/*  TestIntListProcedural.java
  
    Test the integer linked list class using the usual
    procedural style.
  
    Bruce M. Bolden
    May 18, 2000              
    Revised: December 1, 2003
    http://www.cs.uidaho.edu/~bruceb/
 */

import java.io.*;

class TestIntListProcedural
{
   public static void main( String[] args )
   {
       IntList  list1 = new IntList( 1, null );
       System.out.print( "list1: " );
       PrintIntList( list1 );
         
       list1 = new IntList( 1 );
       //System.out.println( head(list1) );
       System.out.print( "list1: " );
       PrintIntList( list1 );

       IntList  list2 = new IntList( 2, list1 );
       IntList  list3 = new IntList( 3, list2 );
       System.out.print( "list3: " );
       PrintIntList( list3 );
       
       //list1 = new IntList( 2, list1 );
       //list1 = new IntList( 3, list1 );       
       list1 = new IntList( 3, new IntList( 2, list1 ));
       System.out.print( "list1: " );
       PrintIntList( list1 );
   }

   //  List manipulation procedures (functions)
   
   static int head( IntList aList )
   {
      return  aList.value;
   }

   static IntList tail( IntList aList )
   {
      return  aList.next;
   }

   static boolean empty( IntList aList )
   {
      return( aList == null );
   }

   static void PrintIntList( IntList aList )
   {
       IntList  tmpList = aList;

       System.out.print( "{ " );
       
       while( tmpList != null )
       {
           System.out.print( head(tmpList) );
           tmpList = tail(tmpList);
           if( tmpList != null )
               System.out.print( ", " );
       }
       
       System.out.println( " }" );
   }
} 

class IntList
{
   int  value;
   IntList  next;

   IntList( int x )
   {
      value = x;
      next  = null;
   }

   IntList( int x, IntList aList )
   {
      value = x;
      next  = aList;
   }
}