Use native PHP JSON functions when available

inc/JSON.php

@@ -130,6 +130,7 @@ class JSON {
 
     /**
      * encodes an arbitrary variable into JSON format
+     * If available the native PHP JSON implementation is used.
      *
      * @param    mixed   $var    any number, boolean, string, array, or object to be encoded.
      *                           see argument 1 to JSON() above for array-parsing behavior.
@@ -140,6 +141,7 @@ class JSON {
      * @access   public
      */
     function encode($var) {
+        if (function_exists('json_encode')) return json_encode($var);
         switch (gettype($var)) {
             case 'boolean':
                 return $var ? 'true' : 'false';
@@ -352,6 +354,7 @@ class JSON {
 
     /**
      * decodes a JSON string into appropriate variable
+     * If available the native PHP JSON implementation is used.
      *
      * @param    string  $str    JSON-formatted string
      *
@@ -363,6 +366,7 @@ class JSON {
      * @access   public
      */
     function decode($str) {
+        if (function_exists('json_decode')) return json_decode($str);
         $str = $this->reduce_string($str);
 
         switch (strtolower($str)) {