mcs/class/System.Web.Extensions/System.Web.Script.Serialization/JsonDeserializer.cs

   1 //
   2 // JsonDeserializer.cs
   3 //
   4 // Author:
   5 //   Marek Habersack <grendel@twistedcode.net>
   6 //
   7 // (C) 2008 Novell, Inc.  http://novell.com/
   8 // Copyright 2011, Xamarin, Inc (http://xamarin.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29 // Code is based on JSON_checker (http://www.json.org/JSON_checker/) and JSON_parser
  30 // (http://fara.cs.uni-potsdam.de/~jsg/json_parser/) C sources.
  31
  32 using System;
  33 using System.Collections;
  34 using System.Collections.Generic;
  35 using System.Data;
  36 using System.Globalization;
  37 using System.IO;
  38 using System.Reflection;
  39 using System.Text;
  40
  41 namespace System.Web.Script.Serialization
  42 {
  43         internal sealed class JsonDeserializer
  44         {
  45                 /* Universal error constant */
  46                 const int __ = -1;
  47                 const int UNIVERSAL_ERROR = __;
  48
  49                 /*
  50                   Characters are mapped into these 31 character classes. This allows for
  51                   a significant reduction in the size of the state transition table.
  52                 */
  53                 const int C_SPACE = 0x00;  /* space */
  54                 const int C_WHITE = 0x01;  /* other whitespace */
  55                 const int C_LCURB = 0x02;  /* {  */
  56                 const int C_RCURB = 0x03;  /* } */
  57                 const int C_LSQRB = 0x04;  /* [ */
  58                 const int C_RSQRB = 0x05;  /* ] */
  59                 const int C_COLON = 0x06;  /* : */
  60                 const int C_COMMA = 0x07;  /* , */
  61                 const int C_QUOTE = 0x08;  /* " */
  62                 const int C_BACKS = 0x09;  /* \ */
  63                 const int C_SLASH = 0x0A;  /* / */
  64                 const int C_PLUS  = 0x0B;  /* + */
  65                 const int C_MINUS = 0x0C;  /* - */
  66                 const int C_POINT = 0x0D;  /* . */
  67                 const int C_ZERO  = 0x0E;  /* 0 */
  68                 const int C_DIGIT = 0x0F;  /* 123456789 */
  69                 const int C_LOW_A = 0x10;  /* a */
  70                 const int C_LOW_B = 0x11;  /* b */
  71                 const int C_LOW_C = 0x12;  /* c */
  72                 const int C_LOW_D = 0x13;  /* d */
  73                 const int C_LOW_E = 0x14;  /* e */
  74                 const int C_LOW_F = 0x15;  /* f */
  75                 const int C_LOW_L = 0x16;  /* l */
  76                 const int C_LOW_N = 0x17;  /* n */
  77                 const int C_LOW_R = 0x18;  /* r */
  78                 const int C_LOW_S = 0x19;  /* s */
  79                 const int C_LOW_T = 0x1A;  /* t */
  80                 const int C_LOW_U = 0x1B;  /* u */
  81                 const int C_ABCDF = 0x1C;  /* ABCDF */
  82                 const int C_E     = 0x1D;  /* E */
  83                 const int C_ETC   = 0x1E;  /* everything else */
  84                 const int C_STAR  = 0x1F;  /* * */
  85                 const int C_I     = 0x20;  /* I */
  86                 const int C_LOW_I = 0x21;  /* i */
  87                 const int C_LOW_Y = 0x22;  /* y */
  88                 const int C_N     = 0x23;  /* N */
  89
  90                 /* The state codes. */
  91                 const int GO = 0x00;  /* start    */
  92                 const int OK = 0x01;  /* ok       */
  93                 const int OB = 0x02;  /* object   */
  94                 const int KE = 0x03;  /* key      */
  95                 const int CO = 0x04;  /* colon    */
  96                 const int VA = 0x05;  /* value    */
  97                 const int AR = 0x06;  /* array    */
  98                 const int ST = 0x07;  /* string   */
  99                 const int ES = 0x08;  /* escape   */
 100                 const int U1 = 0x09;  /* u1       */
 101                 const int U2 = 0x0A;  /* u2       */
 102                 const int U3 = 0x0B;  /* u3       */
 103                 const int U4 = 0x0C;  /* u4       */
 104                 const int MI = 0x0D;  /* minus    */
 105                 const int ZE = 0x0E;  /* zero     */
 106                 const int IN = 0x0F;  /* integer  */
 107                 const int FR = 0x10;  /* fraction */
 108                 const int E1 = 0x11;  /* e        */
 109                 const int E2 = 0x12;  /* ex       */
 110                 const int E3 = 0x13;  /* exp      */
 111                 const int T1 = 0x14;  /* tr       */
 112                 const int T2 = 0x15;  /* tru      */
 113                 const int T3 = 0x16;  /* true     */
 114                 const int F1 = 0x17;  /* fa       */
 115                 const int F2 = 0x18;  /* fal      */
 116                 const int F3 = 0x19;  /* fals     */
 117                 const int F4 = 0x1A;  /* false    */
 118                 const int N1 = 0x1B;  /* nu       */
 119                 const int N2 = 0x1C;  /* nul      */
 120                 const int N3 = 0x1D;  /* null     */
 121                 const int FX = 0x1E;  /* *.* *eE* */
 122                 const int IV = 0x1F;  /* invalid input */
 123                 const int UK = 0x20;  /* unquoted key name */
 124                 const int UI = 0x21; /* ignore during unquoted key name construction */
 125                 const int I1 = 0x22;  /* In */
 126                 const int I2 = 0x23;  /* Inf */
 127                 const int I3 = 0x24;  /* Infi */
 128                 const int I4 = 0x25;  /* Infin */
 129                 const int I5 = 0x26;  /* Infini */
 130                 const int I6 = 0x27;  /* Infinit */
 131                 const int I7 = 0x28;  /* Infinity */
 132                 const int V1 = 0x29;  /* Na */
 133                 const int V2 = 0x2A;  /* NaN */
 134
 135                 /* Actions */
 136                 const int FA = -10; /* false */
 137                 const int TR = -11; /* false */
 138                 const int NU = -12; /* null */
 139                 const int DE = -13; /* double detected by exponent e E */
 140                 const int DF = -14; /* double detected by fraction . */
 141                 const int SB = -15; /* string begin */
 142                 const int MX = -16; /* integer detected by minus */
 143                 const int ZX = -17; /* integer detected by zero */
 144                 const int IX = -18; /* integer detected by 1-9 */
 145                 const int EX = -19; /* next char is escaped */
 146                 const int UC = -20; /* Unicode character read */
 147                 const int SE =  -4; /* string end */
 148                 const int AB =  -5; /* array begin */
 149                 const int AE =  -7; /* array end */
 150                 const int OS =  -6; /* object start */
 151                 const int OE =  -8; /* object end */
 152                 const int EO =  -9; /* empty object */
 153                 const int CM =  -3; /* comma */
 154                 const int CA =  -2; /* colon action */
 155                 const int PX = -21; /* integer detected by plus */
 156                 const int KB = -22; /* unquoted key name begin */
 157                 const int UE = -23; /* unquoted key name end */
 158                 const int IF = -25; /* Infinity */
 159                 const int NN = -26; /* NaN */
 160
 161
 162                 enum JsonMode {
 163                         NONE,
 164                         ARRAY,
 165                         DONE,
 166                         KEY,
 167                         OBJECT
 168                 };
 169
 170                 enum JsonType {
 171                         NONE = 0,
 172                         ARRAY_BEGIN,
 173                         ARRAY_END,
 174                         OBJECT_BEGIN,
 175                         OBJECT_END,
 176                         INTEGER,
 177                         FLOAT,
 178                         NULL,
 179                         TRUE,
 180                         FALSE,
 181                         STRING,
 182                         KEY,
 183                         MAX
 184                 };
 185
 186                 /*
 187                   This array maps the 128 ASCII characters into character classes.
 188                   The remaining Unicode characters should be mapped to C_ETC.
 189                   Non-whitespace control characters are errors.
 190                 */
 191                 static readonly int[] ascii_class = {
 192                         __,      __,      __,      __,      __,      __,      __,      __,
 193                         __,      C_WHITE, C_WHITE, __,      __,      C_WHITE, __,      __,
 194                         __,      __,      __,      __,      __,      __,      __,      __,
 195                         __,      __,      __,      __,      __,      __,      __,      __,
 196
 197                         C_SPACE, C_ETC,   C_QUOTE, C_ETC,   C_ETC,   C_ETC,   C_ETC,   C_QUOTE,
 198                         C_ETC,   C_ETC,   C_STAR,   C_PLUS,  C_COMMA, C_MINUS, C_POINT, C_SLASH,
 199                         C_ZERO,  C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT,
 200                         C_DIGIT, C_DIGIT, C_COLON, C_ETC,   C_ETC,   C_ETC,   C_ETC,   C_ETC,
 201
 202                         C_ETC,   C_ABCDF, C_ABCDF, C_ABCDF, C_ABCDF, C_E,     C_ABCDF, C_ETC,
 203                         C_ETC,   C_I,   C_ETC,   C_ETC,   C_ETC,   C_ETC,   C_N,   C_ETC,
 204                         C_ETC,   C_ETC,   C_ETC,   C_ETC,   C_ETC,   C_ETC,   C_ETC,   C_ETC,
 205                         C_ETC,   C_ETC,   C_ETC,   C_LSQRB, C_BACKS, C_RSQRB, C_ETC,   C_ETC,
 206
 207                         C_ETC,   C_LOW_A, C_LOW_B, C_LOW_C, C_LOW_D, C_LOW_E, C_LOW_F, C_ETC,
 208                         C_ETC,   C_LOW_I, C_ETC,   C_ETC,   C_LOW_L, C_ETC,   C_LOW_N, C_ETC,
 209                         C_ETC,   C_ETC,   C_LOW_R, C_LOW_S, C_LOW_T, C_LOW_U, C_ETC,   C_ETC,
 210                         C_ETC,   C_LOW_Y,   C_ETC,   C_LCURB, C_ETC,   C_RCURB, C_ETC,   C_ETC
 211                 };
 212
 213                 static readonly int[,] state_transition_table = {
 214                 /*
 215                   The state transition table takes the current state and the current symbol,
 216                   and returns either a new state or an action. An action is represented as a
 217                   negative number. A JSON text is accepted if at the end of the text the
 218                   state is OK and if the mode is MODE_DONE.
 219
 220                                            white                  '                   1-9                                   ABCDF  etc
 221                                        space |  {  }  [  ]  :  ,  "  \  /  +  -  .  0  |  a  b  c  d  e  f  l  n  r  s  t  u  |  E  |  *  I  i  y  N */
 222                         /*start    GO*/ {GO,GO,OS,__,AB,__,__,__,SB,__,__,PX,MX,__,ZX,IX,__,__,__,__,__,FA,__,__,__,__,TR,__,__,__,__,__,I1,__,__,V1},
 223                         /*ok       OK*/ {OK,OK,__,OE,__,AE,__,CM,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 224                         /*object   OB*/ {OB,OB,__,EO,__,__,__,__,SB,__,__,__,KB,__,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,__,KB,KB,KB,KB},
 225                         /*key      KE*/ {KE,KE,__,__,__,__,__,__,SB,__,__,__,KB,__,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,KB,__,KB,KB,KB,KB},
 226                         /*colon    CO*/ {CO,CO,__,__,__,__,CA,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 227                         /*value    VA*/ {VA,VA,OS,__,AB,__,__,__,SB,__,__,PX,MX,__,ZX,IX,__,__,__,__,__,FA,__,NU,__,__,TR,__,__,__,__,__,I1,__,__,V1},
 228                         /*array    AR*/ {AR,AR,OS,__,AB,AE,__,__,SB,__,__,PX,MX,__,ZX,IX,__,__,__,__,__,FA,__,NU,__,__,TR,__,__,__,__,__,I1,__,__,V1},
 229                         /*string   ST*/ {ST,__,ST,ST,ST,ST,ST,ST,SE,EX,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST},
 230                         /*escape   ES*/ {__,__,__,__,__,__,__,__,ST,ST,ST,__,__,__,__,__,__,ST,__,__,__,ST,__,ST,ST,__,ST,U1,__,__,__,__,__,__,__,__},
 231                         /*u1       U1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,U2,U2,U2,U2,U2,U2,U2,U2,__,__,__,__,__,__,U2,U2,__,__,__,__,__,__},
 232                         /*u2       U2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,U3,U3,U3,U3,U3,U3,U3,U3,__,__,__,__,__,__,U3,U3,__,__,__,__,__,__},
 233                         /*u3       U3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,U4,U4,U4,U4,U4,U4,U4,U4,__,__,__,__,__,__,U4,U4,__,__,__,__,__,__},
 234                         /*u4       U4*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,UC,UC,UC,UC,UC,UC,UC,UC,__,__,__,__,__,__,UC,UC,__,__,__,__,__,__},
 235                         /*minus    MI*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,ZE,IN,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,I1,__,__,__},
 236                         /*zero     ZE*/ {OK,OK,__,OE,__,AE,__,CM,__,__,__,__,__,DF,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 237                         /*int      IN*/ {OK,OK,__,OE,__,AE,__,CM,__,__,__,__,__,DF,IN,IN,__,__,__,__,DE,__,__,__,__,__,__,__,__,DE,__,__,__,__,__,__},
 238                         /*frac     FR*/ {OK,OK,__,OE,__,AE,__,CM,__,__,__,__,__,__,FR,FR,__,__,__,__,E1,__,__,__,__,__,__,__,__,E1,__,__,__,__,__,__},
 239                         /*e        E1*/ {__,__,__,__,__,__,__,__,__,__,__,E2,E2,__,E3,E3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 240                         /*ex       E2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,E3,E3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 241                         /*exp      E3*/ {OK,OK,__,OE,__,AE,__,CM,__,__,__,__,__,__,E3,E3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 242                         /*tr       T1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,T2,__,__,__,__,__,__,__,__,__,__,__},
 243                         /*tru      T2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,T3,__,__,__,__,__,__,__,__},
 244                         /*true     T3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,OK,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 245                         /*fa       F1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,F2,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 246                         /*fal      F2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,F3,__,__,__,__,__,__,__,__,__,__,__,__,__},
 247                         /*fals     F3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,F4,__,__,__,__,__,__,__,__,__,__},
 248                         /*false    F4*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,OK,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 249                         /*nu       N1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,N2,__,__,__,__,__,__,__,__},
 250                         /*nul      N2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,N3,__,__,__,__,__,__,__,__,__,__,__,__,__},
 251                         /*null     N3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,OK,__,__,__,__,__,__,__,__,__,__,__,__,__},
 252                         /*_.       FX*/ {OK,OK,__,OE,__,AE,__,CM,__,__,__,__,__,__,FR,FR,__,__,__,__,E1,__,__,__,__,__,__,__,__,E1,__,__,__,__,__,__},
 253                         /*inval.   IV*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 254                         /*unq.key  UK*/ {UI,UI,__,__,__,__,UE,__,__,__,__,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,UK,__,UK,UK,UK,UK},
 255                         /*unq.ign. UI*/ {UI,UI,__,__,__,__,UE,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 256                         /*i1       I1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,I2,__,__,__,__,__,__,__,__,__,__,__,__},
 257                         /*i2       I2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,I3,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 258                         /*i3       I3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,I4,__,__},
 259                         /*i4       I4*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,I5,__,__,__,__,__,__,__,__,__,__,__,__},
 260                         /*i5       I5*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,I6,__,__},
 261                         /*i6       I6*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,I7,__,__,__,__,__,__,__,__,__},
 262                         /*i7       I7*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,IF,__},
 263                         /*v1       V1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,V2,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__},
 264                         /*v2       V2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,NN},
 265                 };
 266
 267                 JavaScriptSerializer serializer;
 268                 JavaScriptTypeResolver typeResolver;
 269                 int maxJsonLength;
 270                 int currentPosition;
 271                 int recursionLimit;
 272                 int recursionDepth;
 273
 274                 Stack <JsonMode> modes;
 275                 Stack <object> returnValue;
 276                 JsonType jsonType;
 277
 278                 bool escaped;
 279                 int state;
 280                 Stack <string> currentKey;
 281                 StringBuilder buffer;
 282                 char quoteChar;
 283
 284                 public JsonDeserializer (JavaScriptSerializer serializer)
 285                 {
 286                         this.serializer = serializer;
 287                         this.maxJsonLength = serializer.MaxJsonLength;
 288                         this.recursionLimit = serializer.RecursionLimit;
 289                         this.typeResolver = serializer.TypeResolver;
 290                         this.modes = new Stack <JsonMode> ();
 291                         this.currentKey = new Stack <string> ();
 292                         this.returnValue = new Stack <object> ();
 293                         this.state = GO;
 294                         this.currentPosition = 0;
 295                         this.recursionDepth = 0;
 296                 }
 297
 298                 public object Deserialize (string input)
 299                 {
 300                         if (input == null)
 301                                 throw new ArgumentNullException ("input");
 302
 303                         return Deserialize (new StringReader (input));
 304                 }
 305
 306                 public object Deserialize (TextReader input)
 307                 {
 308                         if (input == null)
 309                                 throw new ArgumentNullException ("input");
 310
 311                         int value;
 312                         buffer = new StringBuilder ();
 313
 314                         while (true) {
 315                                 value = input.Read ();
 316                                 if (value < 0)
 317                                         break;
 318
 319                                 currentPosition++;
 320                                 if (currentPosition > maxJsonLength)
 321                                         throw new ArgumentException ("Maximum JSON input length has been exceeded.");
 322
 323                                 if (!ProcessCharacter ((char) value))
 324                                         throw new InvalidOperationException ("JSON syntax error.");
 325                         }
 326
 327                         object topObject = PeekObject ();
 328                         if (buffer.Length > 0) {
 329                                 object result;
 330
 331                                 if (ParseBuffer (out result)) {
 332                                         if (topObject != null)
 333                                                 StoreValue (result);
 334                                         else
 335                                                 PushObject (result);
 336                                 }
 337                         }
 338
 339                         if (returnValue.Count > 1)
 340                                 throw new InvalidOperationException ("JSON syntax error.");
 341
 342                         object ret = PopObject ();
 343                         return ret;
 344                 }
 345
 346 #if DEBUG
 347                 void DumpObject (string indent, object obj)
 348                 {
 349                         if (obj is Dictionary <string, object>) {
 350                                 Console.WriteLine (indent + "{");
 351                                 foreach (KeyValuePair <string, object> kvp in (Dictionary <string, object>)obj) {
 352                                         Console.WriteLine (indent + "\t\"{0}\": ", kvp.Key);
 353                                         DumpObject (indent + "\t\t", kvp.Value);
 354                                 }
 355                                 Console.WriteLine (indent + "}");
 356                         } else if (obj is object[]) {
 357                                 Console.WriteLine (indent + "[");
 358                                 foreach (object o in (object[])obj)
 359                                         DumpObject (indent + "\t", o);
 360                                 Console.WriteLine (indent + "]");
 361                         } else if (obj != null)
 362                                 Console.WriteLine (indent + obj.ToString ());
 363                         else
 364                                 Console.WriteLine ("null");
 365                 }
 366 #endif
 367
 368                 void DecodeUnicodeChar ()
 369                 {
 370                         int len = buffer.Length;
 371                         if (len < 6)
 372                                 throw new ArgumentException ("Invalid escaped unicode character specification (" + currentPosition + ")");
 373
 374                         int code = Int32.Parse (buffer.ToString ().Substring (len - 4), NumberStyles.HexNumber);
 375                         buffer.Length = len - 6;
 376                         buffer.Append ((char)code);
 377                 }
 378
 379                 string GetModeMessage (JsonMode expectedMode)
 380                 {
 381                         switch (expectedMode) {
 382                                 case JsonMode.ARRAY:
 383                                         return "Invalid array passed in, ',' or ']' expected (" + currentPosition + ")";
 384
 385                                 case JsonMode.KEY:
 386                                         return "Invalid object passed in, key name or ':' expected (" + currentPosition + ")";
 387
 388                                 case JsonMode.OBJECT:
 389                                         return "Invalid object passed in, key value expected (" + currentPosition + ")";
 390
 391                                 default:
 392                                         return "Invalid JSON string";
 393                         }
 394                 }
 395
 396                 void PopMode (JsonMode expectedMode)
 397                 {
 398                         JsonMode mode = PeekMode ();
 399                         if (mode != expectedMode)
 400                                 throw new ArgumentException (GetModeMessage (mode));
 401
 402                         modes.Pop ();
 403                 }
 404
 405                 void PushMode (JsonMode newMode)
 406                 {
 407                         modes.Push (newMode);
 408                 }
 409
 410                 JsonMode PeekMode ()
 411                 {
 412                         if (modes.Count == 0)
 413                                 return JsonMode.NONE;
 414
 415                         return modes.Peek ();
 416                 }
 417
 418                 void PushObject (object o)
 419                 {
 420                         returnValue.Push (o);
 421                 }
 422
 423                 object PopObject (bool notIfLast)
 424                 {
 425                         int count = returnValue.Count;
 426                         if (count == 0)
 427                                 return null;
 428
 429                         if (notIfLast && count == 1)
 430                                 return null;
 431
 432                         return returnValue.Pop ();
 433                 }
 434
 435                 object PopObject ()
 436                 {
 437                         return PopObject (false);
 438                 }
 439
 440                 object PeekObject ()
 441                 {
 442                         if (returnValue.Count == 0)
 443                                 return null;
 444
 445                         return returnValue.Peek ();
 446                 }
 447
 448                 void RemoveLastCharFromBuffer ()
 449                 {
 450                         int len = buffer.Length;
 451                         if (len == 0)
 452                                 return;
 453                         buffer.Length = len - 1;
 454                 }
 455
 456                 bool ParseBuffer (out object result)
 457                 {
 458                         result = null;
 459
 460                         if (jsonType == JsonType.NONE) {
 461                                 buffer.Length = 0;
 462                                 return false;
 463                         }
 464
 465                         string s = buffer.ToString ();
 466                         bool converted = true;
 467                         int intValue;
 468                         long longValue;
 469                         decimal decimalValue;
 470                         double doubleValue;
 471
 472                         switch (jsonType) {
 473                                 case JsonType.INTEGER:
 474                                         /* MS AJAX.NET JSON parser promotes big integers to double */
 475
 476                                         if (Int32.TryParse (s, out intValue))
 477                                                 result = intValue;
 478                                         else if (Int64.TryParse (s, out longValue))
 479                                                 result = longValue;
 480                                         else if (Decimal.TryParse (s, out decimalValue))
 481                                                 result = decimalValue;
 482                                         else if (Double.TryParse (s, out doubleValue))
 483                                                 result = doubleValue;
 484                                         else
 485                                                 converted = false;
 486                                         break;
 487
 488                                 case JsonType.FLOAT:
 489                                         if (Decimal.TryParse (s, out decimalValue))
 490                                                 result = decimalValue;
 491                                         else if (Double.TryParse (s, out doubleValue))
 492                                                 result = doubleValue;
 493                                         else
 494                                                 converted = false;
 495                                         break;
 496
 497                                 case JsonType.TRUE:
 498                                         if (String.Compare (s, "true", StringComparison.Ordinal) == 0)
 499                                                 result = true;
 500                                         else
 501                                                 converted = false;
 502                                         break;
 503
 504                                 case JsonType.FALSE:
 505                                         if (String.Compare (s, "false", StringComparison.Ordinal) == 0)
 506                                                 result = false;
 507                                         else
 508                                                 converted = false;
 509                                         break;
 510
 511                                 case JsonType.NULL:
 512                                         if (String.Compare (s, "null", StringComparison.Ordinal) != 0)
 513                                                 converted = false;
 514                                         break;
 515
 516                                 case JsonType.STRING:
 517                                         if (s.StartsWith ("/Date(", StringComparison.Ordinal) && s.EndsWith (")/", StringComparison.Ordinal)) {
 518                                                 long javaScriptTicks = Convert.ToInt64 (s.Substring (6, s.Length - 8));
 519                                                 result = new DateTime ((javaScriptTicks * 10000) + JsonSerializer.InitialJavaScriptDateTicks, DateTimeKind.Utc);
 520                                         } else
 521                                                 result = s;
 522                                         break;
 523
 524                                 default:
 525                                         throw new InvalidOperationException (String.Format ("Internal error: unexpected JsonType ({0})", jsonType));
 526
 527                         }
 528
 529                         if (!converted)
 530                                 throw new ArgumentException ("Invalid JSON primitive: " + s);
 531
 532                         buffer.Length = 0;
 533                         return true;
 534                 }
 535
 536                 bool ProcessCharacter (char ch)
 537                 {
 538                         int next_class, next_state;
 539
 540                         if (ch >= 128)
 541                                 next_class = C_ETC;
 542                         else {
 543                                 next_class = ascii_class [ch];
 544                                 if (next_class <= UNIVERSAL_ERROR)
 545                                         return false;
 546                         }
 547
 548                         if (escaped) {
 549                                 escaped = false;
 550                                 RemoveLastCharFromBuffer ();
 551
 552                                 switch (ch) {
 553                                         case 'b':
 554                                                 buffer.Append ('\b');
 555                                                 break;
 556                                         case 'f':
 557                                                 buffer.Append ('\f');
 558                                                 break;
 559                                         case 'n':
 560                                                 buffer.Append ('\n');
 561                                                 break;
 562                                         case 'r':
 563                                                 buffer.Append ('\r');
 564                                                 break;
 565                                         case 't':
 566                                                 buffer.Append ('\t');
 567                                                 break;
 568                                         case '"':
 569                                         case '\\':
 570                                         case '/':
 571                                                 buffer.Append (ch);
 572                                                 break;
 573                                         case 'u':
 574                                                 buffer.Append ("\\u");
 575                                                 break;
 576                                         default:
 577                                                 return false;
 578                                 }
 579                         } else if (jsonType != JsonType.NONE || !(next_class == C_SPACE || next_class == C_WHITE))
 580                                 buffer.Append (ch);
 581
 582                         next_state = state_transition_table [state, next_class];
 583                         if (next_state >= 0) {
 584                                 state = next_state;
 585                                 return true;
 586                         }
 587
 588                         object result;
 589                         /* An action to perform */
 590                         switch (next_state) {
 591                                 case UC: /* Unicode character */
 592                                         DecodeUnicodeChar ();
 593                                         state = ST;
 594                                         break;
 595
 596                                 case EX: /* Escaped character */
 597                                         escaped = true;
 598                                         state = ES;
 599                                         break;
 600
 601                                 case MX: /* integer detected by minus */
 602                                         jsonType = JsonType.INTEGER;
 603                                         state = MI;
 604                                         break;
 605
 606                                 case PX: /* integer detected by plus */
 607                                         jsonType = JsonType.INTEGER;
 608                                         state = MI;
 609                                         break;
 610
 611                                 case ZX: /* integer detected by zero */
 612                                         jsonType = JsonType.INTEGER;
 613                                         state = ZE;
 614                                         break;
 615
 616                                 case IX: /* integer detected by 1-9 */
 617                                         jsonType = JsonType.INTEGER;
 618                                         state = IN;
 619                                         break;
 620
 621                                 case DE: /* floating point number detected by exponent*/
 622                                         jsonType = JsonType.FLOAT;
 623                                         state = E1;
 624                                         break;
 625
 626                                 case DF: /* floating point number detected by fraction */
 627                                         jsonType = JsonType.FLOAT;
 628                                         state = FX;
 629                                         break;
 630
 631                                 case SB: /* string begin " or ' */
 632                                         buffer.Length = 0;
 633                                         quoteChar = ch;
 634                                         jsonType = JsonType.STRING;
 635                                         state = ST;
 636                                         break;
 637
 638                                 case KB: /* unquoted key name begin */
 639                                         jsonType = JsonType.STRING;
 640                                         state = UK;
 641                                         break;
 642
 643                                 case UE: /* unquoted key name end ':' */
 644                                         RemoveLastCharFromBuffer ();
 645                                         if (ParseBuffer (out result))
 646                                                 StoreKey (result);
 647                                         jsonType = JsonType.NONE;
 648
 649                                         PopMode (JsonMode.KEY);
 650                                         PushMode (JsonMode.OBJECT);
 651                                         state = VA;
 652                                         buffer.Length = 0;
 653                                         break;
 654
 655                                 case NU: /* n */
 656                                         jsonType = JsonType.NULL;
 657                                         state = N1;
 658                                         break;
 659
 660                                 case FA: /* f */
 661                                         jsonType = JsonType.FALSE;
 662                                         state = F1;
 663                                         break;
 664
 665                                 case TR: /* t */
 666                                         jsonType = JsonType.TRUE;
 667                                         state = T1;
 668                                         break;
 669
 670                                 case EO: /* empty } */
 671                                         result = PopObject (true);
 672                                         if (result != null)
 673                                                 StoreValue (result);
 674                                         PopMode (JsonMode.KEY);
 675                                         state = OK;
 676                                         break;
 677
 678                                 case OE: /* } */
 679                                         RemoveLastCharFromBuffer ();
 680
 681                                         if (ParseBuffer (out result))
 682                                                 StoreValue (result);
 683
 684                                         result = PopObject (true);
 685                                         if (result != null)
 686                                                 StoreValue (result);
 687
 688                                         PopMode (JsonMode.OBJECT);
 689
 690                                         jsonType = JsonType.NONE;
 691                                         state = OK;
 692                                         break;
 693
 694                                 case AE: /* ] */
 695                                         RemoveLastCharFromBuffer ();
 696                                         if (ParseBuffer (out result))
 697                                                 StoreValue (result);
 698                                         PopMode (JsonMode.ARRAY);
 699                                         result = PopObject (true);
 700                                         if (result != null)
 701                                                 StoreValue (result);
 702
 703                                         jsonType = JsonType.NONE;
 704                                         state = OK;
 705                                         break;
 706
 707                                 case OS: /* { */
 708                                         RemoveLastCharFromBuffer ();
 709                                         CreateObject ();
 710                                         PushMode (JsonMode.KEY);
 711
 712                                         state = OB;
 713                                         break;
 714
 715                                 case AB: /* [ */
 716                                         RemoveLastCharFromBuffer ();
 717                                         CreateArray ();
 718                                         PushMode (JsonMode.ARRAY);
 719
 720                                         state = AR;
 721                                         break;
 722
 723                                 case SE: /* string end " or ' */
 724                                         if (ch == quoteChar) {
 725                                                 RemoveLastCharFromBuffer ();
 726
 727                                                 switch (PeekMode ()) {
 728                                                         case JsonMode.KEY:
 729                                                                 if (ParseBuffer (out result))
 730                                                                         StoreKey (result);
 731
 732                                                                 jsonType = JsonType.NONE;
 733                                                                 state = CO;
 734                                                                 buffer.Length = 0;
 735                                                                 break;
 736
 737                                                         case JsonMode.ARRAY:
 738                                                         case JsonMode.OBJECT:
 739                                                                 if (ParseBuffer (out result))
 740                                                                         StoreValue (result);
 741
 742                                                                 jsonType = JsonType.NONE;
 743                                                                 state = OK;
 744                                                                 break;
 745
 746                                                         case JsonMode.NONE: /* A stand-alone string */
 747                                                                 jsonType = JsonType.STRING;
 748                                                                 state = IV; /* the rest of input is invalid */
 749                                                                 if (ParseBuffer (out result))
 750                                                                         PushObject (result);
 751                                                                 break;
 752
 753                                                         default:
 754                                                                 throw new ArgumentException ("Syntax error: string in unexpected place.");
 755                                                 }
 756                                         }
 757                                         break;
 758
 759                                 case CM: /* , */
 760                                         RemoveLastCharFromBuffer ();
 761
 762                                         // With MS.AJAX, a comma resets the recursion depth
 763                                         recursionDepth = 0;
 764
 765                                         bool doStore = ParseBuffer (out result);
 766                                         switch (PeekMode ()) {
 767                                                 case JsonMode.OBJECT:
 768                                                         if (doStore)
 769                                                                 StoreValue (result);
 770                                                         PopMode (JsonMode.OBJECT);
 771                                                         PushMode (JsonMode.KEY);
 772                                                         jsonType = JsonType.NONE;
 773                                                         state = KE;
 774                                                         break;
 775
 776                                                 case JsonMode.ARRAY:
 777                                                         jsonType = JsonType.NONE;
 778                                                         state = VA;
 779                                                         if (doStore)
 780                                                                 StoreValue (result);
 781                                                         break;
 782
 783                                                 default:
 784                                                         throw new ArgumentException ("Syntax error: unexpected comma.");
 785                                         }
 786
 787                                         break;
 788
 789                                 case CA: /* : */
 790                                         RemoveLastCharFromBuffer ();
 791
 792                                         // With MS.AJAX a colon increases recursion depth
 793                                         if (++recursionDepth >= recursionLimit)
 794                                                 throw new ArgumentException ("Recursion limit has been reached on parsing input.");
 795
 796                                         PopMode (JsonMode.KEY);
 797                                         PushMode (JsonMode.OBJECT);
 798                                         state = VA;
 799                                         break;
 800
 801                                 case IF: /* Infinity */
 802                                 case NN: /* NaN */
 803                                         jsonType = JsonType.FLOAT;
 804                                         switch (PeekMode ()) {
 805                                                 case JsonMode.ARRAY:
 806                                                 case JsonMode.OBJECT:
 807                                                         if (ParseBuffer (out result))
 808                                                                 StoreValue (result);
 809
 810                                                         jsonType = JsonType.NONE;
 811                                                         state = OK;
 812                                                         break;
 813
 814                                                 case JsonMode.NONE: /* A stand-alone NaN/Infinity */
 815                                                         jsonType = JsonType.FLOAT;
 816                                                         state = IV; /* the rest of input is invalid */
 817                                                         if (ParseBuffer (out result))
 818                                                                 PushObject (result);
 819                                                         break;
 820
 821                                                 default:
 822                                                         throw new ArgumentException ("Syntax error: misplaced NaN/Infinity.");
 823                                         }
 824                                         buffer.Length = 0;
 825                                         break;
 826
 827                                 default:
 828                                         throw new ArgumentException (GetModeMessage (PeekMode ()));
 829                         }
 830
 831                         return true;
 832                 }
 833
 834                 void CreateArray ()
 835                 {
 836                         var arr = new ArrayList ();
 837                         PushObject (arr);
 838                 }
 839
 840                 void CreateObject ()
 841                 {
 842                         var dict = new Dictionary <string, object> ();
 843                         PushObject (dict);
 844                 }
 845
 846                 void StoreKey (object o)
 847                 {
 848                         string key = o as string;
 849                         if (key != null)
 850                                 key = key.Trim ();
 851
 852                         if (String.IsNullOrEmpty (key))
 853                                 throw new InvalidOperationException ("Internal error: key is null, empty or not a string.");
 854
 855                         currentKey.Push (key);
 856                         Dictionary <string, object> dict = PeekObject () as Dictionary <string, object>;
 857                         if (dict == null)
 858                                 throw new InvalidOperationException ("Internal error: current object is not a dictionary.");
 859
 860                         /* MS AJAX.NET silently overwrites existing currentKey value */
 861                         dict [key] = null;
 862                 }
 863
 864                 void StoreValue (object o)
 865                 {
 866                         Dictionary <string, object> dict = PeekObject () as Dictionary <string, object>;
 867                         if (dict == null) {
 868                                 ArrayList arr = PeekObject () as ArrayList;
 869                                 if (arr == null)
 870                                         throw new InvalidOperationException ("Internal error: current object is not a dictionary or an array.");
 871                                 arr.Add (o);
 872                                 return;
 873                         }
 874
 875                         string key;
 876                         if (currentKey.Count == 0)
 877                                 key = null;
 878                         else
 879                                 key = currentKey.Pop ();
 880
 881                         if (String.IsNullOrEmpty (key))
 882                                 throw new InvalidOperationException ("Internal error: object is a dictionary, but no key present.");
 883
 884                         dict [key] = o;
 885                 }
 886         }
 887 }