178      * @param HTMLPurifier_Token $current Current token variable.
182     protected function forward(&$i, &$current)  argument
192         $current = $this->inputZipper->back[$i];
201      * @param HTMLPurifier_Token $current Current token variable.
206     protected function forwardUntilEndToken(&$i, &$current, &$nesting)  argument
208         $result = $this->forward($i, $current);
215         if ($current instanceof HTMLPurifier_Token_Start) {
217         } elseif ($current instanceof HTMLPurifier_Token_End) {
232      * @param HTMLPurifier_Token $current Current token variable.
236     protected function backward(&$i, &$current)  argument
246         $current = $this->inputZipper->front[$i];