
+++ b/stdlib/source/test/lux/data/number.lux
@@ -12,12 +12,38 @@
      ["r" rev]
      ["f" frac]]]]
   {1
-   ["." /]})
+   ["." /]}
+  ["." / #_
+   ["#." i8]
+   ["#." i16]
+   ["#." i32]
+   ["#." i64]
+   ["#." nat]
+   ["#." int]
+   ["#." rev]
+   ["#." frac]
+   ["#." ratio]
+   ["#." complex]])
 
 (def: clean-commas
   (-> Text Text)
   (text.replace-all "," ""))
 
+(def: sub
+  Test
+  ($_ _.and
+      /i8.test
+      /i16.test
+      /i32.test
+      /i64.test
+      /nat.test
+      /int.test
+      /rev.test
+      /frac.test
+      /ratio.test
+      /complex.test
+      ))
+
 (def: #export test
   Test
   (<| (_.covering /._)
@@ -85,4 +111,5 @@
                                   [f.= f.hex "+dead.BEEF"]
                                   [f.= f.hex "-dead,BE.EF"]
                                   )))))
+          ..sub
           )))
diff --git a/stdlib/source/test/lux/data/number/rev.lux b/stdlib/source/test/lux/data/number/rev.lux
index dfb484fc8..90a29c6d3 100644
--- a/stdlib/source/test/lux/data/number/rev.lux
+++ b/stdlib/source/test/lux/data/number/rev.lux
@@ -48,4 +48,22 @@
                                 (oct ".615,243"))
                            (/.= (hex ".deadBEEF")
                                 (hex ".dead,BEEF"))))
+              (~~ (template [<half> <whole>]
+                    [(_.cover [<half>]
+                              (/.= <whole>
+                                   (/.+ <half> <half>)))]
+
+                    [/./2 .0]
+                    [/./4 /./2]
+                    [/./8 /./4]
+                    [/./16 /./8]
+                    [/./32 /./16]
+                    [/./64 /./32]
+                    [/./128 /./64]
+                    [/./256 /./128]
+                    [/./512 /./256]
+                    [/./1024 /./512]
+                    [/./2048 /./1024]
+                    [/./4096 /./2048]
+                    ))
               ))))
diff --git a/stdlib/source/test/lux/data/sum.lux b/stdlib/source/test/lux/data/sum.lux
index 3bbf65bc9..6a4130229 100644
--- a/stdlib/source/test/lux/data/sum.lux
+++ b/stdlib/source/test/lux/data/sum.lux
@@ -23,7 +23,7 @@
   Test
   (<| (_.covering /._)
       (_.with-cover [.|])
-      (do {@ random.monad}
+      (do {! random.monad}
         [expected random.nat
          shift random.nat])
       ($_ _.and
@@ -59,8 +59,8 @@
                             (: (| Nat Nat))
                             (/.each (n.+ shift) (n.- shift))
                             (case> (0 #1 actual) (n.= (n.- shift expected) actual) _ false))))
-          (do @
-            [size (:: @ map (n.% 5) random.nat)
+          (do !
+            [size (:: ! map (n.% 5) random.nat)
              expected (random.list size random.nat)]
             ($_ _.and
                 (_.cover [/.lefts]
diff --git a/stdlib/source/test/lux/data/text.lux b/stdlib/source/test/lux/data/text.lux
index 6fbee6ec5..5a6b2e4bb 100644
--- a/stdlib/source/test/lux/data/text.lux
+++ b/stdlib/source/test/lux/data/text.lux
@@ -29,8 +29,8 @@
 
 (def: size
   Test
-  (do {@ random.monad}
-    [size (:: @ map (n.% 10) random.nat)
+  (do {! random.monad}
+    [size (:: ! map (n.% 10) random.nat)
      sample (random.unicode size)]
     ($_ _.and
         (_.cover [/.size]
@@ -41,7 +41,7 @@
 
 (def: affix
   Test
-  (do {@ random.monad}
+  (do {! random.monad}
     [inner (random.unicode 1)
      outer (random.filter (|>> (:: /.equivalence = inner) not)
                           (random.unicode 1))
@@ -70,7 +70,7 @@
 
 (def: index
   Test
-  (do {@ random.monad}
+  (do {! random.monad}
     [inner (random.unicode 1)
      outer (random.filter (|>> (:: /.equivalence = inner) not)
                           (random.unicode 1))
@@ -154,11 +154,11 @@
                 (_.cover [/.line-feed]
                          (:: /.equivalence = /.new-line /.line-feed))
                 )))
-      (do {@ random.monad}
-        [size (:: @ map (|>> (n.% 10) inc) random.nat)
+      (do {! random.monad}
+        [size (:: ! map (|>> (n.% 10) inc) random.nat)
          characters (random.set /.hash size (random.ascii/alpha 1))
          #let [sample (|> characters set.to-list /.concat)]
-         expected (:: @ map (n.% size) random.nat)]
+         expected (:: ! map (n.% size) random.nat)]
         (_.cover [/.nth]
                  (case (/.nth expected sample)
                    (#.Some char)
@@ -186,8 +186,8 @@
 
 (def: manipulation
   Test
-  (do {@ random.monad}
-    [size (:: @ map (|>> (n.% 10) (n.+ 2)) random.nat)
+  (do {! random.monad}
+    [size (:: ! map (|>> (n.% 10) (n.+ 2)) random.nat)
      characters (random.set /.hash size (random.ascii/alpha 1))
      separator (random.filter (|>> (set.member? characters) not)
                               (random.ascii/alpha 1))
@@ -274,13 +274,13 @@
                                     _
                                     #0)))
                 ))
-          (do {@ random.monad}
+          (do {! random.monad}
             [sizeP bounded-size
              sizeL bounded-size
              #let [## The wider unicode charset includes control characters that
                    ## can make text replacement work improperly.
                    ## Because of that, I restrict the charset.
-                   normal-char-gen (|> random.nat (:: @ map (|>> (n.% 128) (n.max 1))))]
+                   normal-char-gen (|> random.nat (:: ! map (|>> (n.% 128) (n.max 1))))]
              sep1 (random.text normal-char-gen 1)
              sep2 (random.text normal-char-gen 1)
              #let [part-gen (|> (random.text normal-char-gen sizeP)
diff --git a/stdlib/source/test/lux/host.jvm.lux b/stdlib/source/test/lux/host.jvm.lux
index d5b44b481..355be630f 100644
--- a/stdlib/source/test/lux/host.jvm.lux
+++ b/stdlib/source/test/lux/host.jvm.lux
@@ -93,8 +93,8 @@
 
 (def: miscellaneous
   Test
-  (do {@ r.monad}
-    [sample (:: @ map (|>> (:coerce java/lang/Object))
+  (do {! r.monad}
+    [sample (:: ! map (|>> (:coerce java/lang/Object))
                 (r.ascii 1))]
     ($_ _.and
         (_.test "Can check if an object is of a certain class."
@@ -124,10 +124,10 @@
 
 (def: arrays
   Test
-  (do {@ r.monad}
-    [size (|> r.nat (:: @ map (|>> (n.% 100) (n.max 1))))
-     idx (|> r.nat (:: @ map (n.% size)))
-     value (:: @ map (|>> (:coerce java/lang/Long)) r.int)]
+  (do {! r.monad}
+    [size (|> r.nat (:: ! map (|>> (n.% 100) (n.max 1))))
+     idx (|> r.nat (:: ! map (n.% size)))
+     value (:: ! map (|>> (:coerce java/lang/Long)) r.int)]
     ($_ _.and
         (_.test "Can create arrays of some length."
                 (n.= size (/.array-length (/.array java/lang/Long size))))
diff --git a/stdlib/source/test/lux/meta/annotation.lux b/stdlib/source/test/lux/meta/annotation.lux
index f8f569bde..f0ff06160 100644
--- a/stdlib/source/test/lux/meta/annotation.lux
+++ b/stdlib/source/test/lux/meta/annotation.lux
@@ -35,14 +35,14 @@
 
 (def: (random-sequence random)
   (All [a] (-> (Random a) (Random (List a))))
-  (do {@ random.monad}
-    [size (|> random.nat (:: @ map (nat.% 3)))]
+  (do {! random.monad}
+    [size (|> random.nat (:: ! map (nat.% 3)))]
     (random.list size random)))
 
 (def: (random-record random)
   (All [a] (-> (Random a) (Random (List [a a]))))
-  (do {@ random.monad}
-    [size (|> random.nat (:: @ map (nat.% 3)))]
+  (do {! random.monad}
+    [size (|> random.nat (:: ! map (nat.% 3)))]
     (random.list size (random.and random random))))
 
 (template: (!expect <pattern> <value>)
@@ -57,11 +57,11 @@
 
 (def: typed-value
   Test
-  (do {@ random.monad}
+  (do {! random.monad}
     [key ..random-key]
     (`` ($_ _.and
             (~~ (template [<definition> <random> <constructor> <equivalence>]
-                  [(do {@ random.monad}
+                  [(do {! random.monad}
                      [expected <random>]
                      (_.cover [<definition>]
                               (|> expected <constructor>
@@ -86,10 +86,10 @@
 
 (def: flag
   Test
-  (do {@ random.monad}
+  (do {! random.monad}
     [key ..random-key]
     (`` ($_ _.and
-            (do {@ random.monad}
+            (do !
               [dummy ..random-key
                expected random.bit]
               (_.cover [/.flagged?]
@@ -101,7 +101,7 @@
                                      (..annotation dummy)
                                      (/.flagged? key))))))
             (~~ (template [<definition> <tag>]
-                  [(do {@ random.monad}
+                  [(do !
                      [expected random.bit]
                      (_.cover [<definition>]
                               (and (|> expected code.bit
@@ -120,11 +120,11 @@
 
 (def: arguments
   Test
-  (do {@ random.monad}
+  (do {! random.monad}
     [key ..random-key]
     (`` ($_ _.and
             (~~ (template [<definition> <tag>]
-                  [(do {@ random.monad}
+                  [(do !
                      [expected (random.list 5 (random.ascii/alpha 1))]
                      (_.cover [<definition>]
                               (and (|> expected (list@map code.text) code.tuple
@@ -145,10 +145,10 @@
   Test
   (<| (_.covering /._)
       (_.with-cover [/.Annotation])
-      (do {@ random.monad}
+      (do {! random.monad}
         [key ..random-key]
         ($_ _.and
-            (do {@ random.monad}
+            (do !
               [expected _code.random]
               (_.cover [/.value]
                        (|> expected
@@ -159,7 +159,7 @@
             
             ..typed-value
             
-            (do {@ random.monad}
+            (do !
               [expected (random.ascii/alpha 10)]
               (_.cover [/.documentation]
                        (and (not (|> expected code.text
diff --git a/stdlib/source/test/lux/tool/compiler/language/lux/phase/synthesis/loop.lux b/stdlib/source/test/lux/tool/compiler/language/lux/phase/synthesis/loop.lux
index e42e139d1..2667eedac 100644
--- a/stdlib/source/test/lux/tool/compiler/language/lux/phase/synthesis/loop.lux
+++ b/stdlib/source/test/lux/tool/compiler/language/lux/phase/synthesis/loop.lux
@@ -30,14 +30,14 @@
   (Scenario Synthesis)
   (`` ($_ random.either
           (~~ (template [<synthesis> <random>]
-                [(do {@ random.monad}
-                   [example (:: @ map (|>> <synthesis>) <random>)]
+                [(do {! random.monad}
+                   [example (:: ! map (|>> <synthesis>) <random>)]
                    (wrap [next
                           [example
                            example]]))]
 
                 [//.bit random.bit]
-                [//.i64 (:: @ map .i64 random.nat)]
+                [//.i64 (:: ! map .i64 random.nat)]
                 [//.f64 random.frac]
                 [//.text (random.unicode 1)]
                 ))
@@ -54,8 +54,8 @@
 
 (def: (variable offset arity next)
   (Scenario Variable)
-  (let [local (do {@ random.monad}
-                [register (:: @ map (|>> (n.% arity) inc) random.nat)]
+  (let [local (do {! random.monad}
+                [register (:: ! map (|>> (n.% arity) inc) random.nat)]
                 (wrap [next
                        [(#variable.Local (/.register-optimization offset register))
                         (#variable.Local register)]]))]
@@ -63,8 +63,8 @@
       0 local
       _ ($_ random.either
             local
-            (do {@ random.monad}
-              [foreign (:: @ map (n.% offset) random.nat)]
+            (do {! random.monad}
+              [foreign (:: ! map (n.% offset) random.nat)]
               (wrap [next
                      [(#variable.Local foreign)
                       (#variable.Foreign foreign)]]))))))
@@ -73,7 +73,7 @@
   (Scenario Synthesis)
   (`` ($_ random.either
           (~~ (template [<tag> <random>]
-                [(do {@ random.monad}
+                [(do {! random.monad}
                    [[next [exampleE exampleA]] (<random> offset arity next)]
                    (wrap [next
                           [(<tag> exampleE)
@@ -86,7 +86,7 @@
 (def: (structure offset arity next)
   (Scenario Synthesis)
   ($_ random.either
-      (do {@ random.monad}
+      (do {! random.monad}
         [lefts random.nat
          right? random.bit
          [next [valueE valueA]] (..reference offset arity next)]
@@ -99,7 +99,7 @@
                  {#analysis.lefts lefts
                   #analysis.right? right?
                   #analysis.value valueA})]]))
-      (do {@ random.monad}
+      (do {! random.monad}
         [[next [leftE leftA]] (..reference offset arity next)
          [next [rightE rightA]] (..reference offset arity next)]
         (wrap [next
@@ -116,20 +116,20 @@
                                            [//.path/pop
                                             //.path/pop]])
                              (~~ (template [<path> <random>]
-                                   [(do {@ random.monad}
-                                      [example (:: @ map (|>> <path>) <random>)]
+                                   [(do {! random.monad}
+                                      [example (:: ! map (|>> <path>) <random>)]
                                       (wrap [next
                                              [example
                                               example]]))]
 
                                    [//.path/bit random.bit]
-                                   [//.path/i64 (:: @ map .i64 random.nat)]
+                                   [//.path/i64 (:: ! map .i64 random.nat)]
                                    [//.path/f64 random.frac]
                                    [//.path/text (random.unicode 1)]
                                    ))
                              (~~ (template [<path>]
-                                   [(do {@ random.monad}
-                                      [example (:: @ map (|>> <path>)
+                                   [(do {! random.monad}
+                                      [example (:: ! map (|>> <path>)
                                                    (random.or random.nat
                                                               random.nat))]
                                       (wrap [next
@@ -166,13 +166,13 @@
                                     random.nat))]
     ($_ random.either
         ($_ random.either
-            (do {@ random.monad}
+            (do {! random.monad}
               [[next [inputE inputA]] (..reference offset arity next)
                [next [bodyE bodyA]] (..reference offset arity next)]
               (wrap [next
                      [(//.branch/let [inputE (/.register-optimization offset next) bodyE])
                       (//.branch/let [inputA next bodyA])]]))
-            (do {@ random.monad}
+            (do {! random.monad}
               [[next [testE testA]] (..reference offset arity next)
                [next [thenE thenA]] (..reference offset arity next)
                [next [elseE elseA]] (..reference offset arity next)]
@@ -180,14 +180,14 @@
                      [(//.branch/if [testE thenE elseE])
                       (//.branch/if [testA thenA elseA])]])))
         ($_ random.either
-            (do {@ random.monad}
+            (do {! random.monad}
               [[next [recordE recordA]] (..reference offset arity next)
-               path-length (:: @ map (|>> (n.% 5) inc) random.nat)
+               path-length (:: ! map (|>> (n.% 5) inc) random.nat)
                path (random.list path-length random-member)]
               (wrap [next
                      [(//.branch/get [path recordE])
                       (//.branch/get [path recordA])]]))
-            (do {@ random.monad}
+            (do {! random.monad}
               [[next [inputE inputA]] (..reference offset arity next)
                [next [pathE pathA]] (..path offset arity next)]
               (wrap [next
@@ -216,10 +216,10 @@
 (def: (function offset arity next)
   (Scenario Synthesis)
   ($_ random.either
-      (do {@ random.monad}
+      (do {! random.monad}
         [[next [firstE firstA]] (..variable offset arity next)
          [next [secondE secondA]] (..variable offset arity next)
-         arity (:: @ map (n.max 1) random.nat)
+         arity (:: ! map (n.max 1) random.nat)
          [next [bodyE bodyA]] (..primitive 0 arity next)]
         (wrap [next
                [(//.function/abstraction
@@ -265,11 +265,11 @@
   Test
   (<| (_.covering /._)
       ($_ _.and
-          (do {@ random.monad}
-            [expected-offset (:: @ map (|>> (n.% 5) (n.+ 2)) random.nat)
-             arity (:: @ map (|>> (n.% 5) inc) random.nat)
+          (do {! random.monad}
+            [expected-offset (:: ! map (|>> (n.% 5) (n.+ 2)) random.nat)
+             arity (:: ! map (|>> (n.% 5) inc) random.nat)
              expected-inits (|> random.nat
-                                (:: @ map (|>> .i64 //.i64))
+                                (:: ! map (|>> .i64 //.i64))
                                 (random.list arity))
              [_ [expected iteration]] (..scenario expected-offset arity 0)]
             (_.cover [/.Transform /.optimization /.register-optimization]