Improved exception-definition macro.

127 files changed, 1232 insertions, 1103 deletions

diff --git a/stdlib/source/documentation/lux.lux b/stdlib/source/documentation/lux.lux
index 21b90e2a6..1cf289c4b 100644
--- a/stdlib/source/documentation/lux.lux
+++ b/stdlib/source/documentation/lux.lux
@@ -43,7 +43,7 @@
        /world.documentation
        ))
 
-(def all/1-4
+(def all_1/4
   (List $.Documentation)
   (list ($.definition /.prelude
           (format "The name of the prelude module"
@@ -172,7 +172,7 @@
               (List (Self a))])])
         ))
 
-(def all/2-4
+(def all_2/4
   (List $.Documentation)
   (list ($.definition /.->
           "Function types."
@@ -296,7 +296,7 @@
              )])
         ))
 
-(`` (def all/3-4
+(`` (def all_3/4
       (List $.Documentation)
       (list ($.definition /.not
               "Bit negation."
@@ -620,7 +620,7 @@
                  (setter value my_record))])
             )))
 
-(`` (def all/4-4
+(`` (def all_4/4
       (List $.Documentation)
       (list ($.definition /.revised
               "Modifies the value of a record at a given tag, based on some function."
@@ -909,10 +909,10 @@
 (def .public documentation
   (List $.Documentation)
   (all list#composite
-       all/1-4
-       all/2-4
-       all/3-4
-       all/4-4
+       all_1/4
+       all_2/4
+       all_3/4
+       all_4/4
 
        ..sub_modules
        ))
diff --git a/stdlib/source/documentation/lux/control/concatenative.lux b/stdlib/source/documentation/lux/control/concatenative.lux
index 6c8b17adf..e72231627 100644
--- a/stdlib/source/documentation/lux/control/concatenative.lux
+++ b/stdlib/source/documentation/lux/control/concatenative.lux
@@ -4,7 +4,9 @@
    ["$" documentation]
    [data
     [text
-     ["%" \\format (.only format)]]]
+     ["%" \\format (.only format)]]
+    [collection
+     ["[0]" list]]]
    [math
     [number
      ["n" nat]
@@ -17,74 +19,9 @@
  [\\library
   ["[0]" /]])
 
-(`` (def .public documentation
+(`` (def arithmetic
       (.List $.Documentation)
-      (list ($.module /._
-                      "")
-
-            ($.definition /.value)
-
-            ($.definition /.=>
-              "Concatenative function types."
-              [(=> [Nat] [Nat])]
-              [(All (_ a)
-                 (-> a (=> [] [a])))]
-              [(All (_ t)
-                 (=> [t] []))]
-              [(All (_ a b c)
-                 (=> [a b c] [b c a]))]
-              [(All (_ ,,,0 ,,,1)
-                 (=> [then (=> ,,,0 ,,,1)
-                      else (=> ,,,0 ,,,1)]
-                     ,,,0 [Bit then else] ,,,1))])
-
-            ($.definition /.apply
-              "A generator for functions that turn arity N functions into arity N concatenative functions."
-              [(is (=> [Nat] [Nat])
-                   ((apply 1) ++))])
-
-            (,, (with_template [<arity>]
-                  [(with_expansions [<name> (template.symbol [/._] ["apply_" <arity>])
-                                     <doc> (template.text ["Lift a function of arity " <arity>
-                                                           " into a concatenative function of arity " <arity> "."])]
-                     ($.definition <name>
-                       <doc>))]
-
-                  [1] [2] [3] [4]
-                  [5] [6] [7] [8]
-                  ))
-
-            ($.definition /.push
-              "Push a value onto the stack.")
-
-            ($.definition /.drop
-              "Drop/pop a value from the top of the stack.")
-
-            ($.definition /.nip
-              "Drop the second-to-last value from the top of the stack.")
-
-            ($.definition /.dup
-              "Duplicate the top of the stack.")
-
-            ($.definition /.swap
-              "Swaps the 2 topmost stack values.")
-
-            ($.definition /.left_rotation
-              "Rotes the 3 topmost stack values to the left.")
-
-            ($.definition /.right_rotation
-              "Rotes the 3 topmost stack values to the right.")
-
-            ($.definition /.&&
-              "Groups the 2 topmost stack values as a 2-tuple.")
-
-            ($.definition /.left
-              "Left-injects the top into sum.")
-
-            ($.definition /.right
-              "Right-injects the top into sum.")
-
-            (,, (with_template [<input> <word> <func>]
+      (list (,, (with_template [<input> <word> <func>]
                   [(`` ($.definition (,, (template.symbol [/._] [<word>]))
                          (,, (template.text [<func> " for " <input> " arithmetic."]))))]
 
@@ -132,63 +69,133 @@
                   [Frac f/>  f.>]
                   [Frac f/>= f.>=]
                   ))
-
-            ($.definition /.if
-              "If expression."
-              [(same? "then"
-                      (/.value (|>> (push true)
-                                    (push "then")
-                                    (push "else")
-                                    if)))])
-
-            ($.definition /.call
-              "Executes an anonymous block on the stack.")
-
-            ($.definition /.loop
-              "Executes a block as a loop until it yields #0 to stop.")
-
-            ($.definition /.dip
-              "Executes a block on the stack, save for the topmost value.")
-
-            ($.definition /.dip_2
-              "Executes a block on the stack, save for the 2 topmost values.")
-
-            ($.definition /.do
-              "Do-while loop expression."
-              [(n.= (++ sample)
-                    (/.value (|>> (push sample)
-                                  (push (push false))
-                                  (push (|>> (push 1) n/+))
-                                  do while)))])
-
-            ($.definition /.while
-              "While loop expression."
-              [(n.= (n.+ distance start)
-                    (/.value (|>> (push start)
-                                  (push (|>> dup
-                                             (push start) n/-
-                                             (push distance) n/<))
-                                  (push (|>> (push 1) n/+))
-                                  while)))])
-
-            ($.definition /.compose
-              "Function composition."
-              [(n.= (n.+ 2 sample)
-                    (/.value (|>> (push sample)
-                                  (push (|>> (push 1) n/+))
-                                  (push (|>> (push 1) n/+))
-                                  compose
-                                  call)))])
-
-            ($.definition /.partial
-              "Partial application."
-              [(n.= (n.+ sample sample)
-                    (/.value (|>> (push sample)
-                                  (push sample)
-                                  (push n/+)
-                                  partial
-                                  call)))])
-
-            ($.definition /.?
-              "Choose the top value when #0 and the second-to-top when #1.")
             )))
+
+(`` (def .public documentation
+      (.List $.Documentation)
+      (list.partial ($.module /._
+                              "")
+
+                    ($.definition /.value)
+
+                    ($.definition /.=>
+                      "Concatenative function types."
+                      [(=> [Nat] [Nat])]
+                      [(All (_ a)
+                         (-> a (=> [] [a])))]
+                      [(All (_ t)
+                         (=> [t] []))]
+                      [(All (_ a b c)
+                         (=> [a b c] [b c a]))]
+                      [(All (_ ,,,0 ,,,1)
+                         (=> [then (=> ,,,0 ,,,1)
+                              else (=> ,,,0 ,,,1)]
+                             ,,,0 [Bit then else] ,,,1))])
+
+                    ($.definition /.apply
+                      "A generator for functions that turn arity N functions into arity N concatenative functions."
+                      [(is (=> [Nat] [Nat])
+                           ((apply 1) ++))])
+
+                    (,, (with_template [<arity>]
+                          [(with_expansions [<name> (template.symbol [/._] ["apply_" <arity>])
+                                             <doc> (template.text ["Lift a function of arity " <arity>
+                                                                   " into a concatenative function of arity " <arity> "."])]
+                             ($.definition <name>
+                               <doc>))]
+
+                          [1] [2] [3] [4]
+                          [5] [6] [7] [8]
+                          ))
+
+                    ($.definition /.push
+                      "Push a value onto the stack.")
+
+                    ($.definition /.drop
+                      "Drop/pop a value from the top of the stack.")
+
+                    ($.definition /.nip
+                      "Drop the second-to-last value from the top of the stack.")
+
+                    ($.definition /.dup
+                      "Duplicate the top of the stack.")
+
+                    ($.definition /.swap
+                      "Swaps the 2 topmost stack values.")
+
+                    ($.definition /.left_rotation
+                      "Rotes the 3 topmost stack values to the left.")
+
+                    ($.definition /.right_rotation
+                      "Rotes the 3 topmost stack values to the right.")
+
+                    ($.definition /.&&
+                      "Groups the 2 topmost stack values as a 2-tuple.")
+
+                    ($.definition /.left
+                      "Left-injects the top into sum.")
+
+                    ($.definition /.right
+                      "Right-injects the top into sum.")
+
+                    ($.definition /.if
+                      "If expression."
+                      [(same? "then"
+                              (/.value (|>> (push true)
+                                            (push "then")
+                                            (push "else")
+                                            if)))])
+
+                    ($.definition /.call
+                      "Executes an anonymous block on the stack.")
+
+                    ($.definition /.loop
+                      "Executes a block as a loop until it yields #0 to stop.")
+
+                    ($.definition /.dip
+                      "Executes a block on the stack, save for the topmost value.")
+
+                    ($.definition /.dip_2
+                      "Executes a block on the stack, save for the 2 topmost values.")
+
+                    ($.definition /.do
+                      "Do-while loop expression."
+                      [(n.= (++ sample)
+                            (/.value (|>> (push sample)
+                                          (push (push false))
+                                          (push (|>> (push 1) n/+))
+                                          do while)))])
+
+                    ($.definition /.while
+                      "While loop expression."
+                      [(n.= (n.+ distance start)
+                            (/.value (|>> (push start)
+                                          (push (|>> dup
+                                                     (push start) n/-
+                                                     (push distance) n/<))
+                                          (push (|>> (push 1) n/+))
+                                          while)))])
+
+                    ($.definition /.compose
+                      "Function composition."
+                      [(n.= (n.+ 2 sample)
+                            (/.value (|>> (push sample)
+                                          (push (|>> (push 1) n/+))
+                                          (push (|>> (push 1) n/+))
+                                          compose
+                                          call)))])
+
+                    ($.definition /.partial
+                      "Partial application."
+                      [(n.= (n.+ sample sample)
+                            (/.value (|>> (push sample)
+                                          (push sample)
+                                          (push n/+)
+                                          partial
+                                          call)))])
+
+                    ($.definition /.?
+                      "Choose the top value when #0 and the second-to-top when #1.")
+
+                    ..arithmetic
+                    )))
diff --git a/stdlib/source/documentation/lux/control/exception.lux b/stdlib/source/documentation/lux/control/exception.lux
index 6d0bbc2dd..27e2a28d5 100644
--- a/stdlib/source/documentation/lux/control/exception.lux
+++ b/stdlib/source/documentation/lux/control/exception.lux
@@ -39,14 +39,14 @@
           "Decorate an error message with an Exception and lift it into the error-handling context."
           [(except exception message)])
 
-        ($.definition /.exception
+        ($.definition /.def
           (format "Define a new exception type."
                   \n "It mostly just serves as a way to tag error messages for later catching.")
           ["Simple case:"
-           (exception .public some_exception)]
+           (/.def .public some_exception)]
           ["Complex case:"
-           (exception .public [arbitrary type variables] (some_exception [optional Text
-                                                                          arguments Int])
+           (/.def .public [arbitrary type variables] (some_exception [optional arguments])
+             (/.Exception [Text Int])
              optional_body)])
 
         ($.definition /.report
diff --git a/stdlib/source/documentation/lux/data/text/encoding.lux b/stdlib/source/documentation/lux/data/text/encoding.lux
index f370ef501..44040dbdd 100644
--- a/stdlib/source/documentation/lux/data/text/encoding.lux
+++ b/stdlib/source/documentation/lux/data/text/encoding.lux
@@ -17,7 +17,7 @@
     [($.definition <name>
        (format "'" (/.name <name>) "' text encoding. "))]))
 
-(`` (def all/ibm
+(`` (def all_ibm_1/2
       (List $.Documentation)
       (list (,, (with_template [<name>]
                   [(description <name>)]
@@ -60,6 +60,14 @@
                   [/.ibm_871]
                   [/.ibm_874]
                   [/.ibm_875]
+                  ))
+            )))
+
+(`` (def all_ibm_2/2
+      (List $.Documentation)
+      (list (,, (with_template [<name>]
+                  [(description <name>)]
+
                   [/.ibm_918]
                   [/.ibm_921]
                   [/.ibm_922]
@@ -107,7 +115,7 @@
                   ))
             )))
 
-(`` (def all/iso-mac
+(`` (def all_iso-mac
       (List $.Documentation)
       (list (,, (with_template [<name>]
                   [(description <name>)]
@@ -148,7 +156,7 @@
                   ))
             )))
 
-(`` (def all/utf-koi8
+(`` (def all_utf-koi8
       (List $.Documentation)
       (list (,, (with_template [<name>]
                   [(description <name>)]
@@ -197,9 +205,10 @@
                           ))
 
                     (all list#composite
-                         all/ibm
-                         all/iso-mac
-                         all/utf-koi8
+                         all_ibm_1/2
+                         all_ibm_2/2
+                         all_iso-mac
+                         all_utf-koi8
                          /utf8.documentation
                          )
                     )))
diff --git a/stdlib/source/documentation/lux/math/number/frac.lux b/stdlib/source/documentation/lux/math/number/frac.lux
index 5094916d2..d543143f6 100644
--- a/stdlib/source/documentation/lux/math/number/frac.lux
+++ b/stdlib/source/documentation/lux/math/number/frac.lux
@@ -3,152 +3,157 @@
   [lux (.except)
    ["$" documentation]
    [data
-    ["[0]" text (.only \n)
-     ["%" \\format (.only format)]]]]]
+    [collection
+     ["[0]" list]]]]]
  [\\library
   ["[0]" /]])
 
+(def math
+  (.List $.Documentation)
+  (list ($.definition /.cos)
+        ($.definition /.sin)
+        ($.definition /.tan)
+        ($.definition /.acos)
+        ($.definition /.asin)
+        ($.definition /.atan)
+        ($.definition /.exp)
+        ($.definition /.log)
+        ($.definition /.ceil)
+        ($.definition /.floor)
+        ($.definition /.root_2)
+        ($.definition /.root_3)
+        ($.definition /.round)
+        ($.definition /.factorial)
+        ($.definition /.hypotenuse)
+        ($.definition /.sinh)
+        ($.definition /.csch)
+        ($.definition /.cosh)
+        ($.definition /.sech)
+        ($.definition /.tanh)
+        ($.definition /.coth)
+        ($.definition /.asinh)
+        ($.definition /.acosh)
+        ($.definition /.atanh)
+        ($.definition /.acoth)
+        ($.definition /.asech)
+        ($.definition /.acsch)
+
+        ($.definition /.e
+          "The base of the natural logarithm.")
+
+        ($.definition /.pi
+          "The ratio of a circle's circumference to its diameter.")
+
+        ($.definition /.tau
+          "The ratio of a circle's circumference to its radius.")
+
+        ($.definition /.pow
+          ""
+          [(pow param subject)])
+
+        ($.definition /.atan_2
+          ""
+          [(atan_2 x y)])
+
+        ($.definition /.log_by
+          ""
+          [(log_by base it)])
+        ))
+
 (`` (def .public documentation
       (.List $.Documentation)
-      (list ($.module /._
-                      "")
-
-            ($.definition /.positive?)
-            ($.definition /.negative?)
-            ($.definition /.zero?)
-            ($.definition /.opposite)
-            ($.definition /.abs)
-            ($.definition /.signum)
-            ($.definition /.nat)
-            ($.definition /.int)
-            ($.definition /.rev)
-            ($.definition /.equivalence)
-            ($.definition /.order)
-            ($.definition /.smallest)
-            ($.definition /.biggest)
-            ($.definition /.addition)
-            ($.definition /.multiplication)
-            ($.definition /.minimum)
-            ($.definition /.maximum)
-            ($.definition /.number?)
-            ($.definition /.decimal)
-            ($.definition /.bits)
-            ($.definition /.of_bits)
-            ($.definition /.binary)
-            ($.definition /.octal)
-            ($.definition /.hex)
-            ($.definition /.hash)
-
-            ($.definition /.cos)
-            ($.definition /.sin)
-            ($.definition /.tan)
-            ($.definition /.acos)
-            ($.definition /.asin)
-            ($.definition /.atan)
-            ($.definition /.exp)
-            ($.definition /.log)
-            ($.definition /.ceil)
-            ($.definition /.floor)
-            ($.definition /.root_2)
-            ($.definition /.root_3)
-            ($.definition /.round)
-            ($.definition /.factorial)
-            ($.definition /.hypotenuse)
-            ($.definition /.sinh)
-            ($.definition /.csch)
-            ($.definition /.cosh)
-            ($.definition /.sech)
-            ($.definition /.tanh)
-            ($.definition /.coth)
-            ($.definition /.asinh)
-            ($.definition /.acosh)
-            ($.definition /.atanh)
-            ($.definition /.acoth)
-            ($.definition /.asech)
-            ($.definition /.acsch)
-
-            ($.definition /.=
-              "Frac(tion) equivalence."
-              [(= reference sample)])
-
-            ($.definition /.<
-              "Frac(tion) less-than."
-              [(< reference sample)])
-
-            ($.definition /.<=
-              "Frac(tion) less-than or equal."
-              [(<= reference sample)])
-
-            ($.definition /.>
-              "Frac(tion) greater-than."
-              [(> reference sample)])
-
-            ($.definition /.>=
-              "Frac(tion) greater-than or equal."
-              [(>= reference sample)])
-
-            (,, (with_template [<name> <doc>]
-                  [($.definition <name>
-                     <doc>)]
-
-                  [/.+ "Frac(tion) addition."]
-                  [/.- "Frac(tion) substraction."]
-                  [/.* "Frac(tion) multiplication."]
-                  [/./ "Frac(tion) division."]
-                  [/.% "Frac(tion) remainder."]
-                  ))
-
-            ($.definition /./%
-              ""
-              [(/% param subject)])
-
-            (,, (with_template [<name> <doc>]
-                  [($.definition <name>
-                     <doc>)]
-
-                  [/.min "Frac(tion) minimum."]
-                  [/.max "Frac(tion) minimum."]
-                  ))
-
-            (,, (with_template [<name> <doc>]
-                  [($.definition <name>
-                     <doc>)]
-
-                  [/.not_a_number "Not a number."]
-                  [/.positive_infinity "Positive infinity."]
-                  [/.negative_infinity "Negative infinity."]
-                  ))
-
-            ($.definition /.not_a_number?
-              "Tests whether a frac is actually not-a-number."
-              [(not_a_number? it)])
-
-            ($.definition /.approximately?
-              ""
-              [(approximately? margin_of_error standard value)])
-
-            ($.definition /.mod
-              ""
-              [(mod divisor dividend)])
-
-            ($.definition /.e
-              "The base of the natural logarithm.")
-
-            ($.definition /.pi
-              "The ratio of a circle's circumference to its diameter.")
-
-            ($.definition /.tau
-              "The ratio of a circle's circumference to its radius.")
-
-            ($.definition /.pow
-              ""
-              [(pow param subject)])
-
-            ($.definition /.atan_2
-              ""
-              [(atan_2 x y)])
-
-            ($.definition /.log_by
-              ""
-              [(log_by base it)])
-            )))
+      (list.partial ($.module /._
+                              "")
+
+                    ($.definition /.positive?)
+                    ($.definition /.negative?)
+                    ($.definition /.zero?)
+                    ($.definition /.opposite)
+                    ($.definition /.abs)
+                    ($.definition /.signum)
+                    ($.definition /.nat)
+                    ($.definition /.int)
+                    ($.definition /.rev)
+                    ($.definition /.equivalence)
+                    ($.definition /.order)
+                    ($.definition /.smallest)
+                    ($.definition /.biggest)
+                    ($.definition /.addition)
+                    ($.definition /.multiplication)
+                    ($.definition /.minimum)
+                    ($.definition /.maximum)
+                    ($.definition /.number?)
+                    ($.definition /.decimal)
+                    ($.definition /.bits)
+                    ($.definition /.of_bits)
+                    ($.definition /.binary)
+                    ($.definition /.octal)
+                    ($.definition /.hex)
+                    ($.definition /.hash)
+
+                    ($.definition /.=
+                      "Frac(tion) equivalence."
+                      [(= reference sample)])
+
+                    ($.definition /.<
+                      "Frac(tion) less-than."
+                      [(< reference sample)])
+
+                    ($.definition /.<=
+                      "Frac(tion) less-than or equal."
+                      [(<= reference sample)])
+
+                    ($.definition /.>
+                      "Frac(tion) greater-than."
+                      [(> reference sample)])
+
+                    ($.definition /.>=
+                      "Frac(tion) greater-than or equal."
+                      [(>= reference sample)])
+
+                    (,, (with_template [<name> <doc>]
+                          [($.definition <name>
+                             <doc>)]
+
+                          [/.+ "Frac(tion) addition."]
+                          [/.- "Frac(tion) substraction."]
+                          [/.* "Frac(tion) multiplication."]
+                          [/./ "Frac(tion) division."]
+                          [/.% "Frac(tion) remainder."]
+                          ))
+
+                    ($.definition /./%
+                      ""
+                      [(/% param subject)])
+
+                    (,, (with_template [<name> <doc>]
+                          [($.definition <name>
+                             <doc>)]
+
+                          [/.min "Frac(tion) minimum."]
+                          [/.max "Frac(tion) minimum."]
+                          ))
+
+                    (,, (with_template [<name> <doc>]
+                          [($.definition <name>
+                             <doc>)]
+
+                          [/.not_a_number "Not a number."]
+                          [/.positive_infinity "Positive infinity."]
+                          [/.negative_infinity "Negative infinity."]
+                          ))
+
+                    ($.definition /.not_a_number?
+                      "Tests whether a frac is actually not-a-number."
+                      [(not_a_number? it)])
+
+                    ($.definition /.approximately?
+                      ""
+                      [(approximately? margin_of_error standard value)])
+
+                    ($.definition /.mod
+                      ""
+                      [(mod divisor dividend)])
+
+                    ..math
+                    )))
diff --git a/stdlib/source/documentation/lux/meta/compiler/language/lux/synthesis.lux b/stdlib/source/documentation/lux/meta/compiler/language/lux/synthesis.lux
index af6cc479e..8b14adb0e 100644
--- a/stdlib/source/documentation/lux/meta/compiler/language/lux/synthesis.lux
+++ b/stdlib/source/documentation/lux/meta/compiler/language/lux/synthesis.lux
@@ -6,7 +6,7 @@
     [text (.only \n)
      ["%" \\format (.only format)]]
     [collection
-     ["[0]" list]]]
+     ["[0]" list (.use "[1]#[0]" monoid)]]]
    [meta
     [macro
      ["[0]" template]]]]]
@@ -70,6 +70,44 @@
               [(loop init_parsers iteration_parser)])
             )))
 
+(def all_templates
+  (List $.Documentation)
+  (list ($.definition /.path/pop)
+        ($.definition /.path/side)
+        ($.definition /.path/member)
+        ($.definition /.side/left)
+        ($.definition /.side/right)
+        ($.definition /.member/left)
+        ($.definition /.member/right)
+        ($.definition /.path/bind)
+        ($.definition /.path/then)
+        ($.definition /.path/alt)
+        ($.definition /.path/seq)
+        ($.definition /.unit)
+        ($.definition /.bit)
+        ($.definition /.i64)
+        ($.definition /.f64)
+        ($.definition /.text)
+        ($.definition /.variant)
+        ($.definition /.tuple)
+        ($.definition /.variable)
+        ($.definition /.constant)
+        ($.definition /.variable/local)
+        ($.definition /.variable/foreign)
+        ($.definition /.branch/when)
+        ($.definition /.branch/let)
+        ($.definition /.branch/if)
+        ($.definition /.branch/get)
+        ($.definition /.loop/again)
+        ($.definition /.loop/scope)
+        ($.definition /.function/abstraction)
+        ($.definition /.function/apply)
+        ($.definition /.!bind_top)
+        ($.definition /.!multi_pop)
+        ($.definition /.simple_left_side)
+        ($.definition /.simple_right_side)
+        ))
+
 (def .public documentation
   (List $.Documentation)
   (list.partial ($.module /._
@@ -95,53 +133,21 @@
                 ($.definition /.Handler)
                 ($.definition /.Bundle)
                 ($.definition /.Path)
-                ($.definition /.path/pop)
-                ($.definition /.path/side)
-                ($.definition /.path/member)
-                ($.definition /.side/left)
-                ($.definition /.side/right)
-                ($.definition /.member/left)
-                ($.definition /.member/right)
-                ($.definition /.path/bind)
-                ($.definition /.path/then)
-                ($.definition /.path/alt)
-                ($.definition /.path/seq)
                 ($.definition /.Abstraction)
                 ($.definition /.Apply)
-                ($.definition /.unit)
                 ($.definition /.with_locals)
                 ($.definition /.locals)
                 ($.definition /.with_currying?)
                 ($.definition /.currying?)
                 ($.definition /.with_new_local)
-                ($.definition /.bit)
-                ($.definition /.i64)
-                ($.definition /.f64)
-                ($.definition /.text)
-                ($.definition /.variant)
-                ($.definition /.tuple)
-                ($.definition /.variable)
-                ($.definition /.constant)
-                ($.definition /.variable/local)
-                ($.definition /.variable/foreign)
-                ($.definition /.branch/when)
-                ($.definition /.branch/let)
-                ($.definition /.branch/if)
-                ($.definition /.branch/get)
-                ($.definition /.loop/again)
-                ($.definition /.loop/scope)
-                ($.definition /.function/abstraction)
-                ($.definition /.function/apply)
                 ($.definition /.%path')
                 ($.definition /.%synthesis)
                 ($.definition /.%path)
                 ($.definition /.equivalence)
                 ($.definition /.hash)
-                ($.definition /.!bind_top)
-                ($.definition /.!multi_pop)
-                ($.definition /.simple_left_side)
-                ($.definition /.simple_right_side)
-
 
-                ..\\parser
+                (all list#composite
+                     ..all_templates
+                     ..\\parser
+                     )
                 ))
diff --git a/stdlib/source/documentation/lux/meta/macro/syntax/export.lux b/stdlib/source/documentation/lux/meta/macro/syntax/export.lux
index f436ac551..10191449c 100644
--- a/stdlib/source/documentation/lux/meta/macro/syntax/export.lux
+++ b/stdlib/source/documentation/lux/meta/macro/syntax/export.lux
@@ -15,7 +15,7 @@
   (list ($.module /._
                   "Syntax for marking a definition as an export.")
 
-        ($.definition /.default_policy)
+        ($.definition /.default)
 
         ($.definition /.parser
           ""
diff --git a/stdlib/source/documentation/lux/meta/target/js.lux b/stdlib/source/documentation/lux/meta/target/js.lux
index b52e937f0..0ac24da98 100644
--- a/stdlib/source/documentation/lux/meta/target/js.lux
+++ b/stdlib/source/documentation/lux/meta/target/js.lux
@@ -10,66 +10,13 @@
  [\\library
   ["[0]" /]])
 
-(def .public documentation
+(def all_statement
   (List $.Documentation)
-  (list ($.module /._
-                  "")
-
-        ($.definition /.Code)
-        ($.definition /.code)
-        ($.definition /.Expression)
-        ($.definition /.Computation)
-        ($.definition /.Location)
-        ($.definition /.Statement)
-        ($.definition /.Var)
-        ($.definition /.Access)
-        ($.definition /.Literal)
+  (list ($.definition /.Statement)
         ($.definition /.Loop)
         ($.definition /.Label)
-        ($.definition /.null)
-        ($.definition /.undefined)
-        ($.definition /.boolean)
-        ($.definition /.number)
-        ($.definition /.string)
-        ($.definition /.array)
-        ($.definition /.var)
-        ($.definition /.at)
-        ($.definition /.the)
-        ($.definition /.apply)
-        ($.definition /.do)
-        ($.definition /.object)
-        ($.definition /.,)
         ($.definition /.then)
         ($.definition /.function_definition)
-        ($.definition /.function)
-        ($.definition /.closure)
-        ($.definition /.=)
-        ($.definition /.<)
-        ($.definition /.<=)
-        ($.definition /.>)
-        ($.definition /.>=)
-        ($.definition /.+)
-        ($.definition /.-)
-        ($.definition /.*)
-        ($.definition /./)
-        ($.definition /.%)
-        ($.definition /.left_shift)
-        ($.definition /.arithmetic_right_shift)
-        ($.definition /.logic_right_shift)
-        ($.definition /.or)
-        ($.definition /.and)
-        ($.definition /.bit_xor)
-        ($.definition /.bit_or)
-        ($.definition /.bit_and)
-        ($.definition /.not)
-        ($.definition /.bit_not)
-        ($.definition /.opposite)
-        ($.definition /.to_i32)
-        ($.definition /.i32)
-        ($.definition /.int)
-        ($.definition /.?)
-        ($.definition /.type_of)
-        ($.definition /.new)
         ($.definition /.statement)
         ($.definition /.use_strict)
         ($.definition /.declare)
@@ -90,9 +37,68 @@
         ($.definition /.break_at)
         ($.definition /.continue)
         ($.definition /.continue_at)
-        ($.definition /.++)
-        ($.definition /.--)
         ($.definition /.comment)
         ($.definition /.switch)
-        ($.definition /.not_a_number?)
         ))
+
+(def .public documentation
+  (List $.Documentation)
+  (list.partial ($.module /._
+                          "")
+
+                ($.definition /.Code)
+                ($.definition /.code)
+                ($.definition /.Expression)
+                ($.definition /.Computation)
+                ($.definition /.Location)
+                ($.definition /.Var)
+                ($.definition /.Access)
+                ($.definition /.Literal)
+                ($.definition /.null)
+                ($.definition /.undefined)
+                ($.definition /.boolean)
+                ($.definition /.number)
+                ($.definition /.string)
+                ($.definition /.array)
+                ($.definition /.var)
+                ($.definition /.at)
+                ($.definition /.the)
+                ($.definition /.apply)
+                ($.definition /.do)
+                ($.definition /.object)
+                ($.definition /.,)
+                ($.definition /.function)
+                ($.definition /.closure)
+                ($.definition /.=)
+                ($.definition /.<)
+                ($.definition /.<=)
+                ($.definition /.>)
+                ($.definition /.>=)
+                ($.definition /.+)
+                ($.definition /.-)
+                ($.definition /.*)
+                ($.definition /./)
+                ($.definition /.%)
+                ($.definition /.left_shift)
+                ($.definition /.arithmetic_right_shift)
+                ($.definition /.logic_right_shift)
+                ($.definition /.or)
+                ($.definition /.and)
+                ($.definition /.bit_xor)
+                ($.definition /.bit_or)
+                ($.definition /.bit_and)
+                ($.definition /.not)
+                ($.definition /.bit_not)
+                ($.definition /.opposite)
+                ($.definition /.to_i32)
+                ($.definition /.i32)
+                ($.definition /.int)
+                ($.definition /.?)
+                ($.definition /.type_of)
+                ($.definition /.new)
+                ($.definition /.++)
+                ($.definition /.--)
+                ($.definition /.not_a_number?)
+
+                ..all_statement
+                ))
diff --git a/stdlib/source/documentation/lux/meta/target/lua.lux b/stdlib/source/documentation/lux/meta/target/lua.lux
index 8d7b66680..231242a26 100644
--- a/stdlib/source/documentation/lux/meta/target/lua.lux
+++ b/stdlib/source/documentation/lux/meta/target/lua.lux
@@ -10,60 +10,10 @@
  [\\library
   ["[0]" /]])
 
-(def .public documentation
+(def all_statement
   (List $.Documentation)
-  (list ($.module /._
-                  "")
-
-        ($.definition /.Code)
-        ($.definition /.equivalence)
-        ($.definition /.hash)
-        ($.definition /.manual)
-        ($.definition /.code)
-        ($.definition /.Expression)
-        ($.definition /.Computation)
-        ($.definition /.Location)
-        ($.definition /.Statement)
-        ($.definition /.Literal)
-        ($.definition /.Var)
-        ($.definition /.Access)
+  (list ($.definition /.Statement)
         ($.definition /.Label)
-        ($.definition /.nil)
-        ($.definition /.boolean)
-        ($.definition /.int)
-        ($.definition /.float)
-        ($.definition /.string)
-        ($.definition /.multi)
-        ($.definition /.array)
-        ($.definition /.table)
-        ($.definition /.item)
-        ($.definition /.the)
-        ($.definition /.length)
-        ($.definition /.apply)
-        ($.definition /.do)
-        ($.definition /.=)
-        ($.definition /.<)
-        ($.definition /.<=)
-        ($.definition /.>)
-        ($.definition /.>=)
-        ($.definition /.+)
-        ($.definition /.-)
-        ($.definition /.*)
-        ($.definition /.^)
-        ($.definition /./)
-        ($.definition /.//)
-        ($.definition /.%)
-        ($.definition /.concat)
-        ($.definition /.or)
-        ($.definition /.and)
-        ($.definition /.bit_or)
-        ($.definition /.bit_and)
-        ($.definition /.bit_xor)
-        ($.definition /.bit_shl)
-        ($.definition /.bit_shr)
-        ($.definition /.not)
-        ($.definition /.opposite)
-        ($.definition /.var)
         ($.definition /.label)
         ($.definition /.statement)
         ($.definition /.then)
@@ -84,10 +34,66 @@
         ($.definition /.break)
         ($.definition /.set_label)
         ($.definition /.go_to)
-        ($.definition /.error/1)
-        ($.definition /.print/1)
-        ($.definition /.require/1)
-        ($.definition /.type/1)
-        ($.definition /.ipairs/1)
-        ($.definition /.error/2)
         ))
+
+(def .public documentation
+  (List $.Documentation)
+  (list.partial ($.module /._
+                          "")
+
+                ($.definition /.Code)
+                ($.definition /.equivalence)
+                ($.definition /.hash)
+                ($.definition /.manual)
+                ($.definition /.code)
+                ($.definition /.Expression)
+                ($.definition /.Computation)
+                ($.definition /.Location)
+                ($.definition /.Literal)
+                ($.definition /.Var)
+                ($.definition /.Access)
+                ($.definition /.nil)
+                ($.definition /.boolean)
+                ($.definition /.int)
+                ($.definition /.float)
+                ($.definition /.string)
+                ($.definition /.multi)
+                ($.definition /.array)
+                ($.definition /.table)
+                ($.definition /.item)
+                ($.definition /.the)
+                ($.definition /.length)
+                ($.definition /.apply)
+                ($.definition /.do)
+                ($.definition /.=)
+                ($.definition /.<)
+                ($.definition /.<=)
+                ($.definition /.>)
+                ($.definition /.>=)
+                ($.definition /.+)
+                ($.definition /.-)
+                ($.definition /.*)
+                ($.definition /.^)
+                ($.definition /./)
+                ($.definition /.//)
+                ($.definition /.%)
+                ($.definition /.concat)
+                ($.definition /.or)
+                ($.definition /.and)
+                ($.definition /.bit_or)
+                ($.definition /.bit_and)
+                ($.definition /.bit_xor)
+                ($.definition /.bit_shl)
+                ($.definition /.bit_shr)
+                ($.definition /.not)
+                ($.definition /.opposite)
+                ($.definition /.var)
+                ($.definition /.error/1)
+                ($.definition /.print/1)
+                ($.definition /.require/1)
+                ($.definition /.type/1)
+                ($.definition /.ipairs/1)
+                ($.definition /.error/2)
+
+                ..all_statement
+                ))
diff --git a/stdlib/source/documentation/lux/meta/target/ruby.lux b/stdlib/source/documentation/lux/meta/target/ruby.lux
index d67257929..593504138 100644
--- a/stdlib/source/documentation/lux/meta/target/ruby.lux
+++ b/stdlib/source/documentation/lux/meta/target/ruby.lux
@@ -6,16 +6,13 @@
     [text (.only \n)
      ["%" \\format (.only format)]]
     [collection
-     ["[0]" list]]]]]
+     ["[0]" list (.use "[1]#[0]" monoid)]]]]]
  [\\library
   ["[0]" /]])
 
-(def .public documentation
+(def all_1/3
   (List $.Documentation)
-  (list ($.module /._
-                  "")
-
-        ($.definition /.Code)
+  (list ($.definition /.Code)
         ($.definition /.equivalence)
         ($.definition /.hash)
         ($.definition /.manual)
@@ -50,7 +47,11 @@
         ($.definition /.case_insensitivity_flag)
         ($.definition /.input_record_separator)
         ($.definition /.output_record_separator)
-        ($.definition /.script_name)
+        ))
+
+(def all_2/3
+  (List $.Documentation)
+  (list ($.definition /.script_name)
         ($.definition /.process_id)
         ($.definition /.exit_status)
         ($.definition /.command_line_arguments)
@@ -85,7 +86,11 @@
         ($.definition /.break)
         ($.definition /.function)
         ($.definition /.lambda)
-        ($.definition /.=)
+        ))
+
+(def all_3/3
+  (List $.Documentation)
+  (list ($.definition /.=)
         ($.definition /.<)
         ($.definition /.<=)
         ($.definition /.>)
@@ -112,3 +117,15 @@
         ($.definition /.print/2)
         ($.definition /.throw/1)
         ))
+
+(def .public documentation
+  (List $.Documentation)
+  (list.partial ($.module /._
+                          "")
+
+                (all list#composite
+                     all_1/3
+                     all_2/3
+                     all_3/3
+                     )
+                ))
diff --git a/stdlib/source/documentation/lux/world/net/http/status.lux b/stdlib/source/documentation/lux/world/net/http/status.lux
index 0a65db6dd..03225ca9f 100644
--- a/stdlib/source/documentation/lux/world/net/http/status.lux
+++ b/stdlib/source/documentation/lux/world/net/http/status.lux
@@ -3,25 +3,28 @@
   [lux (.except)
    ["$" documentation]
    [data
-    ["[0]" text (.only \n)
-     ["%" \\format (.only format)]]]
+    ["[0]" text (.only)
+     ["%" \\format (.only format)]]
+    [collection
+     ["[0]" list (.use "[1]#[0]" monoid)]]]
    [meta
     [macro
      ["[0]" template]]]]]
  [\\library
   ["[0]" /]])
 
-(`` (def .public documentation
-      (List $.Documentation)
-      (list ($.module /._
-                      "")
+(def description
+  (template (_ <name>)
+    [($.definition <name>
+       (|> (template.text [<name>])
+           (text.replaced "_" " ")
+           text.upper_cased
+           (format (%.nat <name>) ": ")))]))
 
-            (,, (with_template [<name>]
-                  [($.definition <name>
-                     (|> (template.text [<name>])
-                         (text.replaced "_" " ")
-                         text.upper_cased
-                         (format (%.nat <name>) ": ")))]
+(`` (def all_100-300
+      (List $.Documentation)
+      (list (,, (with_template [<name>]
+                  [(description <name>)]
 
                   ... 1xx Informational response
                   [/.continue]
@@ -51,6 +54,13 @@
                   [/.switch_proxy]
                   [/.temporary_redirect]
                   [/.permanent_redirect]
+                  ))
+            )))
+
+(`` (def all_400-500
+      (List $.Documentation)
+      (list (,, (with_template [<name>]
+                  [(description <name>)]
 
                   ... 4xx Client errors
                   [/.bad_request]
@@ -96,3 +106,14 @@
                   [/.network_authentication_required]
                   ))
             )))
+
+(def .public documentation
+  (List $.Documentation)
+  (list.partial ($.module /._
+                          "")
+
+                (all list#composite
+                     all_100-300
+                     all_400-500
+                     )
+                ))
diff --git a/stdlib/source/experiment/tool/interpreter.lux b/stdlib/source/experiment/tool/interpreter.lux
index cea7bd833..55064903b 100644
--- a/stdlib/source/experiment/tool/interpreter.lux
+++ b/stdlib/source/experiment/tool/interpreter.lux
@@ -4,7 +4,7 @@
    [control
     [monad (.only Monad do)]
     ["[0]" try (.only Try)]
-    ["ex" exception (.only exception)]]
+    ["ex" exception (.only Exception)]]
    [data
     ["[0]" text (.use "[1]#[0]" equivalence)
      ["%" \\format (.only format)]]]
@@ -29,7 +29,8 @@
     ["[0]" console (.only Console)]]]]
  ["[0]" /type])
 
-(exception .public (error [message Text])
+(exception.def .public (error message)
+  (Exception Text)
   message)
 
 (def .public module "<INTERPRETER>")
diff --git a/stdlib/source/library/lux/control/concurrency/actor.lux b/stdlib/source/library/lux/control/concurrency/actor.lux
index e1eb5ff68..d4c50b896 100644
--- a/stdlib/source/library/lux/control/concurrency/actor.lux
+++ b/stdlib/source/library/lux/control/concurrency/actor.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" pipe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     ["[0]" io (.only IO io)]]
    [data
     ["[0]" bit]
@@ -21,8 +21,8 @@
   ["[0]" async (.only Async Resolver)]
   ["[0]" frp (.only Channel Channel')]])
 
-(exception .public poisoned)
-(exception .public dead)
+(exception.def .public poisoned)
+(exception.def .public dead)
 
 (local.let [<Mail> (template (_ Actor s)
                      [(-> s (Actor s) (Async (Try s)))])
diff --git a/stdlib/source/library/lux/control/concurrency/frp.lux b/stdlib/source/library/lux/control/concurrency/frp.lux
index c1b7c9931..b5005661a 100644
--- a/stdlib/source/library/lux/control/concurrency/frp.lux
+++ b/stdlib/source/library/lux/control/concurrency/frp.lux
@@ -9,7 +9,7 @@
    [control
     ["[0]" maybe (.use "[1]#[0]" functor)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     ["[0]" io (.only IO io)]]
    [meta
     ["[0]" type (.only sharing)]]]]
@@ -24,7 +24,7 @@
 (type .public (Channel a)
   (Channel' a a))
 
-(exception .public already_closed)
+(exception.def .public already_closed)
 
 (type .public (Sink w)
   (Interface
diff --git a/stdlib/source/library/lux/control/concurrency/semaphore.lux b/stdlib/source/library/lux/control/concurrency/semaphore.lux
index 557f9fca8..7e2b8c0cd 100644
--- a/stdlib/source/library/lux/control/concurrency/semaphore.lux
+++ b/stdlib/source/library/lux/control/concurrency/semaphore.lux
@@ -7,7 +7,7 @@
     ["[0]" pipe]
     ["[0]" io (.only IO)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format (.only format)]]
@@ -66,7 +66,8 @@
                  <get_in_line>)))))
         signal)))
 
-  (exception .public (semaphore_is_maxed_out [max_positions Nat])
+  (exception.def .public (semaphore_is_maxed_out max_positions)
+    (Exception Nat)
     (exception.report
      (list ["Max Positions" (%.nat max_positions)])))
 
diff --git a/stdlib/source/library/lux/control/concurrency/thread.lux b/stdlib/source/library/lux/control/concurrency/thread.lux
index 25e1d02d8..def0f230d 100644
--- a/stdlib/source/library/lux/control/concurrency/thread.lux
+++ b/stdlib/source/library/lux/control/concurrency/thread.lux
@@ -7,7 +7,7 @@
     ["[0]" monad (.only do)]]
    [control
     ["[0]" try]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     ["[0]" io (.only IO io)]]
    [data
     ["[0]" text]
@@ -161,7 +161,7 @@
      @.python (these)
      
      ... Default
-     (these (exception .public cannot_continue_running_threads)
+     (these (exception.def .public cannot_continue_running_threads)
 
             ... https://en.wikipedia.org/wiki/Event_loop
             ... Starts the event-loop.
diff --git a/stdlib/source/library/lux/control/exception.lux b/stdlib/source/library/lux/control/exception.lux
index 834f8afe8..8d39a9daf 100644
--- a/stdlib/source/library/lux/control/exception.lux
+++ b/stdlib/source/library/lux/control/exception.lux
@@ -1,6 +1,6 @@
 (.require
  [library
-  [lux (.except except with when)
+  [lux (.except except with when def)
    [abstract
     [monad (.only do)]]
    [control
@@ -19,9 +19,7 @@
      ["<[1]>" \\parser (.only Parser)]]
     ["[0]" macro (.only)
      [syntax (.only syntax)
-      ["|[0]|" input]
-      ["[0]" type
-       ["|[1]_[0]|" variable]]]]]]]
+      ["[0]" export]]]]]]
  [//
   ["//" try (.only Try)]])
 
@@ -30,11 +28,11 @@
    [#label Text
     #constructor (-> a Text)]))
 
-(def .public (match? exception error)
+(.def .public (match? exception error)
   (All (_ e) (-> (Exception e) Text Bit))
   (text.starts_with? (the #label exception) error))
 
-(def .public (when exception then try)
+(.def .public (when exception then try)
   (All (_ e a)
     (-> (Exception e) (-> Text a) (Try a)
         (Try a)))
@@ -51,7 +49,7 @@
                          then)}
         {//.#Failure error}))))
 
-(def .public (otherwise else try)
+(.def .public (otherwise else try)
   (All (_ a)
     (-> (-> Text a) (Try a) a))
   (.when try
@@ -61,52 +59,50 @@
     {//.#Failure error}
     (else error)))
 
-(def .public (error exception message)
+(.def .public (error exception message)
   (All (_ e) (-> (Exception e) e Text))
   ((the ..#constructor exception) message))
 
-(def .public (except exception message)
+(.def .public (except exception message)
   (All (_ e a) (-> (Exception e) e (Try a)))
   {//.#Failure (..error exception message)})
 
-(def .public (assertion exception message test)
+(.def .public (assertion exception message test)
   (All (_ e) (-> (Exception e) e Bit (Try Any)))
   (if test
     {//.#Success []}
     (..except exception message)))
 
-(def exceptionP
-  (Parser [Code (List |type_variable|.Variable) [Text (List |input|.Input)] (Maybe Code)])
-  (let [private (is (Parser [(List |type_variable|.Variable) [Text (List |input|.Input)] (Maybe Code)])
-                    (all <>.and
-                         (<>.else (list) (<code>.tuple (<>.some |type_variable|.parser)))
-                         (<>.either (<code>.form (<>.and <code>.local |input|.parser))
-                                    (<>.and <code>.local (<>#in (list))))
-                         (<>.maybe <code>.any)
-                         ))]
-    (all <>.either
-         (<>.and <code>.any private)
-         (<>.and (<>#in (` .private)) private)
-         )))
-
-(def .public exception
-  (syntax (_ [[export_policy t_vars [name inputs] body] ..exceptionP])
-    (macro.with_symbols [g!_ g!descriptor]
+(.def exceptionP
+  (Parser [export.Policy [[Text Code] Code Code]])
+  (export.parser
+   (all <>.either
+        (all <>.and
+             (<code>.form (<>.and <code>.local <code>.any))
+             <code>.any
+             <code>.any)
+        (do <>.monad
+          [name <code>.local]
+          (in [[name (code.local name)]
+               (` (Exception Any))
+               (` "")])))))
+
+(.def .public def
+  (syntax (_ [[export_policy [[name input] type body]] ..exceptionP])
+    (macro.with_symbols [g!descriptor]
       (do meta.monad
-        [current_module meta.current_module_name
-         .let [descriptor (all text#composite "{" current_module "." name "}" text.new_line)
-               g!self (code.local name)]]
-        (in (list (` (def (, export_policy)
-                       (, g!self)
-                       (All ((, g!_) (,* (list#each |type_variable|.format t_vars)))
-                         (..Exception [(,* (list#each (the |input|.#type) inputs))]))
-                       (let [(, g!descriptor) (, (code.text descriptor))]
-                         [..#label (, g!descriptor)
-                          ..#constructor (function ((, g!self) [(,* (list#each (the |input|.#binding) inputs))])
-                                           (at text.monoid (,' composite) (, g!descriptor)
-                                               (, (maybe.else (' "") body))))])))))))))
-
-(def .public (report entries)
+        [current_module meta.current_module_name]
+        (let [descriptor (all text#composite "{" current_module "." name "}" text.new_line)
+              g!self (code.local name)]
+          (in (list (` (.def (, export_policy)
+                         (, g!self)
+                         (, type)
+                         (let [(, g!descriptor) (, (code.text descriptor))]
+                           [..#label (, g!descriptor)
+                            ..#constructor (function ((, g!self) (, input))
+                                             (at text.monoid (,' composite) (, g!descriptor) (, body)))]))))))))))
+
+(.def .public (report entries)
   (-> (List [Text Text]) Text)
   (let [header_separator ": "
         largest_header_size (list#mix (function (_ [header _] max)
@@ -137,7 +133,7 @@
                 (on_entry head)
                 tail))))
 
-(def .public (listing format entries)
+(.def .public (listing format entries)
   (All (_ a)
     (-> (-> a Text) (List a) Text))
   (|> entries
@@ -150,7 +146,7 @@
       list.reversed
       ..report))
 
-(def separator
+(.def separator
   (let [gap (all "lux text concat" text.new_line text.new_line)
         horizontal_line (|> "-" (list.repeated 64) text.together)]
     (all "lux text concat"
@@ -158,14 +154,14 @@
          horizontal_line
          gap)))
 
-(def (decorated prelude error)
+(.def (decorated prelude error)
   (-> Text Text Text)
   (all "lux text concat"
        prelude
        ..separator
        error))
 
-(def .public (with exception message computation)
+(.def .public (with exception message computation)
   (All (_ e a) (-> (Exception e) e (Try a) (Try a)))
   (.when computation
     {//.#Failure error}
diff --git a/stdlib/source/library/lux/control/function/contract.lux b/stdlib/source/library/lux/control/function/contract.lux
index a5f73c098..bc3ac4926 100644
--- a/stdlib/source/library/lux/control/function/contract.lux
+++ b/stdlib/source/library/lux/control/function/contract.lux
@@ -2,7 +2,7 @@
  [library
   [lux (.except)
    [control
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format (.only format)]]]
@@ -16,7 +16,8 @@
      ["<[1]>" \\parser]]]]])
 
 (with_template [<name>]
-  [(exception .public (<name> [condition Code])
+  [(exception.def .public (<name> condition)
+     (Exception Code)
      (exception.report
       (list ["Condition" (%.code condition)])))]
 
diff --git a/stdlib/source/library/lux/control/region.lux b/stdlib/source/library/lux/control/region.lux
index e752b57a9..4216a1e78 100644
--- a/stdlib/source/library/lux/control/region.lux
+++ b/stdlib/source/library/lux/control/region.lux
@@ -13,7 +13,7 @@
     [collection
      ["[0]" list (.use "[1]#[0]" mix)]]]]]
  [//
-  ["[0]" exception (.only Exception exception)]])
+  ["[0]" exception (.only Exception)]])
 
 (type (Cleaner r !)
   (-> r (! (Try Any))))
@@ -31,8 +31,8 @@
           "-----------------------------------------" text.new_line
           text.new_line))
 
-(exception .public [a] (clean_up_error [error Text
-                                        output (Try a)])
+(exception.def .public (clean_up_error [error output])
+  (All (_ a) (Exception [Text (Try a)]))
   (format error
           (when output
             {try.#Success _}
diff --git a/stdlib/source/library/lux/control/remember.lux b/stdlib/source/library/lux/control/remember.lux
index 1b3d0c2f0..be344f2ef 100644
--- a/stdlib/source/library/lux/control/remember.lux
+++ b/stdlib/source/library/lux/control/remember.lux
@@ -7,7 +7,7 @@
     ["<>" parser (.use "[1]#[0]" functor)]
     ["[0]" io]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text
      ["%" \\format (.only format)]]]
@@ -22,10 +22,8 @@
      ["[0]" instant]
      ["[0]" date (.only Date) (.use "[1]#[0]" order)]]]]])
 
-(exception .public (must_remember [deadline Date
-                                   today Date
-                                   message Text
-                                   focus (Maybe Code)])
+(exception.def .public (must_remember [deadline today message focus])
+  (Exception [Date Date Text (Maybe Code)])
   (exception.report
    (list ["Deadline" (%.date deadline)]
          ["Today" (%.date today)]
diff --git a/stdlib/source/library/lux/data/binary.lux b/stdlib/source/library/lux/data/binary.lux
index bc384140e..2803023a5 100644
--- a/stdlib/source/library/lux/data/binary.lux
+++ b/stdlib/source/library/lux/data/binary.lux
@@ -7,7 +7,7 @@
     [monoid (.only Monoid)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format]]
@@ -40,8 +40,8 @@
         (again (++ index) ($ (/.bits_8 index it) output))
         output))))
 
-(exception .public (index_out_of_bounds [size Nat
-                                         index Nat])
+(exception.def .public (index_out_of_bounds [size index])
+  (Exception [Nat Nat])
   (exception.report
    (list ["Size" (%.nat size)]
          ["Index" (%.nat index)])))
@@ -78,9 +78,8 @@
    (def (= reference sample)
      (/.= reference sample))))
 
-(exception .public (cannot_copy [bytes Nat
-                                 source_input Nat
-                                 target_output Nat])
+(exception.def .public (cannot_copy [bytes source_input target_output])
+  (Exception [Nat Nat Nat])
   (exception.report
    (list ["Bytes" (%.nat bytes)]
          ["Source input space" (%.nat source_input)]
@@ -95,9 +94,8 @@
       (exception.except ..cannot_copy [bytes source_input target_output])
       {try.#Success (/.copy! bytes source_offset source target_offset target)})))
 
-(exception .public (slice_out_of_bounds [size Nat
-                                         offset Nat
-                                         length Nat])
+(exception.def .public (slice_out_of_bounds [size offset length])
+  (Exception [Nat Nat Nat])
   (exception.report
    (list ["Size" (%.nat size)]
          ["Offset" (%.nat offset)]
diff --git a/stdlib/source/library/lux/data/collection/dictionary.lux b/stdlib/source/library/lux/data/collection/dictionary.lux
index a2e1282d5..482824d85 100644
--- a/stdlib/source/library/lux/data/collection/dictionary.lux
+++ b/stdlib/source/library/lux/data/collection/dictionary.lux
@@ -9,7 +9,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" product]
     [collection
@@ -599,7 +599,7 @@
     {.#Some _}
     true))
 
-(exception .public key_already_exists)
+(exception.def .public key_already_exists)
 
 (def .public (has' key val dict)
   (All (_ k v) (-> k v (Dictionary k v) (Try (Dictionary k v))))
diff --git a/stdlib/source/library/lux/data/collection/list.lux b/stdlib/source/library/lux/data/collection/list.lux
index c2dff94fc..77e5529b1 100644
--- a/stdlib/source/library/lux/data/collection/list.lux
+++ b/stdlib/source/library/lux/data/collection/list.lux
@@ -46,13 +46,13 @@
     {.#Item [head tail]}
     {.#Item [init (mixes f (f head init) tail)]}))
 
-(def .public (reversed xs)
+(def .public (reversed it)
   (All (_ a)
     (-> (List a) (List a)))
   (mix (function (_ head tail)
          {.#Item head tail})
        {.#End}
-       xs))
+       it))
 
 (def .public (only keep? xs)
   (All (_ a)
@@ -341,26 +341,24 @@
   (implementation
    (def identity
      {.#End})
-   (def (composite xs ys)
-     (.when xs
-       {.#End}
-       ys
-       
-       {.#Item x xs'}
-       {.#Item x (composite xs' ys)}))))
+   (def (composite left right)
+     ... TODO: Use the more obvious implementation once "tail recursion modulo cons" is added to the compiler.
+     (mix (function (_ head tail)
+            {.#Item head tail})
+          right
+          (reversed left)))))
 
 (use "[0]" ..monoid)
 
 (def .public functor
   (Functor List)
   (implementation
-   (def (each f ma)
-     (.when ma
-       {.#End}
-       {.#End}
-       
-       {.#Item a ma'}
-       {.#Item (f a) (each f ma')}))))
+   (def (each f it)
+     ... TODO: Use the more obvious implementation once "tail recursion modulo cons" is added to the compiler.
+     (mix (function (_ head tail)
+            {.#Item (f head) tail})
+          (list)
+          (reversed it)))))
 
 (use "[0]" ..functor)
 
@@ -371,21 +369,21 @@
 
    (def (on fa ff)
      (.when ff
-       {.#End}
-       {.#End}
-       
        {.#Item f ff'}
        (|> ff'
            (on fa)
-           (composite (each f fa)))))))
+           (composite (each f fa)))
+
+       {.#End}
+       {.#End}))))
 
 (def .public monad
   (Monad List)
   (implementation
    (def functor ..functor)
 
-   (def (in a)
-     {.#Item a {.#End}})
+   (def in
+     (|>> list))
 
    (def conjoint
      (|>> reversed (mix composite identity)))))
@@ -406,7 +404,10 @@
                                (is (,, (type_of xs))
                                    (list))])
                           xs')]
-      (.all composite (sorted < pre) (list x) (sorted < post)))))
+      (.all composite
+            (sorted < pre)
+            (list x)
+            (sorted < post)))))
 
 (def .public (empty? xs)
   (All (_ a) (Predicate (List a)))
diff --git a/stdlib/source/library/lux/data/collection/sequence.lux b/stdlib/source/library/lux/data/collection/sequence.lux
index 55c782acf..c015edb06 100644
--- a/stdlib/source/library/lux/data/collection/sequence.lux
+++ b/stdlib/source/library/lux/data/collection/sequence.lux
@@ -15,7 +15,7 @@
     ["<>" parser]
     ["[0]" maybe (.use "[1]#[0]" functor)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     [function
      [predicate (.only Predicate)]]]
    [data
@@ -241,15 +241,15 @@
           (.has #tail (..tail val)))
       )))
 
-(exception incorrect_sequence_structure)
+(exception.def incorrect_sequence_structure)
 
-(exception .public [a] (index_out_of_bounds [sequence (Sequence a)
-                                             index Nat])
+(exception.def .public (index_out_of_bounds [sequence index])
+  (All (_ a) (Exception [(Sequence a) Nat]))
   (exception.report
    (.list ["Size" (at n.decimal encoded (the #size sequence))]
           ["Index" (at n.decimal encoded index)])))
 
-(exception base_was_not_found)
+(exception.def base_was_not_found)
 
 (def .public (within_bounds? sequence idx)
   (All (_ a) (-> (Sequence a) Nat Bit))
diff --git a/stdlib/source/library/lux/data/format/tar.lux b/stdlib/source/library/lux/data/format/tar.lux
index 360ceeb11..e682544bc 100644
--- a/stdlib/source/library/lux/data/format/tar.lux
+++ b/stdlib/source/library/lux/data/format/tar.lux
@@ -8,7 +8,7 @@
     ["<>" parser]
     ["[0]" pipe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" binary (.only Binary)
@@ -71,7 +71,8 @@
          (list#mix n.* 1)
          ++))
 
-   (exception .public (<exception> [value Nat])
+   (exception.def .public (<exception> value)
+     (Exception Nat)
      (exception.report
       (list ["Value" (%.nat value)]
             ["Maximum" (%.nat (-- <limit>))])))
@@ -116,8 +117,8 @@
    as_big]
   )
 
-(exception .public (wrong_character [expected Char
-                                     actual Char])
+(exception.def .public (wrong_character [expected actual])
+  (Exception [Char Char])
   (exception.report
    (list ["Expected" (%.nat expected)]
          ["Actual" (%.nat actual)])))
@@ -227,7 +228,8 @@
                            (n.<= ..last_ascii char)))
                    true)))
 
-(exception .public (not_ascii [text Text])
+(exception.def .public (not_ascii text)
+  (Exception Text)
   (exception.report
    (list ["Text" (%.text text)])))
 
@@ -256,7 +258,8 @@
   [(primitive .public <type>
      <representation>
 
-     (exception .public (<exception> [value Text])
+     (exception.def .public (<exception> value)
+       (Exception Text)
        (exception.report
         (list ["Value" (%.text value)]
               ["Size" (%.nat (text.size value))]
@@ -426,7 +429,8 @@
       <options>
       )
 
-    (exception .public (invalid_link_flag [value Nat])
+    (exception.def .public (invalid_link_flag value)
+      (Exception Nat)
       (exception.report
        (list ["Value" (%.nat value)])))
 
@@ -465,7 +469,8 @@
          try.trusted
          ..small_format))
 
-  (exception .public (invalid_mode [value Nat])
+  (exception.def .public (invalid_mode value)
+    (Exception Nat)
     (exception.report
      (list ["Value" (%.nat value)])))
 
@@ -749,8 +754,8 @@
                                         tar)
                           (\\format.segment ..end_of_archive_size end_of_archive)))))
 
-(exception .public (wrong_checksum [expected Nat
-                                    actual Nat])
+(exception.def .public (wrong_checksum [expected actual])
+  (Exception [Nat Nat])
   (exception.report
    (list ["Expected" (%.nat expected)]
          ["Actual" (%.nat actual)])))
@@ -863,7 +868,7 @@
        (exception.assertion ..wrong_checksum [0 actual]
                             (n.= 0 actual))))))
 
-(exception .public invalid_end_of_archive)
+(exception.def .public invalid_end_of_archive)
 
 (def end_of_archive_parser
   (Parser Any)
diff --git a/stdlib/source/library/lux/data/sum.lux b/stdlib/source/library/lux/data/sum.lux
index 0ed2931d1..72d5d52df 100644
--- a/stdlib/source/library/lux/data/sum.lux
+++ b/stdlib/source/library/lux/data/sum.lux
@@ -3,7 +3,10 @@
   [lux (.except left right)
    [abstract
     [equivalence (.only Equivalence)]
-    [hash (.only Hash)]]]])
+    [hash (.only Hash)]]
+   [data
+    [collection
+     ["[0]" list (.use "[1]#[0]" mix)]]]]])
 
 (with_template [<right?> <name>]
   [(def .public (<name> value)
@@ -32,21 +35,22 @@
       {0 #0 l} {0 #0 (on_left l)}
       {0 #1 r} {0 #1 (on_right r)})))
 
-(with_template [<name> <side> <right?>]
-  [(def .public (<name> items)
-     (All (_ a b) (-> (List (Or a b)) (List <side>)))
-     (when items
-       {.#End}
-       {.#End}
-       
-       {.#Item {0 <right?> x} items'}
-       {.#Item [x (<name> items')]}
-       
-       {.#Item _ items'}
-       (<name> items')))]
+(with_template [<right?> <side> <name>]
+  [(def .public (<name> it)
+     (All (_ t0 t1) (-> (List (Or t0 t1)) (List <side>)))
+     ... TODO: Use the more obvious implementation once "tail recursion modulo cons" is added to the compiler.
+     (list#mix (function (_ head tail)
+                 (when head
+                   {0 <right?> head}
+                   (list.partial head tail)
 
-  [lefts  a #0]
-  [rights b #1]
+                   _
+                   tail))
+               (list)
+               (list.reversed it)))]
+
+  [#0 t0 lefts]
+  [#1 t1 rights]
   )
 
 (def .public (partition xs)
diff --git a/stdlib/source/library/lux/data/text/escape.lux b/stdlib/source/library/lux/data/text/escape.lux
index 2ce6021a6..b09ae72c7 100644
--- a/stdlib/source/library/lux/data/text/escape.lux
+++ b/stdlib/source/library/lux/data/text/escape.lux
@@ -7,7 +7,7 @@
     ["<>" parser]
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [math
     [number (.only hex)
      ["n" nat]]]
@@ -141,21 +141,21 @@
           (again (++ offset) previous current limit)))
       (format previous current))))
 
-(exception .public (dangling_escape [text Text])
+(exception.def .public (dangling_escape text)
+  (Exception Text)
   (exception.report
    (list ["In" (%.text text)]
          ["At" (%.nat (-- (//.size text)))])))
 
-(exception .public (invalid_escape [text Text
-                                    offset Nat
-                                    sigil Char])
+(exception.def .public (invalid_escape [text offset sigil])
+  (Exception [Text Nat Char])
   (exception.report
    (list ["In" (%.text text)]
          ["At" (%.nat offset)]
          ["Name" (%.text (//.of_char sigil))])))
 
-(exception .public (invalid_unicode_escape [text Text
-                                            offset Nat])
+(exception.def .public (invalid_unicode_escape [text offset])
+  (Exception [Text Nat])
   (exception.report
    (list ["In" (%.text text)]
          ["At" (%.nat offset)])))
diff --git a/stdlib/source/library/lux/data/text/regex.lux b/stdlib/source/library/lux/data/text/regex.lux
index 09dba9073..c59578a58 100644
--- a/stdlib/source/library/lux/data/text/regex.lux
+++ b/stdlib/source/library/lux/data/text/regex.lux
@@ -7,7 +7,7 @@
     ["<>" parser (.use "[1]#[0]" monad)]
     ["[0]" maybe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text
@@ -231,8 +231,8 @@
       (in (` (together (<>.many (, base)))))
       )))
 
-(exception .public (incorrect_quantification [from Nat
-                                              to Nat])
+(exception.def .public (incorrect_quantification [from to])
+  (Exception [Nat Nat])
   (exception.report
    (list ["Input" (format (%.nat from) "," (%.nat to))]
          ["Should be" (format (%.nat to) "," (%.nat from))])))
diff --git a/stdlib/source/library/lux/debug.lux b/stdlib/source/library/lux/debug.lux
index 88df6bc7b..c5f95dae2 100644
--- a/stdlib/source/library/lux/debug.lux
+++ b/stdlib/source/library/lux/debug.lux
@@ -9,7 +9,7 @@
     ["[0]" pipe]
     ["[0]" function]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.only)
      ["%" \\format (.only Format)]]
@@ -381,7 +381,8 @@
                    ))
          )))
 
-(exception .public (cannot_represent_value [type Type])
+(exception.def .public (cannot_represent_value type)
+  (Exception Type)
   (exception.report
    (list ["Type" (%.type type)])))
 
@@ -534,8 +535,8 @@
   (-> Text Any)
   ("lux io log" message))
 
-(exception .public (type_hole [location Location
-                               type Type])
+(exception.def .public (type_hole [location type])
+  (Exception [Location Type])
   (exception.report
    (list ["Location" (%.location location)]
          ["Type" (%.type type)])))
@@ -557,7 +558,8 @@
              (<code>.tuple (<>.and <code>.local
                                    (at <>.monad each (|>> {.#Some}) <code>.any)))))
 
-(exception .public (unknown_local_binding [name Text])
+(exception.def .public (unknown_local_binding name)
+  (Exception Text)
   (exception.report
    (list ["Name" (%.text name)])))
 
diff --git a/stdlib/source/library/lux/documentation.lux b/stdlib/source/library/lux/documentation.lux
index dc8e85722..af0d07a07 100644
--- a/stdlib/source/library/lux/documentation.lux
+++ b/stdlib/source/library/lux/documentation.lux
@@ -7,7 +7,7 @@
    [control
     ["<>" parser (.use "[1]#[0]" monad)]
     ["[0]" maybe (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" sum]
     ["[0]" product]
@@ -439,7 +439,8 @@
   (<>.or (<code>.this_text "")
          <code>.any))
 
-(exception .public (unqualified_symbol [name Symbol])
+(exception.def .public (unqualified_symbol name)
+  (Exception Symbol)
   (exception.report
    (list ["Name" (%.symbol name)])))
 
diff --git a/stdlib/source/library/lux/ffi.jvm.lux b/stdlib/source/library/lux/ffi.jvm.lux
index be31fd27a..871f6afec 100644
--- a/stdlib/source/library/lux/ffi.jvm.lux
+++ b/stdlib/source/library/lux/ffi.jvm.lux
@@ -8,7 +8,7 @@
     ["[0]" io]
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only Exception exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text (.use "[1]#[0]" equivalence)
@@ -433,12 +433,13 @@
          (<code>.this (' "abstract"))
          (in []))))
 
-(exception .public (class_names_cannot_contain_periods [name Text])
+(exception.def .public (class_names_cannot_contain_periods name)
+  (Exception Text)
   (exception.report
    (list ["Name" (%.text name)])))
 
-(exception .public (class_name_cannot_be_a_type_variable [name Text
-                                                          type_vars (List (Type Var))])
+(exception.def .public (class_name_cannot_be_a_type_variable [name type_vars])
+  (Exception [Text (List (Type Var))])
   (exception.report
    (list ["Name" (%.text name)]
          ["Type Variables" (exception.listing parser.name type_vars)])))
@@ -471,8 +472,8 @@
                                  (<code>.form (<>.and class_name^ (<>.some (parameter^ type_vars))))))]
     (in (jvm.class (name.safe name) parameters))))
 
-(exception .public (unknown_type_variable [name Text
-                                           type_vars (List (Type Var))])
+(exception.def .public (unknown_type_variable [name type_vars])
+  (Exception [Text (List (Type Var))])
   (exception.report
    (list ["Unexpected type variable" (%.text name)]
          ["Expected type variables" (exception.listing parser.name type_vars)])))
@@ -1028,8 +1029,8 @@
       [body (super_expression declaration,method body)]
       (in (list body)))))
 
-(exception .public (insufficient_parameters [expected Nat
-                                             actual Nat])
+(exception.def .public (insufficient_parameters [expected actual])
+  (Exception [Nat Nat])
   (exception.report
    (list ["Expected" (%.nat expected)]
          ["Actual" (%.nat actual)])))
@@ -1106,8 +1107,8 @@
       (in (list body)))))
 
 (with_template [<member> <name>]
-  [(exception .public (<name> [class Text
-                               member Text])
+  [(exception.def .public (<name> [class member])
+     (Exception [Text Text])
      (exception.report
       (list ["Class" (%.text class)]
             [<member> (%.text member)])))]
@@ -1647,8 +1648,8 @@
                     (list name (` <code>.any))))
        list#conjoint))
 
-(exception .public (cannot_write_to_field [class Text
-                                           field Text])
+(exception.def .public (cannot_write_to_field [class field])
+  (Exception [Text Text])
   (exception.report
    (list ["Class" (%.text class)]
          ["Field" (%.text field)])))
@@ -1881,7 +1882,8 @@
                                   (.is (, (value_type {#ManualPrM} (jvm.array type)))
                                        ("jvm array new object" (, g!size))))))))))))
 
-(exception .public (cannot_convert_to_jvm_type [type .Type])
+(exception.def .public (cannot_convert_to_jvm_type type)
+  (Exception .Type)
   (exception.report
    (list ["Lux type" (%.type type)])))
 
@@ -2108,7 +2110,8 @@
   (syntax (_ [type (..type^ (list))])
     (in (list (..value_type {#ManualPrM} type)))))
 
-(exception .public (cannot_cast_to_non_object [type (Type Value)])
+(exception.def .public (cannot_cast_to_non_object type)
+  (Exception (Type Value))
   (exception.report
    (list ["Signature" (..signature type)]
          ["Reflection" (..reflection type)])))
diff --git a/stdlib/source/library/lux/math.lux b/stdlib/source/library/lux/math.lux
index 0d470214a..eecff5842 100644
--- a/stdlib/source/library/lux/math.lux
+++ b/stdlib/source/library/lux/math.lux
@@ -6,7 +6,7 @@
    [control
     ["<>" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format]]
@@ -41,7 +41,8 @@
    ["[0]" ratio (.only Ratio)]
    ["[0]" complex (.only Complex)]]])
 
-(exception (no_arithmetic_for [type Type])
+(exception.def (no_arithmetic_for type)
+  (Exception Type)
   (exception.report
    (list ["Type" (%.type type)])))
 
diff --git a/stdlib/source/library/lux/math/modular.lux b/stdlib/source/library/lux/math/modular.lux
index 3899e9a55..e9810f66c 100644
--- a/stdlib/source/library/lux/math/modular.lux
+++ b/stdlib/source/library/lux/math/modular.lux
@@ -10,7 +10,7 @@
    [control
     ["<>" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text (.use "[1]#[0]" monoid)
@@ -45,8 +45,8 @@
     [value Int product.right]
     )
   
-  (exception .public [%] (incorrect_modulus [modulus (Modulus %)
-                                             parsed Int])
+  (exception.def .public (incorrect_modulus [modulus parsed])
+    (All (_ %) (Exception [(Modulus %) Int]))
     (exception.report
      (list ["Expected" (i#encoded (//.divisor modulus))]
            ["Actual" (i#encoded parsed)])))
@@ -139,8 +139,8 @@
         _ {.#None})))
   )
 
-(exception .public [r% s%] (moduli_are_not_equal [reference (Modulus r%)
-                                                  subject (Modulus s%)])
+(exception.def .public (moduli_are_not_equal [reference subject])
+  (All (_ r% s%) (Exception [(Modulus r%) (Modulus s%)]))
   (exception.report
    (list ["Reference" (i#encoded (//.divisor reference))]
          ["Subject" (i#encoded (//.divisor subject))])))
diff --git a/stdlib/source/library/lux/math/modulus.lux b/stdlib/source/library/lux/math/modulus.lux
index effc03dd9..69b29f4dd 100644
--- a/stdlib/source/library/lux/math/modulus.lux
+++ b/stdlib/source/library/lux/math/modulus.lux
@@ -5,7 +5,7 @@
     [monad (.only do)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [math
     [number
      ["i" int]]]
@@ -17,7 +17,7 @@
     [type
      [primitive (.except)]]]]])
 
-(exception .public zero_cannot_be_a_modulus)
+(exception.def .public zero_cannot_be_a_modulus)
 
 (primitive .public (Modulus %)
   Int
diff --git a/stdlib/source/library/lux/meta/compiler.lux b/stdlib/source/library/lux/meta/compiler.lux
index 8f9150839..64f5a38fd 100644
--- a/stdlib/source/library/lux/meta/compiler.lux
+++ b/stdlib/source/library/lux/meta/compiler.lux
@@ -4,7 +4,7 @@
    [control
     ["<>" parser (.only)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text]
     ["[0]" binary (.only Binary)
@@ -54,6 +54,7 @@
 (type .public (Instancer s d o)
   (-> (Key d) (List Parameter) (Compiler s d o)))
 
-(exception .public (cannot_compile [module Module])
+(exception.def .public (cannot_compile module)
+  (Exception Module)
   (exception.report
    (list ["Module" module])))
diff --git a/stdlib/source/library/lux/meta/compiler/default/platform.lux b/stdlib/source/library/lux/meta/compiler/default/platform.lux
index 12b6c63f1..d3a60d7b4 100644
--- a/stdlib/source/library/lux/meta/compiler/default/platform.lux
+++ b/stdlib/source/library/lux/meta/compiler/default/platform.lux
@@ -8,7 +8,7 @@
     ["[0]" function]
     ["[0]" maybe]
     ["[0]" try (.only Try) (.use "[1]#[0]" monad)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     [concurrency
      ["[0]" async (.only Async Resolver) (.use "[1]#[0]" monad)]
      ["[0]" stm (.only Var STM)]]]
@@ -387,18 +387,19 @@
         (or (dependence? import (the #depends_on) module)
             (dependence? module (the #depended_by) import))))
 
-    (exception .public (module_cannot_import_itself [module descriptor.Module])
+    (exception.def .public (module_cannot_import_itself module)
+      (Exception descriptor.Module)
       (exception.report
        (list ["Module" (%.text module)])))
 
-    (exception .public (cannot_import_circular_dependency [importer descriptor.Module
-                                                           importee descriptor.Module])
+    (exception.def .public (cannot_import_circular_dependency [importer importee])
+      (Exception [descriptor.Module descriptor.Module])
       (exception.report
        (list ["Importer" (%.text importer)]
              ["Importee" (%.text importee)])))
 
-    (exception .public (cannot_import_twice [importer descriptor.Module
-                                             duplicates (Set descriptor.Module)])
+    (exception.def .public (cannot_import_twice [importer duplicates])
+      (Exception [descriptor.Module (Set descriptor.Module)])
       (exception.report
        (list ["Importer" (%.text importer)]
              ["Duplicates" (%.list %.text (set.list duplicates))])))
@@ -414,7 +415,8 @@
             ... else
             {try.#Success []}))
 
-    (exception .public (cannot_overwrite_extension [extension extension.Name])
+    (exception.def .public (cannot_overwrite_extension extension)
+      (Exception extension.Name)
       (exception.report
        (list ["Extension" (%.text extension)])))
 
@@ -841,8 +843,8 @@
         Type
         (type_literal (-> (List Text) (Try ///.Custom))))
 
-      (exception .public (invalid_custom_compiler [definition Symbol
-                                                   type Type])
+      (exception.def .public (invalid_custom_compiler [definition type])
+        (Exception [Symbol Type])
         (exception.report
          (list ["Definition" (%.symbol definition)]
                ["Expected type" (%.type ..Custom)]
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/coverage.lux b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/coverage.lux
index 3403461fb..8799f8b57 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/coverage.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/coverage.lux
@@ -7,7 +7,7 @@
    [control
     ["[0]" maybe (.use "[1]#[0]" monoid monad)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" bit (.use "[1]#[0]" equivalence)]
     ["[0]" text (.only)
@@ -158,7 +158,8 @@
     {#Exhaustive}
     "*"))
 
-(exception .public (invalid_tuple [size Nat])
+(exception.def .public (invalid_tuple size)
+  (Exception Nat)
   (exception.report
    (list ["Expected size" ">= 2"]
          ["Actual size" (%.nat size)])))
@@ -235,14 +236,14 @@
 ... always be a pattern prior to them that would match the input.
 ... Because of that, the presence of redundant patterns is assumed to
 ... be a bug, likely due to programmer carelessness.
-(exception .public (redundancy [so_far Coverage
-                                addition Coverage])
+(exception.def .public (redundancy [so_far addition])
+  (Exception [Coverage Coverage])
   (exception.report
    (list ["Coverage so-far" (format so_far)]
          ["Additional coverage" (format addition)])))
 
-(exception .public (variant_mismatch [expected Nat
-                                      mismatched Nat])
+(exception.def .public (variant_mismatch [expected mismatched])
+  (Exception [Nat Nat])
   (exception.report
    (list ["Expected cases" (%.nat expected)]
          ["Mismatched cases" (%.nat mismatched)])))
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/inference.lux b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/inference.lux
index d85a576cd..5765aa7a9 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/inference.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/inference.lux
@@ -7,7 +7,7 @@
     ["[0]" pipe]
     ["[0]" maybe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.only)
      ["%" \\format (.only format)]]
@@ -32,20 +32,21 @@
     [meta
      [archive (.only Archive)]]]]])
 
-(exception .public (cannot_infer [type Type
-                                  arguments (List Code)])
+(exception.def .public (cannot_infer [type arguments])
+  (Exception [Type (List Code)])
   (exception.report
    (list ["Type" (%.type type)]
          ["Arguments" (exception.listing %.code arguments)])))
 
-(exception .public (cannot_infer_argument [type Type
-                                           argument Code])
+(exception.def .public (cannot_infer_argument [type argument])
+  (Exception [Type Code])
   (exception.report
    (list ["Type" (%.type type)]
          ["Argument" (%.code argument)])))
 
 (with_template [<name>]
-  [(exception .public (<name> [type Type])
+  [(exception.def .public (<name> type)
+     (Exception Type)
      (exception.report
       (list ["Type" (%.type type)])))]
 
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/macro.lux b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/macro.lux
index b8bf793ec..7abe0bc57 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/macro.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/macro.lux
@@ -6,24 +6,22 @@
     [monad (.only do)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text
      ["%" \\format (.only format)]]]]]
  [/////
   ["[0]" phase]])
 
-(exception .public (expansion_failed [macro Symbol
-                                      inputs (List Code)
-                                      error Text])
+(exception.def .public (expansion_failed [macro inputs error])
+  (Exception [Symbol (List Code) Text])
   (exception.report
    (list ["Macro" (%.symbol macro)]
          ["Inputs" (exception.listing %.code inputs)]
          ["Error" error])))
 
-(exception .public (must_have_single_expansion [macro Symbol
-                                                inputs (List Code)
-                                                outputs (List Code)])
+(exception.def .public (must_have_single_expansion [macro inputs outputs])
+  (Exception [Symbol (List Code) (List Code)])
   (exception.report
    (list ["Macro" (%.symbol macro)]
          ["Inputs" (exception.listing %.code inputs)]
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/module.lux b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/module.lux
index b7a808dbf..e6f531191 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/module.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/module.lux
@@ -7,7 +7,7 @@
    [control
     ["[0]" pipe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.use "[1]#[0]" equivalence)
      ["%" \\format (.only format)]]
@@ -24,13 +24,14 @@
 (type .public Label
   Text)
 
-(exception .public (unknown_module [module Text])
+(exception.def .public (unknown_module module)
+  (Exception Text)
   (exception.report
    (list ["Module" module])))
 
 (with_template [<name>]
-  [(exception .public (<name> [labels (List Label)
-                               owner Type])
+  [(exception.def .public (<name> [labels owner])
+     (Exception [(List Label) Type])
      (exception.report
       (list ["Labels" (text.interposed " " labels)]
             ["Type" (%.type owner)])))]
@@ -39,8 +40,8 @@
   [cannot_declare_labels_for_foreign_type]
   )
 
-(exception .public (cannot_define_more_than_once [name Symbol
-                                                  already_existing Global])
+(exception.def .public (cannot_define_more_than_once [name already_existing])
+  (Exception [Symbol Global])
   (exception.report
    (list ["Definition" (%.symbol name)]
          ["Original" (when already_existing
@@ -59,8 +60,8 @@
                        {.#Slot _}
                        (format "slot " (%.symbol name)))])))
 
-(exception .public (can_only_change_state_of_active_module [module Text
-                                                            state Module_State])
+(exception.def .public (can_only_change_state_of_active_module [module state])
+  (Exception [Text Module_State])
   (exception.report
    (list ["Module" module]
          ["Desired state" (when state
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/scope.lux b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/scope.lux
index c7d17b9cb..ba360a38b 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/analysis/scope.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/analysis/scope.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" maybe (.use "[1]#[0]" monad)]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" text (.use "[1]#[0]" equivalence)]
     ["[0]" product]
@@ -105,8 +105,8 @@
                      {.#Some [ref_type ref]}]})
          )))))
 
-(exception .public no_scope)
-(exception .public drained)
+(exception.def .public no_scope)
+(exception.def .public drained)
 
 (def .public (with_local [name type] action)
   (All (_ a) (-> [Text Type] (Operation a) (Operation a)))
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/generation.lux b/stdlib/source/library/lux/meta/compiler/language/lux/generation.lux
index 1b9dbb961..93e1420f8 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/generation.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/generation.lux
@@ -5,7 +5,7 @@
     [monad (.only do)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     ["[0]" function]]
    [data
     [binary (.only Binary)]
@@ -42,12 +42,14 @@
 (type .public (Buffer declaration)
   (Sequence [artifact.ID (Maybe Text) declaration]))
 
-(exception .public (cannot_interpret [error Text])
+(exception.def .public (cannot_interpret error)
+  (Exception Text)
   (exception.report
    (list ["Error" error])))
 
 (with_template [<name>]
-  [(exception .public (<name> [it artifact.ID])
+  [(exception.def .public (<name> it)
+     (Exception artifact.ID)
      (exception.report
       (list ["Artifact ID" (%.nat it)])))]
 
@@ -119,7 +121,7 @@
 (with_template [<tag>
                 <with_declaration> <with_type> <with_value>
                 <set> <get> <get_type> <exception>]
-  [(exception .public <exception>)
+  [(exception.def .public <exception>)
 
    (def .public <with_declaration>
      (All (_ anchor expression declaration output) <with_type>)
@@ -267,8 +269,8 @@
   [Text #0 [] [] learn_declaration registry.declaration]
   )
 
-(exception .public (unknown_definition [name Symbol
-                                        known_definitions (List category.Definition)])
+(exception.def .public (unknown_definition [name known_definitions])
+  (Exception [Symbol (List category.Definition)])
   (exception.report
    (list ["Definition" (symbol.short name)]
          ["Module" (symbol.module name)]
@@ -312,7 +314,7 @@
           {.#Some [@artifact def]}
           {try.#Success [stateE [[@module @artifact] def]]})))))
 
-(exception .public no_context)
+(exception.def .public no_context)
 
 (def .public (module_id module archive)
   (All (_ anchor expression declaration)
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis.lux
index 9ea79eab0..2775a6787 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis.lux
@@ -4,7 +4,7 @@
    [abstract
     [monad (.only do)]]
    [control
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format (.only format)]]
@@ -36,7 +36,8 @@
      [meta
       [archive (.only Archive)]]]]]])
 
-(exception .public (invalid [syntax Code])
+(exception.def .public (invalid syntax)
+  (Exception Code)
   (exception.report
    (list ["Syntax" (%.code syntax)])))
 
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/complex.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/complex.lux
index 42d01ad16..21c5fba14 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/complex.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/complex.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     ["[0]" state]]
    [data
     ["[0]" product]
@@ -37,13 +37,14 @@
      [meta
       [archive (.only Archive)]]]]]])
 
-(exception .public (not_a_quantified_type [type Type])
+(exception.def .public (not_a_quantified_type type)
+  (Exception Type)
   (exception.report
    (list ["Type" (%.type type)])))
 
 (with_template [<name>]
-  [(exception .public (<name> [type Type
-                               members (List Code)])
+  [(exception.def .public (<name> [type members])
+     (Exception [Type (List Code)])
      (exception.report
       (list ["Type" (%.type type)]
             ["Expression" (%.code (` [(,* members)]))])))]
@@ -53,10 +54,8 @@
   )
 
 (with_template [<name>]
-  [(exception .public (<name> [type Type
-                               lefts Nat
-                               right? Bit
-                               code Code])
+  [(exception.def .public (<name> [type lefts right? code])
+     (Exception [Type Nat Bit Code])
      (exception.report
       (list ["Type" (%.type type)]
             ["Lefts" (%.nat lefts)]
@@ -68,16 +67,15 @@
   [cannot_infer_sum]
   )
 
-(exception .public (cannot_analyse_variant [type Type
-                                            tag Symbol
-                                            code Code])
+(exception.def .public (cannot_analyse_variant [type tag code])
+  (Exception [Type Symbol Code])
   (exception.report
    (list ["Type" (%.type type)]
          ["Tag" (%.symbol tag)]
          ["Expression" (%.code code)])))
 
-(exception .public (cannot_repeat_slot [key Symbol
-                                        record (List [Symbol Code])])
+(exception.def .public (cannot_repeat_slot [key record])
+  (Exception [Symbol (List [Symbol Code])])
   (exception.report
    (list ["Slot" (%.code (code.symbol key))]
          ["Record" (%.code (code.tuple (|> record
@@ -85,16 +83,14 @@
                                                         (list (code.symbol keyI) valC)))
                                            list#conjoint)))])))
 
-(exception .public (slot_does_not_belong_to_record [key Symbol
-                                                    type Type])
+(exception.def .public (slot_does_not_belong_to_record [key type])
+  (Exception [Symbol Type])
   (exception.report
    (list ["Slot" (%.code (code.symbol key))]
          ["Type" (%.type type)])))
 
-(exception .public (record_size_mismatch [expected Nat
-                                          actual Nat
-                                          type Type
-                                          record (List [Symbol Code])])
+(exception.def .public (record_size_mismatch [expected actual type record])
+  (Exception [Nat Nat Type (List [Symbol Code])])
   (exception.report
    (list ["Expected" (%.nat expected)]
          ["Actual" (%.nat actual)]
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/function.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/function.lux
index 7864fd3d5..30f87ec84 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/function.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/function.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text (.only)
@@ -31,19 +31,16 @@
     [reference (.only)
      [variable (.only)]]]]])
 
-(exception .public (cannot_analyse [expected Type
-                                    function Text
-                                    argument Text
-                                    body Code])
+(exception.def .public (cannot_analyse [expected function argument body])
+  (Exception [Type Text Text Code])
   (exception.report
    (list ["Type" (%.type expected)]
          ["Function" function]
          ["Argument" argument]
          ["Body" (%.code body)])))
 
-(exception .public (cannot_apply [:function: Type
-                                  functionC Code
-                                  arguments (List Code)])
+(exception.def .public (cannot_apply [:function: functionC arguments])
+  (Exception [Type Code (List Code)])
   (exception.report
    (list ["Function type" (%.type :function:)]
          ["Function" (%.code functionC)]
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/reference.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/reference.lux
index d71fa4ad0..51816df59 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/reference.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/reference.lux
@@ -4,7 +4,7 @@
    [abstract
     [monad (.only do)]]
    [control
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.use "[1]#[0]" equivalence)
      ["%" \\format (.only format)]]]
@@ -22,21 +22,21 @@
      ["[1][0]" reference]
      ["[1]" phase]]]]])
 
-(exception .public (foreign_module_has_not_been_imported [current Text
-                                                          foreign Text
-                                                          quoted Text
-                                                          definition Symbol])
+(exception.def .public (foreign_module_has_not_been_imported [current foreign quoted definition])
+  (Exception [Text Text Text Symbol])
   (exception.report
    (list ["Current" current]
          ["Foreign" foreign]
          ["Quoted" quoted]
          ["Definition" (%.symbol definition)])))
 
-(exception .public (definition_has_not_been_exported [definition Symbol])
+(exception.def .public (definition_has_not_been_exported definition)
+  (Exception Symbol)
   (exception.report
    (list ["Definition" (%.symbol definition)])))
 
-(exception .public (labels_are_not_definitions [definition Symbol])
+(exception.def .public (labels_are_not_definitions definition)
+  (Exception Symbol)
   (exception.report
    (list ["Label" (%.symbol definition)])))
 
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/when.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/when.lux
index ceb60e374..84fd24cc2 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/when.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/analysis/when.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     [text
@@ -38,29 +38,30 @@
      [///
       ["[1]" phase]]]]]])
 
-(exception .public (mismatch [type Type
-                              pattern Code])
+(exception.def .public (mismatch [type pattern])
+  (Exception [Type Code])
   (exception.report
    (list ["Type" (%.type type)]
          ["Pattern" (%.code pattern)])))
 
-(exception .public (sum_has_no_case [case Nat
-                                     type Type])
+(exception.def .public (sum_has_no_case [case type])
+  (Exception [Nat Type])
   (exception.report
    (list ["Case" (%.nat case)]
          ["Type" (%.type type)])))
 
-(exception .public (invalid [it Code])
+(exception.def .public (invalid it)
+  (Exception Code)
   (exception.report
    (list ["Pattern" (%.code it)])))
 
-(exception .public (non_tuple [type Type])
+(exception.def .public (non_tuple type)
+  (Exception Type)
   (exception.report
    (list ["Type" (%.type type)])))
 
-(exception .public (non_exhaustive [input Code
-                                    branches (List [Code Code])
-                                    coverage Coverage])
+(exception.def .public (non_exhaustive [input branches coverage])
+  (Exception [Code (List [Code Code]) Coverage])
   (exception.report
    (list ["Input" (%.code input)]
          ["Branches" (%.code (code.tuple (|> branches
@@ -69,7 +70,7 @@
                                              list#conjoint)))]
          ["Coverage" (/coverage.format coverage)])))
 
-(exception .public empty_branches)
+(exception.def .public empty_branches)
 
 (def (quantified envs baseT)
   (-> (List (List Type)) Type Type)
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/declaration.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/declaration.lux
index cd102ce48..832944c9c 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/declaration.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/declaration.lux
@@ -6,7 +6,7 @@
     ["[0]" monad (.only do)]]
    [control
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format (.only format)]]
@@ -28,15 +28,18 @@
     [meta
      [archive (.only Archive)]]]]])
 
-(exception .public (not_a_declaration [code Code])
+(exception.def .public (not_a_declaration code)
+  (Exception Code)
   (exception.report
    (list ["Declaration" (%.code code)])))
 
-(exception .public (invalid_macro_call [code Code])
+(exception.def .public (invalid_macro_call code)
+  (Exception Code)
   (exception.report
    (list ["Code" (%.code code)])))
 
-(exception .public (macro_was_not_found [name Symbol])
+(exception.def .public (macro_was_not_found name)
+  (Exception Symbol)
   (exception.report
    (list ["Name" (%.symbol name)])))
 
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension.lux
index 0ad49b88e..aa15450d3 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension.lux
@@ -8,7 +8,7 @@
    [control
     ["[0]" function]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text (.use "[1]#[0]" order)
@@ -64,27 +64,26 @@
 (type .public (Phase s i o)
   (//.Phase (State s i o) i o))
 
-(exception .public (cannot_overwrite [name Name])
+(exception.def .public (cannot_overwrite name)
+  (Exception Name)
   (exception.report
    (list ["Extension" (%.text name)])))
 
-(exception .public (incorrect_arity [name Name
-                                     arity Nat
-                                     args Nat])
+(exception.def .public (incorrect_arity [name arity args])
+  (Exception [Name Nat Nat])
   (exception.report
    (list ["Extension" (%.text name)]
          ["Expected" (%.nat arity)]
          ["Actual" (%.nat args)])))
 
-(exception .public [a] (invalid_syntax [name Name
-                                        %format (Format a)
-                                        inputs (List a)])
+(exception.def .public (invalid_syntax [name %format inputs])
+  (All (_ a) (Exception [Name (Format a) (List a)]))
   (exception.report
    (list ["Extension" (%.text name)]
          ["Inputs" (exception.listing %format inputs)])))
 
-(exception .public [s i o] (unknown [name Name
-                                     bundle (Bundle s i o)])
+(exception.def .public (unknown [name bundle])
+  (All (_ s i o) (Exception [Name (Bundle s i o)]))
   (exception.report
    (list ["Extension" (%.text name)]
          ["Available" (|> bundle
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/analysis/jvm.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/analysis/jvm.lux
index 9b8eabe1b..eecfece1f 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/analysis/jvm.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/analysis/jvm.lux
@@ -9,7 +9,7 @@
     ["[0]" pipe]
     ["[0]" maybe (.use "[1]#[0]" functor)]
     ["[0]" try (.only Try) (.use "[1]#[0]" monad)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     [function
      ["[0]" predicate]]]
    [data
@@ -157,8 +157,8 @@
   (getInterfaces [] [(java/lang/Class java/lang/Object)]))
 
 (with_template [<name>]
-  [(exception .public (<name> [class External
-                               field Text])
+  [(exception.def .public (<name> [class field])
+     (exception.Exception [External Text])
      (exception.report
       (list ["Class" (%.text class)]
             ["Field" (%.text field)])))]
@@ -167,15 +167,15 @@
   [deprecated_field]
   )
 
-(exception .public (deprecated_method [class External
-                                       method Text
-                                       type .Type])
+(exception.def .public (deprecated_method [class method type])
+  (exception.Exception [External Text .Type])
   (exception.report
    (list ["Class" (%.text class)]
          ["Method" (%.text method)]
          ["Type" (%.type type)])))
 
-(exception .public (deprecated_class [class External])
+(exception.def .public (deprecated_class class)
+  (exception.Exception External)
   (exception.report
    (list ["Class" (%.text class)])))
 
@@ -244,7 +244,8 @@
     #throws (List .Type)]))
 
 (with_template [<name>]
-  [(exception .public (<name> [type .Type])
+  [(exception.def .public (<name> type)
+     (exception.Exception .Type)
      (exception.report
       (list ["Type" (%.type type)])))]
 
@@ -255,7 +256,8 @@
   )
 
 (with_template [<name>]
-  [(exception .public (<name> [class External])
+  [(exception.def .public (<name> class)
+     (exception.Exception External)
      (exception.report
       (list ["Class/type" (%.text class)])))]
 
@@ -265,12 +267,8 @@
   )
 
 (with_template [<name>]
-  [(exception .public (<name> [class_variables (List (Type Var))
-                               class External
-                               method Text
-                               method_variables (List (Type Var))
-                               inputsJT (List (Type Value))
-                               hints (List Method_Signature)])
+  [(exception.def .public (<name> [class_variables class method method_variables inputsJT hints])
+     (exception.Exception [(List (Type Var)) External Text (List (Type Var)) (List (Type Value)) (List Method_Signature)])
      (exception.report
       (list ["Class Variables" (exception.listing ..signature class_variables)]
             ["Class" class]
@@ -283,22 +281,20 @@
   [too_many_candidates]
   )
 
-(exception .public (cannot_cast [from (Type Value)
-                                 to (Type Value)
-                                 value Code])
+(exception.def .public (cannot_cast [from to value])
+  (exception.Exception [(Type Value) (Type Value) Code])
   (exception.report
    (list ["From" (..signature from)]
          ["To" (..signature to)]
          ["Value" (%.code value)])))
 
 (with_template [<name>]
-  [(exception .public (<name> [message Text])
+  [(exception.def .public (<name> message)
+     (exception.Exception Text)
      message)]
 
   [primitives_cannot_have_type_parameters]
-
   [cannot_possibly_be_an_instance]
-
   [unknown_type_var]
   )
 
@@ -1747,8 +1743,9 @@
   )
 
 (with_template [<name>]
-  [(exception .public (<name> [expected (List [(Type Class) Text (Type Method)])
-                               actual (List [(Type Class) Text (Type Method)])])
+  [(exception.def .public (<name> [expected actual])
+     (exception.Exception [(List [(Type Class) Text (Type Method)])
+                 (List [(Type Class) Text (Type Method)])])
      (let [%method (is (%.Format [(Type Class) Text (Type Method)])
                        (function (_ [super name type])
                          (format (..signature super) " :: " (%.text name) " " (..signature type))))]
@@ -2257,15 +2254,14 @@
            <code>.any
            )))
 
-(exception .public (unknown_super [name Text
-                                   supers (List (Type Class))])
+(exception.def .public (unknown_super [name supers])
+  (exception.Exception [Text (List (Type Class))])
   (exception.report
    (list ["Name" (%.text name)]
          ["Available" (exception.listing (|>> parser.read_class product.left) supers)])))
 
-(exception .public (mismatched_super_parameters [name Text
-                                                 expected Nat
-                                                 actual Nat])
+(exception.def .public (mismatched_super_parameters [name expected actual])
+  (exception.Exception [Text Nat Nat])
   (exception.report
    (list ["Name" (%.text name)]
          ["Expected" (%.nat expected)]
@@ -2372,10 +2368,8 @@
                (not (list.any? (matched? sub) super_set)))
              sub_set))
 
-(exception .public (class_parameter_mismatch [name Text
-                                              declaration (Type Class)
-                                              expected (List Text)
-                                              actual (List (Type Parameter))])
+(exception.def .public (class_parameter_mismatch [name declaration expected actual])
+  (exception.Exception [Text (Type Class) (List Text) (List (Type Parameter))])
   (exception.report
    (list ["Class" (%.text name)]
          ["Declaration" (signature.signature (jvm.signature declaration))]
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/analysis/lux.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/analysis/lux.lux
index 98912da07..981d1a7a1 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/analysis/lux.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/analysis/lux.lux
@@ -7,7 +7,7 @@
     ["<>" parser]
     ["[0]" maybe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.only)
      ["%" \\format (.only format)]]
@@ -83,7 +83,8 @@
 
 ... TODO: Get rid of this ASAP
 (these
- (exception .public (char_text_must_be_size_1 [text Text])
+ (exception.def .public (char_text_must_be_size_1 text)
+   (Exception Text)
    (exception.report
     (list ["Text" (%.text text)])))
  
@@ -203,7 +204,8 @@
         (<| (typeA.expecting input)
             (phase archive valueC))))]))
 
-(exception .public (not_a_type [symbol Symbol])
+(exception.def .public (not_a_type symbol)
+  (Exception Symbol)
   (exception.report
    (list ["Symbol" (%.symbol symbol)])))
 
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/declaration/lux.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/declaration/lux.lux
index c917dd6a0..050c6263d 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/declaration/lux.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/declaration/lux.lux
@@ -8,7 +8,7 @@
     ["<>" parser]
     ["[0]" maybe (.use "[1]#[0]" functor)]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" binary]
     ["[0]" product]
@@ -332,16 +332,15 @@
         (in [/////declaration.#imports imports
              /////declaration.#referrals (list)])))]))
 
-(exception .public (cannot_alias_an_alias [local Alias
-                                           foreign Alias
-                                           target Symbol])
+(exception.def .public (cannot_alias_an_alias [local foreign target])
+  (Exception [Alias Alias Symbol])
   (exception.report
    (list ["Local alias" (%.symbol local)]
          ["Foreign alias" (%.symbol foreign)]
          ["Target definition" (%.symbol target)])))
 
-(exception .public (cannot_alias_a_label [local Alias
-                                          foreign Alias])
+(exception.def .public (cannot_alias_a_label [local foreign])
+  (Exception [Alias Alias])
   (exception.report
    (list ["Alias" (%.symbol local)]
          ["Label" (%.symbol foreign)])))
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/generation/jvm/host.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/generation/jvm/host.lux
index 0d7953920..88906a74f 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/generation/jvm/host.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/extension/generation/jvm/host.lux
@@ -6,7 +6,7 @@
    [control
     ["<>" parser]
     ["[0]" maybe (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     [binary
@@ -364,7 +364,8 @@
     (-> (Type category) Text))
   (|>> type.signature signature.signature))
 
-(exception .public (not_an_object_array [arrayJT (Type Array)])
+(exception.def .public (not_an_object_array arrayJT)
+  (Exception (Type Array))
   (exception.report
    (list ["JVM type" (..signature arrayJT)])))
 
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/js.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/js.lux
index 009b99257..911215b10 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/js.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/js.lux
@@ -4,7 +4,7 @@
    [abstract
     [monad (.only do)]]
    [control
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [meta
     [macro
      ["^" pattern]]
@@ -33,7 +33,7 @@
       [reference (.only)
        [variable (.only)]]]]]]])
 
-(exception .public cannot_recur_as_an_expression)
+(exception.def .public cannot_recur_as_an_expression)
 
 (def (expression archive synthesis)
   Phase
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/jvm/host.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/jvm/host.lux
index 973ab7cad..a7f0a8444 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/jvm/host.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/jvm/host.lux
@@ -7,7 +7,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     ["[0]" io (.only IO io)]
     [concurrency
      ["[0]" atom (.only Atom atom)]]]
@@ -66,21 +66,21 @@
 (def init::type (type.method [(list) (list) type.void (list)]))
 (def init::modifier (all modifier#composite method.public method.static method.strict))
 
-(exception .public (cannot_load [class Text
-                                 error Text])
+(exception.def .public (cannot_load [class error])
+  (Exception [Text Text])
   (exception.report
    (list ["Class" class]
          ["Error" error])))
 
-(exception .public (invalid_field [class Text
-                                   field Text
-                                   error Text])
+(exception.def .public (invalid_field [class field error])
+  (Exception [Text Text Text])
   (exception.report
    (list ["Class" class]
          ["Field" field]
          ["Error" error])))
 
-(exception .public (invalid_value [class Text])
+(exception.def .public (invalid_value class)
+  (Exception Text)
   (exception.report
    (list ["Class" class])))
 
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/lua.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/lua.lux
index 08fbc07cf..ef70e5688 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/lua.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/lua.lux
@@ -4,7 +4,7 @@
    [abstract
     [monad (.only do)]]
    [control
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [meta
     [macro
      ["^" pattern]]
@@ -33,7 +33,7 @@
       [reference (.only)
        [variable (.only)]]]]]]])
 
-(exception .public cannot_recur_as_an_expression)
+(exception.def .public cannot_recur_as_an_expression)
 
 (def (expression archive synthesis)
   Phase
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/php.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/php.lux
index 12e2dffd3..b78a425d9 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/php.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/php.lux
@@ -4,7 +4,7 @@
    [abstract
     [monad (.only do)]]
    [control
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [meta
     [macro
      ["^" pattern]]
@@ -66,7 +66,7 @@
     (//////phase#each _.return (/function.function statement expression archive abstraction))
     ))
 
-(exception .public cannot_recur_as_an_expression)
+(exception.def .public cannot_recur_as_an_expression)
 
 (def .public (expression archive synthesis)
   Phase
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/python.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/python.lux
index b2692261f..4f2ead520 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/python.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/python.lux
@@ -4,7 +4,7 @@
    [abstract
     [monad (.only do)]]
    [control
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [meta
     [macro
      ["^" pattern]]
@@ -33,7 +33,7 @@
       [reference (.only)
        [variable (.only)]]]]]]])
 
-(exception .public cannot_recur_as_an_expression)
+(exception.def .public cannot_recur_as_an_expression)
 
 (def .public (expression archive synthesis)
   Phase
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/r/procedure/common.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/r/procedure/common.lux
index f57141564..f1ce04dee 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/r/procedure/common.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/r/procedure/common.lux
@@ -2,7 +2,7 @@
  lux
  (lux (control [library
                 [monad (.only do)]]
-               ["ex" exception (.only exception)]
+               ["ex" exception]
                ["p" parser])
       (data ["e" error]
             [text]
@@ -62,7 +62,8 @@
   Unary
   (runtimeT.lux//try riskyO))
 
-(exception .public (Wrong_Syntax [message Text])
+(exception.def .public (Wrong_Syntax message)
+  (Exception Text)
   message)
 
 (def .public (wrong_syntax procedure args)
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/ruby.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/ruby.lux
index 9c2719467..8d89f45cd 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/ruby.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/generation/ruby.lux
@@ -4,7 +4,7 @@
    [abstract
     [monad (.only do)]]
    [control
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [meta
     [macro
      ["^" pattern]]
@@ -33,7 +33,7 @@
       [reference (.only)
        [variable (.only)]]]]]]])
 
-(exception .public cannot_recur_as_an_expression)
+(exception.def .public cannot_recur_as_an_expression)
 
 (def (expression archive synthesis)
   Phase
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/synthesis/function.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/synthesis/function.lux
index c1a6184d1..95fc2cc39 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/synthesis/function.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/synthesis/function.lux
@@ -7,7 +7,7 @@
    [control
     ["[0]" pipe]
     ["[0]" maybe (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format (.only format)]]
@@ -31,8 +31,8 @@
     ["[1][0]" reference (.only)
      ["[1]/[0]" variable (.only Register Variable)]]]]])
 
-(exception .public (cannot_find_foreign_variable_in_environment [foreign Register
-                                                                 environment (Environment Synthesis)])
+(exception.def .public (cannot_find_foreign_variable_in_environment [foreign environment])
+  (Exception [Register (Environment Synthesis)])
   (exception.report
    (list ["Foreign" (%.nat foreign)]
          ["Environment" (exception.listing /.%synthesis environment)])))
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/phase/synthesis/variable.lux b/stdlib/source/library/lux/meta/compiler/language/lux/phase/synthesis/variable.lux
index 0f0d88bdd..553a7e662 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/phase/synthesis/variable.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/phase/synthesis/variable.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" maybe (.use "[1]#[0]" functor)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text (.only)
@@ -218,7 +218,8 @@
              {.#Item head tail}])))))
 
 (with_template [<name>]
-  [(exception .public (<name> [register Register])
+  [(exception.def .public (<name> register)
+     (Exception Register)
      (exception.report
       (list ["Register" (%.nat register)])))]
 
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/program.lux b/stdlib/source/library/lux/meta/compiler/language/lux/program.lux
index 864a8f817..0024c1fca 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/program.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/program.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     [text
@@ -28,7 +28,8 @@
   Text
   "")
 
-(exception .public (cannot_find_program [modules (List descriptor.Module)])
+(exception.def .public (cannot_find_program modules)
+  (Exception (List descriptor.Module))
   (exception.report
    (list ["Modules" (exception.listing %.text modules)])))
 
diff --git a/stdlib/source/library/lux/meta/compiler/language/lux/syntax.lux b/stdlib/source/library/lux/meta/compiler/language/lux/syntax.lux
index bbf548818..c74188b26 100644
--- a/stdlib/source/library/lux/meta/compiler/language/lux/syntax.lux
+++ b/stdlib/source/library/lux/meta/compiler/language/lux/syntax.lux
@@ -32,7 +32,7 @@
    [control
     ["<>" parser]
     ["[0]" maybe]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.only)
      [\\parser (.only Offset)]
@@ -162,7 +162,8 @@
   [symbol.separator symbol_separator]
   )
 
-(exception .public (end_of_file [module Text])
+(exception.def .public (end_of_file module)
+  (Exception Text)
   (exception.report
    (list ["Module" (%.text module)])))
 
@@ -173,10 +174,8 @@
   (let [end (|> start (!n/+ amount_of_input_shown) (n.min ("lux text size" input)))]
     (!clip start end input)))
 
-(exception .public (unrecognized_input [[file line column] Location
-                                        context Text
-                                        input Text
-                                        offset Offset])
+(exception.def .public (unrecognized_input [[file line column] context input offset])
+  (Exception [Location Text Text Offset])
   (exception.report
    (list ["File" file]
          ["Line" (%.nat line)]
@@ -184,7 +183,8 @@
          ["Context" (%.text context)]
          ["Input" (input_at offset input)])))
 
-(exception .public (text_cannot_contain_new_lines [text Text])
+(exception.def .public (text_cannot_contain_new_lines text)
+  (Exception Text)
   (exception.report
    (list ["Text" (%.text text)])))
 
diff --git a/stdlib/source/library/lux/meta/compiler/meta/archive.lux b/stdlib/source/library/lux/meta/compiler/meta/archive.lux
index bcbdcaff4..f492ed908 100644
--- a/stdlib/source/library/lux/meta/compiler/meta/archive.lux
+++ b/stdlib/source/library/lux/meta/compiler/meta/archive.lux
@@ -8,7 +8,7 @@
     ["<>" parser]
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     ["[0]" function]]
    [data
     ["[0]" product]
@@ -42,22 +42,22 @@
 (type .public Output
   (Sequence [artifact.ID (Maybe Text) Binary]))
 
-(exception .public (unknown_document [module descriptor.Module
-                                      known_modules (List descriptor.Module)])
+(exception.def .public (unknown_document [module known_modules])
+  (Exception [descriptor.Module (List descriptor.Module)])
   (exception.report
    (list ["Module" (%.text module)]
          ["Known Modules" (exception.listing %.text known_modules)])))
 
-(exception .public (cannot_replace_document [module descriptor.Module
-                                             old (Document Any)
-                                             new (Document Any)])
+(exception.def .public (cannot_replace_document [module old new])
+  (Exception [descriptor.Module (Document Any) (Document Any)])
   (exception.report
    (list ["Module" (%.text module)]
          ["Old key" (signature.description (document.signature old))]
          ["New key" (signature.description (document.signature new))])))
 
 (with_template [<name>]
-  [(exception .public (<name> [it descriptor.Module])
+  [(exception.def .public (<name> it)
+     (Exception descriptor.Module)
      (exception.report
       (list ["Module" (%.text it)])))]
 
@@ -246,8 +246,8 @@
           [version /#next]
           (\\format.result ..format))))
 
-  (exception .public (version_mismatch [expected Version
-                                        actual Version])
+  (exception.def .public (version_mismatch [expected actual])
+    (Exception [Version Version])
     (exception.report
      (list ["Expected" (%.nat expected)]
            ["Actual" (%.nat actual)])))
diff --git a/stdlib/source/library/lux/meta/compiler/meta/archive/module/document.lux b/stdlib/source/library/lux/meta/compiler/meta/archive/module/document.lux
index 3baa41932..3c0df9cbc 100644
--- a/stdlib/source/library/lux/meta/compiler/meta/archive/module/document.lux
+++ b/stdlib/source/library/lux/meta/compiler/meta/archive/module/document.lux
@@ -6,7 +6,7 @@
    [control
     ["<>" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [collection
      ["[0]" dictionary (.only Dictionary)]]
@@ -20,8 +20,8 @@
   ["[0]" signature (.only Signature) (.use "[1]#[0]" equivalence)]
   ["[0]" key (.only Key)]])
 
-(exception .public (invalid_signature [expected Signature
-                                       actual Signature])
+(exception.def .public (invalid_signature [expected actual])
+  (Exception [Signature Signature])
   (exception.report
    (list ["Expected" (signature.description expected)]
          ["Actual" (signature.description actual)])))
diff --git a/stdlib/source/library/lux/meta/compiler/meta/archive/registry.lux b/stdlib/source/library/lux/meta/compiler/meta/archive/registry.lux
index 9f1e240d9..e3d675ec0 100644
--- a/stdlib/source/library/lux/meta/compiler/meta/archive/registry.lux
+++ b/stdlib/source/library/lux/meta/compiler/meta/archive/registry.lux
@@ -7,7 +7,7 @@
     ["<>" parser]
     ["[0]" pipe]
     ["[0]" maybe (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" binary
@@ -145,7 +145,8 @@
                              dependencies]))
            artifacts)))
 
-  (exception .public (invalid_category [tag Nat])
+  (exception.def .public (invalid_category tag)
+    (Exception Nat)
     (exception.report
      (list ["Tag" (%.nat tag)])))
 
diff --git a/stdlib/source/library/lux/meta/compiler/meta/cache/module.lux b/stdlib/source/library/lux/meta/compiler/meta/cache/module.lux
index 619e3db90..a78ddc424 100644
--- a/stdlib/source/library/lux/meta/compiler/meta/cache/module.lux
+++ b/stdlib/source/library/lux/meta/compiler/meta/cache/module.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" pipe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [binary (.only Binary)]
     ["[0]" product]
@@ -25,9 +25,8 @@
    [archive
     ["[0]" module]]]])
 
-(exception .public (cannot_enable [archive file.Path
-                                   @module module.ID
-                                   error Text])
+(exception.def .public (cannot_enable [archive @module error])
+  (Exception [file.Path module.ID Text])
   (exception.report
    (list ["Archive" archive]
          ["Module ID" (%.nat @module)]
diff --git a/stdlib/source/library/lux/meta/compiler/meta/import.lux b/stdlib/source/library/lux/meta/compiler/meta/import.lux
index 500de0a6f..334c2aa13 100644
--- a/stdlib/source/library/lux/meta/compiler/meta/import.lux
+++ b/stdlib/source/library/lux/meta/compiler/meta/import.lux
@@ -6,7 +6,7 @@
    [control
     ["<>" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     [concurrency
      ["[0]" async (.only Async)]]]
    [data
@@ -29,10 +29,10 @@
 (def Action
   (type_literal (All (_ a) (Async (Try a)))))
 
-(exception .public useless_tar_entry)
+(exception.def .public useless_tar_entry)
 
-(exception .public (duplicate [library Library
-                               module Module])
+(exception.def .public (duplicate [library module])
+  (Exception [Library Module])
   (exception.report
    (list ["Module" (%.text module)]
          ["Library" (%.text library)])))
diff --git a/stdlib/source/library/lux/meta/compiler/meta/io/context.lux b/stdlib/source/library/lux/meta/compiler/meta/io/context.lux
index e6a80f7a5..ae87b57af 100644
--- a/stdlib/source/library/lux/meta/compiler/meta/io/context.lux
+++ b/stdlib/source/library/lux/meta/compiler/meta/io/context.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     [concurrency
      ["[0]" async (.only Async) (.use "[1]#[0]" monad)]]
     [function
@@ -32,13 +32,14 @@
     [module
      [descriptor (.only Module)]]]]])
 
-(exception .public (cannot_find_module [importer Module
-                                        module Module])
+(exception.def .public (cannot_find_module [importer module])
+  (Exception [Module Module])
   (exception.report
    (list ["Module" (%.text module)]
          ["Importer" (%.text importer)])))
 
-(exception .public (cannot_read_module [module Module])
+(exception.def .public (cannot_read_module module)
+  (Exception Module)
   (exception.report
    (list ["Module" (%.text module)])))
 
diff --git a/stdlib/source/library/lux/meta/configuration.lux b/stdlib/source/library/lux/meta/configuration.lux
index b98d92ee1..d8bf76a9a 100644
--- a/stdlib/source/library/lux/meta/configuration.lux
+++ b/stdlib/source/library/lux/meta/configuration.lux
@@ -8,7 +8,7 @@
    [control
     ["<>" parser]
     ["[0]" maybe (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" text (.use "[1]#[0]" equivalence)
      ["%" \\format]
@@ -66,7 +66,7 @@
                         (<text>.slice (<text>.some! (<text>.none_of! ..end)))))]
     (<>.some (<>.and parser' parser'))))
 
-(exception .public invalid)
+(exception.def .public invalid)
 
 (def configuration
   (<code>.Parser Configuration)
diff --git a/stdlib/source/library/lux/meta/macro/context.lux b/stdlib/source/library/lux/meta/macro/context.lux
index 5a347775d..dc2911506 100644
--- a/stdlib/source/library/lux/meta/macro/context.lux
+++ b/stdlib/source/library/lux/meta/macro/context.lux
@@ -5,7 +5,7 @@
     [monad (.only do)]]
    [control
     ["?" parser]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     ["[0]" maybe]
     [function
      [predicate (.only Predicate)]]]
@@ -24,7 +24,8 @@
 (type .public Stack
   List)
 
-(exception .public (no_definition [it Symbol])
+(exception.def .public (no_definition it)
+  (Exception Symbol)
   (exception.report
    (list ["Definition" (symbol#encoded it)])))
 
@@ -44,7 +45,7 @@
       {.#None}
       (meta.failure (exception.error ..no_definition [it])))))
 
-(exception .public no_active_context)
+(exception.def .public no_active_context)
 
 (.def .public (peek' _ context)
   (All (_ a) (-> (Stack a) Symbol (Meta a)))
@@ -63,7 +64,7 @@
   (syntax (_ [g!it (at ?.monad each code.symbol ?code.global)])
     (in (list (` (..peek' (, g!it) (.symbol (, g!it))))))))
 
-(exception .public no_example)
+(exception.def .public no_example)
 
 (.def .public (search' _ ? context)
   (All (_ a) (-> (Stack a) (Predicate a) Symbol (Meta a)))
diff --git a/stdlib/source/library/lux/meta/macro/local.lux b/stdlib/source/library/lux/meta/macro/local.lux
index c69b32f95..48ca7db43 100644
--- a/stdlib/source/library/lux/meta/macro/local.lux
+++ b/stdlib/source/library/lux/meta/macro/local.lux
@@ -6,7 +6,7 @@
    [control
     ["<>" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text]
@@ -19,13 +19,14 @@
  ["[0]" // (.only)
   [syntax (.only syntax)]])
 
-(exception .public (unknown_module [module Text])
+(exception.def .public (unknown_module module)
+  (Exception Text)
   (exception.report
    (list ["Module" (text.format module)])))
 
 (with_template [<name>]
-  [(exception .public (<name> [module Text
-                               definition Text])
+  [(exception.def .public (<name> [module definition])
+     (Exception [Text Text])
      (exception.report
       (list ["Module" (text.format module)]
             ["Definition" (text.format definition)])))]
diff --git a/stdlib/source/library/lux/meta/macro/syntax/definition.lux b/stdlib/source/library/lux/meta/macro/syntax/definition.lux
index 0f6be7510..0db62599f 100644
--- a/stdlib/source/library/lux/meta/macro/syntax/definition.lux
+++ b/stdlib/source/library/lux/meta/macro/syntax/definition.lux
@@ -6,7 +6,7 @@
     [monad (.only do)]]
    [control
     ["<>" parser]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" sum]
     ["[0]" product]
@@ -81,7 +81,8 @@
              <code>.bit
              ))))
 
-(exception .public (lacks_type [definition Definition])
+(exception.def .public (lacks_type definition)
+  (Exception Definition)
   (exception.report
    (list ["Definition" (%.code (..format definition))])))
 
diff --git a/stdlib/source/library/lux/meta/macro/syntax/export.lux b/stdlib/source/library/lux/meta/macro/syntax/export.lux
index 04e5c730a..98db6124e 100644
--- a/stdlib/source/library/lux/meta/macro/syntax/export.lux
+++ b/stdlib/source/library/lux/meta/macro/syntax/export.lux
@@ -9,30 +9,34 @@
     ["[0]" code
      ["<[1]>" \\parser (.only Parser)]]]]])
 
-(def .public default_policy
-  Code
+(type .public Policy
+  Code)
+
+(def .public default
+  Policy
   (` .private))
 
 (`` (def policy
-      (Parser Code)
+      (Parser Policy)
       (do [! <>.monad]
         [candidate <code>.next]
         (when candidate
           [_ {.#Symbol ["" _]}]
-          (in default_policy)
+          (in default)
 
-          (,, (with_template [<pattern>]
-                [<pattern>
+          (,, (with_template [<tag>]
+                [[_ {<tag> _}]
                  (do !
                    [_ <code>.any]
                    (in candidate))]
 
-                [[_ {.#Bit _}]]
-                [[_ {.#Symbol _}]]))
+                [.#Bit]
+                [.#Symbol]
+                ))
           
           _
-          (in default_policy)))))
+          (in default)))))
 
 (def .public parser
-  (All (_ a) (-> (Parser a) (Parser [Code a])))
+  (All (_ a) (-> (Parser a) (Parser [Policy a])))
   (<>.and ..policy))
diff --git a/stdlib/source/library/lux/meta/macro/template.lux b/stdlib/source/library/lux/meta/macro/template.lux
index a045bd235..829c971cf 100644
--- a/stdlib/source/library/lux/meta/macro/template.lux
+++ b/stdlib/source/library/lux/meta/macro/template.lux
@@ -6,7 +6,7 @@
    [control
     ["<>" parser (.use "[1]#[0]" functor)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" bit (.use "[1]#[0]" codec)]
     ["[0]" text]
@@ -127,8 +127,8 @@
     #parameters (List Text)
     #template (List Code)]))
 
-(exception .public (irregular_arguments [expected Nat
-                                         actual Nat])
+(exception.def .public (irregular_arguments [expected actual])
+  (Exception [Nat Nat])
   (exception.report
    (list ["Expected" (at nat.decimal encoded expected)]
          ["Actual" (at nat.decimal encoded actual)])))
diff --git a/stdlib/source/library/lux/meta/macro/vocabulary.lux b/stdlib/source/library/lux/meta/macro/vocabulary.lux
index 3f54c9db4..ce47d7f96 100644
--- a/stdlib/source/library/lux/meta/macro/vocabulary.lux
+++ b/stdlib/source/library/lux/meta/macro/vocabulary.lux
@@ -7,7 +7,7 @@
     [monad (.only do)]]
    [control
     ["?" parser (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]]]]
+    ["[0]" exception (.only Exception)]]]]
  ["[0]" // (.only)
   [syntax (.only syntax)
    ["[0]" export]]
@@ -17,8 +17,8 @@
    ["[0]" type (.only)
     [primitive (.except)]]]])
 
-(exception .public (invalid_type [expected Type
-                                  actual Type])
+(exception.def .public (invalid_type [expected actual])
+  (Exception [Type Type])
   (exception.report
    (list ["Expected" (type.format expected)]
          ["Actual" (type.format actual)])))
diff --git a/stdlib/source/library/lux/meta/target/jvm/bytecode.lux b/stdlib/source/library/lux/meta/target/jvm/bytecode.lux
index 57ea8caf8..fb54ac19a 100644
--- a/stdlib/source/library/lux/meta/target/jvm/bytecode.lux
+++ b/stdlib/source/library/lux/meta/target/jvm/bytecode.lux
@@ -11,7 +11,7 @@
     ["[0]" state (.only +State)]
     ["[0]" maybe]
     ["[0]" try (.only Try) (.use "[1]#[0]" monad)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" product]
     [text
@@ -129,15 +129,13 @@
                    [..relative#identity
                     (the #next tracker)]]}))
 
-(exception .public (label_has_already_been_set [label Label])
+(exception.def .public (label_has_already_been_set label)
+  (exception.Exception Label)
   (exception.report
    (list ["Label" (%.nat label)])))
 
-(exception .public (mismatched_environments [instruction Symbol
-                                             label Label
-                                             address Address
-                                             expected Stack
-                                             actual Stack])
+(exception.def .public (mismatched_environments [instruction label address expected actual])
+  (exception.Exception [Symbol Label Address Stack Stack])
   (exception.report
    (list ["Instruction" (%.symbol instruction)]
          ["Label" (%.nat label)]
@@ -679,7 +677,8 @@
       
       _ (..arbitrary_double value))))
 
-(exception .public (invalid_register [id Nat])
+(exception.def .public (invalid_register id)
+  (exception.Exception Nat)
   (exception.report
    (list ["ID" (%.nat id)])))
 
@@ -781,13 +780,13 @@
   [$0 $1 sipush _.sipush S2]
   )
 
-(exception .public (unknown_label [label Label])
+(exception.def .public (unknown_label label)
+  (exception.Exception Label)
   (exception.report
    (list ["Label" (%.nat label)])))
 
-(exception .public (cannot_do_a_big_jump [label Label
-                                          @from Address
-                                          jump Big_Jump])
+(exception.def .public (cannot_do_a_big_jump [label @from jump])
+  (exception.Exception [Label Address Big_Jump])
   (exception.report
    (list ["Label" (%.nat label)]
          ["Start" (|> @from /address.value //unsigned.value %.nat)]
@@ -809,7 +808,8 @@
         (try#each (|>> {.#Left}) (//signed.s4 jump))
         (try#each (|>> {.#Right}) (//signed.s2 jump)))))
 
-(exception .public (unset_label [label Label])
+(exception.def .public (unset_label label)
+  (exception.Exception Label)
   (exception.report
    (list ["Label" (%.nat label)])))
 
@@ -938,7 +938,7 @@
     {.#Right small}
     (/jump.lifted small)))
 
-(exception .public invalid_tableswitch)
+(exception.def .public invalid_tableswitch)
 
 (def .public (tableswitch minimum default [at_minimum afterwards])
   (-> S4 Label [Label (List Label)] (Bytecode Any))
@@ -976,7 +976,7 @@
                             (exception.except ..invalid_tableswitch []))))
                       []]]))))))
 
-(exception .public invalid_lookupswitch)
+(exception.def .public invalid_lookupswitch)
 
 (def .public (lookupswitch default cases)
   (-> Label (List [S4 Label]) (Bytecode Any))
@@ -1042,7 +1042,8 @@
     [register (..register register)]
     (..bytecode $0 $0 (/registry.for register) _.iinc [register increase])))
 
-(exception .public (multiarray_cannot_be_zero_dimensional [class (Type Object)])
+(exception.def .public (multiarray_cannot_be_zero_dimensional class)
+  (exception.Exception (Type Object))
   (exception.report
    (list ["Class" (..reflection class)])))
 
@@ -1128,8 +1129,8 @@
   [putfield  $2 _.putfield/1  $3 _.putfield/2]
   )
 
-(exception .public (invalid_range_for_try [start Address
-                                           end Address])
+(exception.def .public (invalid_range_for_try [start end])
+  (exception.Exception [Address Address])
   (exception.report
    (list ["Start" (|> start /address.value //unsigned.value %.nat)]
          ["End" (|> end /address.value //unsigned.value %.nat)])))
diff --git a/stdlib/source/library/lux/meta/target/jvm/bytecode/environment.lux b/stdlib/source/library/lux/meta/target/jvm/bytecode/environment.lux
index dd33b7853..a7e687751 100644
--- a/stdlib/source/library/lux/meta/target/jvm/bytecode/environment.lux
+++ b/stdlib/source/library/lux/meta/target/jvm/bytecode/environment.lux
@@ -6,7 +6,7 @@
     [monoid (.only Monoid)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]]]
+    ["[0]" exception (.only Exception)]]]]
  [/
   ["/[0]" limit (.only Limit)
    ["/[0]" stack (.only Stack)]
@@ -49,7 +49,7 @@
          [environment (left environment)]
          (right environment))))))
 
-(exception .public discontinuity)
+(exception.def .public discontinuity)
 
 (def .public (stack environment)
   (-> Environment (Try Stack))
@@ -64,8 +64,8 @@
   (-> Environment Environment)
   (.has ..#stack {.#None}))
 
-(exception .public (mismatched_stacks [expected Stack
-                                       actual Stack])
+(exception.def .public (mismatched_stacks [expected actual])
+  (Exception [Stack Stack])
   (exception.report
    (list ["Expected" (/stack.text expected)]
          ["Actual" (/stack.text actual)])))
diff --git a/stdlib/source/library/lux/meta/target/jvm/encoding/signed.lux b/stdlib/source/library/lux/meta/target/jvm/encoding/signed.lux
index 430263c8d..11a43668f 100644
--- a/stdlib/source/library/lux/meta/target/jvm/encoding/signed.lux
+++ b/stdlib/source/library/lux/meta/target/jvm/encoding/signed.lux
@@ -6,7 +6,7 @@
     [order (.only Order)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format (.only format)]]
@@ -43,8 +43,8 @@
      (def (< reference sample)
        (i.< (representation reference) (representation sample)))))
 
-  (exception .public (value_exceeds_the_scope [value Int
-                                               scope Nat])
+  (exception.def .public (value_exceeds_the_scope [value scope])
+    (Exception [Int Nat])
     (exception.report
      (list ["Value" (%.int value)]
            ["Scope (in bytes)" (%.nat scope)])))
diff --git a/stdlib/source/library/lux/meta/target/jvm/encoding/unsigned.lux b/stdlib/source/library/lux/meta/target/jvm/encoding/unsigned.lux
index 1c2bc77a6..0c6e7cde3 100644
--- a/stdlib/source/library/lux/meta/target/jvm/encoding/unsigned.lux
+++ b/stdlib/source/library/lux/meta/target/jvm/encoding/unsigned.lux
@@ -6,7 +6,7 @@
     [order (.only Order)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format (.only format)]]
@@ -44,18 +44,15 @@
        (n.< (representation reference)
             (representation sample)))))
 
-  (exception .public (value_exceeds_the_maximum [type Symbol
-                                                 value Nat
-                                                 maximum (Unsigned Any)])
+  (exception.def .public (value_exceeds_the_maximum [type value maximum])
+    (Exception [Symbol Nat (Unsigned Any)])
     (exception.report
      (list ["Type" (%.symbol type)]
            ["Value" (%.nat value)]
            ["Maximum" (%.nat (representation maximum))])))
 
-  (exception .public [brand] (subtraction_cannot_yield_negative_value
-                              [type Symbol
-                               parameter (Unsigned brand)
-                               subject (Unsigned brand)])
+  (exception.def .public (subtraction_cannot_yield_negative_value [type parameter subject])
+    (All (_ brand) (Exception [Symbol (Unsigned brand) (Unsigned brand)]))
     (exception.report
      (list ["Type" (%.symbol type)]
            ["Parameter" (%.nat (representation parameter))]
diff --git a/stdlib/source/library/lux/meta/target/jvm/loader.lux b/stdlib/source/library/lux/meta/target/jvm/loader.lux
index c8d70c482..3f2c4dd39 100644
--- a/stdlib/source/library/lux/meta/target/jvm/loader.lux
+++ b/stdlib/source/library/lux/meta/target/jvm/loader.lux
@@ -6,7 +6,7 @@
     [monad (.only do)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     ["[0]" io (.only IO)]
     [concurrency
      ["[0]" atom (.only Atom)]]]
@@ -23,16 +23,18 @@
 (type .public Library
   (Atom (Dictionary Text Binary)))
 
-(exception .public (already_stored [class Text])
+(exception.def .public (already_stored class)
+  (Exception Text)
   (exception.report
    (list ["Class" class])))
 
-(exception .public (unknown [class Text])
+(exception.def .public (unknown class)
+  (Exception Text)
   (exception.report
    (list ["Class" class])))
 
-(exception .public (cannot_define [class Text
-                                   error Text])
+(exception.def .public (cannot_define [class error])
+  (Exception [Text Text])
   (exception.report
    (list ["Class" class]
          ["Error" error])))
diff --git a/stdlib/source/library/lux/meta/target/jvm/reflection.lux b/stdlib/source/library/lux/meta/target/jvm/reflection.lux
index a33bc6507..2a0ad37a8 100644
--- a/stdlib/source/library/lux/meta/target/jvm/reflection.lux
+++ b/stdlib/source/library/lux/meta/target/jvm/reflection.lux
@@ -6,7 +6,7 @@
     ["[0]" monad (.only do)]]
    [control
     ["[0]" try (.only Try) (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.use "[1]#[0]" equivalence)
      ["%" \\format (.only format)]
@@ -96,12 +96,14 @@
   (isArray [] boolean)
   (getComponentType [] (java/lang/Class java/lang/Object)))
 
-(exception .public (unknown_class [class External])
+(exception.def .public (unknown_class class)
+  (Exception External)
   (exception.report
    (list ["Class" (%.text class)])))
 
 (with_template [<name>]
-  [(exception .public (<name> [jvm_type java/lang/reflect/Type])
+  [(exception.def .public (<name> jvm_type)
+     (Exception java/lang/reflect/Type)
      (exception.report
       (list ["Type" (java/lang/reflect/Type::getTypeName jvm_type)]
             ["Class" (|> jvm_type java/lang/Object::getClass java/lang/Object::toString)])))]
@@ -267,23 +269,22 @@
       {.#None}
       <else>)))
 
-(exception .public (cannot_correspond [class (java/lang/Class java/lang/Object)
-                                       type Type])
+(exception.def .public (cannot_correspond [class type])
+  (Exception [(java/lang/Class java/lang/Object) Type])
   (exception.report
    (list ["Class" (java/lang/Object::toString class)]
          ["Type" (%.type type)])))
 
-(exception .public (type_parameter_mismatch [expected Nat
-                                             actual Nat
-                                             class (java/lang/Class java/lang/Object)
-                                             type Type])
+(exception.def .public (type_parameter_mismatch [expected actual class type])
+  (Exception [Nat Nat (java/lang/Class java/lang/Object) Type])
   (exception.report
    (list ["Expected" (%.nat expected)]
          ["Actual" (%.nat actual)]
          ["Class" (java/lang/Object::toString class)]
          ["Type" (%.type type)])))
 
-(exception .public (non_jvm_type [type Type])
+(exception.def .public (non_jvm_type type)
+  (Exception Type)
   (exception.report
    (list ["Type" (%.type type)])))
 
@@ -327,17 +328,16 @@
     _
     (exception.except ..non_jvm_type [type])))
 
-(exception .public (mistaken_field_owner [field java/lang/reflect/Field
-                                          owner (java/lang/Class java/lang/Object)
-                                          target (java/lang/Class java/lang/Object)])
+(exception.def .public (mistaken_field_owner [field owner target])
+  (Exception [java/lang/reflect/Field (java/lang/Class java/lang/Object) (java/lang/Class java/lang/Object)])
   (exception.report
    (list ["Field" (java/lang/Object::toString field)]
          ["Owner" (java/lang/Object::toString owner)]
          ["Target" (java/lang/Object::toString target)])))
 
 (with_template [<name>]
-  [(exception .public (<name> [field Text
-                               class (java/lang/Class java/lang/Object)])
+  [(exception.def .public (<name> [field class])
+     (Exception [Text (java/lang/Class java/lang/Object)])
      (exception.report
       (list ["Field" (%.text field)]
             ["Class" (java/lang/Object::toString class)])))]
diff --git a/stdlib/source/library/lux/meta/target/jvm/type/lux.lux b/stdlib/source/library/lux/meta/target/jvm/type/lux.lux
index 4f6d9076f..89639ce4d 100644
--- a/stdlib/source/library/lux/meta/target/jvm/type/lux.lux
+++ b/stdlib/source/library/lux/meta/target/jvm/type/lux.lux
@@ -6,7 +6,7 @@
    [control
     ["<>" parser (.use "[1]#[0]" monad)]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text (.use "[1]#[0]" equivalence)
@@ -44,7 +44,8 @@
   Mapping
   (dictionary.empty text.hash))
 
-(exception .public (unknown_var [var Text])
+(exception.def .public (unknown_var var)
+  (Exception Text)
   (exception.report
    (list ["Var" (%.text var)])))
 
diff --git a/stdlib/source/library/lux/meta/type/check.lux b/stdlib/source/library/lux/meta/type/check.lux
index 184864469..718f27931 100644
--- a/stdlib/source/library/lux/meta/type/check.lux
+++ b/stdlib/source/library/lux/meta/type/check.lux
@@ -8,7 +8,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only Exception exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text (.use "[1]#[0]" monoid equivalence)]
@@ -32,30 +32,31 @@
   (template (_ reference subject)
     [("lux text =" reference subject)]))
 
-(exception .public (unknown_type_var [id Nat])
-  (exception.report
-   (list ["ID" (n#encoded id)])))
+(with_template [<name>]
+  [(exception.def .public (<name> id)
+     (Exception Nat)
+     (exception.report
+      (list ["ID" (n#encoded id)])))]
 
-(exception .public (unbound_type_var [id Nat])
-  (exception.report
-   (list ["ID" (n#encoded id)])))
+  [unknown_type_var]
+  [unbound_type_var]
+  )
 
-(exception .public (invalid_type_application [funcT Type
-                                              argT Type])
+(exception.def .public (invalid_type_application [funcT argT])
+  (Exception [Type Type])
   (exception.report
    (list ["Type function" (//.format funcT)]
          ["Type argument" (//.format argT)])))
 
-(exception .public (cannot_rebind_var [id Nat
-                                       type Type
-                                       bound Type])
+(exception.def .public (cannot_rebind_var [id type bound])
+  (Exception [Nat Type Type])
   (exception.report
    (list ["Var" (n#encoded id)]
          ["Wanted type" (//.format type)]
          ["Current type" (//.format bound)])))
 
-(exception .public (type_check_failed [expected Type
-                                       actual Type])
+(exception.def .public (type_check_failed [expected actual])
+  (Exception [Type Type])
   (exception.report
    (list ["Expected" (//.format expected)]
          ["Actual" (//.format actual)])))
@@ -338,7 +339,8 @@
                 (set.member? it @1))
               (..ring @0)))
 
-(exception .public (cannot_identify [var Var])
+(exception.def .public (cannot_identify var)
+  (Exception Var)
   (exception.report
    (list ["Var" (n#encoded var)])))
 
diff --git a/stdlib/source/library/lux/meta/type/dynamic.lux b/stdlib/source/library/lux/meta/type/dynamic.lux
index a10d24530..6c69e7417 100644
--- a/stdlib/source/library/lux/meta/type/dynamic.lux
+++ b/stdlib/source/library/lux/meta/type/dynamic.lux
@@ -4,7 +4,7 @@
    ["[0]" debug]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format]]]
@@ -16,8 +16,8 @@
  ["[0]" // (.only)
   ["[0]" primitive (.only primitive)]])
 
-(exception .public (wrong_type [expected Type
-                                actual Type])
+(exception.def .public (wrong_type [expected actual])
+  (Exception [Type Type])
   (exception.report
    (list ["Expected" (%.type expected)]
          ["Actual" (%.type actual)])))
diff --git a/stdlib/source/library/lux/meta/type/resource.lux b/stdlib/source/library/lux/meta/type/resource.lux
index 7b1a83195..904ee3129 100644
--- a/stdlib/source/library/lux/meta/type/resource.lux
+++ b/stdlib/source/library/lux/meta/type/resource.lux
@@ -7,7 +7,7 @@
    [control
     ["<>" parser]
     ["[0]" maybe]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     [text
      ["%" \\format (.only format)]]
@@ -102,11 +102,12 @@
       (at  monad in [keys (representation resource)])))
   )
 
-(exception .public (index_cannot_be_repeated [index Nat])
+(exception.def .public (index_cannot_be_repeated index)
+  (Exception Nat)
   (exception.report
    (list ["Index" (%.nat index)])))
 
-(exception .public amount_cannot_be_zero)
+(exception.def .public amount_cannot_be_zero)
 
 (def indices
   (Parser (List Nat))
diff --git a/stdlib/source/library/lux/meta/version.lux b/stdlib/source/library/lux/meta/version.lux
index af8da3bce..b25439e57 100644
--- a/stdlib/source/library/lux/meta/version.lux
+++ b/stdlib/source/library/lux/meta/version.lux
@@ -5,7 +5,7 @@
     [monad (.only do)]]
    [control
     ["<>" parser]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" text (.use "[1]#[0]" equivalence)]
     [collection
@@ -28,7 +28,7 @@
       [it meta.version]
       (in (list (code.text it))))))
 
-(exception .public invalid)
+(exception.def .public invalid)
 
 (def .public for
   (syntax (_ [specializations (<>.some (<>.and <code>.text <code>.any))
diff --git a/stdlib/source/library/lux/test/property.lux b/stdlib/source/library/lux/test/property.lux
index e18d7b36b..2e1739797 100644
--- a/stdlib/source/library/lux/test/property.lux
+++ b/stdlib/source/library/lux/test/property.lux
@@ -8,7 +8,7 @@
     ["[0]" pipe]
     ["[0]" maybe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     ["[0]" io]
     [concurrency
      ["[0]" atom (.only Atom)]
@@ -106,7 +106,7 @@
   (format documentation ..separator ..separator
           "Failed with this seed: " (%.nat seed)))
 
-(exception .public must_try_test_at_least_once)
+(exception.def .public must_try_test_at_least_once)
 
 (def .public (times amount test)
   (-> Nat Test Test)
@@ -230,7 +230,8 @@
                      (|>> (//.covering (, module)))
                      (, test)))))))
 
-(exception .public (error_during_execution [error Text])
+(exception.def .public (error_during_execution error)
+  (Exception Text)
   (exception.report
    (list ["Error" (%.text error)])))
 
diff --git a/stdlib/source/library/lux/world/console.lux b/stdlib/source/library/lux/world/console.lux
index 71761bead..440063bca 100644
--- a/stdlib/source/library/lux/world/console.lux
+++ b/stdlib/source/library/lux/world/console.lux
@@ -7,7 +7,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try (.only Try) (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     ["[0]" io (.only IO io) (.use "[1]#[0]" functor)]
     [concurrency
      ["[0]" async (.only Async) (.use "[1]#[0]" monad)]
@@ -41,7 +41,7 @@
              [write]
              [close])))))
 
-(exception .public cannot_close)
+(exception.def .public cannot_close)
 
 (with_expansions [<jvm> (these (import java/lang/String
                                  "[1]::[0]")
@@ -64,7 +64,7 @@
                                  ("read_only" "static" in java/io/InputStream)
                                  ("read_only" "static" out java/io/PrintStream))
 
-                               (exception .public cannot_open)
+                               (exception.def .public cannot_open)
 
                                (def .public default
                                  (IO (Try (Console IO)))
@@ -117,7 +117,7 @@
                      ("static" stdout Writable_Stream)
                      ("static" stdin Readable_Stream))
 
-                   (exception .public cannot_read)
+                   (exception.def .public cannot_read)
 
                    (def !read
                      (template (_ <type> <query>)
diff --git a/stdlib/source/library/lux/world/environment.lux b/stdlib/source/library/lux/world/environment.lux
index ba941b30e..69d8dce95 100644
--- a/stdlib/source/library/lux/world/environment.lux
+++ b/stdlib/source/library/lux/world/environment.lux
@@ -8,7 +8,7 @@
               ["[0]" io (.only IO)]
               ["[0]" maybe (.use "[1]#[0]" functor)]
               ["[0]" try (.only Try)]
-              ["[0]" exception (.only exception)]
+              ["[0]" exception (.only Exception)]
               [concurrency
                ["[0]" atom]
                ["[0]" async (.only Async)]]]
@@ -36,7 +36,8 @@
             [file (.only Path)]
             [shell (.only Exit)]])))
 
-(exception .public (unknown_environment_variable [name Text])
+(exception.def .public (unknown_environment_variable name)
+  (Exception Text)
   (exception.report
    (list ["Name" (%.text name)])))
 
diff --git a/stdlib/source/library/lux/world/file.lux b/stdlib/source/library/lux/world/file.lux
index eb4bb69fa..1e2bdd90d 100644
--- a/stdlib/source/library/lux/world/file.lux
+++ b/stdlib/source/library/lux/world/file.lux
@@ -7,7 +7,7 @@
               ["[0]" pipe]
               ["[0]" maybe (.use "[1]#[0]" functor)]
               ["[0]" try (.only Try) (.use "[1]#[0]" functor)]
-              ["[0]" exception (.only exception)]
+              ["[0]" exception (.only Exception)]
               ["[0]" io (.only IO) (.use "[1]#[0]" functor)]
               ["[0]" function]
               [concurrency
@@ -147,7 +147,8 @@
   (format parent (at fs separator) child))
 
 (with_template [<name>]
-  [(exception .public (<name> [file Path])
+  [(exception.def .public (<name> file)
+     (Exception Path)
      (exception.report
       (list ["Path" file])))]
 
@@ -813,7 +814,8 @@
        ...        (def default_separator (..DIRECTORY_SEPARATOR))
 
        ...        (with_template [<name>]
-       ...          [(exception .public (<name> [file Path])
+       ...          [(exception.def .public (<name> file)
+       ...             (Exception Path)
        ...             (exception.report
        ...              (list ["Path" file])))]
        
diff --git a/stdlib/source/library/lux/world/file/watch.lux b/stdlib/source/library/lux/world/file/watch.lux
index c0d79ea50..f5f64dcf5 100644
--- a/stdlib/source/library/lux/world/file/watch.lux
+++ b/stdlib/source/library/lux/world/file/watch.lux
@@ -8,7 +8,7 @@
     ["[0]" io (.only IO)]
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     [concurrency
      ["[0]" async (.only Async)]
      ["[0]" stm (.only STM Var)]]
@@ -96,7 +96,8 @@
        poll)))
 
 (with_template [<name>]
-  [(exception .public (<name> [path //.Path])
+  [(exception.def .public (<name> path)
+     (Exception //.Path)
      (exception.report
       (list ["Path" (%.text path)])))]
 
diff --git a/stdlib/source/library/lux/world/shell.lux b/stdlib/source/library/lux/world/shell.lux
index 5ab10bba6..bd7829907 100644
--- a/stdlib/source/library/lux/world/shell.lux
+++ b/stdlib/source/library/lux/world/shell.lux
@@ -7,7 +7,7 @@
    [control
     ["[0]" function]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     ["[0]" io (.only IO)]
     [security
      ["?" policy (.only Context Safety Safe)]]
@@ -230,7 +230,7 @@
                                  (destroy [] "io" "try" void)
                                  (waitFor [] "io" "try" int))
 
-                               (exception .public no_more_output)
+                               (exception.def .public no_more_output)
 
                                (def (default_process process)
                                  (-> java/lang/Process (IO (Try (Process IO))))
diff --git a/stdlib/source/library/lux/world/time.lux b/stdlib/source/library/lux/world/time.lux
index 22a0d85f3..853b0429f 100644
--- a/stdlib/source/library/lux/world/time.lux
+++ b/stdlib/source/library/lux/world/time.lux
@@ -11,7 +11,7 @@
     ["<>" parser (.only)]
     ["[0]" pipe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.use "[1]#[0]" monoid)
      ["<[1]>" \\parser (.only Parser)]]]
@@ -39,7 +39,8 @@
   Nat
   (.nat (duration.millis duration.day)))
 
-(exception .public (time_exceeds_a_day [time Nat])
+(exception.def .public (time_exceeds_a_day time)
+  (Exception Nat)
   (exception.report
    (list ["Time (in milli-seconds)" (n#encoded time)]
          ["Maximum (in milli-seconds)" (n#encoded (-- limit))])))
@@ -58,7 +59,8 @@
              (at <>.monad in 0)))
 
 (with_template [<maximum> <parser> <exception> <sub_parser>]
-  [(exception .public (<exception> [value Nat])
+  [(exception.def .public (<exception> value)
+     (Exception Nat)
      (exception.report
       (list ["Value" (n#encoded value)]
             ["Minimum" (n#encoded 0)]
diff --git a/stdlib/source/library/lux/world/time/date.lux b/stdlib/source/library/lux/world/time/date.lux
index 09fd828ae..30c182179 100644
--- a/stdlib/source/library/lux/world/time/date.lux
+++ b/stdlib/source/library/lux/world/time/date.lux
@@ -11,7 +11,7 @@
     ["<>" parser (.only)]
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.use "[1]#[0]" monoid)
      ["<[1]>" \\parser (.only Parser)]]
@@ -50,9 +50,8 @@
   (or (n.< ..minimum_day day)
       (n.> (..month_days year month) day)))
 
-(exception .public (invalid_day [year Year
-                                 month Month
-                                 day Nat])
+(exception.def .public (invalid_day [year month day])
+  (Exception [Year Month Nat])
   (exception.report
    (list ["Value" (n#encoded day)]
          ["Minimum" (n#encoded ..minimum_day)]
@@ -154,7 +153,8 @@
              (at <>.monad in 0)))
 
 (with_template [<minimum> <maximum> <parser> <exception>]
-  [(exception .public (<exception> [value Nat])
+  [(exception.def .public (<exception> value)
+     (Exception Nat)
      (exception.report
       (list ["Value" (n#encoded value)]
             ["Minimum" (n#encoded <minimum>)]
diff --git a/stdlib/source/library/lux/world/time/day.lux b/stdlib/source/library/lux/world/time/day.lux
index f763fbb8f..67a7600d3 100644
--- a/stdlib/source/library/lux/world/time/day.lux
+++ b/stdlib/source/library/lux/world/time/day.lux
@@ -9,7 +9,7 @@
     [codec (.only Codec)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.use "[1]#[0]" monoid)]]
    [math
@@ -95,7 +95,8 @@
        {#Saturday}  {#Friday}
        {#Sunday}    {#Saturday}))))
 
-(exception .public (not_a_day_of_the_week [value Text])
+(exception.def .public (not_a_day_of_the_week value)
+  (Exception Text)
   (exception.report
    (list ["Value" (text.format value)])))
 
@@ -153,7 +154,8 @@
          <number>])
       (<pairs>)))
 
-  (exception .public (invalid_day [number Nat])
+  (exception.def .public (invalid_day number)
+    (Exception Nat)
     (exception.report
      (list ["Number" (at n.decimal encoded number)]
            ["Valid range" (all "lux text concat"
diff --git a/stdlib/source/library/lux/world/time/month.lux b/stdlib/source/library/lux/world/time/month.lux
index 35f56020d..814eb32c9 100644
--- a/stdlib/source/library/lux/world/time/month.lux
+++ b/stdlib/source/library/lux/world/time/month.lux
@@ -9,7 +9,7 @@
     [codec (.only Codec)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.use "[1]#[0]" monoid)]]
    [math
@@ -79,7 +79,8 @@
          <number>])
       (<pairs>)))
 
-  (exception .public (invalid_month [number Nat])
+  (exception.def .public (invalid_month number)
+    (Exception Nat)
     (exception.report
      (list ["Number" (at n.decimal encoded number)]
            ["Valid range" (all "lux text concat"
@@ -208,7 +209,8 @@
         {#November}
         {#December}))
 
-(exception .public (not_a_month_of_the_year [value Text])
+(exception.def .public (not_a_month_of_the_year value)
+  (Exception Text)
   (exception.report
    (list ["Value" (text.format value)])))
 
diff --git a/stdlib/source/library/lux/world/time/year.lux b/stdlib/source/library/lux/world/time/year.lux
index ae01271f5..8826f089d 100644
--- a/stdlib/source/library/lux/world/time/year.lux
+++ b/stdlib/source/library/lux/world/time/year.lux
@@ -9,7 +9,7 @@
    [control
     ["<>" parser (.only)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" text (.use "[1]#[0]" monoid)
      ["<[1]>" \\parser (.only Parser)]]]
@@ -33,7 +33,7 @@
     year
     (-- year)))
 
-(exception .public there_is_no_year_0)
+(exception.def .public there_is_no_year_0)
 
 ... https://en.wikipedia.org/wiki/Gregorian_calendar
 (primitive .public Year
diff --git a/stdlib/source/parser/lux/data/binary.lux b/stdlib/source/parser/lux/data/binary.lux
index 37fc881d3..2a1bf3304 100644
--- a/stdlib/source/parser/lux/data/binary.lux
+++ b/stdlib/source/parser/lux/data/binary.lux
@@ -8,7 +8,7 @@
    [control
     ["//" parser (.use "[1]#[0]" monad)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["/" binary
      ["[1]" \\unsafe (.only Binary)]]
@@ -38,8 +38,8 @@
 (.type .public Parser
   (//.Parser [Offset Binary]))
 
-(exception .public (binary_was_not_fully_read [binary_length Nat
-                                               bytes_read Nat])
+(exception.def .public (binary_was_not_fully_read [binary_length bytes_read])
+  (Exception [Nat Nat])
   (exception.report
    (.list ["Binary length" (%.nat binary_length)]
           ["Bytes read" (%.nat bytes_read)])))
@@ -89,9 +89,8 @@
 (def .public size_32 Size (n.* 2 size_16))
 (def .public size_64 Size (n.* 2 size_32))
 
-(exception .public (range_out_of_bounds [length Nat
-                                         start Nat
-                                         end Nat])
+(exception.def .public (range_out_of_bounds [length start end])
+  (Exception [Nat Nat Nat])
   (exception.report
    (.list ["Length" (%.nat length)]
           ["Range start" (%.nat start)]
@@ -126,8 +125,8 @@
   (Parser Frac)
   (//#each frac.of_bits ..bits_64))
 
-(exception .public (invalid_tag [range Nat
-                                 byte Nat])
+(exception.def .public (invalid_tag [range byte])
+  (Exception [Nat Nat])
   (exception.report
    (.list ["Tag range" (%.nat range)]
           ["Tag value" (%.nat byte)])))
@@ -160,7 +159,8 @@
   (Parser Any)
   (//#in []))
 
-(exception .public (not_a_bit [value Nat])
+(exception.def .public (not_a_bit value)
+  (Exception Nat)
   (exception.report
    (.list ["Expected values" "either 0 or 1"]
           ["Actual value" (%.nat value)])))
@@ -251,7 +251,7 @@
    (|>> (//.and value)
         (..or ..any))))
 
-(exception .public set_elements_are_not_unique)
+(exception.def .public set_elements_are_not_unique)
 
 (def .public (set hash value)
   (All (_ a) (-> (Hash a) (Parser a) (Parser (Set a))))
diff --git a/stdlib/source/parser/lux/data/collection/tree.lux b/stdlib/source/parser/lux/data/collection/tree.lux
index 38132cdb4..198460164 100644
--- a/stdlib/source/parser/lux/data/collection/tree.lux
+++ b/stdlib/source/parser/lux/data/collection/tree.lux
@@ -6,7 +6,7 @@
    [control
     ["//" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]]]
+    ["[0]" exception]]]]
  [\\library
   [/ (.only Tree)
    ["[0]" zipper (.only Zipper)]]])
@@ -29,7 +29,7 @@
   (function (_ zipper)
     {try.#Success [zipper (zipper.value zipper)]}))
 
-(exception .public cannot_move_further)
+(exception.def .public cannot_move_further)
 
 (with_template [<name> <direction>]
   [(def .public <name>
diff --git a/stdlib/source/parser/lux/data/format/json.lux b/stdlib/source/parser/lux/data/format/json.lux
index e1c1178e0..aff96d9b7 100644
--- a/stdlib/source/parser/lux/data/format/json.lux
+++ b/stdlib/source/parser/lux/data/format/json.lux
@@ -6,7 +6,7 @@
    [control
     ["//" parser (.use "[1]#[0]" functor)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" bit]
     ["[0]" text (.use "[1]#[0]" equivalence monoid)]
@@ -25,11 +25,12 @@
 (type .public (Parser a)
   (//.Parser (List JSON) a))
 
-(exception .public (unconsumed_input [input (List JSON)])
+(exception.def .public (unconsumed_input input)
+  (Exception (List JSON))
   (exception.report
    (list ["Input" (exception.listing /.format input)])))
 
-(exception .public empty_input)
+(exception.def .public empty_input)
 
 (def .public (result parser json)
   (All (_ a) (-> (Parser a) JSON (Try a)))
@@ -55,7 +56,8 @@
         {.#Item head tail}
         {try.#Success [tail head]})))
 
-(exception .public (unexpected_value [value JSON])
+(exception.def .public (unexpected_value value)
+  (Exception JSON)
   (exception.report
    (list ["Value" (/.format value)])))
 
@@ -77,8 +79,8 @@
   [string  /.String  /.#String]
   )
 
-(exception .public [a] (value_mismatch [reference JSON
-                                        sample JSON])
+(exception.def .public (value_mismatch [reference sample])
+  (Exception [JSON JSON])
   (exception.report
    (list ["Reference" (/.format reference)]
          ["Sample" (/.format sample)])))
diff --git a/stdlib/source/parser/lux/data/format/xml.lux b/stdlib/source/parser/lux/data/format/xml.lux
index 38d0d33da..ce03568f6 100644
--- a/stdlib/source/parser/lux/data/format/xml.lux
+++ b/stdlib/source/parser/lux/data/format/xml.lux
@@ -6,7 +6,7 @@
    [control
     ["//" parser]
     ["[0]" try (.only Try) (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text
      ["%" \\format (.only format)]]
@@ -21,22 +21,23 @@
 (type .public (Parser a)
   (//.Parser [Attrs (List XML)] a))
 
-(exception .public empty_input)
-(exception .public unexpected_input)
+(exception.def .public empty_input)
+(exception.def .public unexpected_input)
 
-(exception .public (wrong_tag [expected Tag
-                               actual Tag])
+(exception.def .public (wrong_tag [expected actual])
+  (Exception [Tag Tag])
   (exception.report
    (list ["Expected" (%.text (/.tag expected))]
          ["Actual" (%.text (/.tag actual))])))
 
-(exception .public (unknown_attribute [expected Attribute
-                                       available (List Attribute)])
+(exception.def .public (unknown_attribute [expected available])
+  (Exception [Attribute (List Attribute)])
   (exception.report
    (list ["Expected" (%.text (/.attribute expected))]
          ["Available" (exception.listing (|>> /.attribute %.text) available)])))
 
-(exception .public (unconsumed_inputs [inputs (List XML)])
+(exception.def .public (unconsumed_inputs inputs)
+  (Exception (List XML))
   (exception.report
    (list ["Inputs" (exception.listing (at /.codec encoded) inputs)])))
 
@@ -124,7 +125,7 @@
       {.#Item head tail}
       {try.#Success [[attrs tail] head]})))
 
-(exception .public nowhere)
+(exception.def .public nowhere)
 
 (def .public (somewhere parser)
   (All (_ a) (-> (Parser a) (Parser a)))
diff --git a/stdlib/source/parser/lux/data/text.lux b/stdlib/source/parser/lux/data/text.lux
index 28320b351..50bb41cb3 100644
--- a/stdlib/source/parser/lux/data/text.lux
+++ b/stdlib/source/parser/lux/data/text.lux
@@ -7,7 +7,7 @@
     ["//" parser]
     ["[0]" maybe]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["/" text (.only Char) (.use "[1]#[0]" monoid)]
     ["[0]" product]
@@ -29,8 +29,8 @@
   Offset
   0)
 
-(exception .public cannot_parse)
-(exception .public cannot_slice)
+(exception.def .public cannot_parse)
+(exception.def .public cannot_slice)
 
 (type .public Parser
   (//.Parser [Offset Text]))
@@ -56,15 +56,15 @@
   (-> Offset Text Text)
   (|> tape (/.clip_since offset) maybe.trusted))
 
-(exception .public (unconsumed_input [offset Offset
-                                      tape Text])
+(exception.def .public (unconsumed_input [offset tape])
+  (Exception [Offset Text])
   (exception.report
    (list ["Offset" (n#encoded offset)]
          ["Input size" (n#encoded (/.size tape))]
          ["Remaining input" (..left_over offset tape)])))
 
-(exception .public (expected_to_fail [offset Offset
-                                      tape Text])
+(exception.def .public (expected_to_fail [offset tape])
+  (Exception [Offset Text])
   (exception.report
    (list ["Offset" (n#encoded offset)]
          ["Input" (..left_over offset tape)])))
@@ -134,7 +134,8 @@
   [not! Slice ..any!]
   )
 
-(exception .public (cannot_match [reference Text])
+(exception.def .public (cannot_match reference)
+  (Exception Text)
   (exception.report
    (list ["Reference" (/.format reference)])))
 
@@ -230,8 +231,8 @@
        (..range! (char "A") (char "F"))))
 
 (with_template [<name>]
-  [(exception .public (<name> [options Text
-                               character Char])
+  [(exception.def .public (<name> [options character])
+     (Exception [Text Char])
      (exception.report
       (list ["Options" (/.format options)]
             ["Character" (/.format (/.of_char character))])))]
@@ -278,7 +279,8 @@
   [none_of! .not ..character_should_not_be]
   )
 
-(exception .public (character_does_not_satisfy_predicate [character Char])
+(exception.def .public (character_does_not_satisfy_predicate character)
+  (Exception Char)
   (exception.report
    (list ["Character" (/.format (/.of_char character))])))
 
diff --git a/stdlib/source/parser/lux/meta/compiler/language/lux/analysis.lux b/stdlib/source/parser/lux/meta/compiler/language/lux/analysis.lux
index 0d98f3bd4..968085cc4 100644
--- a/stdlib/source/parser/lux/meta/compiler/language/lux/analysis.lux
+++ b/stdlib/source/parser/lux/meta/compiler/language/lux/analysis.lux
@@ -6,7 +6,7 @@
    [control
     ["//" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" bit]
     ["[0]" text (.only)
@@ -37,13 +37,15 @@
               (list#each /.format)
               (text.interposed " "))))
 
-(exception .public (cannot_parse [input (List Analysis)])
-  (exception.report
-   (list ["Input" (exception.listing /.format input)])))
+(with_template [<name>]
+  [(exception.def .public (<name> input)
+     (Exception (List Analysis))
+     (exception.report
+      (list ["Input" (exception.listing /.format input)])))]
 
-(exception .public (unconsumed_input [input (List Analysis)])
-  (exception.report
-   (list ["Input" (exception.listing /.format input)])))
+  [cannot_parse]
+  [unconsumed_input]
+  )
 
 (type .public Parser
   (//.Parser (List Analysis)))
diff --git a/stdlib/source/parser/lux/meta/compiler/language/lux/synthesis.lux b/stdlib/source/parser/lux/meta/compiler/language/lux/synthesis.lux
index fda40e0cd..2cb179d28 100644
--- a/stdlib/source/parser/lux/meta/compiler/language/lux/synthesis.lux
+++ b/stdlib/source/parser/lux/meta/compiler/language/lux/synthesis.lux
@@ -6,7 +6,7 @@
    [control
     ["//" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" bit]
     ["[0]" text (.only)
@@ -30,25 +30,24 @@
  [\\library
   ["[0]" / (.only Synthesis Abstraction)]])
 
-(exception .public (cannot_parse [input (List Synthesis)])
-  (exception.report
-   (list ["Input" (exception.listing /.%synthesis input)])))
-
-(exception .public (unconsumed_input [input (List Synthesis)])
-  (exception.report
-   (list ["Input" (exception.listing /.%synthesis input)])))
+(with_template [<name>]
+  [(exception.def .public (<name> input)
+     (Exception (List Synthesis))
+     (exception.report
+      (list ["Input" (exception.listing /.%synthesis input)])))]
 
-(exception .public (expected_empty_input [input (List Synthesis)])
-  (exception.report
-   (list ["Input" (exception.listing /.%synthesis input)])))
+  [cannot_parse]
+  [unconsumed_input]
+  [expected_empty_input]
+  )
 
-(exception .public (wrong_arity [expected Arity
-                                 actual Arity])
+(exception.def .public (wrong_arity [expected actual])
+  (Exception [Arity Arity])
   (exception.report
    (list ["Expected" (%.nat expected)]
          ["Actual" (%.nat actual)])))
 
-(exception .public empty_input)
+(exception.def .public empty_input)
 
 (type .public Parser
   (//.Parser (List Synthesis)))
diff --git a/stdlib/source/parser/lux/meta/type.lux b/stdlib/source/parser/lux/meta/type.lux
index f93efcd6d..1dec4fbb1 100644
--- a/stdlib/source/parser/lux/meta/type.lux
+++ b/stdlib/source/parser/lux/meta/type.lux
@@ -6,7 +6,7 @@
    [control
     ["//" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception (.only Exception)]
     ["[0]" function]]
    [data
     ["[0]" text (.use "[1]#[0]" monoid)
@@ -30,7 +30,8 @@
     [{.#Primitive "" {.#End}}]))
 
 (with_template [<name>]
-  [(exception .public (<name> [type Type])
+  [(exception.def .public (<name> type)
+     (Exception Type)
      (exception.report
       (list ["Type" (%.type type)])))]
 
@@ -47,8 +48,8 @@
   )
 
 (with_template [<name>]
-  [(exception .public (<name> [expected Type
-                               actual Type])
+  [(exception.def .public (<name> [expected actual])
+     (Exception [Type Type])
      (exception.report
       (list ["Expected" (%.type expected)]
             ["Actual" (%.type actual)])))]
@@ -57,9 +58,10 @@
   [wrong_parameter]
   )
 
-(exception .public empty_input)
+(exception.def .public empty_input)
 
-(exception .public (unconsumed_input [remaining (List Type)])
+(exception.def .public (unconsumed_input remaining)
+  (Exception (List Type))
   (exception.report
    (list ["Types" (|> remaining
                       (list#each (|>> %.type (format text.new_line "* ")))
diff --git a/stdlib/source/parser/lux/world/environment.lux b/stdlib/source/parser/lux/world/environment.lux
index 10230d5a1..3b8a3049b 100644
--- a/stdlib/source/parser/lux/world/environment.lux
+++ b/stdlib/source/parser/lux/world/environment.lux
@@ -4,7 +4,7 @@
    [control
     ["//" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     ["[0]" text (.only)
@@ -18,7 +18,8 @@
 (type .public Environment
   (Dictionary Property Text))
 
-(exception .public (unknown_property [property Property])
+(exception.def .public (unknown_property property)
+  (Exception Property)
   (exception.report
    (list ["Property" (%.text property)])))
 
diff --git a/stdlib/source/program/aedifex.lux b/stdlib/source/program/aedifex.lux
index 27127e3da..dc378103b 100644
--- a/stdlib/source/program/aedifex.lux
+++ b/stdlib/source/program/aedifex.lux
@@ -9,7 +9,7 @@
     ["[0]" io (.only IO)]
     ["[0]" maybe]
     ["[0]" try (.only Try) (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     [concurrency
      ["[0]" async (.only Async) (.use "[1]#[0]" monad)]]]
    [data
@@ -94,8 +94,8 @@
            (in {try.#Failure ""})))]
     (in output)))
 
-(exception (cannot_find_repository [repository Text
-                                    options (Dictionary Text Address)])
+(exception.def (cannot_find_repository [repository options])
+  (Exception [Text (Dictionary Text Address)])
   (exception.report
    (list ["Repository" (%.text repository)]
          ["Options" (exception.listing (function (_ [name repo])
@@ -126,7 +126,7 @@
          (..fail! error))))
     (at io.monad in [])))
 
-(exception .public invalid_operation)
+(exception.def .public invalid_operation)
 
 (`` (def write_only
       (Console IO)
diff --git a/stdlib/source/program/aedifex/artifact/time/date.lux b/stdlib/source/program/aedifex/artifact/time/date.lux
index 84e33836a..d1f9a0899 100644
--- a/stdlib/source/program/aedifex/artifact/time/date.lux
+++ b/stdlib/source/program/aedifex/artifact/time/date.lux
@@ -7,7 +7,7 @@
    [control
     ["<>" parser]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text
      ["%" \\format]
@@ -34,7 +34,8 @@
 (def min_year +1,000)
 (def max_year +9,999)
 
-(exception .public (year_is_out_of_range [year year.Year])
+(exception.def .public (year_is_out_of_range year)
+  (Exception year.Year)
   (exception.report
    (list ["Minimum" (%.int ..min_year)]
          ["Maximum" (%.int ..max_year)]
diff --git a/stdlib/source/program/aedifex/command/build.lux b/stdlib/source/program/aedifex/command/build.lux
index 20492bf69..107ae46a4 100644
--- a/stdlib/source/program/aedifex/command/build.lux
+++ b/stdlib/source/program/aedifex/command/build.lux
@@ -7,7 +7,7 @@
     [monad (.only do)]]
    [control
     ["[0]" try (.only Try) (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     ["[0]" io (.only IO)]
     [concurrency
      ["[0]" async (.only Async) (.use "[1]#[0]" monad)]]]
@@ -80,8 +80,8 @@
   ["lux-ruby" ruby_lux_name]
   )
 
-(exception .public no_available_lux)
-(exception .public no_specified_program)
+(exception.def .public no_available_lux)
+(exception.def .public no_specified_program)
 
 (type .public Lux
   (Variant
diff --git a/stdlib/source/program/aedifex/dependency/resolution.lux b/stdlib/source/program/aedifex/dependency/resolution.lux
index 81eb16502..571d2d966 100644
--- a/stdlib/source/program/aedifex/dependency/resolution.lux
+++ b/stdlib/source/program/aedifex/dependency/resolution.lux
@@ -10,7 +10,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try (.only Try) (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only Exception exception)]
+    ["[0]" exception (.only Exception)]
     [function
      ["[0]" predicate (.only Predicate)]]
     [concurrency
@@ -60,9 +60,8 @@
     ["[1]/[0]" snapshot]]]])
 
 (with_template [<name>]
-  [(exception .public (<name> [artifact Artifact
-                               extension Extension
-                               hash Text])
+  [(exception.def .public (<name> [artifact extension hash])
+     (Exception [Artifact Extension Text])
      (exception.report
       (list ["Artifact" (///artifact.format artifact)]
             ["Extension" (%.text extension)]
@@ -156,7 +155,8 @@
   (Equivalence Resolution)
   (dictionary.equivalence ///package.equivalence))
 
-(exception .public (cannot_resolve [dependency Dependency])
+(exception.def .public (cannot_resolve dependency)
+  (Exception Dependency)
   (exception.report
    (list ["Artifact" (%.text (///artifact.format (the //.#artifact dependency)))]
          ["Type" (%.text (the //.#type dependency))])))
diff --git a/stdlib/source/program/aedifex/hash.lux b/stdlib/source/program/aedifex/hash.lux
index eedf5e464..64e9784d3 100644
--- a/stdlib/source/program/aedifex/hash.lux
+++ b/stdlib/source/program/aedifex/hash.lux
@@ -81,15 +81,16 @@
   (def hex_per_chunk
     (n.* hex_per_byte i64.bytes_per_i64))
 
-  (exception .public (not_a_hash [size Nat
-                                  value Text])
+  (exception.def .public (not_a_hash [size value])
+    (Exception [Nat Text])
     (exception.report
      (list ["Pseudo hash" (%.text value)]
            ["Expected size" (%.nat size)]
            ["Actual size" (%.nat (text.size value))])))
   
   (with_template [<name> <size>]
-    [(exception .public (<name> [data Binary])
+    [(exception.def .public (<name> data)
+       (Exception Binary)
        (exception.report
         (list ["Pseudo hash" (%.text (..encoded data))]
               ["Expected size" (%.nat <size>)]
diff --git a/stdlib/source/program/aedifex/profile.lux b/stdlib/source/program/aedifex/profile.lux
index fa00bc64c..2d9d41b4c 100644
--- a/stdlib/source/program/aedifex/profile.lux
+++ b/stdlib/source/program/aedifex/profile.lux
@@ -6,7 +6,7 @@
     [equivalence (.only Equivalence)]]
    [control
     ["[0]" maybe (.use "[1]#[0]" monoid)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" product]
     ["[0]" text (.use "[1]#[0]" equivalence)]
@@ -276,4 +276,4 @@
         #lua (!runtime #lua runtime.default_lua)
         #ruby (!runtime #ruby runtime.default_ruby)]))))
 
-(exception .public no_identity)
+(exception.def .public no_identity)
diff --git a/stdlib/source/program/aedifex/project.lux b/stdlib/source/program/aedifex/project.lux
index 2f4d853af..9d0a00f43 100644
--- a/stdlib/source/program/aedifex/project.lux
+++ b/stdlib/source/program/aedifex/project.lux
@@ -41,12 +41,13 @@
    (def composite
      (dictionary.composite_with (at //.monoid composite)))))
 
-(exception .public (unknown_profile [name Name])
+(exception.def .public (unknown_profile name)
+  (Exception Name)
   (exception.report
    (list ["Name" (%.text name)])))
 
-(exception .public (circular_dependency [dependee Name
-                                         dependent Name])
+(exception.def .public (circular_dependency [dependee dependent])
+  (Exception [Name Name])
   (exception.report
    (list ["Dependent" (%.text dependent)]
          ["Dependee" (%.text dependee)])))
diff --git a/stdlib/source/program/aedifex/repository/remote.lux b/stdlib/source/program/aedifex/repository/remote.lux
index bb89a6235..34488b544 100644
--- a/stdlib/source/program/aedifex/repository/remote.lux
+++ b/stdlib/source/program/aedifex/repository/remote.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" io (.only IO)]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception (.only Exception)]]
    [data
     ["[0]" product]
     [text
@@ -34,8 +34,8 @@
   URL)
 
 (with_template [<name>]
-  [(exception .public (<name> [url URL
-                               status Nat])
+  [(exception.def .public (<name> [url status])
+     (Exception [URL Nat])
      (exception.report
       (list ["URL" (%.text url)]
             ["Status Code" (%.nat status)])))]
diff --git a/stdlib/source/test/aedifex/command/version.lux b/stdlib/source/test/aedifex/command/version.lux
index 7d2877738..169b20ef6 100644
--- a/stdlib/source/test/aedifex/command/version.lux
+++ b/stdlib/source/test/aedifex/command/version.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" maybe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     [concurrency
      ["[0]" async (.only Async)]]]
    [data
@@ -28,7 +28,7 @@
  [\\program
   ["[0]" /]])
 
-(exception .public console_is_closed!)
+(exception.def .public console_is_closed!)
 
 (def mock
   (Mock [Bit Text])
diff --git a/stdlib/source/test/aedifex/repository.lux b/stdlib/source/test/aedifex/repository.lux
index fbb3ef01b..fd26f3898 100644
--- a/stdlib/source/test/aedifex/repository.lux
+++ b/stdlib/source/test/aedifex/repository.lux
@@ -43,13 +43,15 @@
   (-> Version Artifact)
   (|>> ["com.github.luxlang" "test-artifact"]))
 
-(exception (not_found [uri URI])
-  (exception.report
-   (list ["URI" (%.text uri)])))
+(with_template [<name>]
+  [(exception.def (<name> uri)
+     (Exception URI)
+     (exception.report
+      (list ["URI" (%.text uri)])))]
 
-(exception (cannot_upload [uri URI])
-  (exception.report
-   (list ["URI" (%.text uri)])))
+  [not_found]
+  [cannot_upload]
+  )
 
 (type Store
   (Dictionary URI Binary))
diff --git a/stdlib/source/test/lux/control/concurrency/actor.lux b/stdlib/source/test/lux/control/concurrency/actor.lux
index d11016a4b..e8d3568fd 100644
--- a/stdlib/source/test/lux/control/concurrency/actor.lux
+++ b/stdlib/source/test/lux/control/concurrency/actor.lux
@@ -5,7 +5,7 @@
     [monad (.only do)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     ["[0]" io (.only IO io)]]
    [data
     [text
@@ -27,7 +27,7 @@
     ["[0]" async (.only Async Resolver) (.use "[1]#[0]" monad)]
     ["[0]" frp]]]])
 
-(exception got_wrecked)
+(exception.def got_wrecked)
 
 (def counter
   (/.Behavior Nat)
diff --git a/stdlib/source/test/lux/control/exception.lux b/stdlib/source/test/lux/control/exception.lux
index d90494bd9..5c29d3103 100644
--- a/stdlib/source/test/lux/control/exception.lux
+++ b/stdlib/source/test/lux/control/exception.lux
@@ -17,11 +17,12 @@
    [//
     ["[0]" try (.only Try)]]]])
 
-(/.exception an_exception)
-(/.exception another_exception)
+(/.def an_exception)
+(/.def another_exception)
 
 (def label "YOLO")
-(/.exception (custom_exception [value Nat])
+(/.def (custom_exception value)
+  (/.Exception Nat)
   (/.report (list [label (%.nat value)])))
 
 (def .public test
@@ -104,7 +105,7 @@
                       {try.#Failure message}
                       (and (text.contains? (/.error ..an_exception []) message)
                            (text.contains? (/.error ..another_exception []) message)))))
-             (_.coverage [/.exception]
+             (_.coverage [/.def]
                (when (/.except ..custom_exception [expected])
                  {try.#Success _}
                  false
diff --git a/stdlib/source/test/lux/control/region.lux b/stdlib/source/test/lux/control/region.lux
index 54e22f811..a859fd904 100644
--- a/stdlib/source/test/lux/control/region.lux
+++ b/stdlib/source/test/lux/control/region.lux
@@ -28,9 +28,9 @@
   ["[0]" / (.only Region)
    [//
     ["[0]" thread (.only Thread)]
-    ["[0]" exception (.only Exception exception)]]]])
+    ["[0]" exception (.only Exception)]]]])
 
-(exception oops)
+(exception.def oops)
 
 (def (success? result)
   (All (_ a) (-> (Try a) Bit))
diff --git a/stdlib/source/test/lux/meta/compiler/language/lux/analysis.lux b/stdlib/source/test/lux/meta/compiler/language/lux/analysis.lux
index 69e3885f8..201661c8e 100644
--- a/stdlib/source/test/lux/meta/compiler/language/lux/analysis.lux
+++ b/stdlib/source/test/lux/meta/compiler/language/lux/analysis.lux
@@ -9,7 +9,7 @@
     ["<>" parser]
     ["[0]" pipe]
     ["[0]" try]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     ["[0]" function]
     ["[0]" maybe]]
    [data
@@ -373,7 +373,7 @@
 
 (with_expansions [<id> (static.random_nat)
                   <exception> (template.symbol ["exception_" <id>])]
-  (exception <exception>)
+  (exception.def <exception>)
 
   (def test|phase
     Test
diff --git a/stdlib/source/test/lux/meta/compiler/phase.lux b/stdlib/source/test/lux/meta/compiler/phase.lux
index 18cad7805..cc82568de 100644
--- a/stdlib/source/test/lux/meta/compiler/phase.lux
+++ b/stdlib/source/test/lux/meta/compiler/phase.lux
@@ -9,7 +9,7 @@
    [control
     ["[0]" pipe]
     ["[0]" try (.use "[1]#[0]" functor)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" text (.use "[1]#[0]" equivalence)
      ["%" \\format (.only format)]]]
@@ -43,7 +43,7 @@
       _
       false)))
 
-(exception oops)
+(exception.def oops)
 
 (def test|error
   Test
diff --git a/stdlib/source/test/lux/meta/macro/syntax/export.lux b/stdlib/source/test/lux/meta/macro/syntax/export.lux
index e074f64ae..68a999ad5 100644
--- a/stdlib/source/test/lux/meta/macro/syntax/export.lux
+++ b/stdlib/source/test/lux/meta/macro/syntax/export.lux
@@ -31,7 +31,7 @@
   (<| (_.covering /._)
       (do random.monad
         [[expected_export_policy expected_un_exported] ..export]
-        (_.coverage [/.parser /.default_policy]
+        (_.coverage [/.parser /.default]
           (|> (when expected_export_policy
                 {.#Some expected_export_policy}
                 (list expected_export_policy (code.nat expected_un_exported))
@@ -41,7 +41,7 @@
               (<code>.result (/.parser <code>.nat))
               (try#each (function (_ [actual_export_policy actual_un_exported])
                           (|> expected_export_policy
-                              (maybe.else /.default_policy)
+                              (maybe.else /.default)
                               (code#= actual_export_policy)
                               (and (n.= expected_un_exported actual_un_exported)))))
               (try.else false))))))
diff --git a/stdlib/source/test/lux/meta/type/check.lux b/stdlib/source/test/lux/meta/type/check.lux
index b6459169f..441070482 100644
--- a/stdlib/source/test/lux/meta/type/check.lux
+++ b/stdlib/source/test/lux/meta/type/check.lux
@@ -11,7 +11,7 @@
     ["[0]" pipe]
     ["[0]" function]
     ["[0]" try]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" bit (.use "[1]#[0]" equivalence)]
     ["[0]" product]
@@ -129,7 +129,7 @@
   (Random Type)
   (primitive_type 2))
 
-(exception yolo)
+(exception.def yolo)
 
 (def error_handling
   Test
diff --git a/stdlib/source/test/lux/world/console.lux b/stdlib/source/test/lux/world/console.lux
index 1cac08a06..e4d595dec 100644
--- a/stdlib/source/test/lux/world/console.lux
+++ b/stdlib/source/test/lux/world/console.lux
@@ -6,7 +6,7 @@
    [control
     ["[0]" io]
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]]
+    ["[0]" exception]]
    [data
     ["[0]" text (.use "[1]#[0]" equivalence)
      ["%" \\format (.only format)]]]
@@ -19,7 +19,7 @@
  [\\specification
   ["$[0]" /]])
 
-(exception dead)
+(exception.def dead)
 
 (def mock
   (/.Mock [Bit Text])
diff --git a/stdlib/source/test/lux/world/shell.lux b/stdlib/source/test/lux/world/shell.lux
index ce6b1b984..32e2d3494 100644
--- a/stdlib/source/test/lux/world/shell.lux
+++ b/stdlib/source/test/lux/world/shell.lux
@@ -5,7 +5,7 @@
     [monad (.only do)]]
    [control
     ["[0]" try (.only Try)]
-    ["[0]" exception (.only exception)]
+    ["[0]" exception]
     ["[0]" io (.only IO)]
     [concurrency
      ["[0]" async (.only Async)]]]
@@ -30,7 +30,7 @@
  [\\specification
   ["$[0]" /]])
 
-(exception dead)
+(exception.def dead)
 
 (def (mock [environment working_directory command arguments])
   (-> [Environment Path /.Command (List /.Argument)]