/[pcre]/code/trunk/pcre_scanner.cc
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Contents of /code/trunk/pcre_scanner.cc

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Revision 87 - (show annotations) (download)
Sat Feb 24 21:41:21 2007 UTC (7 years, 6 months ago) by nigel
File size: 5058 byte(s)
Load pcre-6.5 into code/trunk.

1 // Copyright (c) 2005, Google Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 // * Redistributions of source code must retain the above copyright
9 // notice, this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above
11 // copyright notice, this list of conditions and the following disclaimer
12 // in the documentation and/or other materials provided with the
13 // distribution.
14 // * Neither the name of Google Inc. nor the names of its
15 // contributors may be used to endorse or promote products derived from
16 // this software without specific prior written permission.
17 //
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 //
30 // Author: Sanjay Ghemawat
31
32 #include <vector>
33 #include <assert.h>
34 #include "config.h"
35 #include "pcre_scanner.h"
36
37 using std::vector;
38
39 namespace pcrecpp {
40
41 Scanner::Scanner()
42 : data_(),
43 input_(data_),
44 skip_(NULL),
45 should_skip_(false),
46 save_comments_(false),
47 comments_(NULL),
48 comments_offset_(0) {
49 }
50
51 Scanner::Scanner(const string& in)
52 : data_(in),
53 input_(data_),
54 skip_(NULL),
55 should_skip_(false),
56 save_comments_(false),
57 comments_(NULL),
58 comments_offset_(0) {
59 }
60
61 Scanner::~Scanner() {
62 delete skip_;
63 delete comments_;
64 }
65
66 void Scanner::Skip(const char* re) {
67 delete skip_;
68 if (re != NULL) {
69 skip_ = new RE(re);
70 should_skip_ = true;
71 ConsumeSkip();
72 } else {
73 skip_ = NULL;
74 should_skip_ = false;
75 }
76 }
77
78 void Scanner::DisableSkip() {
79 assert(skip_ != NULL);
80 should_skip_ = false;
81 }
82
83 void Scanner::EnableSkip() {
84 assert(skip_ != NULL);
85 should_skip_ = true;
86 ConsumeSkip();
87 }
88
89 int Scanner::LineNumber() const {
90 // TODO: Make it more efficient by keeping track of the last point
91 // where we computed line numbers and counting newlines since then.
92 // We could use std:count, but not all systems have it. :-(
93 int count = 1;
94 for (const char* p = data_.data(); p < input_.data(); ++p)
95 if (*p == '\n')
96 ++count;
97 return count;
98 }
99
100 int Scanner::Offset() const {
101 return input_.data() - data_.c_str();
102 }
103
104 bool Scanner::LookingAt(const RE& re) const {
105 int consumed;
106 return re.DoMatch(input_, RE::ANCHOR_START, &consumed, 0, 0);
107 }
108
109
110 bool Scanner::Consume(const RE& re,
111 const Arg& arg0,
112 const Arg& arg1,
113 const Arg& arg2) {
114 const bool result = re.Consume(&input_, arg0, arg1, arg2);
115 if (result && should_skip_) ConsumeSkip();
116 return result;
117 }
118
119 // helper function to consume *skip_ and honour save_comments_
120 void Scanner::ConsumeSkip() {
121 if (save_comments_) {
122 if (NULL == comments_) {
123 comments_ = new vector<StringPiece>;
124 }
125 const char *start_data = input_.data();
126 skip_->Consume(&input_);
127 // already pointing one past end, so no need to +1
128 int length = input_.data() - start_data;
129 if (length > 0) {
130 comments_->push_back(StringPiece(start_data, length));
131 }
132 } else {
133 skip_->Consume(&input_);
134 }
135 }
136
137
138 void Scanner::GetComments(int start, int end, vector<StringPiece> *ranges) {
139 // short circuit out if we've not yet initialized comments_
140 // (e.g., when save_comments is false)
141 if (!comments_) {
142 return;
143 }
144 // TODO: if we guarantee that comments_ will contain StringPieces
145 // that are ordered by their start, then we can do a binary search
146 // for the first StringPiece at or past start and then scan for the
147 // ones contained in the range, quit early (use equal_range or
148 // lower_bound)
149 for (vector<StringPiece>::const_iterator it = comments_->begin();
150 it != comments_->end(); ++it) {
151 if ((it->data() >= data_.c_str() + start &&
152 it->data() + it->size() <= data_.c_str() + end)) {
153 ranges->push_back(*it);
154 }
155 }
156 }
157
158
159 void Scanner::GetNextComments(vector<StringPiece> *ranges) {
160 // short circuit out if we've not yet initialized comments_
161 // (e.g., when save_comments is false)
162 if (!comments_) {
163 return;
164 }
165 for (vector<StringPiece>::const_iterator it =
166 comments_->begin() + comments_offset_;
167 it != comments_->end(); ++it) {
168 ranges->push_back(*it);
169 ++comments_offset_;
170 }
171 }
172
173 } // namespace pcrecpp

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