1/*
2 * Copyright (c) 2015, Intel Corporation
3 *
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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
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19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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27 */
28
29/** \file
30 * \brief Lookahead/lookbehind zero-width assertions.
31 */
32
33#ifndef _RE_COMPONENTASSERTION_H_
34#define _RE_COMPONENTASSERTION_H_
35
36#include "ComponentSequence.h"
37
38namespace ue2 {
39
40class ComponentAssertion : public ComponentSequence {
41 friend class DumpVisitor;
42 friend class PrintVisitor;
43public:
44 enum Direction {
45 LOOKAHEAD, //!< lookahead (forward) assertion
46 LOOKBEHIND //!< lookbehind (backward) assertion
47 };
48
49 enum Sense {
50 POS, //!< positive assertion, (?=...) or (?<=...)
51 NEG //!< negative assertion, (?!...) or (?<!...)
52 };
53
54 ComponentAssertion(enum Direction dir, enum Sense sense);
55 ~ComponentAssertion() override;
56 ComponentAssertion *clone() const override;
57 Component *accept(ComponentVisitor &v) override;
58 void accept(ConstComponentVisitor &v) const override;
59
60 std::vector<PositionInfo> first() const override;
61 std::vector<PositionInfo> last() const override;
62
63 bool empty() const override;
64 void notePositions(GlushkovBuildState &bs) override;
65 void buildFollowSet(GlushkovBuildState &bs,
66 const std::vector<PositionInfo> &lastPos) override;
67 bool repeatable() const override;
68
69private:
70 enum Direction m_dir;
71 enum Sense m_sense;
72};
73
74} // namespace ue2
75
76#endif
77