--- a/json.ur	Wed May 02 11:47:37 2012 -0400
+++ b/json.ur	Wed May 02 11:47:37 2012 -0400
@@ -25,6 +25,7 @@
     end
 
 fun toJson [a] (j : json a) : a -> string = j.ToJson
+fun fromJson' [a] (j : json a) : string -> a * string = j.FromJson
 
 fun fromJson [a] (j : json a) (s : string) : a =
     let
@@ -278,7 +279,7 @@
                        error <xml>JSON variant doesn't begin with brace</xml>
                    else
                        let
-                           val (name, s') = unescape s
+                           val (name, s') = unescape (skipSpaces (String.suffix s 1))
                            val s' = skipSpaces s'
                            val s' = if String.length s' = 0 || String.sub s' 0 <> #":" then
                                         error <xml>No colon after JSON object field name</xml>
@@ -314,3 +315,25 @@
                    }
 
 val json_unit : json unit = json_record {} {}
+
+functor Recursive (M : sig
+                       con t :: Type -> Type
+                       val json_t : a ::: Type -> json a -> json (t a)
+                   end) = struct
+    open M
+
+    datatype r = Rec of t r
+
+    fun rTo (Rec x) = (json_t {ToJson = rTo,
+                               FromJson = fn _ => error <xml>Tried to FromJson in ToJson!</xml>}).ToJson x
+
+    fun rFrom s =
+        let
+            val (x, s') = (json_t {ToJson = fn _ => error <xml>Tried to ToJson in FromJson!</xml>,
+                                   FromJson = rFrom}).FromJson s
+        in
+            (Rec x, s')
+        end
+
+    val json_r = {ToJson = rTo, FromJson = rFrom}
+end