01: /*
02: * WebSphinx web-crawling toolkit
03: *
04: * Copyright (c) 1998-2002 Carnegie Mellon University. All rights
05: * reserved.
06: *
07: * Redistribution and use in source and binary forms, with or without
08: * modification, are permitted provided that the following conditions
09: * are met:
10: *
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: *
14: * 2. Redistributions in binary form must reproduce the above copyright
15: * notice, this list of conditions and the following disclaimer in
16: * the documentation and/or other materials provided with the
17: * distribution.
18: *
19: * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND
20: * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21: * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY
23: * NOR ITS EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30: *
31: */
32:
33: package websphinx;
34:
35: import java.util.Enumeration;
36:
37: public abstract class PatternMatcher implements Enumeration {
38: Region match = null;
39: boolean yielded = true;
40:
41: public boolean hasMoreElements() {
42: if (yielded) {
43: match = findNext();
44: yielded = false;
45: }
46: return match != null;
47: }
48:
49: public Object nextElement() {
50: return nextMatch();
51: }
52:
53: public Region nextMatch() {
54: if (!yielded) {
55: yielded = true;
56: return match;
57: }
58: match = findNext();
59: return match;
60: }
61:
62: protected abstract Region findNext();
63:
64: }
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