/**
  * Initialize compiler
  *
  * @param string $lexer_class  class name
  * @param string $parser_class class name
  * @param hiweb_tpl $smurty       global instance
  */
 public function __construct($lexer_class, $parser_class, $smurty)
 {
     $this->smurty = $smurty;
     parent::__construct();
     // get required plugins
     $this->lexer_class = $lexer_class;
     $this->parser_class = $parser_class;
 }