source: branches/libc-0.6/src/gcc/libjava/java/util/List.java

/* List.java -- An ordered collection which allows indexed access
   Copyright (C) 1998, 2001 Free Software Foundation, Inc.

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package java.util;

/**
 * An ordered collection (also known as a list). This collection allows
 * access to elements by position, as well as control on where elements
 * are inserted. Unlike sets, duplicate elements are permitted by this
 * general contract (if a subclass forbids duplicates, this should be
 * documented).
 * <p>
 *
 * List places additional requirements on <code>iterator</code>,
 * <code>add</code>, <code>remove</code>, <code>equals</code>, and
 * <code>hashCode</code>, in addition to requiring more methods. List
 * indexing is 0-based (like arrays), although some implementations may
 * require time proportional to the index to obtain an arbitrary element.
 * The List interface is incompatible with Set; you cannot implement both
 * simultaneously.
 * <p>
 *
 * Lists also provide a <code>ListIterator</code> which allows bidirectional
 * traversal and other features atop regular iterators. Lists can be
 * searched for arbitrary elements, and allow easy insertion and removal
 * of multiple elements in one method call.
 * <p>
 *
 * Note: While lists may contain themselves as elements, this leads to
 * undefined (usually infinite recursive) behavior for some methods like
 * hashCode or equals.
 *
 * @author Original author unknown
 * @author Eric Blake <[email protected]>
 * @see Collection
 * @see Set
 * @see ArrayList
 * @see LinkedList
 * @see Vector
 * @see Arrays#asList(Object[])
 * @see Collections#nCopies(int, Object)
 * @see Collections#EMPTY_LIST
 * @see AbstractList
 * @see AbstractSequentialList
 * @since 1.2
 * @status updated to 1.4
 */
public interface List extends Collection
{
  /**
   * Insert an element into the list at a given position (optional operation).
   * This shifts all existing elements from that position to the end one
   * index to the right. This version of add has no return, since it is
   * assumed to always succeed if there is no exception.
   *
   * @param index the location to insert the item
   * @param o the object to insert
   * @throws UnsupportedOperationException if this list does not support the
   *         add operation
   * @throws IndexOutOfBoundsException if index &lt; 0 || index &gt; size()
   * @throws ClassCastException if o cannot be added to this list due to its
   *         type
   * @throws IllegalArgumentException if o cannot be added to this list for
   *         some other reason
   */
  void add(int index, Object o);

  /**
   * Add an element to the end of the list (optional operation). If the list
   * imposes restraints on what can be inserted, such as no null elements,
   * this should be documented.
   *
   * @param o the object to add
   * @return true, as defined by Collection for a modified list
   * @throws UnsupportedOperationException if this list does not support the
   *         add operation
   * @throws ClassCastException if o cannot be added to this list due to its
   *         type
   * @throws IllegalArgumentException if o cannot be added to this list for
   *         some other reason
   */
  boolean add(Object o);

  /**
   * Insert the contents of a collection into the list at a given position