package position;
import java.util.Iterator;
import  exceptions.*;

/**
 * An interface for positional lists.
 * @author Roberto Tamassia, Michael Goodrich
 */
//Copyright (c) 2003 Brown University, Providence, RI
//Additional modifications and methods by xgiovio

public interface PositionList<E> extends Iterable<E> {


  public int size();

  public boolean isEmpty();

  public Position<E> first() throws EmptyListException;

  public Position<E> last() throws EmptyListException;

  public Position<E> next(Position<E> p)      throws InvalidPositionException, BoundaryViolationException;

  public Position<E> prev(Position<E> p)      throws InvalidPositionException, BoundaryViolationException;

  public void addFirst(E e);

  public void addLast(E e);

  public Position<E> addAfter(Position<E> p, E e)         throws InvalidPositionException;

  public Position<E> addBefore(Position<E> p, E e)       throws InvalidPositionException;

  public E remove(Position<E> p) throws InvalidPositionException;

  public E set(Position<E> p, E e) throws InvalidPositionException;

  public Iterable<Position<E>> positions();


}