+
+ $str = ' '.$str.' ';
+
+ // \w, \b and a few others do not match on a unicode character
+ // set for performance reasons. As a result words like über
+ // will not match on a word boundary. Instead, we'll assume that
+ // a bad word will be bookended by any of these characters.
+ $delim = '[-_\'\"`(){}<>\[\]|!?@#%&,.:;^~*+=\/ 0-9\n\r\t]';