package step7;
import java.util.List;
import step7.expr.yyLex;
/** output {@link expr} tree in postfix notation.
  */
public class postfix implements jag.Visitor {

%%

List: Object Object { {$1}; {$2}; `" "+classname($0)`; }
  | Object          { {$1}; `" "+classname($0)`; };

Number:             { `" "+$0`; };

%%
  /** return last component of (inner) classname.
    */
  protected static String classname (Object obj) {
    String name = obj.getClass().getName();
    return name.substring(name.lastIndexOf("$")+1);
  }
  /** read an expression from standard input and output it in postorder.
    */
  public static void main (String[] args) throws Exception {
    new postfix().visit(new expr().yyparse(new yyLex(System.in)));
    System.out.println();
  }
}