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      1 /*
      2     http://www.JSON.org/json2.js
      3     2009-04-16
      4 
      5     Public Domain.
      6 
      7     NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.
      8 
      9     See http://www.JSON.org/js.html
     10 
     11     This file creates a global JSON object containing two methods: stringify
     12     and parse.
     13 
     14         JSON.stringify(value, replacer, space)
     15             value       any JavaScript value, usually an object or array.
     16 
     17             replacer    an optional parameter that determines how object
     18                         values are stringified for objects. It can be a
     19                         function or an array of strings.
     20 
     21             space       an optional parameter that specifies the indentation
     22                         of nested structures. If it is omitted, the text will
     23                         be packed without extra whitespace. If it is a number,
     24                         it will specify the number of spaces to indent at each
     25                         level. If it is a string (such as '\t' or ' '),
     26                         it contains the characters used to indent at each level.
     27 
     28             This method produces a JSON text from a JavaScript value.
     29 
     30             When an object value is found, if the object contains a toJSON
     31             method, its toJSON method will be called and the result will be
     32             stringified. A toJSON method does not serialize: it returns the
     33             value represented by the name/value pair that should be serialized,
     34             or undefined if nothing should be serialized. The toJSON method
     35             will be passed the key associated with the value, and this will be
     36             bound to the object holding the key.
     37 
     38             For example, this would serialize Dates as ISO strings.
     39 
     40                 Date.prototype.toJSON = function (key) {
     41                     function f(n) {
     42                         // Format integers to have at least two digits.
     43                         return n < 10 ? '0' + n : n;
     44                     }
     45 
     46                     return this.getUTCFullYear()   + '-' +
     47                          f(this.getUTCMonth() + 1) + '-' +
     48                          f(this.getUTCDate())      + 'T' +
     49                          f(this.getUTCHours())     + ':' +
     50                          f(this.getUTCMinutes())   + ':' +
     51                          f(this.getUTCSeconds())   + 'Z';
     52                 };
     53 
     54             You can provide an optional replacer method. It will be passed the
     55             key and value of each member, with this bound to the containing
     56             object. The value that is returned from your method will be
     57             serialized. If your method returns undefined, then the member will
     58             be excluded from the serialization.
     59 
     60             If the replacer parameter is an array of strings, then it will be
     61             used to select the members to be serialized. It filters the results
     62             such that only members with keys listed in the replacer array are
     63             stringified.
     64 
     65             Values that do not have JSON representations, such as undefined or
     66             functions, will not be serialized. Such values in objects will be
     67             dropped; in arrays they will be replaced with null. You can use
     68             a replacer function to replace those with JSON values.
     69             JSON.stringify(undefined) returns undefined.
     70 
     71             The optional space parameter produces a stringification of the
     72             value that is filled with line breaks and indentation to make it
     73             easier to read.
     74 
     75             If the space parameter is a non-empty string, then that string will
     76             be used for indentation. If the space parameter is a number, then
     77             the indentation will be that many spaces.
     78 
     79             Example:
     80 
     81             text = JSON.stringify(['e', {pluribus: 'unum'}]);
     82             // text is '["e",{"pluribus":"unum"}]'
     83 
     84 
     85             text = JSON.stringify(['e', {pluribus: 'unum'}], null, '\t');
     86             // text is '[\n\t"e",\n\t{\n\t\t"pluribus": "unum"\n\t}\n]'
     87 
     88             text = JSON.stringify([new Date()], function (key, value) {
     89                 return this[key] instanceof Date ?
     90                     'Date(' + this[key] + ')' : value;
     91             });
     92             // text is '["Date(---current time---)"]'
     93 
     94 
     95         JSON.parse(text, reviver)
     96             This method parses a JSON text to produce an object or array.
     97             It can throw a SyntaxError exception.
     98 
     99             The optional reviver parameter is a function that can filter and
    100             transform the results. It receives each of the keys and values,
    101             and its return value is used instead of the original value.
    102             If it returns what it received, then the structure is not modified.
    103             If it returns undefined then the member is deleted.
    104 
    105             Example:
    106 
    107             // Parse the text. Values that look like ISO date strings will
    108             // be converted to Date objects.
    109 
    110             myData = JSON.parse(text, function (key, value) {
    111                 var a;
    112                 if (typeof value === 'string') {
    113                     a =
    114 /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)Z$/.exec(value);
    115                     if (a) {
    116                         return new Date(Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4],
    117                             +a[5], +a[6]));
    118                     }
    119                 }
    120                 return value;
    121             });
    122 
    123             myData = JSON.parse('["Date(09/09/2001)"]', function (key, value) {
    124                 var d;
    125                 if (typeof value === 'string' &&
    126                         value.slice(0, 5) === 'Date(' &&
    127                         value.slice(-1) === ')') {
    128                     d = new Date(value.slice(5, -1));
    129                     if (d) {
    130                         return d;
    131                     }
    132                 }
    133                 return value;
    134             });
    135 
    136 
    137     This is a reference implementation. You are free to copy, modify, or
    138     redistribute.
    139 
    140     This code should be minified before deployment.
    141     See http://javascript.crockford.com/jsmin.html
    142 
    143     USE YOUR OWN COPY. IT IS EXTREMELY UNWISE TO LOAD CODE FROM SERVERS YOU DO
    144     NOT CONTROL.
    145 */
    146 
    147 /*jslint evil: true */
    148 
    149 /*global JSON */
    150 
    151 /*members "", "\b", "\t", "\n", "\f", "\r", "\"", JSON, "\\", apply,
    152     call, charCodeAt, getUTCDate, getUTCFullYear, getUTCHours,
    153     getUTCMinutes, getUTCMonth, getUTCSeconds, hasOwnProperty, join,
    154     lastIndex, length, parse, prototype, push, replace, slice, stringify,
    155     test, toJSON, toString, valueOf
    156 */
    157 
    158 // Create a JSON object only if one does not already exist. We create the
    159 // methods in a closure to avoid creating global variables.
    160 
    161 if (!this.JSON) {
    162     JSON = {};
    163 }
    164 (function () {
    165 
    166     function f(n) {
    167         // Format integers to have at least two digits.
    168         return n < 10 ? '0' + n : n;
    169     }
    170 
    171     if (typeof Date.prototype.toJSON !== 'function') {
    172 
    173         Date.prototype.toJSON = function (key) {
    174 
    175             return this.getUTCFullYear()   + '-' +
    176                  f(this.getUTCMonth() + 1) + '-' +
    177                  f(this.getUTCDate())      + 'T' +
    178                  f(this.getUTCHours())     + ':' +
    179                  f(this.getUTCMinutes())   + ':' +
    180                  f(this.getUTCSeconds())   + 'Z';
    181         };
    182     }
    183 
    184     var cx = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
    185         escapable = /[\\\"\x00-\x1f]/g,
    186         gap,
    187         indent,
    188         meta = {    // table of character substitutions
    189             '\b': '\\b',
    190             '\t': '\\t',
    191             '\n': '\\n',
    192             '\f': '\\f',
    193             '\r': '\\r',
    194             '"' : '\\"',
    195             '\\': '\\\\'
    196         },
    197         rep;
    198 
    199 
    200     function quote(string) {
    201 
    202 // If the string contains no control characters, no quote characters, and no
    203 // backslash characters, then we can safely slap some quotes around it.
    204 // Otherwise we must also replace the offending characters with safe escape
    205 // sequences.
    206 
    207         escapable.lastIndex = 0;
    208         return escapable.test(string) ?
    209             '"' + string.replace(escapable, function (a) {
    210                 var c = meta[a];
    211                 return typeof c === 'string' ? c :
    212                     '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
    213             }) + '"' :
    214             '"' + string + '"';
    215     }
    216 
    217 
    218     function str(key, holder) {
    219 
    220 // Produce a string from holder[key].
    221 
    222         var i,          // The loop counter.
    223             k,          // The member key.
    224             v,          // The member value.
    225             length,
    226             mind = gap,
    227             partial,
    228             value = holder[key];
    229 
    230 // If the value has a toJSON method, call it to obtain a replacement value.
    231 
    232         if (value && typeof value === 'object' &&
    233                 typeof value.toJSON === 'function') {
    234             value = value.toJSON(key);
    235         }
    236 
    237 // If we were called with a replacer function, then call the replacer to
    238 // obtain a replacement value.
    239 
    240         if (typeof rep === 'function') {
    241             value = rep.call(holder, key, value);
    242         }
    243 
    244 // What happens next depends on the value's type.
    245 
    246         if (value && ((typeof value) === "object")) {
    247             if (value.constructor === String || value.constructor === Number || value.constructor === Boolean)
    248                 value = value.valueOf();
    249         }
    250 
    251         switch (typeof value) {
    252         case 'string':
    253             return quote(value);
    254 
    255         case 'number':
    256 
    257 // JSON numbers must be finite. Encode non-finite numbers as null.
    258 
    259             return isFinite(value) ? String(value) : 'null';
    260 
    261         case 'boolean':
    262         case 'null':
    263 
    264 // If the value is a boolean or null, convert it to a string. Note:
    265 // typeof null does not produce 'null'. The case is included here in
    266 // the remote chance that this gets fixed someday.
    267 
    268             return String(value);
    269 
    270 // If the type is 'object', we might be dealing with an object or an array or
    271 // null.
    272 
    273         case 'object':
    274 
    275 // Due to a specification blunder in ECMAScript, typeof null is 'object',
    276 // so watch out for that case.
    277 
    278             if (!value) {
    279                 return 'null';
    280             }
    281 
    282 // Make an array to hold the partial results of stringifying this object value.
    283 
    284             gap += indent;
    285             partial = [];
    286 
    287 // Is the value an array?
    288 
    289             if (Object.prototype.toString.apply(value) === '[object Array]') {
    290 
    291 // The value is an array. Stringify every element. Use null as a placeholder
    292 // for non-JSON values.
    293 
    294                 length = value.length;
    295                 for (i = 0; i < length; i += 1) {
    296                     partial[i] = str(i, value) || 'null';
    297                 }
    298 
    299 // Join all of the elements together, separated with commas, and wrap them in
    300 // brackets.
    301 
    302                 v = partial.length === 0 ? '[]' :
    303                     gap ? '[\n' + gap +
    304                             partial.join(',\n' + gap) + '\n' +
    305                                 mind + ']' :
    306                           '[' + partial.join(',') + ']';
    307                 gap = mind;
    308                 return v;
    309             }
    310 
    311 // If the replacer is an array, use it to select the members to be stringified.
    312 
    313             if (rep && typeof rep === 'object') {
    314                 length = rep.length;
    315                 for (i = 0; i < length; i += 1) {
    316                     k = rep[i];
    317                     if (typeof k === 'string') {
    318                         v = str(k, value);
    319                         if (v) {
    320                             partial.push(quote(k) + (gap ? ': ' : ':') + v);
    321                         }
    322                     }
    323                 }
    324             } else {
    325 
    326 // Otherwise, iterate through all of the keys in the object.
    327 
    328                 for (k in value) {
    329                     if (Object.hasOwnProperty.call(value, k)) {
    330                         v = str(k, value);
    331                         if (v) {
    332                             partial.push(quote(k) + (gap ? ': ' : ':') + v);
    333                         }
    334                     }
    335                 }
    336             }
    337 
    338 // Join all of the member texts together, separated with commas,
    339 // and wrap them in braces.
    340 
    341             v = partial.length === 0 ? '{}' :
    342                 gap ? '{\n' + gap + partial.join(',\n' + gap) + '\n' +
    343                         mind + '}' : '{' + partial.join(',') + '}';
    344             gap = mind;
    345             return v;
    346         }
    347     }
    348 
    349 // If the JSON object does not yet have a stringify method, give it one.
    350 
    351     if (typeof JSON.stringify !== 'function') {
    352         JSON.stringify = function (value, replacer, space) {
    353 
    354 // The stringify method takes a value and an optional replacer, and an optional
    355 // space parameter, and returns a JSON text. The replacer can be a function
    356 // that can replace values, or an array of strings that will select the keys.
    357 // A default replacer method can be provided. Use of the space parameter can
    358 // produce text that is more easily readable.
    359 
    360             var i;
    361             gap = '';
    362             indent = '';
    363 
    364 // If the space parameter is a number, make an indent string containing that
    365 // many spaces.
    366 
    367             if (typeof space === 'number') {
    368                 for (i = 0; i < space; i += 1) {
    369                     indent += ' ';
    370                 }
    371 
    372 // If the space parameter is a string, it will be used as the indent string.
    373 
    374             } else if (typeof space === 'string') {
    375                 indent = space;
    376             }
    377 
    378 // If there is a replacer, it must be a function or an array.
    379 // Otherwise, throw an error.
    380 
    381             rep = replacer;
    382             if (replacer && typeof replacer !== 'function' &&
    383                     (typeof replacer !== 'object' ||
    384                      typeof replacer.length !== 'number')) {
    385                 throw new Error('JSON.stringify');
    386             }
    387 
    388 // Make a fake root object containing our value under the key of ''.
    389 // Return the result of stringifying the value.
    390 
    391             return str('', {'': value});
    392         };
    393     }
    394 
    395 
    396 // If the JSON object does not yet have a parse method, give it one.
    397 
    398     if (typeof JSON.parse !== 'function') {
    399         JSON.parse = function (text, reviver) {
    400 
    401 // The parse method takes a text and an optional reviver function, and returns
    402 // a JavaScript value if the text is a valid JSON text.
    403 
    404             var j;
    405 
    406             function walk(holder, key) {
    407 
    408 // The walk method is used to recursively walk the resulting structure so
    409 // that modifications can be made.
    410 
    411                 var k, v, value = holder[key];
    412                 if (value && typeof value === 'object') {
    413                     for (k in value) {
    414                         if (Object.hasOwnProperty.call(value, k)) {
    415                             v = walk(value, k);
    416                             if (v !== undefined) {
    417                                 value[k] = v;
    418                             } else {
    419                                 delete value[k];
    420                             }
    421                         }
    422                     }
    423                 }
    424                 return reviver.call(holder, key, value);
    425             }
    426 
    427 
    428 // Parsing happens in four stages. In the first stage, we replace certain
    429 // Unicode characters with escape sequences. JavaScript handles many characters
    430 // incorrectly, either silently deleting them, or treating them as line endings.
    431 
    432             cx.lastIndex = 0;
    433             if (cx.test(text)) {
    434                 text = text.replace(cx, function (a) {
    435                     return '\\u' +
    436                         ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
    437                 });
    438             }
    439 
    440 // In the second stage, we run the text against regular expressions that look
    441 // for non-JSON patterns. We are especially concerned with '()' and 'new'
    442 // because they can cause invocation, and '=' because it can cause mutation.
    443 // But just to be safe, we want to reject all unexpected forms.
    444 
    445 // We split the second stage into 4 regexp operations in order to work around
    446 // crippling inefficiencies in IE's and Safari's regexp engines. First we
    447 // replace the JSON backslash pairs with '@' (a non-JSON character). Second, we
    448 // replace all simple value tokens with ']' characters. Third, we delete all
    449 // open brackets that follow a colon or comma or that begin the text. Finally,
    450 // we look to see that the remaining characters are only whitespace or ']' or
    451 // ',' or ':' or '{' or '}'. If that is so, then the text is safe for eval.
    452 
    453             if (/^[\],:{}\s]*$/.
    454 test(text.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g, '@').
    455 replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']').
    456 replace(/(?:^|:|,)(?:\s*\[)+/g, ''))) {
    457 
    458 // In the third stage we use the eval function to compile the text into a
    459 // JavaScript structure. The '{' operator is subject to a syntactic ambiguity
    460 // in JavaScript: it can begin a block or an object literal. We wrap the text
    461 // in parens to eliminate the ambiguity.
    462 
    463                 j = eval('(' + text + ')');
    464 
    465 // In the optional fourth stage, we recursively walk the new structure, passing
    466 // each name/value pair to a reviver function for possible transformation.
    467 
    468                 return typeof reviver === 'function' ?
    469                     walk({'': j}, '') : j;
    470             }
    471 
    472 // If the text is not JSON parseable, then a SyntaxError is thrown.
    473 
    474             throw new SyntaxError('JSON.parse');
    475         };
    476     }
    477 }());
    478