code: public function parseFilteredValue() {
          list($type, $filters) = $this->pop('FILTERED_VALUE');
          $value = array_shift($filters);
          $opening = '';
          $closing = '';
  
          foreach($filters as $filter) {
              if(function_exists($filter)) {
                  $opening .= $filter . '(';
                  $closing .= ')';
              } else {
                  $opening .= '\Katar\Katar::getInstance()->filter(\'' .
                      $filter . '\', ';
                  $closing .= ')';
              }
          }
  
          return '$output .= ' . $opening . $value . $closing . ";\n";
      }
docs: Parses a FILTERED_VALUE expression