import list.dl.*;
import list.dl.algo.*;
import java.io.*;

class DLListDriver
{
   public static void main (String[] args)
   {
      DLList dlList = new DLList ();
      displayList (dlList);
      dlList.insertLeftFront (new Integer (78));
      displayList (dlList);
      dlList.insertLeftFront (new Integer (-63));
      displayList (dlList);
      dlList.insertRightFront (new Integer (-99));
      displayList (dlList);
      dlList.insertRightFront (new Integer (55));
      displayList (dlList);

      /*
      // Well-behave removal test:
      System.out.println ("Remove " + dlList.remRightFirst ());
      displayList (dlList);
      System.out.println ("Remove " + dlList.remLeftFirst ());
      displayList (dlList);
      System.out.println ("Remove " + dlList.remRightFirst ());
      displayList (dlList);
      System.out.println ("Remove " + dlList.remLeftFirst ());
      displayList (dlList);
      */

      try
      {
         DLList leftEnd = (DLList)dlList.executeLeft (GetLeftEnd.Singleton, null);
         System.out.println ("Remove " + leftEnd.remRightFirst ());
         displayList (dlList);
         leftEnd = (DLList)dlList.executeLeft (GetLeftEnd.Singleton, null);
         System.out.println ("Remove " + leftEnd.remRightFirst ());
         displayList (dlList);  // What is dlList now?
         leftEnd = (DLList)dlList.executeLeft (GetLeftEnd.Singleton, null);
         // Explain what happens in the following:
         System.out.println ("Remove " + leftEnd.remRightFirst ());
         displayList (dlList);
         leftEnd = (DLList)dlList.executeLeft (GetLeftEnd.Singleton, null);
         System.out.println ("Remove " + leftEnd.remRightFirst ());
         displayList (dlList);
      }
      catch (Exception e)
      {
         System.out.println (e);
      }
      /*
      */
      try
      {
         System.out.print ("Press Enter to quit...");
         System.in.read ();
      }
      catch (Exception e)
      {
      }
   }

   private static void displayList (DLList dlList)
   {
      System.out.print ("List is (");
      dlList.execute (PrintList.Singleton, null);
      System.out.println (" )");
      System.out.println ("Cardinality is: " + (Integer) dlList.execute (ElementCount.Singleton, null));
   }
}