New module just for the Char type + fixes to JSON parsing.

12 files changed, 393 insertions, 201 deletions

diff --git a/stdlib/source/library/lux/data/format/json.lux b/stdlib/source/library/lux/data/format/json.lux
index a5b036478..32cfd2a3e 100644
--- a/stdlib/source/library/lux/data/format/json.lux
+++ b/stdlib/source/library/lux/data/format/json.lux
@@ -360,29 +360,34 @@
                      offset (<text>.many <text>.decimal)]
                     (in (all text#composite mark (if signed?' "-" "") offset))))]
     (when (f#decoded (all text#composite (if signed? "-" "") digits "." decimals exp))
-      {try.#Failure message}
-      (<>.failure message)
-      
       {try.#Success value}
-      (in value))))
+      (in value)
+
+      {try.#Failure message}
+      (<>.failure message))))
 
 (def escaped_parser
   (Parser Text)
-  (all <>.either
-       (<>.after (<text>.this "\t")
-                 (<>#in text.tab))
-       (<>.after (<text>.this "\b")
-                 (<>#in text.back_space))
-       (<>.after (<text>.this "\n")
-                 (<>#in text.new_line))
-       (<>.after (<text>.this "\r")
-                 (<>#in text.carriage_return))
-       (<>.after (<text>.this "\f")
-                 (<>#in text.form_feed))
-       (<>.after (<text>.this (text#composite "\" text.double_quote))
-                 (<>#in text.double_quote))
-       (<>.after (<text>.this "\\")
-                 (<>#in "\"))))
+  (`` (all <>.either
+           (,, (with_template [<when> <then>]
+                 [(<>.after (<text>.this <when>)
+                            (<>#in <then>))]
+
+                 ["\t" text.tab]
+                 ["\b" text.back_space]
+                 ["\n" text.new_line]
+                 ["\r" text.carriage_return]
+                 ["\f" text.form_feed]
+                 [(text#composite "\" text.double_quote) text.double_quote]
+                 ["\\" "\"]
+                 ))
+           (<>.after (<text>.this "\u")
+                     (|> <text>.hexadecimal!
+                         (<text>.exactly! 4)
+                         <text>.slice
+                         (<>.codec n.hex)
+                         (<>#each text.of_char)))
+           )))
 
 (def string_parser
   (Parser String)
@@ -425,15 +430,17 @@
 
 (def json_parser
   (Parser JSON)
-  (<>.rec
-   (function (_ json_parser)
-     (all <>.or
-          null_parser
-          boolean_parser
-          number_parser
-          string_parser
-          (array_parser json_parser)
-          (object_parser json_parser)))))
+  (<| (<>.after ..space_parser)
+      (<>.before ..space_parser)
+      (<>.rec
+       (function (_ json_parser)
+         (all <>.or
+              null_parser
+              boolean_parser
+              number_parser
+              string_parser
+              (array_parser json_parser)
+              (object_parser json_parser))))))
 
 (def .public codec
   (Codec Text JSON)
diff --git a/stdlib/source/library/lux/data/format/tar.lux b/stdlib/source/library/lux/data/format/tar.lux
index cc6317ae5..9220719da 100644
--- a/stdlib/source/library/lux/data/format/tar.lux
+++ b/stdlib/source/library/lux/data/format/tar.lux
@@ -15,7 +15,8 @@
      ["[1]!" \\unsafe]
      ["[0]" \\format (.only Format) (.use "[1]#[0]" monoid)]
      ["<[1]>" \\parser (.only Parser)]]
-    ["[0]" text (.only Char)
+    ["[0]" text (.only)
+     [char (.only Char)]
      ["%" \\format]
      [encoding
       ["[0]" utf8]]]
diff --git a/stdlib/source/library/lux/data/text.lux b/stdlib/source/library/lux/data/text.lux
index 2df34e163..c66e10c61 100644
--- a/stdlib/source/library/lux/data/text.lux
+++ b/stdlib/source/library/lux/data/text.lux
@@ -18,10 +18,9 @@
      ["n" nat]
      ["[0]" i64]]]
    [meta
-    ["@" target]]]])
-
-(type .public Char
-  Nat)
+    ["@" target]]]]
+ [/
+  ["[0]" char (.only Char)]])
 
 ... TODO: Instead of ints, chars should be produced fron nats.
 ... (The JVM specifies chars as 16-bit unsigned integers)
@@ -33,18 +32,19 @@
   [(def .public <long> (..of_char <code>))
    (def .public <short> <long>)]
 
-  [00 \0  null]
-  [07 \a  alarm]
-  [08 \b  back_space]
-  [09 \t  tab]
-  [10 \n  new_line]
-  [11 \v  vertical_tab]
-  [12 \f  form_feed]
-  [13 \r  carriage_return]
-  [34 \'' double_quote]
+  [char.\0  \0  null]
+  [char.\a  \a  alarm]
+  [char.\b  \b  back_space]
+  [char.\t  \t  tab]
+  [char.\n  \n  new_line]
+  [char.\v  \v  vertical_tab]
+  [char.\f  \f  form_feed]
+  [char.\r  \r  carriage_return]
+  [char.\'' \'' double_quote]
   )
 
 (def .public line_feed
+  Text
   ..new_line)
 
 (def .public size
diff --git a/stdlib/source/library/lux/data/text/char.lux b/stdlib/source/library/lux/data/text/char.lux
new file mode 100644
index 000000000..fd419342f
--- /dev/null
+++ b/stdlib/source/library/lux/data/text/char.lux
@@ -0,0 +1,59 @@
+(.require
+ [library
+  [lux (.except)]])
+
+(type .public Unicode
+  Nat)
+
+(type .public Char
+  Unicode)
+
+... https://en.wikipedia.org/wiki/ASCII
+(with_template [<code> <short> <long>]
+  [(def .public <long> Char <code>)
+   (def .public <short> Char <long>)]
+
+  [00 \0  null]
+  [07 \a  alarm]
+  [08 \b  back_space]
+  [09 \t  tab]
+  [10 \n  new_line]
+  [11 \v  vertical_tab]
+  [12 \f  form_feed]
+  [13 \r  carriage_return]
+  [34 \'' double_quote]
+  )
+
+(def .public line_feed
+  Char
+  ..new_line)
+
+(with_template [<code> <long>]
+  [(def .public <long> Char <code>)]
+
+  [001 start_of_heading]
+  [002 start_of_text]
+  [003 end_of_text]
+  [004 end_of_transmission]
+  [005 enquiry]
+  [006 acknowledgement]
+  [014 shift_out]
+  [015 shift_in]
+  [016 data_link_escape]
+  [017 device_control_1]
+  [018 device_control_2]
+  [019 device_control_3]
+  [020 device_control_4]
+  [021 negative_acknowledgement]
+  [022 synchronous_idle]
+  [023 end_of_transmission_block]
+  [024 cancel]
+  [025 end_of_medium]
+  [026 substitute]
+  [027 escape]
+  [028 file_separator]
+  [029 group_separator]
+  [030 record_separator]
+  [031 unit_separator]
+  [127 delete]
+  )
diff --git a/stdlib/source/library/lux/data/text/escape.lux b/stdlib/source/library/lux/data/text/escape.lux
index 46e2ca8e2..f16005def 100644
--- a/stdlib/source/library/lux/data/text/escape.lux
+++ b/stdlib/source/library/lux/data/text/escape.lux
@@ -17,7 +17,8 @@
     [macro
      [syntax (.only syntax)]
      ["^" pattern]]]]]
- ["[0]" // (.only Char)
+ ["[0]" // (.only)
+  [char (.only Char)]
   ["%" \\format (.only format)]])
 
 (def sigil "\")
diff --git a/stdlib/source/library/lux/data/text/unicode/block.lux b/stdlib/source/library/lux/data/text/unicode/block.lux
index bb61c05be..7a97b8803 100644
--- a/stdlib/source/library/lux/data/text/unicode/block.lux
+++ b/stdlib/source/library/lux/data/text/unicode/block.lux
@@ -13,7 +13,8 @@
    [meta
     [type
      [primitive (.except)]]]]]
- [/// (.only Char)])
+ [///
+  [char (.only Char)]])
 
 (primitive .public Block
   (Interval Char)
diff --git a/stdlib/source/library/lux/data/text/unicode/set.lux b/stdlib/source/library/lux/data/text/unicode/set.lux
index 771fb287f..732a52ddc 100644
--- a/stdlib/source/library/lux/data/text/unicode/set.lux
+++ b/stdlib/source/library/lux/data/text/unicode/set.lux
@@ -12,13 +12,13 @@
    [meta
     [type (.only by_example)
      [primitive (.except)]]]]]
- ["[0]" /
-  ["/[1]" //
-   [// (.only Char)]
-   ["[1][0]" block (.only Block)]]])
+ [//
+  ["[0]" block (.only Block)]
+  [//
+   [char (.only Char)]]])
 
 (def builder
-  (tree.builder //block.monoid))
+  (tree.builder block.monoid))
 
 (def :@:
   (by_example [@]
@@ -52,103 +52,103 @@
 
   (def character/0
     Set
-    (..set [//block.basic_latin
-            (list //block.latin_1_supplement
-                  //block.latin_extended_a
-                  //block.latin_extended_b
-                  //block.ipa_extensions
-                  //block.spacing_modifier_letters
-                  //block.combining_diacritical_marks
-                  //block.greek_and_coptic
-                  //block.cyrillic
-                  //block.cyrillic_supplementary
-                  //block.armenian
-                  //block.hebrew
-                  //block.arabic
-                  //block.syriac
-                  //block.thaana
-                  //block.devanagari
-                  //block.bengali
-                  //block.gurmukhi
-                  //block.gujarati
-                  //block.oriya
-                  //block.tamil
-                  //block.telugu
-                  //block.kannada
-                  //block.malayalam
-                  //block.sinhala
-                  //block.thai
-                  //block.lao
-                  //block.tibetan
-                  //block.myanmar
-                  //block.georgian)]))
+    (..set [block.basic_latin
+            (list block.latin_1_supplement
+                  block.latin_extended_a
+                  block.latin_extended_b
+                  block.ipa_extensions
+                  block.spacing_modifier_letters
+                  block.combining_diacritical_marks
+                  block.greek_and_coptic
+                  block.cyrillic
+                  block.cyrillic_supplementary
+                  block.armenian
+                  block.hebrew
+                  block.arabic
+                  block.syriac
+                  block.thaana
+                  block.devanagari
+                  block.bengali
+                  block.gurmukhi
+                  block.gujarati
+                  block.oriya
+                  block.tamil
+                  block.telugu
+                  block.kannada
+                  block.malayalam
+                  block.sinhala
+                  block.thai
+                  block.lao
+                  block.tibetan
+                  block.myanmar
+                  block.georgian)]))
 
   (def character/1
     Set
-    (..set [//block.hangul_jamo
-            (list //block.ethiopic
-                  //block.cherokee
-                  //block.unified_canadian_aboriginal_syllabics
-                  //block.ogham
-                  //block.runic
-                  //block.tagalog
-                  //block.hanunoo
-                  //block.buhid
-                  //block.tagbanwa
-                  //block.khmer
-                  //block.mongolian
-                  //block.limbu
-                  //block.tai_le
-                  //block.khmer_symbols
-                  //block.phonetic_extensions
-                  //block.latin_extended_additional
-                  //block.greek_extended
-                  //block.general_punctuation
-                  //block.superscripts_and_subscripts
-                  //block.currency_symbols
-                  //block.combining_diacritical_marks_for_symbols
-                  //block.letterlike_symbols
-                  //block.number_forms
-                  //block.arrows
-                  //block.mathematical_operators
-                  //block.miscellaneous_technical
-                  //block.control_pictures
-                  //block.optical_character_recognition
-                  //block.enclosed_alphanumerics
-                  //block.box_drawing)]))
+    (..set [block.hangul_jamo
+            (list block.ethiopic
+                  block.cherokee
+                  block.unified_canadian_aboriginal_syllabics
+                  block.ogham
+                  block.runic
+                  block.tagalog
+                  block.hanunoo
+                  block.buhid
+                  block.tagbanwa
+                  block.khmer
+                  block.mongolian
+                  block.limbu
+                  block.tai_le
+                  block.khmer_symbols
+                  block.phonetic_extensions
+                  block.latin_extended_additional
+                  block.greek_extended
+                  block.general_punctuation
+                  block.superscripts_and_subscripts
+                  block.currency_symbols
+                  block.combining_diacritical_marks_for_symbols
+                  block.letterlike_symbols
+                  block.number_forms
+                  block.arrows
+                  block.mathematical_operators
+                  block.miscellaneous_technical
+                  block.control_pictures
+                  block.optical_character_recognition
+                  block.enclosed_alphanumerics
+                  block.box_drawing)]))
 
   (def character/2
     Set
-    (..set [//block.block_elements
-            (list //block.geometric_shapes
-                  //block.miscellaneous_symbols
-                  //block.dingbats
-                  //block.miscellaneous_mathematical_symbols_a
-                  //block.supplemental_arrows_a
-                  //block.braille_patterns
-                  //block.supplemental_arrows_b
-                  //block.miscellaneous_mathematical_symbols_b
-                  //block.supplemental_mathematical_operators
-                  //block.miscellaneous_symbols_and_arrows
-                  //block.cjk_radicals_supplement
-                  //block.kangxi_radicals
-                  //block.ideographic_description_characters
-                  //block.cjk_symbols_and_punctuation
-                  //block.hiragana
-                  //block.katakana
-                  //block.bopomofo
-                  //block.hangul_compatibility_jamo
-                  //block.kanbun
-                  //block.bopomofo_extended
-                  //block.katakana_phonetic_extensions
-                  //block.enclosed_cjk_letters_and_months
-                  //block.cjk_compatibility
-                  //block.cjk_unified_ideographs_extension_a
-                  //block.yijing_hexagram_symbols
-                  //block.cjk_unified_ideographs
-                  //block.yi_syllables
-                  //block.yi_radicals
-                  //block.hangul_syllables
+    (..set [block.block_elements
+            (list block.geometric_shapes
+                  block.miscellaneous_symbols
+                  block.dingbats
+                  block.miscellaneous_mathematical_symbols_a
+                  block.supplemental_arrows_a
+                  block.braille_patterns
+                  block.supplemental_arrows_b
+                  block.miscellaneous_mathematical_symbols_b
+                  block.supplemental_mathematical_operators
+                  block.miscellaneous_symbols_and_arrows
+                  block.cjk_radicals_supplement
+                  block.kangxi_radicals
+                  block.ideographic_description_characters
+                  block.cjk_symbols_and_punctuation
+                  block.hiragana
+                  block.katakana
+                  block.bopomofo
+                  block.hangul_compatibility_jamo
+                  block.kanbun
+                  block.bopomofo_extended
+                  block.katakana_phonetic_extensions
+                  block.enclosed_cjk_letters_and_months
+                  block.cjk_compatibility
+                  block.cjk_unified_ideographs_extension_a
+                  block.yijing_hexagram_symbols
+                  block.cjk_unified_ideographs
+                  block.yi_syllables
+                  block.yi_radicals
+                  block.hangul_syllables
                   )]))
 
   (def .public character
@@ -161,37 +161,37 @@
 
   (def .public non_character
     Set
-    (..set [//block.high_surrogates
-            (list  //block.high_private_use_surrogates
-                   //block.low_surrogates
-                   //block.private_use_area
-                   //block.cjk_compatibility_ideographs
-                   //block.alphabetic_presentation_forms
-                   //block.arabic_presentation_forms_a
-                   //block.variation_selectors
-                   //block.combining_half_marks
-                   //block.cjk_compatibility_forms
-                   //block.small_form_variants
-                   //block.arabic_presentation_forms_b
-                   //block.halfwidth_and_fullwidth_forms
-                   //block.specials
-                   ... //block.linear_b_syllabary
-                   ... //block.linear_b_ideograms
-                   ... //block.aegean_numbers
-                   ... //block.old_italic
-                   ... //block.gothic
-                   ... //block.ugaritic
-                   ... //block.deseret
-                   ... //block.shavian
-                   ... //block.osmanya
-                   ... //block.cypriot_syllabary
-                   ... //block.byzantine_musical_symbols
-                   ... //block.musical_symbols
-                   ... //block.tai_xuan_jing_symbols
-                   ... //block.mathematical_alphanumeric_symbols
-                   ... //block.cjk_unified_ideographs_extension_b
-                   ... //block.cjk_compatibility_ideographs_supplement
-                   ... //block.tags
+    (..set [block.high_surrogates
+            (list  block.high_private_use_surrogates
+                   block.low_surrogates
+                   block.private_use_area
+                   block.cjk_compatibility_ideographs
+                   block.alphabetic_presentation_forms
+                   block.arabic_presentation_forms_a
+                   block.variation_selectors
+                   block.combining_half_marks
+                   block.cjk_compatibility_forms
+                   block.small_form_variants
+                   block.arabic_presentation_forms_b
+                   block.halfwidth_and_fullwidth_forms
+                   block.specials
+                   ... block.linear_b_syllabary
+                   ... block.linear_b_ideograms
+                   ... block.aegean_numbers
+                   ... block.old_italic
+                   ... block.gothic
+                   ... block.ugaritic
+                   ... block.deseret
+                   ... block.shavian
+                   ... block.osmanya
+                   ... block.cypriot_syllabary
+                   ... block.byzantine_musical_symbols
+                   ... block.musical_symbols
+                   ... block.tai_xuan_jing_symbols
+                   ... block.mathematical_alphanumeric_symbols
+                   ... block.cjk_unified_ideographs_extension_b
+                   ... block.cjk_compatibility_ideographs_supplement
+                   ... block.tags
                    )]))
 
   (def .public full
@@ -205,18 +205,18 @@
     (-> Set Char)
     (|>> representation
          tree.tag
-         //block.start))
+         block.start))
 
   (def .public end
     (-> Set Char)
     (|>> representation
          tree.tag
-         //block.end))
+         block.end))
 
   (def .public (member? set character)
     (-> Set Char Bit)
     (loop (again [tree (representation set)])
-      (if (//block.within? (tree.tag tree) character)
+      (if (block.within? (tree.tag tree) character)
         (when (tree.root tree)
           {0 #0 _}
           true
@@ -230,8 +230,8 @@
     (Equivalence Set)
     (implementation
      (def (= reference subject)
-       (set#= (set.of_list //block.hash (tree.tags (representation reference)))
-              (set.of_list //block.hash (tree.tags (representation subject)))))))
+       (set#= (set.of_list block.hash (tree.tags (representation reference)))
+              (set.of_list block.hash (tree.tags (representation subject)))))))
   )
 
 (with_template [<name> <blocks>]
@@ -239,10 +239,10 @@
      Set
      (..set <blocks>))]
 
-  [ascii         [//block.basic_latin (list)]]
-  [alphabetic    [//block.upper_case (list //block.lower_case)]]
-  [alpha_numeric [//block.upper_case (list //block.lower_case //block.numeric)]]
-  [numeric       [//block.numeric (list)]]
-  [upper_case    [//block.upper_case (list)]]
-  [lower_case    [//block.lower_case (list)]]
+  [ascii         [block.basic_latin (list)]]
+  [alphabetic    [block.upper_case (list block.lower_case)]]
+  [alpha_numeric [block.upper_case (list block.lower_case block.numeric)]]
+  [numeric       [block.numeric (list)]]
+  [upper_case    [block.upper_case (list)]]
+  [lower_case    [block.lower_case (list)]]
   )
diff --git a/stdlib/source/library/lux/math/number/int.lux b/stdlib/source/library/lux/math/number/int.lux
index 711e36c8f..4de53bfe9 100644
--- a/stdlib/source/library/lux/math/number/int.lux
+++ b/stdlib/source/library/lux/math/number/int.lux
@@ -13,9 +13,7 @@
     ["[0]" maybe]
     ["[0]" try (.only Try)]
     [function
-     [predicate (.only Predicate)]]]
-   [data
-    [text (.only Char)]]]]
+     [predicate (.only Predicate)]]]]]
  ["[0]" //
   ["[1][0]" nat]
   ["[1][0]" i64]])
diff --git a/stdlib/source/library/lux/math/random.lux b/stdlib/source/library/lux/math/random.lux
index 7f08ef23a..0027d81a9 100644
--- a/stdlib/source/library/lux/math/random.lux
+++ b/stdlib/source/library/lux/math/random.lux
@@ -7,7 +7,8 @@
     [apply (.only Apply)]
     ["[0]" monad (.only Monad do)]]
    [data
-    ["[0]" text (.only Char) (.use "[1]#[0]" monoid)
+    ["[0]" text (.use "[1]#[0]" monoid)
+     [char (.only Char)]
      ["[0]" unicode
       ["[1]" set]]]
     [collection
diff --git a/stdlib/source/library/lux/world/console.lux b/stdlib/source/library/lux/world/console.lux
index ac83dcc9f..37d8b3b07 100644
--- a/stdlib/source/library/lux/world/console.lux
+++ b/stdlib/source/library/lux/world/console.lux
@@ -13,7 +13,8 @@
      ["[0]" async (.only Async) (.use "[1]#[0]" monad)]
      ["[0]" atom]]]
    [data
-    ["[0]" text (.only Char)
+    ["[0]" text (.only)
+     [char (.only Char)]
      ["%" \\format (.only format)]]]
    [meta
     ["@" target]]]])
diff --git a/stdlib/source/library/lux/world/net/http/header.lux b/stdlib/source/library/lux/world/net/http/header.lux
index 9c8a75ff0..662310def 100644
--- a/stdlib/source/library/lux/world/net/http/header.lux
+++ b/stdlib/source/library/lux/world/net/http/header.lux
@@ -1,9 +1,11 @@
 (.require
  [library
   [lux (.except has)
+   [abstract
+    ["[0]" monad (.only do)]]
    [control
     ["[0]" pipe]
-    ["[0]" try (.only Try)]
+    ["[0]" try (.only Try) (.use "[1]#[0]" monad)]
     ["[0]" exception (.only Exception)]]
    [data
     ["[0]" text (.only)
@@ -17,7 +19,9 @@
  [//
   ["[0]" mime (.only MIME)]
   ["[0]" cookie]
-  [// (.only URL)]])
+  [// (.only URL)
+   ["[0]" uri
+    ["[1]" encoding]]]])
 
 (type .public Headers
   (Dictionary Text Text))
@@ -88,17 +92,20 @@
   [#name "Set-Cookie"
    #in (|>> dictionary.entries
             (list#mix (function (_ [name value] previous)
-                        (when previous
-                          "" (%.format name ..assignment value)
-                          _ (%.format previous ..separator name ..assignment value)))
+                        (with_expansions [<key,value> (these (uri.encoded name) ..assignment value)]
+                          (when previous
+                            "" (%.format <key,value>)
+                            _ (%.format previous ..separator <key,value>))))
                       ""))
    #out (|>> (text.all_split_by ..separator)
-             (list#mix (function (_ cookie jar)
-                         (when (text.split_by ..assignment cookie)
-                           {.#Some [name value]}
-                           (dictionary.has name value jar)
-                           
-                           {.#None}
-                           jar))
-                       cookie.empty)
-             {try.#Success})])
+             (monad.mix try.monad
+                        (function (_ cookie jar)
+                          (when (text.split_by ..assignment cookie)
+                            {.#Some [name value]}
+                            (do try.monad
+                              [name (uri.decoded name)]
+                              (in (dictionary.has name value jar)))
+                            
+                            {.#None}
+                            (try#in jar)))
+                        cookie.empty))])
diff --git a/stdlib/source/library/lux/world/net/uri/encoding.lux b/stdlib/source/library/lux/world/net/uri/encoding.lux
new file mode 100644
index 000000000..91a5c2020
--- /dev/null
+++ b/stdlib/source/library/lux/world/net/uri/encoding.lux
@@ -0,0 +1,116 @@
+... https://en.wikipedia.org/wiki/Percent-encoding
+(.require
+ [library
+  [lux (.except)
+   [abstract
+    [monad (.only do)]]
+   [control
+    ["[0]" try (.only Try)]
+    ["[0]" exception (.only Exception)]]
+   [data
+    ["[0]" text (.only)
+     [char (.only Char)]]
+    [collection
+     ["[0]" set (.only Set)]]]
+   [math
+    [number
+     ["[0]" nat]]]]])
+
+(type .public URI_Encoded
+  Text)
+
+(with_expansions [<reserved> (these [" " "%20"]
+                                    ["!" "%21"]
+                                    ["#" "%23"]
+                                    ["$" "%24"]
+                                    ["%" "%25"]
+                                    ["&" "%26"]
+                                    ["'" "%27"]
+                                    ["(" "%28"]
+                                    [")" "%29"]
+                                    ["*" "%2A"]
+                                    ["+" "%2B"]
+                                    ["," "%2C"]
+                                    ["/" "%2F"]
+                                    [":" "%3A"]
+                                    [";" "%3B"]
+                                    ["=" "%3D"]
+                                    ["?" "%3F"]
+                                    ["@" "%40"]
+                                    ["[" "%5B"]
+                                    ["]" "%5D"])]
+  (def .public reserved
+    (Set Char)
+    (set.of_list nat.hash
+                 (`` (list (,, (with_template [<char> <encoding>]
+                                 [(char <char>)]
+                                 
+                                 <reserved>))))))
+  
+  (def .public (encoded input)
+    (-> Text URI_Encoded)
+    (let [size (text.size input)]
+      (loop (again [index 0
+                    slice_start 0
+                    output ""])
+        (if (nat.< size index)
+          (`` (when (.text_char# index input)
+                (,, (with_template [<char> <encoding>]
+                      [(char <char>)
+                       (let [index' (++ index)]
+                         (again index'
+                                index'
+                                (all .text_composite#
+                                     output
+                                     (.text_clip# slice_start (nat.- slice_start index) input)
+                                     <encoding>)))]
+
+                      <reserved>))
+                
+                _
+                (again (++ index)
+                       slice_start
+                       output)))
+          (all .text_composite#
+               output
+               (.text_clip# slice_start (nat.- slice_start index) input))))))
+  )
+
+(def escape (char "%"))
+
+(exception.def (invalid it)
+  (Exception URI_Encoded)
+  (exception.report
+   (list ["Value" (text.format it)])))
+
+(def .public (decoded input)
+  (-> URI_Encoded (Try Text))
+  (let [size (text.size input)]
+    (loop (again [index 0
+                  slice_start 0
+                  output ""])
+      (if (nat.< size index)
+        (`` (when (.text_char# index input)
+              ..escape
+              (let [encoding_start (++ index)
+                    encoding_end (++ encoding_start)]
+                (if (nat.< size encoding_end)
+                  (do try.monad
+                    [value (|> input
+                               (.text_clip# encoding_start 2)
+                               (at nat.hex decoded))
+                     .let [index' (++ encoding_end)]]
+                    (again index'
+                           index'
+                           (all .text_composite# output
+                                (.text_clip# slice_start (nat.- slice_start index) input)
+                                (text.of_char value))))
+                  (exception.except ..invalid [input])))
+              
+              _
+              (again (++ index)
+                     slice_start
+                     output)))
+        {try.#Success (|> input
+                          (.text_clip# slice_start (nat.- slice_start index))
+                          (.text_composite# output))}))))