/**
 * Simple collections that allow you to add elements and
 * grab the occasional element.  Different subinterfaces
 * provide different policies for which element you get
 * when you grab an element.
 *
 * @author Samuel A. Rebelsky
 */
public interface Linear
{
  // +--------------------------------------------------
  // | Design Notes |
  // +---------------+

  /*
     At Arjun's request, we're making the key methods throw
     exceptions rather than expecting users to check 
     preconditions.
   */

  // +--------------------------------------------------
  // | Methods |
  // +---------+

  /**
   * Add a new element to the structure.
   *
   * @exception FullStructureException
   *   When there is no room for another element.
   */
  public void add(Object element)
    throws FullStructureException;

  /**
   * Get an element from the structure, deleting the element
   * from the structure.
   *
   * @exception EmptyStructureException
   */
  public Object get()
    throws EmptyStructureException;

  /**
   * Determine the next value to be returned by get.
   *
   * @exception EmptyStructureException
   */
  public Object peek()
    throws EmptyStructureException;

  /**
   * Determine if the structure is empty.
   */
  public boolean isEmpty();
} // interface Linear