- Added formatters for JSON, XML and time types.

9 files changed, 148 insertions, 144 deletions

diff --git a/stdlib/source/lux/data/coll/dict.lux b/stdlib/source/lux/data/coll/dict.lux
index ac6a47891..0af8ed43e 100644
--- a/stdlib/source/lux/data/coll/dict.lux
+++ b/stdlib/source/lux/data/coll/dict.lux
@@ -7,7 +7,6 @@
                    [array #+ Array "Array/" Functor<Array> Fold<Array>])
              [bit]
              [product]
-             text/format
              [number])
        ))
 
diff --git a/stdlib/source/lux/data/format/json.lux b/stdlib/source/lux/data/format/json.lux
index 6d7ed16a7..c4951f188 100644
--- a/stdlib/source/lux/data/format/json.lux
+++ b/stdlib/source/lux/data/format/json.lux
@@ -9,10 +9,9 @@
                 codec
                 ["p" parser "p/" Monad<Parser>])
        (data [bool]
-             [text "Text/" Eq<Text> Monoid<Text>]
-             text/format
+             [text "text/" Eq<Text> Monoid<Text>]
              (text ["l" lexer])
-             [number "Real/" Codec<Text,Real>]
+             [number "real/" Codec<Text,Real> "nat/" Codec<Text,Nat>]
              maybe
              ["R" result]
              [sum]
@@ -116,18 +115,18 @@
 
 (def: (show-array show-json elems)
   (-> (-> JSON Text) (-> Array Text))
-  (format "["
-          (|> elems (Vector/map show-json) vector;to-list (text;join-with ","))
-          "]"))
+  ($_ text/append "["
+      (|> elems (Vector/map show-json) vector;to-list (text;join-with ","))
+      "]"))
 
 (def: (show-object show-json object)
   (-> (-> JSON Text) (-> Object Text))
-  (format "{"
-          (|> object
-              d;entries
-              (L/map (function [[key value]] (format (show-string key) ":" (show-json value))))
-              (text;join-with ","))
-          "}"))
+  ($_ text/append "{"
+      (|> object
+          d;entries
+          (L/map (function [[key value]] ($_ text/append (show-string key) ":" (show-json value))))
+          (text;join-with ","))
+      "}"))
 
 (def: (show-json json)
   (-> JSON Text)
@@ -156,7 +155,7 @@
     (#R;Success (d;keys obj))
 
     _
-    (#R;Error (format "Cannot get the fields of a non-object."))))
+    (#R;Error ($_ text/append "Cannot get the fields of a non-object."))))
 
 (def: #export (get key json)
   {#;doc "A JSON object field getter."}
@@ -168,10 +167,10 @@
       (#R;Success value)
 
       #;None
-      (#R;Error (format "Missing field " (show-string key) " on object.")))
+      (#R;Error ($_ text/append "Missing field " (show-string key) " on object.")))
 
     _
-    (#R;Error (format "Cannot get field " (show-string key) " of a non-object."))))
+    (#R;Error ($_ text/append "Cannot get field " (show-string key) " of a non-object."))))
 
 (def: #export (set key value json)
   {#;doc "A JSON object field setter."}
@@ -181,18 +180,18 @@
     (#R;Success (#Object (d;put key value obj)))
 
     _
-    (#R;Error (format "Cannot set field " (show-string key) " of a non-object."))))
+    (#R;Error ($_ text/append "Cannot set field " (show-string key) " of a non-object."))))
 
 (do-template [<name> <tag> <type> <desc>]
   [(def: #export (<name> key json)
-     {#;doc (#;TextA (format "A JSON object field getter for " <desc> "."))}
+     {#;doc (#;TextA ($_ text/append "A JSON object field getter for " <desc> "."))}
      (-> Text JSON (R;Result <type>))
      (case (get key json)
        (#R;Success (<tag> value))
        (#R;Success value)
 
        (#R;Success _)
-       (#R;Error (format "Wrong value type at key " (show-string key)))
+       (#R;Error ($_ text/append "Wrong value type at key " (show-string key)))
 
        (#R;Error error)
        (#R;Error error)))]
@@ -206,7 +205,7 @@
 
 (do-template [<name> <type> <tag> <desc>]
   [(def: #export (<name> value)
-     {#;doc (#;TextA (format "A JSON generator for " <desc> "."))}
+     {#;doc (#;TextA ($_ text/append "A JSON generator for " <desc> "."))}
      (Gen <type>)
      (<tag> value))]
 
@@ -269,8 +268,8 @@
              [mark (l;one-of "eE")
               signed?' (l;this? "-")
               offset (l;many l;decimal)]
-             (wrap (format mark (if signed?' "-" "") offset))))]
-    (case (Real/decode (format (if signed? "-" "") digits "." decimals exp))
+             (wrap ($_ text/append mark (if signed?' "-" "") offset))))]
+    (case (real/decode ($_ text/append (if signed? "-" "") digits "." decimals exp))
       (#R;Error message)
       (p;fail message)
       
@@ -295,11 +294,11 @@
         (do p;Monad<Parser>
           [chars (l;some (l;none-of "\\\""))
            stop l;peek]
-          (if (Text/= "\\" stop)
+          (if (text/= "\\" stop)
             (do @
               [escaped escaped~
                next-chars (recur [])]
-              (wrap (format chars escaped next-chars)))
+              (wrap ($_ text/append chars escaped next-chars)))
             (wrap chars))))))
 
 (def: (kv~ json~)
@@ -378,14 +377,14 @@
 ## Syntax
 (do-template [<name> <type> <tag> <desc> <pre>]
   [(def: #export (<name> json)
-     {#;doc (#;TextA (format "Reads a JSON value as " <desc> "."))}
+     {#;doc (#;TextA ($_ text/append "Reads a JSON value as " <desc> "."))}
      (Parser <type>)
      (case json
        (<tag> value)
        (#R;Success (<pre> value))
 
        _
-       (#R;Error (format "JSON value is not " <desc> ": " (show-json json)))))]
+       (#R;Error ($_ text/append "JSON value is not " <desc> ": " (show-json json)))))]
 
   [unit Unit #Null    "unit" id]
   [bool Bool #Boolean "bool" id]
@@ -396,28 +395,28 @@
 
 (do-template [<test> <check> <type> <eq> <encoder> <tag> <desc> <pre>]
   [(def: #export (<test> test json)
-     {#;doc (#;TextA (format "Asks whether a JSON value is a " <desc> "."))}
+     {#;doc (#;TextA ($_ text/append "Asks whether a JSON value is a " <desc> "."))}
      (-> <type> (Parser Bool))
      (case json
        (<tag> value)
        (#R;Success (:: <eq> = test (<pre> value)))
 
        _
-       (#R;Error (format "JSON value is not a " <desc> ": " (show-json json)))))
+       (#R;Error ($_ text/append "JSON value is not a " <desc> ": " (show-json json)))))
 
    (def: #export (<check> test json)
-     {#;doc (#;TextA (format "Ensures a JSON value is a " <desc> "."))}
+     {#;doc (#;TextA ($_ text/append "Ensures a JSON value is a " <desc> "."))}
      (-> <type> (Parser Unit))
      (case json
        (<tag> value)
        (let [value (<pre> value)]
          (if (:: <eq> = test value)
            (#R;Success [])
-           (#R;Error (format "Value mismatch: "
-                             (<encoder> test) "=/=" (<encoder> value)))))
+           (#R;Error ($_ text/append "Value mismatch: "
+                         (<encoder> test) "=/=" (<encoder> value)))))
 
        _
-       (#R;Error (format "JSON value is not a " <desc> ": " (show-json json)))))]
+       (#R;Error ($_ text/append "JSON value is not a " <desc> ": " (show-json json)))))]
 
   [bool? bool! Bool bool;Eq<Bool>   (:: bool;Codec<Text,Bool> encode)   #Boolean "boolean" id]
   [int?  int!  Int  number;Eq<Int>  (:: number;Codec<Text,Int> encode)  #Number  "number"  real-to-int]
@@ -453,7 +452,7 @@
         (wrap elems))
 
       _
-      (#R;Error (format "JSON value is not an array: " (show-json json))))))
+      (#R;Error ($_ text/append "JSON value is not an array: " (show-json json))))))
 
 (def: #export (object parser)
   {#;doc "Parses a JSON object, assuming that every field's value can be parsed the same way."}
@@ -471,7 +470,7 @@
         (wrap (d;from-list text;Hash<Text> kvs)))
 
       _
-      (#R;Error (format "JSON value is not an object: " (show-json json))))))
+      (#R;Error ($_ text/append "JSON value is not an object: " (show-json json))))))
 
 (def: #export (nth idx parser)
   {#;doc "Parses an element inside a JSON array."}
@@ -486,13 +485,13 @@
           (#R;Success output)
 
           (#R;Error error)
-          (#R;Error (format "JSON array index [" (%n idx) "]: (" error ") @ " (show-json json))))
+          (#R;Error ($_ text/append "JSON array index [" (nat/encode idx) "]: (" error ") @ " (show-json json))))
 
         #;None
-        (#R;Error (format "JSON array does not have index " (%n idx) " @ " (show-json json))))
+        (#R;Error ($_ text/append "JSON array does not have index " (nat/encode idx) " @ " (show-json json))))
       
       _
-      (#R;Error (format "JSON value is not an array: " (show-json json))))))
+      (#R;Error ($_ text/append "JSON value is not an array: " (show-json json))))))
 
 (def: #export (field field-name parser)
   {#;doc "Parses a field inside a JSON object."}
@@ -505,10 +504,10 @@
         (#R;Success output)
 
         (#R;Error error)
-        (#R;Error (format "Failed to get JSON object field " (show-string field-name) ": (" error ") @ " (show-json json))))
+        (#R;Error ($_ text/append "Failed to get JSON object field " (show-string field-name) ": (" error ") @ " (show-json json))))
 
       (#R;Error _)
-      (#R;Error (format "JSON object does not have field " (show-string field-name) " @ " (show-json json))))))
+      (#R;Error ($_ text/append "JSON object does not have field " (show-string field-name) " @ " (show-json json))))))
 
 (def: #export any
   {#;doc "Just returns the JSON input without applying any logic."}
@@ -583,10 +582,10 @@
       (#Array parts)
       (if (n.= size (vector;size parts))
         (#R;Success [])
-        (#R;Error (format "JSON array does no have size " (%n size) " " (show-json json))))
+        (#R;Error ($_ text/append "JSON array does no have size " (nat/encode size) " " (show-json json))))
 
       _
-      (#R;Error (format "JSON value is not an array: " (show-json json))))))
+      (#R;Error ($_ text/append "JSON value is not an array: " (show-json json))))))
 
 (def: #export (object-fields! wanted-fields)
   {#;doc "Ensures that every field in the list of wanted-fields is present in a JSON object."}
@@ -599,10 +598,10 @@
                  (list;every? (list;member? text;Eq<Text> wanted-fields)
                               actual-fields))
           (#R;Success [])
-          (#R;Error (format "JSON object has wrong field-set. Expected: [" (text;join-with ", " wanted-fields) "]. Actual: [" (text;join-with ", " actual-fields) "]"))))
+          (#R;Error ($_ text/append "JSON object has wrong field-set. Expected: [" (text;join-with ", " wanted-fields) "]. Actual: [" (text;join-with ", " actual-fields) "]"))))
 
       _
-      (#R;Error (format "JSON value is not an object: " (show-json json))))))
+      (#R;Error ($_ text/append "JSON value is not an object: " (show-json json))))))
 
 ## [Structures]
 (struct: #export _ (Eq JSON)
@@ -876,7 +875,7 @@
           ## Bound type-vars
           (poly;bound env :x:)
           ## If all else fails...
-          (macro;fail (format "Cannot create JSON encoder for: " (%type :x:)))
+          (macro;fail ($_ text/append "Cannot create JSON encoder for: " (type;to-text :x:)))
           ))))
 
 (def: #hidden (rec-decode non-rec)
@@ -1063,7 +1062,7 @@
             [g!bound (poly;bound env :x:)]
             (wrap g!bound))
           ## If all else fails...
-          (macro;fail (format "Cannot create JSON decoder for: " (%type :x:)))
+          (macro;fail ($_ text/append "Cannot create JSON decoder for: " (type;to-text :x:)))
           ))))
 
 (syntax: #export (Codec<JSON,?> :x:)
diff --git a/stdlib/source/lux/data/format/xml.lux b/stdlib/source/lux/data/format/xml.lux
index 94bb19089..e3a76fce2 100644
--- a/stdlib/source/lux/data/format/xml.lux
+++ b/stdlib/source/lux/data/format/xml.lux
@@ -4,14 +4,13 @@
                 [eq #+ Eq]
                 codec
                 ["p" parser "p/" Monad<Parser>])
-       (data [text "t/" Eq<Text>]
-             text/format
+       (data [text "text/" Eq<Text> Monoid<Text>]
              (text ["l" lexer])
              [number]
              ["R" result]
              [product]
              [maybe "m/" Monad<Maybe>]
-             [ident "Ident/" Eq<Ident>]
+             [ident "Ident/" Eq<Ident> Codec<Text,Ident>]
              (coll [list "L/" Monad<List>]
                    ["d" dict]
                    (tree ["T" rose]
@@ -75,7 +74,7 @@
                     l;alpha)
      tail (l;some (p;either (l;one-of "_.-")
                             l;alpha-num))]
-    (wrap (format head tail))))
+    (wrap ($_ text/append head tail))))
 
 (def: namespaced-symbol^
   (l;Lexer Ident)
@@ -119,9 +118,9 @@
                 spaced^
                 (p;after (l;this "/"))
                 (l;enclosed ["<" ">"]))]
-    (p;assert (format "Close tag does not match open tag.\n"
-                      "Expected: " (%ident expected) "\n"
-                      "  Actual: " (%ident actual) "\n")
+    (p;assert ($_ text/append "Close tag does not match open tag.\n"
+                  "Expected: " (Ident/encode expected) "\n"
+                  "  Actual: " (Ident/encode actual) "\n")
               (Ident/= expected actual))))
 
 (def: comment^
@@ -197,14 +196,14 @@
   (-> Tag Text)
   (case namespace
     "" name
-    _ (format namespace ":" name)))
+    _ ($_ text/append namespace ":" name)))
 
 (def: (write-attrs attrs)
   (-> Attrs Text)
   (|> attrs
       d;entries
       (L/map (function [[key value]]
-               (format (write-tag key) "=" "\""(sanitize-value value) "\"")))
+               ($_ text/append (write-tag key) "=" "\""(sanitize-value value) "\"")))
       (text;join-with " ")))
 
 (def: xml-header
@@ -213,24 +212,24 @@
 
 (def: #export (write input)
   (-> XML Text)
-  (format xml-header
-          (loop [input input]
-            (case input
-              (#Text value)
-              (sanitize-value value)
-              
-              (#Node xml-tag xml-attrs xml-children)
-              (let [tag (write-tag xml-tag)
-                    attrs (if (d;empty? xml-attrs)
-                            ""
-                            (format " " (write-attrs xml-attrs)))]
-                (if (list;empty? xml-children)
-                  (format "<" tag attrs "/>")
-                  (format "<" tag attrs ">"
-                          (|> xml-children
-                              (L/map recur)
-                              (text;join-with ""))
-                          "</" tag ">")))))))
+  ($_ text/append xml-header
+      (loop [input input]
+        (case input
+          (#Text value)
+          (sanitize-value value)
+          
+          (#Node xml-tag xml-attrs xml-children)
+          (let [tag (write-tag xml-tag)
+                attrs (if (d;empty? xml-attrs)
+                        ""
+                        ($_ text/append " " (write-attrs xml-attrs)))]
+            (if (list;empty? xml-children)
+              ($_ text/append "<" tag attrs "/>")
+              ($_ text/append "<" tag attrs ">"
+                  (|> xml-children
+                      (L/map recur)
+                      (text;join-with ""))
+                  "</" tag ">")))))))
 
 ## [Structs]
 (struct: #export _ (Codec Text XML)
@@ -241,7 +240,7 @@
   (def: (= reference sample)
     (case [reference sample]
       [(#Text reference/value) (#Text sample/value)]
-      (t/= reference/value sample/value)
+      (text/= reference/value sample/value)
 
       [(#Node reference/tag reference/attrs reference/children)
        (#Node sample/tag sample/attrs sample/children)]
diff --git a/stdlib/source/lux/data/text/format.lux b/stdlib/source/lux/data/text/format.lux
index 61a8600cb..88ea5ecc0 100644
--- a/stdlib/source/lux/data/text/format.lux
+++ b/stdlib/source/lux/data/text/format.lux
@@ -6,7 +6,12 @@
              [number]
              [text]
              [ident]
-             (coll [list "L/" Monad<List>]))
+             (coll [list "L/" Monad<List>])
+             (format [xml]
+                     [json]))
+       (time [instant]
+             [duration]
+             [date])
        [type]
        [macro]
        (macro [code]
@@ -32,18 +37,23 @@
      (Formatter <type>)
      <formatter>)]
 
-  [%b     Bool  (:: bool;Codec<Text,Bool> encode)]
-  [%n     Nat   (:: number;Codec<Text,Nat> encode)]
-  [%i     Int   (:: number;Codec<Text,Int> encode)]
-  [%d     Deg   (:: number;Codec<Text,Deg> encode)]
-  [%r     Real  (:: number;Codec<Text,Real> encode)]
-  [%t     Text  text;encode]
-  [%ident Ident (:: ident;Codec<Text,Ident> encode)]
-  [%code  Code  code;to-text]
-  [%type  Type  type;to-text]
-  [%bin   Nat   (:: number;Binary@Codec<Text,Nat> encode)]
-  [%oct   Nat   (:: number;Octal@Codec<Text,Nat> encode)]
-  [%hex   Nat   (:: number;Hex@Codec<Text,Nat> encode)]
+  [%b        Bool              (:: bool;Codec<Text,Bool> encode)]
+  [%n        Nat               (:: number;Codec<Text,Nat> encode)]
+  [%i        Int               (:: number;Codec<Text,Int> encode)]
+  [%d        Deg               (:: number;Codec<Text,Deg> encode)]
+  [%r        Real              (:: number;Codec<Text,Real> encode)]
+  [%t        Text              text;encode]
+  [%ident    Ident             (:: ident;Codec<Text,Ident> encode)]
+  [%code     Code              code;to-text]
+  [%type     Type              type;to-text]
+  [%bin      Nat               (:: number;Binary@Codec<Text,Nat> encode)]
+  [%oct      Nat               (:: number;Octal@Codec<Text,Nat> encode)]
+  [%hex      Nat               (:: number;Hex@Codec<Text,Nat> encode)]
+  [%xml      xml;XML           (:: xml;Codec<Text,XML> encode)]
+  [%json     json;JSON         (:: json;Codec<Text,JSON> encode)]
+  [%instant  instant;Instant   (:: instant;Codec<Text,Instant> encode)]
+  [%duration duration;Duration (:: duration;Codec<Text,Duration> encode)]
+  [%date     date;Date         (:: date;Codec<Text,Date> encode)]
   )
 
 (def: #export (%list formatter)
diff --git a/stdlib/source/lux/data/text/lexer.lux b/stdlib/source/lux/data/text/lexer.lux
index f30e09c94..984fc4b09 100644
--- a/stdlib/source/lux/data/text/lexer.lux
+++ b/stdlib/source/lux/data/text/lexer.lux
@@ -5,8 +5,7 @@
                 [monad #+ do Monad]
                 codec
                 ["p" parser])
-       (data [text "T/" Order<Text>]
-             text/format
+       (data [text "text/" Monoid<Text>]
              [product]
              [maybe]
              ["R" result]
@@ -27,7 +26,7 @@
 
 (def: (unconsumed-input-error offset tape)
   (-> Offset Text Text)
-  (format "Unconsumed input: " (remaining offset tape)))
+  ($_ text/append "Unconsumed input: " (remaining offset tape)))
 
 (def: #export (run input lexer)
   (All [a] (-> Text (Lexer a) (R;Result a)))
@@ -73,7 +72,7 @@
       (#R;Success [[(n.+ (text;size reference) offset) tape] []])
 
       _
-      (#R;Error (format "Could not match: " (text;encode reference) " @ " tape)))))
+      (#R;Error ($_ text/append "Could not match: " (text;encode reference) " @ " tape)))))
 
 (def: #export (this? reference)
   {#;doc "Lex a text if it matches the given sample."}
@@ -124,14 +123,14 @@
   (do p;Monad<Parser>
     [char any
      #let [char' (assume (text;nth +0 char))]
-     _ (p;assert (format "Character is not within range: " (text;from-code bottom) "-" (text;from-code top))
+     _ (p;assert ($_ text/append "Character is not within range: " (text;from-code bottom) "-" (text;from-code top))
                  (and (n.>= bottom char')
                       (n.<= top char')))]
     (wrap char)))
 
 (do-template [<name> <bottom> <top> <desc>]
   [(def: #export <name>
-     {#;doc (#;TextA (format "Only lex " <desc> " characters."))}
+     {#;doc (#;TextA ($_ text/append "Only lex " <desc> " characters."))}
      (Lexer Text)
      (range (char <bottom>) (char <top>)))]
 
@@ -168,7 +167,7 @@
       (let [output (text;from-code output)]
         (if (text;contains? output options)
           (#R;Success [[(n.inc offset) tape] output])
-          (#R;Error (format "Character (" output ") is not one of: " options))))
+          (#R;Error ($_ text/append "Character (" output ") is not one of: " options))))
 
       _
       (#R;Error cannot-lex-error))))
@@ -182,7 +181,7 @@
       (let [output (text;from-code output)]
         (if (;not (text;contains? output options))
           (#R;Success [[(n.inc offset) tape] output])
-          (#R;Error (format "Character (" output ") is one of: " options))))
+          (#R;Error ($_ text/append "Character (" output ") is one of: " options))))
 
       _
       (#R;Error cannot-lex-error))))
@@ -195,7 +194,7 @@
       (#;Some output)
       (if (p output)
         (#R;Success [[(n.inc offset) tape] (text;from-code output)])
-        (#R;Error (format "Character does not satisfy predicate: " (text;from-code output))))
+        (#R;Error ($_ text/append "Character does not satisfy predicate: " (text;from-code output))))
 
       _
       (#R;Error cannot-lex-error))))
@@ -210,7 +209,7 @@
   (do p;Monad<Parser>
     [=left left
      =right right]
-    (wrap (format =left =right))))
+    (wrap ($_ text/append =left =right))))
 
 (do-template [<name> <base> <doc>]
   [(def: #export (<name> p)
diff --git a/stdlib/source/lux/macro/poly.lux b/stdlib/source/lux/macro/poly.lux
index b1031296b..560847afd 100644
--- a/stdlib/source/lux/macro/poly.lux
+++ b/stdlib/source/lux/macro/poly.lux
@@ -3,15 +3,14 @@
   (lux (control ["M" monad #+ do Monad]
                 [eq]
                 ["p" parser])
-       (data [text]
-             text/format
+       (data [text "text/" Monoid<Text>]
              (coll [list "List/" Fold<List> Monad<List>]
                    [dict #+ Dict])
              [number]
              [product]
              [bool]
              [maybe]
-             [ident "Ident/" Eq<Ident>])
+             [ident "Ident/" Eq<Ident> Codec<Text,Ident>])
        [macro #+ with-gensyms "Lux/" Monad<Lux>]
        (macro [code]
               ["s" syntax #+ syntax: Syntax]
@@ -37,7 +36,7 @@
          (Lux/wrap [])
 
          _
-         (macro;fail (format "Not " <name> " type: " (%type :type:))))))]
+         (macro;fail ($_ text/append "Not " <name> " type: " (type;to-text :type:))))))]
 
   [void "Void" #;Void]
   [unit "Unit" #;Unit]
@@ -52,7 +51,7 @@
          (Lux/wrap [])
 
          _
-         (macro;fail (format "Not " <name> " type: " (%type :type:))))))]
+         (macro;fail ($_ text/append "Not " <name> " type: " (type;to-text :type:))))))]
 
   [bool "Bool"]
   [nat  "Nat"]
@@ -94,7 +93,7 @@
          (Lux/wrap [:left: :right:])
 
          _
-         (macro;fail (format "Not a " ($Code$ <tag>) " type: " (%type :type:))))))
+         (macro;fail ($_ text/append "Not a " ($Code$ <tag>) " type: " (type;to-text :type:))))))
 
    (def: #export <multi>
      (Matcher (List Type))
@@ -102,7 +101,7 @@
        (let [members (<flattener> (type;un-name :type:))]
          (if (n.> +1 (list;size members))
            (Lux/wrap members)
-           (macro;fail (format "Not a " ($Code$ <tag>) " type: " (%type :type:)))))))]
+           (macro;fail ($_ text/append "Not a " ($Code$ <tag>) " type: " (type;to-text :type:)))))))]
 
   [sum    sum+    type;flatten-variant #;Sum]
   [prod   prod+   type;flatten-tuple   #;Product]
@@ -118,7 +117,7 @@
         (wrap [tags :def:]))
 
       _
-      (macro;fail (format "Unnamed types cannot have tags: " (%type :type:))))))
+      (macro;fail ($_ text/append "Unnamed types cannot have tags: " (type;to-text :type:))))))
 
 (def: #export polymorphic
   (Matcher [(List Code) Type])
@@ -202,7 +201,7 @@
       (Lux/wrap :arg:)
 
       _
-      (macro;fail (format "Not " (%ident name) " type: " (%type :type:))))))
+      (macro;fail ($_ text/append "Not " (Ident/encode name) " type: " (type;to-text :type:))))))
 
 (def: #export (apply-2 name)
   (-> Ident (Matcher [Type Type]))
@@ -214,7 +213,7 @@
       (Lux/wrap [:arg0: :arg1:])
 
       _
-      (macro;fail (format "Not " (%ident name) " type: " (%type :type:))))))
+      (macro;fail ($_ text/append "Not " (Ident/encode name) " type: " (type;to-text :type:))))))
 
 (def: #export recursive
   (Matcher Type)
@@ -224,7 +223,7 @@
       (Lux/wrap :type:')
 
       _
-      (macro;fail (format "Not a recursive type: " (%type :type:))))))
+      (macro;fail ($_ text/append "Not a recursive type: " (type;to-text :type:))))))
 
 (def: (adjusted-idx env idx)
   (-> Env Nat Nat)
@@ -243,10 +242,10 @@
         (Lux/wrap poly-ast)
 
         #;None
-        (macro;fail (format "Unknown bound type: " (%type :type:))))
+        (macro;fail ($_ text/append "Unknown bound type: " (type;to-text :type:))))
 
       _
-      (macro;fail (format "Not a bound type: " (%type :type:))))))
+      (macro;fail ($_ text/append "Not a bound type: " (type;to-text :type:))))))
 
 (def: #export (recursion env)
   (-> Env (Matcher Code))
@@ -271,7 +270,7 @@
         (wrap call)
 
         _
-        (macro;fail (format "Type is not a recursive instance: " (%type :type:))))
+        (macro;fail ($_ text/append "Type is not a recursive instance: " (type;to-text :type:))))
       )))
 
 (def: #export (self env)
@@ -285,7 +284,7 @@
       (Lux/wrap self-call)
 
       _
-      (macro;fail (format "Type is not a recursive self-call: " (%type :type:))))))
+      (macro;fail ($_ text/append "Type is not a recursive self-call: " (type;to-text :type:))))))
 
 (def: #export (var env var-id)
   (-> Env Nat (Matcher Unit))
@@ -296,7 +295,7 @@
       (Lux/wrap [])
 
       _
-      (macro;fail (format "Not a bound type: " (%type :type:))))))
+      (macro;fail ($_ text/append "Not a bound type: " (type;to-text :type:))))))
 
 ## [Syntax]
 (def: #export (extend-env [funcT funcA] type-vars env)
diff --git a/stdlib/source/lux/time/instant.lux b/stdlib/source/lux/time/instant.lux
index e4e079983..2901d5828 100644
--- a/stdlib/source/lux/time/instant.lux
+++ b/stdlib/source/lux/time/instant.lux
@@ -8,9 +8,8 @@
                 [monad #+ do Monad]
                 ["p" parser])
        (data [text "text/" Monoid<Text>]
-             (text ["l" lexer]
-                   format)
-             [number]
+             (text ["l" lexer])
+             [number "int/" Codec<Text,Int>]
              ["R" result]
              (coll [list "L/" Fold<List> Functor<List>]
                    ["v" vector "v/" Functor<Vector> Fold<Vector>]))
@@ -30,9 +29,9 @@
     (-> Instant Int)
     (|>. @repr))
 
-  (def: #export (span param subject)
+  (def: #export (span from to)
     (-> Instant Instant duration;Duration)
-    (duration;from-millis (i.- (@repr param) (@repr subject))))
+    (duration;from-millis (i.- (@repr from) (@repr to))))
 
   (def: #export (shift duration instant)
     (-> duration;Duration Instant Instant)
@@ -133,8 +132,8 @@
 (def: (pad value)
   (-> Int Text)
   (if (i.< 10 value)
-    (text/append "0" (%i value))
-    (%i value)))
+    (text/append "0" (int/encode value))
+    (int/encode value)))
 
 (def: (adjust-negative space duration)
   (-> duration;Duration duration;Duration duration;Duration)
@@ -145,10 +144,10 @@
 (def: (encode-millis millis)
   (-> Int Text)
   (cond (i.= 0 millis)   ""
-        (i.< 10 millis)  (format ".00" (%i millis))
-        (i.< 100 millis) (format ".0" (%i millis))
+        (i.< 10 millis)  ($_ text/append ".00" (int/encode millis))
+        (i.< 100 millis) ($_ text/append ".0" (int/encode millis))
         ## (i.< 1_000 millis)
-        (format "." (%i millis))))
+        ($_ text/append "." (int/encode millis))))
 
 (def: seconds-per-day Int (duration;query duration;second duration;day))
 (def: days-up-to-epoch Int 719468)
@@ -202,13 +201,13 @@
         [minutes day-time] [(duration;query duration;minute day-time) (duration;frame duration;minute day-time)]
         [seconds millis] [(duration;query duration;second day-time) (duration;frame duration;second day-time)]
         ]
-    (format (%i year) "-" (pad month) "-" (pad day) "T"
-            (pad hours) ":" (pad minutes) ":" (pad seconds)
-            (|> millis
-                (adjust-negative duration;second)
-                duration;to-millis
-                encode-millis)
-            "Z")))
+    ($_ text/append (int/encode year) "-" (pad month) "-" (pad day) "T"
+        (pad hours) ":" (pad minutes) ":" (pad seconds)
+        (|> millis
+            (adjust-negative duration;second)
+            duration;to-millis
+            encode-millis)
+        "Z")))
 
 ## Codec::decode
 (def: lex-year
diff --git a/stdlib/source/lux/type/model.lux b/stdlib/source/lux/type/model.lux
index 58b6d2fee..e77a8ac70 100644
--- a/stdlib/source/lux/type/model.lux
+++ b/stdlib/source/lux/type/model.lux
@@ -3,8 +3,7 @@
   (lux (control [applicative]
                 [monad #+ do Monad]
                 ["p" parser "p/" Monad<Parser>])
-       (data [text "text/" Eq<Text>]
-             text/format
+       (data [text "text/" Eq<Text> Monoid<Text>]
              ["R" result]
              (coll [list "L/" Functor<List> Monoid<List>]))
        [macro #+ Monad<Lux>]
@@ -12,8 +11,7 @@
               ["s" syntax #+ syntax:]
               (syntax ["cs" common]
                       (common ["csr" reader]
-                              ["csw" writer])))
-       type/auto))
+                              ["csw" writer])))))
 
 (def: (get k plist)
   (All [a]
@@ -57,7 +55,7 @@
 
 (def: representation-name
   (-> Text Text)
-  (|>. (format "{" kind "@" module "}")
+  (|>. ($_ text/append "{" kind "@" module "}")
        (let [[module kind] (ident-for #;;Representation)])))
 
 (def: (install-casts' this-module-name name type-vars)
@@ -79,7 +77,7 @@
                                                                                   (~ value)))))
 
                                                                   _
-                                                                  (macro;fail (format "Wrong syntax for " down-cast))))])))
+                                                                  (macro;fail ($_ text/append "Wrong syntax for " down-cast))))])))
                            (update@ #;defs (put up-cast (: Def
                                                            [Macro macro-anns
                                                             (function [tokens]
@@ -91,7 +89,7 @@
                                                                                 (~ value)))))
 
                                                                 _
-                                                                (macro;fail (format "Wrong syntax for " up-cast))))]))))]]
+                                                                (macro;fail ($_ text/append "Wrong syntax for " up-cast))))]))))]]
     (function [compiler]
       (#R;Success [(update@ #;modules (put this-module-name this-module) compiler)
                    []]))))
@@ -120,9 +118,10 @@
         (wrap (list)))
 
       _
-      (macro;fail (format "Cannot temporarily define casting functions ("
-                          down-cast " & " up-cast
-                          ") because definitions like that already exist.")))))
+      (macro;fail ($_ text/append
+                      "Cannot temporarily define casting functions ("
+                      down-cast " & " up-cast
+                      ") because definitions like that already exist.")))))
 
 (syntax: #hidden (un-install-casts)
   (do Monad<Lux>
@@ -136,14 +135,15 @@
         (wrap (list)))
 
       _
-      (macro;fail (format "Cannot un-define casting functions ("
-                          down-cast " & " up-cast
-                          ") because they do not exist.")))))
+      (macro;fail ($_ text/append
+                      "Cannot un-define casting functions ("
+                      down-cast " & " up-cast
+                      ") because they do not exist.")))))
 
 (def: declaration
   (s;Syntax [Text (List Text)])
   (p;either (s;form (p;seq s;local-symbol (p;some s;local-symbol)))
-            (p;seq s;local-symbol (::: wrap (list)))))
+            (p;seq s;local-symbol (:: p;Monad<Parser> wrap (list)))))
 
 (syntax: #export (model: [export csr;export]
                    [[name type-vars] declaration]
diff --git a/stdlib/test/test/lux/time/instant.lux b/stdlib/test/test/lux/time/instant.lux
index 40ab587d7..2343beac1 100644
--- a/stdlib/test/test/lux/time/instant.lux
+++ b/stdlib/test/test/lux/time/instant.lux
@@ -15,7 +15,7 @@
 
 (def: boundary Int 99_999_999_999_999)
 
-(def: instant
+(def: #export instant
   (r;Random @;Instant)
   (|> r;int (:: r;Monad<Random> map (|>. (i.% boundary) @;from-millis))))