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 | |
38 | namespace ue2 { |
39 | |
40 | class ComponentEmpty : public Component { |
41 | friend class DumpVisitor; |
42 | public: |
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 | |