/*

 * Copyright 2000-2006 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.util;

/**

 * Marker interface used by <tt>List</tt> implementations to indicate that

 * they support fast (generally constant time) random access.  The primary

 * purpose of this interface is to allow generic algorithms to alter their

 * behavior to provide good performance when applied to either random or

 * sequential access lists.

 *

 * <p>The best algorithms for manipulating random access lists (such as

 * <tt>ArrayList</tt>) can produce quadratic behavior when applied to

 * sequential access lists (such as <tt>LinkedList</tt>).  Generic list

 * algorithms are encouraged to check whether the given list is an

 * <tt>instanceof</tt> this interface before applying an algorithm that would

 * provide poor performance if it were applied to a sequential access list,

 * and to alter their behavior if necessary to guarantee acceptable

 * performance.

 *

 * <p>It is recognized that the distinction between random and sequential

 * access is often fuzzy.  For example, some <tt>List</tt> implementations

 * provide asymptotically linear access times if they get huge, but constant

 * access times in practice.  Such a <tt>List</tt> implementation

 * should generally implement this interface.  As a rule of thumb, a

 * <tt>List</tt> implementation should implement this interface if,

 * for typical instances of the class, this loop:

 * <pre>

 *     for (int i=0, n=list.size(); i < n; i++)

 *         list.get(i);

 * </pre>

 * runs faster than this loop:

 * <pre>

 *     for (Iterator i=list.iterator(); i.hasNext(); )

 *         i.next();

 * </pre>

 *

 * <p>This interface is a member of the

 * <a href="{@docRoot}/../technotes/guides/collections/index.html">

 * Java Collections Framework</a>.

 *

 * @since 1.4

 */

public interface RandomAccess {

}