1/*
2 * Copyright (c) 2015, Intel Corporation
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * * Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of Intel Corporation nor the names of its contributors
13 * may be used to endorse or promote products derived from this software
14 * without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** \file
30 * \brief Represents an empty regex element, like (?m)
31 */
32
33#ifndef PARSER_COMPONENT_EMPTY_H_
34#define PARSER_COMPONENT_EMPTY_H_
35
36#include "Component.h"
37
38namespace ue2 {
39
40class ComponentEmpty : public Component {
41 friend class DumpVisitor;
42public:
43 ComponentEmpty();
44 ~ComponentEmpty() override;
45 ComponentEmpty *clone() const override;
46
47 Component *accept(ComponentVisitor &v) override {
48 Component *c = v.visit(this);
49 v.post(this);
50 return c;
51 }
52
53 void accept(ConstComponentVisitor &v) const override {
54 v.pre(*this);
55 v.during(*this);
56 v.post(*this);
57 }
58
59 std::vector<PositionInfo> first() const override;
60 std::vector<PositionInfo> last() const override;
61 bool empty() const override;
62 bool vacuous_everywhere() const override;
63 bool repeatable() const override;
64 void notePositions(GlushkovBuildState &bs) override;
65 void buildFollowSet(GlushkovBuildState &bs,
66 const std::vector<PositionInfo> &lastPos) override;
67
68 bool checkEmbeddedStartAnchor(bool at_start) const override;
69 bool checkEmbeddedEndAnchor(bool at_end) const override;
70
71};
72
73} // namespace ue2
74
75#endif // PARSER_COMPONENT_EMPTY_H_
76