<?php
defined('BASEPATH') OR exit('No direct script access allowed');

/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */

/**
 * Converts to and from JSON format.
 *
 * JSON (JavaScript Object Notation) is a lightweight data-interchange
 * format. It is easy for humans to read and write. It is easy for machines
 * to parse and generate. It is based on a subset of the JavaScript
 * Programming Language, Standard ECMA-262 3rd Edition - December 1999.
 * This feature can also be found in  Python. JSON is a text format that is
 * completely language independent but uses conventions that are familiar
 * to programmers of the C-family of languages, including C, C++, C#, Java,
 * JavaScript, Perl, TCL, and many others. These properties make JSON an
 * ideal data-interchange language.
 *
 * This package provides a simple encoder and decoder for JSON notation. It
 * is intended for use with client-side Javascript applications that make
 * use of HTTPRequest to perform server communication functions - data can
 * be encoded into JSON notation for use in a client-side javascript, or
 * decoded from incoming Javascript requests. JSON format is native to
 * Javascript, and can be directly eval()'ed with no further parsing
 * overhead
 *
 * All strings should be in ASCII or UTF-8 format!
 *
 * LICENSE: Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met: Redistributions of source code must retain the
 * above copyright notice, this list of conditions and the following
 * disclaimer. Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
 * NO EVENT SHALL CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * @category
 * @package     Services_JSON
 * @author      Michal Migurski <mike-json@teczno.com>
 * @author      Matt Knapp <mdknapp[at]gmail[dot]com>
 * @author      Brett Stimmerman <brettstimmerman[at]gmail[dot]com>
 * @copyright   2005 Michal Migurski
 * @version     CVS: $Id: JSON.php,v 1.31 2006/06/28 05:54:17 migurski Exp $
 * @license     http://www.opensource.org/licenses/bsd-license.php
 * @link        http://pear.php.net/pepr/pepr-proposal-show.php?id=198
 */

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_SLICE', 1);

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_IN_STR', 2);

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_IN_ARR', 3);

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_IN_OBJ', 4);

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_IN_CMT', 5);

/**
 * Behavior switch for Services_JSON::decode()
 */
define('SERVICES_JSON_LOOSE_TYPE', 16);

/**
 * Behavior switch for Services_JSON::decode()
 */
define('SERVICES_JSON_SUPPRESS_ERRORS', 32);

/**
 * Converts to and from JSON format.
 *
 * Brief example of use:
 *
 * <code>
 * // create a new instance of Services_JSON
 * $json = new Services_JSON();
 *
 * // convert a complexe value to JSON notation, and send it to the browser
 * $value = array('foo', 'bar', array(1, 2, 'baz'), array(3, array(4)));
 * $output = $json->encode($value);
 *
 * print($output);
 * // prints: ["foo","bar",[1,2,"baz"],[3,[4]]]
 *
 * // accept incoming POST data, assumed to be in JSON notation
 * $input = file_get_contents('php://input', 1000000);
 * $value = $json->decode($input);
 * </code>
 */
class Services_JSON
{
	/**
	 * constructs a new JSON instance
	 *
	 * @param    int     $use    object behavior flags; combine with boolean-OR
	 *
	 *                           possible values:
	 *                           - SERVICES_JSON_LOOSE_TYPE:  loose typing.
	 *                                   "{...}" syntax creates associative arrays
	 *                                   instead of objects in decode().
	 *                           - SERVICES_JSON_SUPPRESS_ERRORS:  error suppression.
	 *                                   Values which can't be encoded (e.g. resources)
	 *                                   appear as NULL instead of throwing errors.
	 *                                   By default, a deeply-nested resource will
	 *                                   bubble up with an error, so all return values
	 *                                   from encode() should be checked with isError()
	 */
	function __construct($use = 0)
	{
		$this->use = $use;
	}

	/**
	 * PHP4 Constructor.
	 */
	function Services_JSON($use = 0)
	{
		return self::__construct($use);
	}

	
	/**
	 * convert a string from one UTF-16 char to one UTF-8 char
	 *
	 * Normally should be handled by mb_convert_encoding, but
	 * provides a slower PHP-only method for installations
	 * that lack the multibye string extension.
	 *
	 * @param    string  $utf16  UTF-16 character
	 * @return   string  UTF-8 character
	 * @access   private
	 */
	function utf162utf8($utf16)
	{
		// oh please oh please oh please oh please oh please
		if (function_exists('mb_convert_encoding'))
		{
			return mb_convert_encoding($utf16, 'UTF-8', 'UTF-16');
		}
		
		$bytes = (ord($utf16{0}) << 8) | ord($utf16{1});
		
		switch (true)
		{
			case ((0x7F & $bytes) == $bytes):
				// this case should never be reached, because we are in ASCII range
				// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
				return chr(0x7F & $bytes);
			
			case (0x07FF & $bytes) == $bytes:
				// return a 2-byte UTF-8 character
				// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
				return chr(0xC0 | (($bytes >> 6) & 0x1F)) . chr(0x80 | ($bytes & 0x3F));
			
			case (0xFFFF & $bytes) == $bytes:
				// return a 3-byte UTF-8 character
				// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
				return chr(0xE0 | (($bytes >> 12) & 0x0F)) . chr(0x80 | (($bytes >> 6) & 0x3F)) . chr(0x80 | ($bytes & 0x3F));
		}
		
		// ignoring UTF-32 for now, sorry
		return '';
	}
	
	/**
	 * convert a string from one UTF-8 char to one UTF-16 char
	 *
	 * Normally should be handled by mb_convert_encoding, but
	 * provides a slower PHP-only method for installations
	 * that lack the multibye string extension.
	 *
	 * @param    string  $utf8   UTF-8 character
	 * @return   string  UTF-16 character
	 * @access   private
	 */
	function utf82utf16($utf8)
	{
		// oh please oh please oh please oh please oh please
		if (function_exists('mb_convert_encoding'))
		{
			return mb_convert_encoding($utf8, 'UTF-16', 'UTF-8');
		}
		
		switch (strlen($utf8))
		{
			case 1:
				// this case should never be reached, because we are in ASCII range
				// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
				return $utf8;
			
			case 2:
				// return a UTF-16 character from a 2-byte UTF-8 char
				// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
				return chr(0x07 & (ord($utf8{0}) >> 2)) . chr((0xC0 & (ord($utf8{0}) << 6)) | (0x3F & ord($utf8{1})));
			
			case 3:
				// return a UTF-16 character from a 3-byte UTF-8 char
				// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
				return chr((0xF0 & (ord($utf8{0}) << 4)) | (0x0F & (ord($utf8{1}) >> 2))) . chr((0xC0 & (ord($utf8{1}) << 6)) | (0x7F & ord($utf8{2})));
		}
		
		// ignoring UTF-32 for now, sorry
		return '';
	}
	
	/**
	 * encodes an arbitrary variable into JSON format
	 *
	 * @param    mixed   $var    any number, boolean, string, array, or object to be encoded.
	 *                           see argument 1 to Services_JSON() above for array-parsing behavior.
	 *                           if var is a strng, note that encode() always expects it
	 *                           to be in ASCII or UTF-8 format!
	 *
	 * @return   mixed   JSON string representation of input var or an error if a problem occurs
	 * @access   public
	 */
	function encode($var)
	{
		switch (gettype($var))
		{
			case 'boolean':
				return $var ? 'true' : 'false';
			
			case 'NULL':
				return 'null';
			
			case 'integer':
				return (int) $var;
			
			case 'double':
			case 'float':
				return (float) $var;
			
			case 'string':
				// STRINGS ARE EXPECTED TO BE IN ASCII OR UTF-8 FORMAT
				$ascii      = '';
				$strlen_var = strlen($var);
				
				/*
				 * Iterate over every character in the string,
				 * escaping with a slash or encoding to UTF-8 where necessary
				 */
				for ($c = 0; $c < $strlen_var; ++$c)
				{
					
					$ord_var_c = ord($var{$c});
					
					switch (true)
					{
						case $ord_var_c == 0x08:
							$ascii .= '\b';
							break;
						case $ord_var_c == 0x09:
							$ascii .= '\t';
							break;
						case $ord_var_c == 0x0A:
							$ascii .= '\n';
							break;
						case $ord_var_c == 0x0C:
							$ascii .= '\f';
							break;
						case $ord_var_c == 0x0D:
							$ascii .= '\r';
							break;
						
						case $ord_var_c == 0x22:
						case $ord_var_c == 0x2F:
						case $ord_var_c == 0x5C:
							// double quote, slash, slosh
							$ascii .= '\\' . $var{$c};
							break;
						
						case (($ord_var_c >= 0x20) && ($ord_var_c <= 0x7F)):
							// characters U-00000000 - U-0000007F (same as ASCII)
							$ascii .= $var{$c};
							break;
						
						case (($ord_var_c & 0xE0) == 0xC0):
							// characters U-00000080 - U-000007FF, mask 110XXXXX
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c, ord($var{$c + 1}));
							$c += 1;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;
						
						case (($ord_var_c & 0xF0) == 0xE0):
							// characters U-00000800 - U-0000FFFF, mask 1110XXXX
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c, ord($var{$c + 1}), ord($var{$c + 2}));
							$c += 2;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;
						
						case (($ord_var_c & 0xF8) == 0xF0):
							// characters U-00010000 - U-001FFFFF, mask 11110XXX
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c, ord($var{$c + 1}), ord($var{$c + 2}), ord($var{$c + 3}));
							$c += 3;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;
						
						case (($ord_var_c & 0xFC) == 0xF8):
							// characters U-00200000 - U-03FFFFFF, mask 111110XX
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c, ord($var{$c + 1}), ord($var{$c + 2}), ord($var{$c + 3}), ord($var{$c + 4}));
							$c += 4;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;
						
						case (($ord_var_c & 0xFE) == 0xFC):
							// characters U-04000000 - U-7FFFFFFF, mask 1111110X
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c, ord($var{$c + 1}), ord($var{$c + 2}), ord($var{$c + 3}), ord($var{$c + 4}), ord($var{$c + 5}));
							$c += 5;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;
					}
				}
				
				return '"' . $ascii . '"';
			
			case 'array':
				/*
				 * As per JSON spec if any array key is not an integer
				 * we must treat the the whole array as an object. We
				 * also try to catch a sparsely populated associative
				 * array with numeric keys here because some JS engines
				 * will create an array with empty indexes up to
				 * max_index which can cause memory issues and because
				 * the keys, which may be relevant, will be remapped
				 * otherwise.
				 *
				 * As per the ECMA and JSON specification an object may
				 * have any string as a property. Unfortunately due to
				 * a hole in the ECMA specification if the key is a
				 * ECMA reserved word or starts with a digit the
				 * parameter is only accessible using ECMAScript's
				 * bracket notation.
				 */
				
				// treat as a JSON object
				if (is_array($var) && count($var) && (array_keys($var) !== range(0, sizeof($var) - 1)))
				{
					$properties = array_map(array(
						$this,
						'name_value'
					), array_keys($var), array_values($var));
					
					foreach ($properties as $property)
					{
						if (Services_JSON::isError($property))
						{
							return $property;
						}
					}
					
					return '{' . join(',', $properties) . '}';
				}
				
				// treat it like a regular array
				$elements = array_map(array(
					$this,
					'encode'
				), $var);
				
				foreach ($elements as $element)
				{
					if (Services_JSON::isError($element))
					{
						return $element;
					}
				}
				
				return '[' . join(',', $elements) . ']';
			
			case 'object':
				$vars = get_object_vars($var);
				
				$properties = array_map(array(
					$this,
					'name_value'
				), array_keys($vars), array_values($vars));
				
				foreach ($properties as $property)
				{
					if (Services_JSON::isError($property))
					{
						return $property;
					}
				}
				
				return '{' . join(',', $properties) . '}';
			
			default:
				return ($this->use & SERVICES_JSON_SUPPRESS_ERRORS) ? 'null' : new Services_JSON_Error(gettype($var) . " can not be encoded as JSON string");
		}
	}
	
	/**
	 * array-walking function for use in generating JSON-formatted name-value pairs
	 *
	 * @param    string  $name   name of key to use
	 * @param    mixed   $value  reference to an array element to be encoded
	 *
	 * @return   string  JSON-formatted name-value pair, like '"name":value'
	 * @access   private
	 */
	function name_value($name, $value)
	{
		$encoded_value = $this->encode($value);
		
		if (Services_JSON::isError($encoded_value))
		{
			return $encoded_value;
		}
		
		return $this->encode(strval($name)) . ':' . $encoded_value;
	}
	
	/**
	 * reduce a string by removing leading and trailing comments and whitespace
	 *
	 * @param    $str    string      string value to strip of comments and whitespace
	 *
	 * @return   string  string value stripped of comments and whitespace
	 * @access   private
	 */
	function reduce_string($str)
	{
		$str = preg_replace(array(
			
			// eliminate single line comments in '// ...' form
			'#^\s*//(.+)$#m',
			
			// eliminate multi-line comments in '/* ... */' form, at start of string
			'#^\s*/\*(.+)\*/#Us',
			
			// eliminate multi-line comments in '/* ... */' form, at end of string
			'#/\*(.+)\*/\s*$#Us'
			
		), '', $str);
		
		// eliminate extraneous space
		return trim($str);
	}
	
	/**
	 * decodes a JSON string into appropriate variable
	 *
	 * @param    string  $str    JSON-formatted string
	 *
	 * @return   mixed   number, boolean, string, array, or object
	 *                   corresponding to given JSON input string.
	 *                   See argument 1 to Services_JSON() above for object-output behavior.
	 *                   Note that decode() always returns strings
	 *                   in ASCII or UTF-8 format!
	 * @access   public
	 */
	function decode($str)
	{
		$str = $this->reduce_string($str);
		
		switch (strtolower($str))
		{
			case 'true':
				return true;
			
			case 'false':
				return false;
			
			case 'null':
				return null;
			
			default:
				$m = array();
				
				if (is_numeric($str))
				{
					// Lookie-loo, it's a number
					
					// This would work on its own, but I'm trying to be
					// good about returning integers where appropriate:
					// return (float)$str;
					
					// Return float or int, as appropriate
					return ((float) $str == (integer) $str) ? (integer) $str : (float) $str;
					
				}
				elseif (preg_match('/^("|\').*(\1)$/s', $str, $m) && $m[1] == $m[2])
				{
					// STRINGS RETURNED IN UTF-8 FORMAT
					$delim       = substr($str, 0, 1);
					$chrs        = substr($str, 1, -1);
					$utf8        = '';
					$strlen_chrs = strlen($chrs);
					
					for ($c = 0; $c < $strlen_chrs; ++$c)
					{
						
						$substr_chrs_c_2 = substr($chrs, $c, 2);
						$ord_chrs_c      = ord($chrs{$c});
						
						switch (true)
						{
							case $substr_chrs_c_2 == '\b':
								$utf8 .= chr(0x08);
								++$c;
								break;
							case $substr_chrs_c_2 == '\t':
								$utf8 .= chr(0x09);
								++$c;
								break;
							case $substr_chrs_c_2 == '\n':
								$utf8 .= chr(0x0A);
								++$c;
								break;
							case $substr_chrs_c_2 == '\f':
								$utf8 .= chr(0x0C);
								++$c;
								break;
							case $substr_chrs_c_2 == '\r':
								$utf8 .= chr(0x0D);
								++$c;
								break;
							
							case $substr_chrs_c_2 == '\\"':
							case $substr_chrs_c_2 == '\\\'':
							case $substr_chrs_c_2 == '\\\\':
							case $substr_chrs_c_2 == '\\/':
								if (($delim == '"' && $substr_chrs_c_2 != '\\\'') OR ($delim == "'" && $substr_chrs_c_2 != '\\"'))
								{
									$utf8 .= $chrs{++$c};
								}
								break;
							
							case preg_match('/\\\u[0-9A-F]{4}/i', substr($chrs, $c, 6)):
								// single, escaped unicode character
								$utf16 = chr(hexdec(substr($chrs, ($c + 2), 2))) . chr(hexdec(substr($chrs, ($c + 4), 2)));
								$utf8 .= $this->utf162utf8($utf16);
								$c += 5;
								break;
							
							case ($ord_chrs_c >= 0x20) && ($ord_chrs_c <= 0x7F):
								$utf8 .= $chrs{$c};
								break;
							
							case ($ord_chrs_c & 0xE0) == 0xC0:
								// characters U-00000080 - U-000007FF, mask 110XXXXX
								//see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
								$utf8 .= substr($chrs, $c, 2);
								++$c;
								break;
							
							case ($ord_chrs_c & 0xF0) == 0xE0:
								// characters U-00000800 - U-0000FFFF, mask 1110XXXX
								// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
								$utf8 .= substr($chrs, $c, 3);
								$c += 2;
								break;
							
							case ($ord_chrs_c & 0xF8) == 0xF0:
								// characters U-00010000 - U-001FFFFF, mask 11110XXX
								// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
								$utf8 .= substr($chrs, $c, 4);
								$c += 3;
								break;
							
							case ($ord_chrs_c & 0xFC) == 0xF8:
								// characters U-00200000 - U-03FFFFFF, mask 111110XX
								// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
								$utf8 .= substr($chrs, $c, 5);
								$c += 4;
								break;
							
							case ($ord_chrs_c & 0xFE) == 0xFC:
								// characters U-04000000 - U-7FFFFFFF, mask 1111110X
								// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
								$utf8 .= substr($chrs, $c, 6);
								$c += 5;
								break;
								
						}
						
					}
					
					return $utf8;
					
				}
				elseif (preg_match('/^\[.*\]$/s', $str) OR preg_match('/^\{.*\}$/s', $str))
				{
					// array, or object notation
					
					if ($str{0} == '[')
					{
						$stk = array(
							SERVICES_JSON_IN_ARR
						);
						$arr = array();
					}
					else
					{
						if ($this->use & SERVICES_JSON_LOOSE_TYPE)
						{
							$stk = array(
								SERVICES_JSON_IN_OBJ
							);
							$obj = array();
						}
						else
						{
							$stk = array(
								SERVICES_JSON_IN_OBJ
							);
							$obj = new stdClass();
						}
					}
					
					array_push($stk, array(
						'what' => SERVICES_JSON_SLICE,
						'where' => 0,
						'delim' => false
					));
					
					$chrs = substr($str, 1, -1);
					$chrs = $this->reduce_string($chrs);
					
					if ($chrs == '')
					{
						if (reset($stk) == SERVICES_JSON_IN_ARR)
						{
							return $arr;
							
						}
						else
						{
							return $obj;
							
						}
					}
					
					//print("\nparsing {$chrs}\n");
					
					$strlen_chrs = strlen($chrs);
					
					for ($c = 0; $c <= $strlen_chrs; ++$c)
					{
						
						$top             = end($stk);
						$substr_chrs_c_2 = substr($chrs, $c, 2);
						
						if (($c == $strlen_chrs) OR (($chrs{$c} == ',') && ($top['what'] == SERVICES_JSON_SLICE)))
						{
							// found a comma that is not inside a string, array, etc.,
							// OR we've reached the end of the character list
							$slice = substr($chrs, $top['where'], ($c - $top['where']));
							array_push($stk, array(
								'what' => SERVICES_JSON_SLICE,
								'where' => ($c + 1),
								'delim' => false
							));
							//print("Found split at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");
							
							if (reset($stk) == SERVICES_JSON_IN_ARR)
							{
								// we are in an array, so just push an element onto the stack
								array_push($arr, $this->decode($slice));
								
							}
							elseif (reset($stk) == SERVICES_JSON_IN_OBJ)
							{
								// we are in an object, so figure
								// out the property name and set an
								// element in an associative array,
								// for now
								$parts = array();
								
								if (preg_match('/^\s*(["\'].*[^\\\]["\'])\s*:\s*(\S.*),?$/Uis', $slice, $parts))
								{
									// "name":value pair
									$key = $this->decode($parts[1]);
									$val = $this->decode($parts[2]);
									
									if ($this->use & SERVICES_JSON_LOOSE_TYPE)
									{
										$obj[$key] = $val;
									}
									else
									{
										$obj->$key = $val;
									}
								}
								elseif (preg_match('/^\s*(\w+)\s*:\s*(\S.*),?$/Uis', $slice, $parts))
								{
									// name:value pair, where name is unquoted
									$key = $parts[1];
									$val = $this->decode($parts[2]);
									
									if ($this->use & SERVICES_JSON_LOOSE_TYPE)
									{
										$obj[$key] = $val;
									}
									else
									{
										$obj->$key = $val;
									}
								}
								
							}
							
						}
						elseif ((($chrs{$c} == '"') OR ($chrs{$c} == "'")) && ($top['what'] != SERVICES_JSON_IN_STR))
						{
							// found a quote, and we are not inside a string
							array_push($stk, array(
								'what' => SERVICES_JSON_IN_STR,
								'where' => $c,
								'delim' => $chrs{$c}
							));
							//print("Found start of string at {$c}\n");
							
						}
						elseif (($chrs{$c} == $top['delim']) && ($top['what'] == SERVICES_JSON_IN_STR) && ((strlen(substr($chrs, 0, $c)) - strlen(rtrim(substr($chrs, 0, $c), '\\'))) % 2 != 1))
						{
							// found a quote, we're in a string, and it's not escaped
							// we know that it's not escaped becase there is _not_ an
							// odd number of backslashes at the end of the string so far
							array_pop($stk);
							//print("Found end of string at {$c}: ".substr($chrs, $top['where'], (1 + 1 + $c - $top['where']))."\n");
							
						}
						elseif (($chrs{$c} == '[') && in_array($top['what'], array(
							SERVICES_JSON_SLICE,
							SERVICES_JSON_IN_ARR,
							SERVICES_JSON_IN_OBJ
						)))
						{
							// found a left-bracket, and we are in an array, object, or slice
							array_push($stk, array(
								'what' => SERVICES_JSON_IN_ARR,
								'where' => $c,
								'delim' => false
							));
							//print("Found start of array at {$c}\n");
							
						}
						elseif (($chrs{$c} == ']') && ($top['what'] == SERVICES_JSON_IN_ARR))
						{
							// found a right-bracket, and we're in an array
							array_pop($stk);
							//print("Found end of array at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");
							
						}
						elseif (($chrs{$c} == '{') && in_array($top['what'], array(
							SERVICES_JSON_SLICE,
							SERVICES_JSON_IN_ARR,
							SERVICES_JSON_IN_OBJ
						)))
						{
							// found a left-brace, and we are in an array, object, or slice
							array_push($stk, array(
								'what' => SERVICES_JSON_IN_OBJ,
								'where' => $c,
								'delim' => false
							));
							//print("Found start of object at {$c}\n");
							
						}
						elseif (($chrs{$c} == '}') && ($top['what'] == SERVICES_JSON_IN_OBJ))
						{
							// found a right-brace, and we're in an object
							array_pop($stk);
							//print("Found end of object at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");
							
						}
						elseif (($substr_chrs_c_2 == '/*') && in_array($top['what'], array(
							SERVICES_JSON_SLICE,
							SERVICES_JSON_IN_ARR,
							SERVICES_JSON_IN_OBJ
						)))
						{
							// found a comment start, and we are in an array, object, or slice
							array_push($stk, array(
								'what' => SERVICES_JSON_IN_CMT,
								'where' => $c,
								'delim' => false
							));
							$c++;
							//print("Found start of comment at {$c}\n");
							
						}
						elseif (($substr_chrs_c_2 == '*/') && ($top['what'] == SERVICES_JSON_IN_CMT))
						{
							// found a comment end, and we're in one now
							array_pop($stk);
							$c++;
							
							for ($i = $top['where']; $i <= $c; ++$i)
								$chrs = substr_replace($chrs, ' ', $i, 1);
							
							//print("Found end of comment at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");
							
						}
						
					}
					
					if (reset($stk) == SERVICES_JSON_IN_ARR)
					{
						return $arr;
						
					}
					elseif (reset($stk) == SERVICES_JSON_IN_OBJ)
					{
						return $obj;
						
					}
					
				}
		}
	}
	
	/**
	 * @todo Ultimately, this should just call PEAR::isError()
	 */
	function isError($data, $code = null)
	{
		if (class_exists('pear'))
		{
			return PEAR::isError($data, $code);
		}
		elseif (is_object($data) && (get_class($data) == 'services_json_error' OR is_subclass_of($data, 'services_json_error')))
		{
			return true;
		}
		
		return false;
	}
}

if (class_exists('PEAR_Error'))
{	
	class Services_JSON_Error extends PEAR_Error
	{
		function __construct($message = 'unknown error', $code = null, $mode = null, $options = null, $userinfo = null)
		{
			parent::PEAR_Error($message, $code, $mode, $options, $userinfo);
		}

		function Services_JSON_Error($message = 'unknown error', $code = null, $mode = null, $options = null, $userinfo = null)
		{
			return self::__construct($message, $code, $mode, $options, $userinfo);
		}
	}
	
}
else
{	
	/**
	 * @todo Ultimately, this class shall be descended from PEAR_Error
	 */
	class Services_JSON_Error
	{
		function __construct($message = 'unknown error', $code = null, $mode = null, $options = null, $userinfo = null) {}
		function Services_JSON_Error($message = 'unknown error', $code = null, $mode = null, $options = null, $userinfo = null)
		{
			return self::__construct($message, $code, $mode, $options, $userinfo);
		}
	}
	
}
