From 065e8a4d8122d4616b570496915d2c0e2c78cd6b Mon Sep 17 00:00:00 2001
From: Eduardo Julian
Date: Thu, 11 Aug 2022 04:15:07 -0400
Subject: Re-named the "case" macro to "when".

---
 stdlib/source/parser/lux/data/binary.lux           |  8 ++---
 stdlib/source/parser/lux/data/collection/tree.lux  |  2 +-
 stdlib/source/parser/lux/data/format/json.lux      | 28 +++++++++---------
 stdlib/source/parser/lux/data/format/xml.lux       | 22 +++++++-------
 stdlib/source/parser/lux/data/text.lux             | 24 +++++++--------
 stdlib/source/parser/lux/meta/code.lux             | 34 +++++++++++-----------
 .../lux/meta/compiler/language/lux/analysis.lux    | 14 ++++-----
 .../lux/meta/compiler/language/lux/synthesis.lux   | 18 ++++++------
 stdlib/source/parser/lux/meta/type.lux             | 28 +++++++++---------
 stdlib/source/parser/lux/program.lux               | 12 ++++----
 stdlib/source/parser/lux/world/environment.lux     |  2 +-
 11 files changed, 96 insertions(+), 96 deletions(-)

(limited to 'stdlib/source/parser')

diff --git a/stdlib/source/parser/lux/data/binary.lux b/stdlib/source/parser/lux/data/binary.lux
index d1cf273f3..37fc881d3 100644
--- a/stdlib/source/parser/lux/data/binary.lux
+++ b/stdlib/source/parser/lux/data/binary.lux
@@ -56,7 +56,7 @@
 
 (def .public (result parser input)
   (All (_ a) (-> (Parser a) Binary (Try a)))
-  (case (parser [0 input])
+  (when (parser [0 input])
     {try.#Success [[end _] output]}
     (let [length (/.size input)]
       (if (n#= end length)
@@ -138,7 +138,7 @@
        [flag (is (Parser Nat)
                  ..bits_8)]
        (with_expansions [<case>+' (template.spliced <case>+)]
-         (case flag
+         (when flag
            (^.with_template [<number> <tag> <parser>]
              [<number> (`` (at ! each (|>> {(,, (template.spliced <tag>))}) <parser>))])
            (<case>+')
@@ -170,14 +170,14 @@
   (do //.monad
     [value (is (Parser Nat)
                ..bits_8)]
-    (case value
+    (when value
       0 (in #0)
       1 (in #1)
       _ (//.lifted (exception.except ..not_a_bit [value])))))
 
 (def .public (segment size)
   (-> Nat (Parser Binary))
-  (case size
+  (when size
     0 (//#in (/.empty 0))
     _ (function (_ [start binary])
         (let [end (n#+ size start)]
diff --git a/stdlib/source/parser/lux/data/collection/tree.lux b/stdlib/source/parser/lux/data/collection/tree.lux
index 5d10ce15b..38132cdb4 100644
--- a/stdlib/source/parser/lux/data/collection/tree.lux
+++ b/stdlib/source/parser/lux/data/collection/tree.lux
@@ -35,7 +35,7 @@
   [(def .public <name>
      (All (_ t) (Parser t []))
      (function (_ zipper)
-       (case (<direction> zipper)
+       (when (<direction> zipper)
          {.#None}
          (exception.except ..cannot_move_further [])
 
diff --git a/stdlib/source/parser/lux/data/format/json.lux b/stdlib/source/parser/lux/data/format/json.lux
index d440cd091..e1c1178e0 100644
--- a/stdlib/source/parser/lux/data/format/json.lux
+++ b/stdlib/source/parser/lux/data/format/json.lux
@@ -33,9 +33,9 @@
 
 (def .public (result parser json)
   (All (_ a) (-> (Parser a) JSON (Try a)))
-  (case (//.result parser (list json))
+  (when (//.result parser (list json))
     {try.#Success [remainder output]}
-    (case remainder
+    (when remainder
       {.#End}
       {try.#Success output}
 
@@ -48,7 +48,7 @@
 (def .public any
   (Parser JSON)
   (<| (function (_ inputs))
-      (case inputs
+      (when inputs
         {.#End}
         (exception.except ..empty_input [])
         
@@ -64,7 +64,7 @@
      (Parser <type>)
      (do //.monad
        [head ..any]
-       (case head
+       (when head
          {<tag> value}
          (in value)
 
@@ -88,7 +88,7 @@
      (-> <type> (Parser Bit))
      (do //.monad
        [head ..any]
-       (case head
+       (when head
          {<tag> value}
          (in (at <equivalence> = test value))
 
@@ -99,7 +99,7 @@
      (-> <type> (Parser Any))
      (do //.monad
        [head ..any]
-       (case head
+       (when head
          {<tag> value}
          (if (at <equivalence> = test value)
            (in [])
@@ -122,14 +122,14 @@
   (All (_ a) (-> (Parser a) (Parser a)))
   (do //.monad
     [head ..any]
-    (case head
+    (when head
       {/.#Array values}
-      (case (//.result parser (sequence.list values))
+      (when (//.result parser (sequence.list values))
         {try.#Failure error}
         (//.failure error)
 
         {try.#Success [remainder output]}
-        (case remainder
+        (when remainder
           {.#End}
           (in output)
 
@@ -143,9 +143,9 @@
   (All (_ a) (-> (Parser a) (Parser a)))
   (do //.monad
     [head ..any]
-    (case head
+    (when head
       {/.#Object kvs}
-      (case (|> kvs
+      (when (|> kvs
                 dictionary.entries
                 (list#each (function (_ [key value])
                              (list {/.#String key} value)))
@@ -155,7 +155,7 @@
         (//.failure error)
 
         {try.#Success [remainder output]}
-        (case remainder
+        (when remainder
           {.#End}
           (in output)
 
@@ -168,10 +168,10 @@
 (def .public (field field_name parser)
   (All (_ a) (-> Text (Parser a) (Parser a)))
   (function (again inputs)
-    (case inputs
+    (when inputs
       (list.partial {/.#String key} value inputs')
       (if (text#= key field_name)
-        (case (//.result parser (list value))
+        (when (//.result parser (list value))
           {try.#Success [{.#End} output]}
           {try.#Success [inputs' output]}
 
diff --git a/stdlib/source/parser/lux/data/format/xml.lux b/stdlib/source/parser/lux/data/format/xml.lux
index 0a54431e2..38d0d33da 100644
--- a/stdlib/source/parser/lux/data/format/xml.lux
+++ b/stdlib/source/parser/lux/data/format/xml.lux
@@ -42,7 +42,7 @@
 
 (def (result' parser attrs documents)
   (All (_ a) (-> (Parser a) Attrs (List XML) (Try a)))
-  (case (//.result parser [attrs documents])
+  (when (//.result parser [attrs documents])
     {try.#Success [[attrs' remaining] output]}
     (if (list.empty? remaining)
       {try.#Success output}
@@ -58,12 +58,12 @@
 (def .public text
   (Parser Text)
   (function (_ [attrs documents])
-    (case documents
+    (when documents
       {.#End}
       (exception.except ..empty_input [])
       
       {.#Item head tail}
-      (case head
+      (when head
         {/.#Text value}
         {try.#Success [[attrs tail] value]}
         
@@ -73,12 +73,12 @@
 (def .public tag
   (Parser Tag)
   (function (_ [attrs documents])
-    (case documents
+    (when documents
       {.#End}
       (exception.except ..empty_input [])
       
       {.#Item head _}
-      (case head
+      (when head
         {/.#Text _}
         (exception.except ..unexpected_input [])
         
@@ -88,7 +88,7 @@
 (def .public (attribute name)
   (-> Attribute (Parser Text))
   (function (_ [attrs documents])
-    (case (dictionary.value name attrs)
+    (when (dictionary.value name attrs)
       {.#None}
       (exception.except ..unknown_attribute [name (dictionary.keys attrs)])
       
@@ -98,12 +98,12 @@
 (def .public (node expected parser)
   (All (_ a) (-> Tag (Parser a) (Parser a)))
   (function (_ [attrs documents])
-    (case documents
+    (when documents
       {.#End}
       (exception.except ..empty_input [])
       
       {.#Item head tail}
-      (case head
+      (when head
         {/.#Text _}
         (exception.except ..unexpected_input [])
         
@@ -117,7 +117,7 @@
 (def .public any
   (Parser XML)
   (function (_ [attrs documents])
-    (case documents
+    (when documents
       {.#End}
       (exception.except ..empty_input [])
       
@@ -129,12 +129,12 @@
 (def .public (somewhere parser)
   (All (_ a) (-> (Parser a) (Parser a)))
   (function (again [attrs input])
-    (case (//.result parser [attrs input])
+    (when (//.result parser [attrs input])
       {try.#Success [[attrs remaining] output]}
       {try.#Success [[attrs remaining] output]}
       
       {try.#Failure error}
-      (case input
+      (when input
         {.#End}
         (exception.except ..nowhere [])
         
diff --git a/stdlib/source/parser/lux/data/text.lux b/stdlib/source/parser/lux/data/text.lux
index 75c30816f..28320b351 100644
--- a/stdlib/source/parser/lux/data/text.lux
+++ b/stdlib/source/parser/lux/data/text.lux
@@ -45,7 +45,7 @@
   (do //.monad
     [[basis distance] parser]
     (function (_ (^.let input [offset tape]))
-      (case (/.clip basis distance tape)
+      (when (/.clip basis distance tape)
         {.#Some output}
         {try.#Success [input output]}
 
@@ -71,7 +71,7 @@
 
 (def .public (result parser input)
   (All (_ a) (-> (Parser a) Text (Try a)))
-  (case (parser [..beginning input])
+  (when (parser [..beginning input])
     {try.#Failure msg}
     {try.#Failure msg}
     
@@ -100,7 +100,7 @@
 (def .public any
   (Parser Text)
   (function (_ [offset tape])
-    (case (/.char offset tape)
+    (when (/.char offset tape)
       {.#Some output}
       {try.#Success [[("lux i64 +" 1 offset) tape] (/.of_char output)]}
 
@@ -110,7 +110,7 @@
 (def .public any!
   (Parser Slice)
   (function (_ [offset tape])
-    (case (/.char offset tape)
+    (when (/.char offset tape)
       {.#Some _}
       {try.#Success [[("lux i64 +" 1 offset) tape]
                      [#basis offset
@@ -123,7 +123,7 @@
   [(`` (def .public (<name> parser)
          (All (_ a) (-> (Parser a) (Parser <type>)))
          (function (_ input)
-           (case (parser input)
+           (when (parser input)
              {try.#Failure msg}
              (<any> input)
              
@@ -141,7 +141,7 @@
 (def .public (this reference)
   (-> Text (Parser Any))
   (function (_ [offset tape])
-    (case (/.index_since offset reference tape)
+    (when (/.index_since offset reference tape)
       {.#Some where}
       (if (n.= offset where)
         {try.#Success [[("lux i64 +" (/.size reference) offset) tape]
@@ -161,7 +161,7 @@
 (def .public next
   (Parser Text)
   (function (_ (^.let input [offset tape]))
-    (case (/.char offset tape)
+    (when (/.char offset tape)
       {.#Some output}
       {try.#Success [input (/.of_char output)]}
 
@@ -244,7 +244,7 @@
   [(def .public (<name> options)
      (-> Text (Parser Text))
      (function (_ [offset tape])
-       (case (/.char offset tape)
+       (when (/.char offset tape)
          {.#Some output}
          (let [output' (/.of_char output)]
            (if (<modifier> (/.contains? output' options))
@@ -262,7 +262,7 @@
   [(def .public (<name> options)
      (-> Text (Parser Slice))
      (function (_ [offset tape])
-       (case (/.char offset tape)
+       (when (/.char offset tape)
          {.#Some output}
          (let [output' (/.of_char output)]
            (if (<modifier> (/.contains? output' options))
@@ -285,7 +285,7 @@
 (def .public (satisfies parser)
   (-> (-> Char Bit) (Parser Text))
   (function (_ [offset tape])
-    (case (/.char offset tape)
+    (when (/.char offset tape)
       {.#Some output}
       (if (parser output)
         {try.#Success [[("lux i64 +" 1 offset) tape] (/.of_char output)]}
@@ -297,7 +297,7 @@
 (def .public (satisfies! parser)
   (-> (-> Char Bit) (Parser Slice))
   (function (_ [offset tape])
-    (case (/.char offset tape)
+    (when (/.char offset tape)
       {.#Some output}
       (if (parser output)
         {try.#Success [[("lux i64 +" 1 offset) tape]
@@ -390,7 +390,7 @@
 (def .public (local local_input parser)
   (All (_ a) (-> Text (Parser a) (Parser a)))
   (function (_ real_input)
-    (case (..result parser local_input)
+    (when (..result parser local_input)
       {try.#Failure error}
       {try.#Failure error}
 
diff --git a/stdlib/source/parser/lux/meta/code.lux b/stdlib/source/parser/lux/meta/code.lux
index 844c0e1c2..b0a23eb8c 100644
--- a/stdlib/source/parser/lux/meta/code.lux
+++ b/stdlib/source/parser/lux/meta/code.lux
@@ -23,7 +23,7 @@
 
 (def (un_paired pairs)
   (All (_ a) (-> (List [a a]) (List a)))
-  (case pairs
+  (when pairs
     {.#End}
     {.#End}
     
@@ -42,7 +42,7 @@
 (def .public any
   (Parser Code)
   (function (_ tokens)
-    (case tokens
+    (when tokens
       {.#End}
       {try.#Failure "There are no tokens to parse!"}
       
@@ -52,7 +52,7 @@
 (def .public next
   (Parser Code)
   (function (_ tokens)
-    (case tokens
+    (when tokens
       {.#End}
       {try.#Failure "There are no tokens to parse!"}
       
@@ -64,7 +64,7 @@
      (def .public <query>
        (Parser <type>)
        (function (_ tokens)
-         (case tokens
+         (when tokens
            {.#Item [[_ {<tag> x}] tokens']}
            {try.#Success [tokens' x]}
 
@@ -74,7 +74,7 @@
      (def .public (<check> expected)
        (-> <type> (Parser Any))
        (function (_ tokens)
-         (case tokens
+         (when tokens
            {.#Item [[_ {<tag> actual}] tokens']}
            (if (at <eq> = expected actual)
              {try.#Success [tokens' []]}
@@ -95,7 +95,7 @@
 (def .public (this code)
   (-> Code (Parser Any))
   (function (_ tokens)
-    (case tokens
+    (when tokens
       {.#Item [token tokens']}
       (if (code#= code token)
         {try.#Success [tokens' []]}
@@ -109,7 +109,7 @@
   (def .public local
     (Parser Text)
     (function (_ tokens)
-      (case tokens
+      (when tokens
         {.#Item [[_ {.#Symbol ["" x]}] tokens']}
         {try.#Success [tokens' x]}
 
@@ -119,7 +119,7 @@
   (def .public (this_local expected)
     (-> Text (Parser Any))
     (function (_ tokens)
-      (case tokens
+      (when tokens
         {.#Item [[_ {.#Symbol ["" actual]}] tokens']}
         (if (at text.equivalence = expected actual)
           {try.#Success [tokens' []]}
@@ -132,7 +132,7 @@
   (def .public global
     (Parser Symbol)
     (function (_ tokens)
-      (case tokens
+      (when tokens
         {.#Item [[_ {.#Symbol ["" short]}] tokens']}
         <failure>
         
@@ -145,7 +145,7 @@
   (def .public (this_global expected)
     (-> Symbol (Parser Any))
     (function (_ tokens)
-      (case tokens
+      (when tokens
         {.#Item [[_ {.#Symbol ["" actual]}] tokens']}
         <failure>
         
@@ -162,9 +162,9 @@
      (All (_ a)
        (-> (Parser a) (Parser a)))
      (function (_ tokens)
-       (case tokens
+       (when tokens
          {.#Item [[_ {<tag> members}] tokens']}
-         (case (p members)
+         (when (p members)
            {try.#Success [{.#End} x]} {try.#Success [tokens' x]}
            _                          {try.#Failure (all text#composite "Parser was expected to fully consume " <desc> (remaining_inputs tokens))})
 
@@ -179,25 +179,25 @@
 (def .public end
   (Parser Any)
   (function (_ tokens)
-    (case tokens
+    (when tokens
       {.#End} {try.#Success [tokens []]}
       _       {try.#Failure (all text#composite "Expected list of tokens to be empty!" (remaining_inputs tokens))})))
 
 (def .public end?
   (Parser Bit)
   (function (_ tokens)
-    {try.#Success [tokens (case tokens
+    {try.#Success [tokens (when tokens
                             {.#End} true
                             _       false)]}))
 
 (def .public (result parser inputs)
   (All (_ a) (-> (Parser a) (List Code) (Try a)))
-  (case (parser inputs)
+  (when (parser inputs)
     {try.#Failure error}
     {try.#Failure error}
 
     {try.#Success [unconsumed value]}
-    (case unconsumed
+    (when unconsumed
       {.#End}
       {try.#Success value}
 
@@ -220,6 +220,6 @@
     [sample ..next
      result (//.or parser
                    ..any)]
-    (case result
+    (when result
       {.#Left _} (//.failure (text#composite "Did NOT expect to parse code: " (code.format sample)))
       {.#Right output} (in output))))
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 e8be9f6dc..0d98f3bd4 100644
--- a/stdlib/source/parser/lux/meta/compiler/language/lux/analysis.lux
+++ b/stdlib/source/parser/lux/meta/compiler/language/lux/analysis.lux
@@ -50,7 +50,7 @@
 
 (def .public (result parser input)
   (All (_ a) (-> (Parser a) (List Analysis) (Try a)))
-  (case (parser input)
+  (when (parser input)
     {try.#Failure error}
     {try.#Failure error}
 
@@ -63,7 +63,7 @@
 (def .public any
   (Parser Analysis)
   (function (_ input)
-    (case input
+    (when input
       {.#End}
       (exception.except ..cannot_parse input)
       
@@ -73,7 +73,7 @@
 (def .public end
   (Parser Any)
   (function (_ tokens)
-    (case tokens
+    (when tokens
       {.#End} {try.#Success [tokens []]}
       _       {try.#Failure (format "Expected list of tokens to be empty!"
                                     (remaining_inputs tokens))})))
@@ -81,7 +81,7 @@
 (def .public end?
   (Parser Bit)
   (function (_ tokens)
-    {try.#Success [tokens (case tokens
+    {try.#Success [tokens (when tokens
                             {.#End} true
                             _       false)]}))
 
@@ -89,7 +89,7 @@
   [(`` (these (def .public <query>
                 (Parser <type>)
                 (function (_ input)
-                  (case input
+                  (when input
                     (list.partial (<tag> x) input')
                     {try.#Success [input' x]}
 
@@ -99,7 +99,7 @@
               (def .public (<assertion> expected)
                 (-> <type> (Parser Any))
                 (function (_ input)
-                  (case input
+                  (when input
                     (list.partial (<tag> actual) input')
                     (if (at <eq> = expected actual)
                       {try.#Success [input' []]}
@@ -122,7 +122,7 @@
 (def .public (tuple parser)
   (All (_ a) (-> (Parser a) (Parser a)))
   (function (_ input)
-    (case input
+    (when input
       (list.partial (/.tuple head) tail)
       (do try.monad
         [output (..result parser head)]
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 9431da2a7..fda40e0cd 100644
--- a/stdlib/source/parser/lux/meta/compiler/language/lux/synthesis.lux
+++ b/stdlib/source/parser/lux/meta/compiler/language/lux/synthesis.lux
@@ -55,7 +55,7 @@
 
 (def .public (result parser input)
   (All (_ a) (-> (Parser a) (List Synthesis) (Try a)))
-  (case (parser input)
+  (when (parser input)
     {try.#Failure error}
     {try.#Failure error}
 
@@ -68,7 +68,7 @@
 (def .public any
   (Parser Synthesis)
   (.function (_ input)
-    (case input
+    (when input
       {.#End}
       (exception.except ..empty_input [])
       
@@ -78,14 +78,14 @@
 (def .public end
   (Parser Any)
   (.function (_ tokens)
-    (case tokens
+    (when tokens
       {.#End} {try.#Success [tokens []]}
       _       (exception.except ..expected_empty_input [tokens]))))
 
 (def .public end?
   (Parser Bit)
   (.function (_ tokens)
-    {try.#Success [tokens (case tokens
+    {try.#Success [tokens (when tokens
                             {.#End} true
                             _       false)]}))
 
@@ -93,7 +93,7 @@
   [(`` (def .public <query>
          (Parser <type>)
          (.function (_ input)
-           (case input
+           (when input
              (list.partial (<tag> x) input')
              {try.#Success [input' x]}
 
@@ -103,7 +103,7 @@
    (`` (def .public (<assertion> expected)
          (-> <type> (Parser Any))
          (.function (_ input)
-           (case input
+           (when input
              (list.partial (<tag> actual) input')
              (if (at <eq> = expected actual)
                {try.#Success [input' []]}
@@ -124,7 +124,7 @@
 (def .public (tuple parser)
   (All (_ a) (-> (Parser a) (Parser a)))
   (.function (_ input)
-    (case input
+    (when input
       (list.partial (/.tuple head) tail)
       (do try.monad
         [output (..result parser head)]
@@ -136,7 +136,7 @@
 (def .public (function expected parser)
   (All (_ a) (-> Arity (Parser a) (Parser [(Environment Synthesis) a])))
   (.function (_ input)
-    (case input
+    (when input
       (list.partial (/.function/abstraction [environment actual body]) tail)
       (if (n.= expected actual)
         (do try.monad
@@ -150,7 +150,7 @@
 (def .public (loop init_parsers iteration_parser)
   (All (_ a b) (-> (Parser a) (Parser b) (Parser [Register a b])))
   (.function (_ input)
-    (case input
+    (when input
       (list.partial (/.loop/scope [start inits iteration]) tail)
       (do try.monad
         [inits (..result init_parsers inits)
diff --git a/stdlib/source/parser/lux/meta/type.lux b/stdlib/source/parser/lux/meta/type.lux
index b7cc07bef..f93efcd6d 100644
--- a/stdlib/source/parser/lux/meta/type.lux
+++ b/stdlib/source/parser/lux/meta/type.lux
@@ -77,12 +77,12 @@
 
 (def (result' env poly types)
   (All (_ a) (-> Env (Parser a) (List Type) (Try a)))
-  (case (//.result poly [env types])
+  (when (//.result poly [env types])
     {try.#Failure error}
     {try.#Failure error}
 
     {try.#Success [[env' remaining] output]}
-    (case remaining
+    (when remaining
       {.#End}
       {try.#Success output}
 
@@ -101,7 +101,7 @@
 (def (with_env temp poly)
   (All (_ a) (-> Env (Parser a) (Parser a)))
   (.function (_ [env inputs])
-    (case (//.result poly [temp inputs])
+    (when (//.result poly [temp inputs])
       {try.#Failure error}
       {try.#Failure error}
 
@@ -111,7 +111,7 @@
 (def .public next
   (Parser Type)
   (.function (_ [env inputs])
-    (case inputs
+    (when inputs
       {.#End}
       (exception.except ..empty_input [])
 
@@ -121,7 +121,7 @@
 (def .public any
   (Parser Type)
   (.function (_ [env inputs])
-    (case inputs
+    (when inputs
       {.#End}
       (exception.except ..empty_input [])
 
@@ -131,7 +131,7 @@
 (def .public (local types poly)
   (All (_ a) (-> (List Type) (Parser a) (Parser a)))
   (.function (_ [env pass_through])
-    (case (result' env poly types)
+    (when (result' env poly types)
       {try.#Failure error}
       {try.#Failure error}
 
@@ -147,7 +147,7 @@
   (.function (_ [env inputs])
     (let [current_id (dictionary.size env)
           g!var (label current_id)]
-      (case (//.result poly
+      (when (//.result poly
                        [(dictionary.has current_id [type g!var] env)
                         inputs])
         {try.#Failure error}
@@ -261,9 +261,9 @@
   (do //.monad
     [env ..env
      headT any]
-    (case headT
+    (when headT
       {.#Parameter idx}
-      (case (dictionary.value (..argument env idx) env)
+      (when (dictionary.value (..argument env idx) env)
         {.#Some [poly_type poly_code]}
         (in poly_code)
 
@@ -278,7 +278,7 @@
   (do //.monad
     [env ..env
      headT any]
-    (case headT
+    (when headT
       {.#Parameter idx}
       (if (n.= id (..argument env idx))
         (in [])
@@ -291,7 +291,7 @@
   (Parser Nat)
   (do //.monad
     [headT any]
-    (case headT
+    (when headT
       {.#Ex ex_id}
       (in ex_id)
 
@@ -302,7 +302,7 @@
   (Parser [Symbol Type])
   (do //.monad
     [inputT any]
-    (case inputT
+    (when inputT
       {.#Named name anonymousT}
       (in [name anonymousT])
 
@@ -313,7 +313,7 @@
   (All (_ a) (-> (Parser a) (Parser [Code a])))
   (do [! //.monad]
     [headT any]
-    (case (/.anonymous headT)
+    (when (/.anonymous headT)
       {.#Apply (|recursion_dummy|) {.#UnivQ _ headT'}}
       (do !
         [[recT _ output] (|> poly
@@ -330,7 +330,7 @@
   (do //.monad
     [env ..env
      headT any]
-    (case (/.anonymous headT)
+    (when (/.anonymous headT)
       (^.multi {.#Apply (|recursion_dummy|) {.#Parameter funcT_idx}}
                (n.= 0 (..argument env funcT_idx))
                [(dictionary.value 0 env) {.#Some [self_type self_call]}])
diff --git a/stdlib/source/parser/lux/program.lux b/stdlib/source/parser/lux/program.lux
index eff42b3ad..c9ec8b72a 100644
--- a/stdlib/source/parser/lux/program.lux
+++ b/stdlib/source/parser/lux/program.lux
@@ -15,9 +15,9 @@
 
 (def .public (result parser inputs)
   (All (_ a) (-> (Parser a) (List Text) (Try a)))
-  (case (//.result parser inputs)
+  (when (//.result parser inputs)
     {try.#Success [remaining output]}
-    (case remaining 
+    (when remaining 
       {.#End}
       {try.#Success output}
 
@@ -30,7 +30,7 @@
 (def .public any
   (Parser Text)
   (function (_ inputs)
-    (case inputs
+    (when inputs
       {.#Item arg inputs'}
       {try.#Success [inputs' arg]}
       
@@ -58,9 +58,9 @@
   (All (_ a) (-> (Parser a) (Parser a)))
   (function (_ inputs)
     (loop (again [immediate inputs])
-      (case (//.result cli immediate)
+      (when (//.result cli immediate)
         {try.#Failure try}
-        (case immediate
+        (when immediate
           {.#End}
           {try.#Failure try}
           
@@ -76,7 +76,7 @@
 (def .public end
   (Parser Any)
   (function (_ inputs)
-    (case inputs
+    (when inputs
       {.#End} {try.#Success [inputs []]}
       _       {try.#Failure (format "Unknown parameters: " (text.interposed " " inputs))})))
 
diff --git a/stdlib/source/parser/lux/world/environment.lux b/stdlib/source/parser/lux/world/environment.lux
index 311048fdf..10230d5a1 100644
--- a/stdlib/source/parser/lux/world/environment.lux
+++ b/stdlib/source/parser/lux/world/environment.lux
@@ -32,7 +32,7 @@
 (def .public (property name)
   (-> Property (Parser Text))
   (function (_ environment)
-    (case (dictionary.value name environment)
+    (when (dictionary.value name environment)
       {.#Some value}
       {try.#Success [environment value]}
       
-- 
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