/**
 * Lists that change.
 *
 * @author Samuel A. Rebelsky
 * @author Yvonne Palm
 * @author Jonathan "Don't I get to make suggestions, too?" Wellons
 *
 *
 *
 * @author "Better Never Than Late" Leach
 */
public interface MutableList
{
  /**
   * Determine if the list is empty
   */
  public boolean isEmpty();

  /**
   * Update the list by adding an element to the front.
   */
  public void addToFront(Object newThingy);

  /**
   * Update the list by removing the first element.  Return
   * that element.
   */
  public Object removeFirst()
    throws Exception;

  /**
   * Get the length.
   */
  public int length();

  /**
   * Get the first element (non-destructively).
   */
  public Object getFirst()
    throws Exception;

  /**
   * Convert to a string for ease of printing.
   */
  public String toString();

  /**
   * Make an independent copy of this list.
   */
  public MutableList copyMe();
} // interface MutableList