001/* RandomAccess.java -- A tagging interface that lists can use to tailor
002   operations to the correct algorithm
003   Copyright (C) 2001, 2005  Free Software Foundation, Inc.
004
005This file is part of GNU Classpath.
006
007GNU Classpath is free software; you can redistribute it and/or modify
008it under the terms of the GNU General Public License as published by
009the Free Software Foundation; either version 2, or (at your option)
010any later version.
011
012GNU Classpath is distributed in the hope that it will be useful, but
013WITHOUT ANY WARRANTY; without even the implied warranty of
014MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
015General Public License for more details.
016
017You should have received a copy of the GNU General Public License
018along with GNU Classpath; see the file COPYING.  If not, write to the
019Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02002110-1301 USA.
021
022Linking this library statically or dynamically with other modules is
023making a combined work based on this library.  Thus, the terms and
024conditions of the GNU General Public License cover the whole
025combination.
026
027As a special exception, the copyright holders of this library give you
028permission to link this library with independent modules to produce an
029executable, regardless of the license terms of these independent
030modules, and to copy and distribute the resulting executable under
031terms of your choice, provided that you also meet, for each linked
032independent module, the terms and conditions of the license of that
033module.  An independent module is a module which is not derived from
034or based on this library.  If you modify this library, you may extend
035this exception to your version of the library, but you are not
036obligated to do so.  If you do not wish to do so, delete this
037exception statement from your version. */
038
039
040package java.util;
041
042/**
043 * Marker interface used to inform <code>List</code> implementations that
044 * they support fast (usually constant time) random access. This allows
045 * generic list algorithms to tailor their behavior based on the list
046 * type.
047 * <p>
048 *
049 * For example, some sorts are n*log(n) on an array, but decay to quadratic
050 * time on a linked list.  As a rule of thumb, this interface should be
051 * used is this loop:<br>
052 * <code>for (int i = 0, n = list.size(); i &lt; n; i++) list.get(i);</code>
053 * <br>runs faster than this loop:<br>
054 * <code>for (Iterator i = list.iterator(); i.hasNext(); ) i.next();</code>
055 *
056 * @author Eric Blake (ebb9@email.byu.edu)
057 * @see List
058 * @since 1.4
059 * @status updated to 1.4
060 */
061public interface RandomAccess
062{
063  // Tagging interface only.
064}