| /* Sequence.java -- a sequence of integers. |
| Copyright (C) 2004, 2006 Free Software Foundation, Inc. |
| |
| This file is a part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or (at |
| your option) any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 |
| USA |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.java.security.util; |
| |
| import java.util.AbstractList; |
| import java.util.LinkedList; |
| |
| /** |
| * A monotonic sequence of integers in the finite field 2<sup>32</sup>. |
| */ |
| public final class Sequence |
| extends AbstractList |
| { |
| private final Integer[] sequence; |
| |
| /** |
| * Create a sequence of integers from 0 to <i>end</i>, with an increment of |
| * 1. If <i>end</i> is less than 0, then the sequence will wrap around |
| * through all positive integers then negative integers until the end value is |
| * reached. Naturally, this will result in an enormous object, so don't do |
| * this. |
| * |
| * @param end The ending value. |
| */ |
| public Sequence(int end) |
| { |
| this(0, end, 1); |
| } |
| |
| /** |
| * Create a sequence of integers from <i>start</i> to <i>end</i>, with an |
| * increment of 1. If <i>end</i> is less than <i>start</i>, then the |
| * sequence will wrap around until the end value is reached. Naturally, this |
| * will result in an enormous object, so don't do this. |
| * |
| * @param start The starting value. |
| * @param end The ending value. |
| */ |
| public Sequence(int start, int end) |
| { |
| this(start, end, 1); |
| } |
| |
| /** |
| * Create a sequence of integers from <i>start</i> to <i>end</i>, with an |
| * increment of <i>span</i>. If <i>end</i> is less than <i>start</i>, then |
| * the sequence will wrap around until the end value is reached. Naturally, |
| * this will result in an enormous object, so don't do this. |
| * <p> |
| * <i>span</i> can be negative, resulting in a decresing sequence. |
| * <p> |
| * If <i>span</i> is 0, then the sequence will contain {<i>start</i>, |
| * <i>end</i>} if <i>start</i> != <i>end</i>, or just the singleton |
| * <i>start</i> if <i>start</i> == <i>end</i>. |
| * |
| * @param start The starting value. |
| * @param end The ending value. |
| * @param span The increment value. |
| */ |
| public Sequence(int start, int end, int span) |
| { |
| if (span == 0) |
| { |
| if (start != end) |
| sequence = new Integer[] { Integer.valueOf(start), |
| Integer.valueOf(end) }; |
| else |
| sequence = new Integer[] { Integer.valueOf(start) }; |
| } |
| else |
| { |
| LinkedList l = new LinkedList(); |
| for (int i = start; i != end; i += span) |
| l.add(Integer.valueOf(i)); |
| |
| l.add(Integer.valueOf(end)); |
| sequence = (Integer[]) l.toArray(new Integer[l.size()]); |
| } |
| } |
| |
| public Object get(int index) |
| { |
| if (index < 0 || index >= size()) |
| throw new IndexOutOfBoundsException("index=" + index + ", size=" + size()); |
| return sequence[index]; |
| } |
| |
| public int size() |
| { |
| return sequence.length; |
| } |
| |
| public Object[] toArray() |
| { |
| return (Object[]) sequence.clone(); |
| } |
| } |