// This file is copyrighted and is part of nzdis-oql package. 
// See the file LICENSE for copyright information and the terms and conditions for copying, distributing and modifications of nzdis-oql package.
// @copyright@

package nzdis.lang.oql.app;

/**/
import nzdis.lang.oql.analysis.DepthFirstAdapter;
import nzdis.lang.oql.node.*;

/**
 * Simple OQL AST walker. This is simple OQL Abstract Syntax Tree walker
 * which will visit each of the nodes and print on standard output the
 * name of particular node visited. This class can be very usefull while
 * testing the tree structure for a given OQL sentence.
 *
 *@author Mariusz Nowostawski
 *@version @version@ $Revision: 1.1 $
 */
class PrintWalker extends DepthFirstAdapter {

  int indent = 0;

  void indent(){
    String s = new String ("");
    for(int i=0; i < indent; i++) s += " "; 
    System.out.print(s);
  }
    
  public void defaultIn(Node node) {
    indent();
    System.out.println(node.getClass().toString().substring(27));
    indent++;
  }
  
  public void defaultOut(Node node) {
    indent--;
  }
  
  public void defaultCase(Node node) {
    indent();
    System.out.println(node.getClass().toString().substring(27)+": " + ((Token) node).getText());
  }
  
}