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 Alternations (foo|bar|baz). |
31 | */ |
32 | |
33 | |
34 | #include "ComponentAlternation.h" |
35 | |
36 | #include "buildstate.h" |
37 | #include "position.h" |
38 | #include "position_info.h" |
39 | #include "nfagraph/ng_builder.h" |
40 | #include "ue2common.h" |
41 | |
42 | #include <algorithm> |
43 | |
44 | using namespace std; |
45 | |
46 | namespace ue2 { |
47 | |
48 | ComponentAlternation::ComponentAlternation() { |
49 | // empty |
50 | } |
51 | |
52 | ComponentAlternation::~ComponentAlternation() { |
53 | // empty |
54 | } |
55 | |
56 | ComponentAlternation::ComponentAlternation(const ComponentAlternation &other) |
57 | : Component(other) { |
58 | for (const auto &c : other.children) { |
59 | assert(c); |
60 | children.push_back(unique_ptr<Component>(c->clone())); |
61 | } |
62 | } |
63 | |
64 | ComponentAlternation * ComponentAlternation::clone() const { |
65 | return new ComponentAlternation(*this); |
66 | } |
67 | |
68 | Component *ComponentAlternation::accept(ComponentVisitor &v) { |
69 | Component *c = v.visit(this); |
70 | if (c != this) { |
71 | v.post(this); |
72 | return c; |
73 | } |
74 | |
75 | for (auto i = children.begin(), e = children.end(); i != e; ++i) { |
76 | Component *child = i->get(); |
77 | c = (*i)->accept(v); |
78 | if (c != child) { |
79 | // Child has been replaced (new Component pointer) or we've been |
80 | // instructed to delete it (null). |
81 | i->reset(c); |
82 | } |
83 | } |
84 | |
85 | // Remove deleted children. |
86 | children.erase(remove(children.begin(), children.end(), nullptr), |
87 | children.end()); |
88 | |
89 | v.post(this); |
90 | return this; |
91 | } |
92 | |
93 | void ComponentAlternation::accept(ConstComponentVisitor &v) const { |
94 | v.pre(*this); |
95 | for (auto i = children.begin(), e = children.end(); i != e; ++i) { |
96 | (*i)->accept(v); |
97 | if (i + 1 != e) { |
98 | v.during(*this); |
99 | } |
100 | } |
101 | |
102 | v.post(*this); |
103 | } |
104 | |
105 | void ComponentAlternation::append(unique_ptr<Component> component) { |
106 | children.push_back(move(component)); |
107 | } |
108 | |
109 | vector<PositionInfo> ComponentAlternation::first() const { |
110 | // firsts come from all our subcomponents in position order. This will |
111 | // maintain left-to-right priority order. |
112 | vector<PositionInfo> firsts, subfirsts; |
113 | |
114 | for (const auto &c : children) { |
115 | subfirsts = c->first(); |
116 | firsts.insert(firsts.end(), subfirsts.begin(), subfirsts.end()); |
117 | } |
118 | return firsts; |
119 | } |
120 | |
121 | vector<PositionInfo> ComponentAlternation::last() const { |
122 | vector<PositionInfo> lasts, sublasts; |
123 | |
124 | for (const auto &c : children) { |
125 | sublasts = c->last(); |
126 | lasts.insert(lasts.end(), sublasts.begin(), sublasts.end()); |
127 | } |
128 | return lasts; |
129 | } |
130 | |
131 | bool ComponentAlternation::empty(void) const { |
132 | // an alternation can be empty if any of its components are empty |
133 | for (const auto &c : children) { |
134 | if (c->empty()) { |
135 | return true; |
136 | } |
137 | } |
138 | |
139 | return false; |
140 | } |
141 | |
142 | void ComponentAlternation::notePositions(GlushkovBuildState &bs) { |
143 | u32 pb = bs.getBuilder().numVertices(); |
144 | for (auto &c : children) { |
145 | c->notePositions(bs); |
146 | } |
147 | recordPosBounds(pb, bs.getBuilder().numVertices()); |
148 | } |
149 | |
150 | void ComponentAlternation::buildFollowSet(GlushkovBuildState &bs, |
151 | const vector<PositionInfo> &lastPos) { |
152 | for (auto &c : children) { |
153 | c->buildFollowSet(bs, lastPos); |
154 | } |
155 | } |
156 | |
157 | bool ComponentAlternation::checkEmbeddedStartAnchor(bool at_start) const { |
158 | bool rv = at_start; |
159 | for (const auto &c : children) { |
160 | rv &= c->checkEmbeddedStartAnchor(at_start); |
161 | } |
162 | |
163 | return rv; |
164 | } |
165 | |
166 | bool ComponentAlternation::checkEmbeddedEndAnchor(bool at_end) const { |
167 | bool rv = at_end; |
168 | for (const auto &c : children) { |
169 | rv &= c->checkEmbeddedEndAnchor(at_end); |
170 | } |
171 | |
172 | return rv; |
173 | } |
174 | |
175 | bool ComponentAlternation::vacuous_everywhere(void) const { |
176 | for (const auto &c : children) { |
177 | if (c->vacuous_everywhere()) { |
178 | return true; |
179 | } |
180 | } |
181 | return false; |
182 | } |
183 | |
184 | void ComponentAlternation::optimise(bool connected_to_sds) { |
185 | for (auto &c : children) { |
186 | c->optimise(connected_to_sds); |
187 | } |
188 | } |
189 | |
190 | } // namespace ue2 |
191 | |