01: /* (c) Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
02: [See end of file]
03:
04: $Id: NullIterator.java,v 1.10 2008/01/02 12:07:36 andy_seaborne Exp $
05: */
06:
07: package com.hp.hpl.jena.util.iterator;
08:
09: /**
10: An empty iterator. The specialised versions of andThen() eliminate left operands
11: that are empty iterators from cascaded sequences.
12: */
13: public class NullIterator extends NiceIterator {
14: public static NullIterator instance = new NullIterator();
15:
16: public ExtendedIterator andThen(ClosableIterator it) {
17: return it instanceof ExtendedIterator ? (ExtendedIterator) it
18: : super .andThen(it);
19: }
20: }
21:
22: /*
23: (c) Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
24: All rights reserved.
25:
26: Redistribution and use in source and binary forms, with or without
27: modification, are permitted provided that the following conditions
28: are met:
29: 1. Redistributions of source code must retain the above copyright
30: notice, this list of conditions and the following disclaimer.
31: 2. Redistributions in binary form must reproduce the above copyright
32: notice, this list of conditions and the following disclaimer in the
33: documentation and/or other materials provided with the distribution.
34: 3. The name of the author may not be used to endorse or promote products
35: derived from this software without specific prior written permission.
36:
37: THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
38: IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
39: OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
40: IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
41: INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42: NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
43: DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
44: THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
45: (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
46: THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
47: */
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