Version 3.18.1
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File: json/js/parse-shim.js

            /**
             * <p>The JSON module adds support for serializing JavaScript objects into
             * JSON strings and parsing JavaScript objects from strings in JSON format.</p>
             *
             * <p>The JSON namespace is added to your YUI instance including static methods
             * Y.JSON.parse(..) and Y.JSON.stringify(..).</p>
             *
             * <p>The functionality and method signatures follow the ECMAScript 5
             * specification.  In browsers with native JSON support, the native
             * implementation is used.</p>
             *
             * <p>The <code>json</code> module is a rollup of <code>json-parse</code> and
             * <code>json-stringify</code>.</p>
             *
             * <p>As their names suggest, <code>json-parse</code> adds support for parsing
             * JSON data (Y.JSON.parse) and <code>json-stringify</code> for serializing
             * JavaScript data into JSON strings (Y.JSON.stringify).  You may choose to
             * include either of the submodules individually if you don't need the
             * complementary functionality, or include the rollup for both.</p>
             *
             * @module json
             * @main json
             * @class JSON
             * @static
             */
            
            /**
             * Provides Y.JSON.parse method to accept JSON strings and return native
             * JavaScript objects.
             *
             * @module json
             * @submodule json-parse
             * @for JSON
             * @static
             */
            
            
                /**
                 * Replace certain Unicode characters that JavaScript may handle incorrectly
                 * during eval--either by deleting them or treating them as line
                 * endings--with escape sequences.
                 * IMPORTANT NOTE: This regex will be used to modify the input if a match is
                 * found.
                 *
                 * @property _UNICODE_EXCEPTIONS
                 * @type {RegExp}
                 * @private
                 */
            var _UNICODE_EXCEPTIONS = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
            
            
                /**
                 * First step in the safety evaluation.  Regex used to replace all escape
                 * sequences (i.e. "\\", etc) with '@' characters (a non-JSON character).
                 *
                 * @property _ESCAPES
                 * @type {RegExp}
                 * @private
                 */
                _ESCAPES = /\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g,
            
                /**
                 * Second step in the safety evaluation.  Regex used to replace all simple
                 * values with ']' characters.
                 *
                 * @property _VALUES
                 * @type {RegExp}
                 * @private
                 */
                _VALUES  = /"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g,
            
                /**
                 * Third step in the safety evaluation.  Regex used to remove all open
                 * square brackets following a colon, comma, or at the beginning of the
                 * string.
                 *
                 * @property _BRACKETS
                 * @type {RegExp}
                 * @private
                 */
                _BRACKETS = /(?:^|:|,)(?:\s*\[)+/g,
            
                /**
                 * Final step in the safety evaluation.  Regex used to test the string left
                 * after all previous replacements for invalid characters.
                 *
                 * @property _UNSAFE
                 * @type {RegExp}
                 * @private
                 */
                _UNSAFE = /[^\],:{}\s]/,
            
                /**
                 * Replaces specific unicode characters with their appropriate \unnnn
                 * format. Some browsers ignore certain characters during eval.
                 *
                 * @method escapeException
                 * @param c {String} Unicode character
                 * @return {String} the \unnnn escapement of the character
                 * @private
                 */
                _escapeException = function (c) {
                    return '\\u'+('0000'+(+(c.charCodeAt(0))).toString(16)).slice(-4);
                },
            
                /**
                 * Traverses nested objects, applying a reviver function to each (key,value)
                 * from the scope if the key:value's containing object.  The value returned
                 * from the function will replace the original value in the key:value pair.
                 * If the value returned is undefined, the key will be omitted from the
                 * returned object.
                 *
                 * @method _revive
                 * @param data {MIXED} Any JavaScript data
                 * @param reviver {Function} filter or mutation function
                 * @return {MIXED} The results of the filtered data
                 * @private
                 */
                _revive = function (data, reviver) {
                    var walk = function (o,key) {
                        var k,v,value = o[key];
                        if (value && typeof value === 'object') {
                            for (k in value) {
                                if (value.hasOwnProperty(k)) {
                                    v = walk(value, k);
                                    if (v === undefined) {
                                        delete value[k];
                                    } else {
                                        value[k] = v;
                                    }
                                }
                            }
                        }
                        return reviver.call(o,key,value);
                    };
            
                    return typeof reviver === 'function' ? walk({'':data},'') : data;
                };
            
            /**
             * Parse a JSON string, returning the native JavaScript representation.
             *
             * @param s {string} JSON string data
             * @param reviver {function} (optional) function(k,v) passed each key value
             *          pair of object literals, allowing pruning or altering values
             * @return {MIXED} the native JavaScript representation of the JSON string
             * @throws SyntaxError
             * @method parse
             * @static
             */
            // JavaScript implementation in lieu of native browser support.  Based on
            // the json2.js library from http://json.org
            Y.JSON.parse = function (s,reviver) {
                if (typeof s !== 'string') {
                    s += '';
                }
            
                // Replace certain Unicode characters that are otherwise handled
                // incorrectly by some browser implementations.
                // NOTE: This modifies the input if such characters are found!
                s = s.replace(_UNICODE_EXCEPTIONS, _escapeException);
            
                // Test for any remaining invalid characters
                if (!_UNSAFE.test(s.replace(_ESCAPES,'@').
                                    replace(_VALUES,']').
                                    replace(_BRACKETS,''))) {
            
                    // Eval the text into a JavaScript data structure, apply any
                    // reviver function, and return
                    return _revive(eval('(' + s + ')'), reviver);
                }
            
                throw new SyntaxError('JSON.parse');
            };
            
            // Property available for testing if the implementation being used
            // is native or a shim
            Y.JSON.parse.isShim = true;