1 ////////////////////////////////////////////////////////////////////////////////
2 // MillScript: an Open Spice interpreter and batch website creation tool
3 // Copyright (C) 2001-2004 Open World Ltd
4 //
5 // This file is part of MillScript.
6 //
7 // MillScript is free software; you can redistribute it and/or modify it under
8 // the terms of the GNU General Public License as published by the Free
9 // Software Foundation; either version 2 of the License, or (at your option)
10 // any later version.
11 //
12 // MillScript is distributed in the hope that it will be useful, but WITHOUT
13 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 // more details.
16 //
17 // You should have received a copy of the GNU General Public License along with
18 // MillScript; if not, write to the Free Software Foundation, Inc., 59 Temple
19 // Place, Suite 330, Boston, MA 02111-1307 USA
20 ////////////////////////////////////////////////////////////////////////////////
21 package org.millscript.millscript.datatypes;
22
23 import java.util.AbstractSet;
24 import java.util.Iterator;
25
26 /**
27 * An implementation of <code>Set</code>, that will never contain any elements.
28 * This is used in the implementation of {@link NullMapWithDefault}.
29 *
30 * @deprecated As of MillScript 10.2.0, this functionallity has been subsumed
31 * by the MillScript-Util project and it's Map API, see
32 * {@link org.millscript.commons.util.map.IEmptyMap}.
33 */
34 @Deprecated
35 public class NullSet extends AbstractSet< Object > {
36
37 /**
38 * Always returns zero, as this set never contains any values.
39 *
40 * @return zero, as this set never contains any values
41 */
42 @Override
43 public int size() { return 0; }
44
45 /**
46 * Returns a special NullIterator, as this set will never contain any
47 * values.
48 *
49 * @return a iterator with no items
50 */
51 @Override
52 public Iterator< Object > iterator() {
53 return new NullIterator();
54 }
55
56 }