/[pcre]/code/tags/pcre-6.3/pcre_scanner.cc
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Contents of /code/tags/pcre-6.3/pcre_scanner.cc

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Revision 84 - (hide annotations) (download)
Sat Feb 24 21:41:08 2007 UTC (7 years, 5 months ago) by nigel
File size: 4967 byte(s)
Tag code/trunk as code/tags/pcre-6.3.

1 nigel 77 // Copyright (c) 2005, Google Inc.
2     // All rights reserved.
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5     // modification, are permitted provided that the following conditions are
6     // met:
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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.
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16     // this software without specific prior written permission.
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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 <algorithm> // for count()
34     #include <assert.h>
35     #include "config.h"
36     #include "pcre_scanner.h"
37    
38     using std::vector;
39    
40     namespace pcrecpp {
41    
42     Scanner::Scanner()
43     : data_(),
44     input_(data_),
45     skip_(NULL),
46     should_skip_(false),
47     save_comments_(false),
48     comments_(NULL),
49     comments_offset_(0) {
50     }
51    
52     Scanner::Scanner(const string& in)
53     : data_(in),
54     input_(data_),
55     skip_(NULL),
56     should_skip_(false),
57     save_comments_(false),
58     comments_(NULL),
59     comments_offset_(0) {
60     }
61    
62     Scanner::~Scanner() {
63     delete skip_;
64     delete comments_;
65     }
66    
67     void Scanner::Skip(const char* re) {
68     delete skip_;
69     if (re != NULL) {
70     skip_ = new RE(re);
71     should_skip_ = true;
72     ConsumeSkip();
73     } else {
74     skip_ = NULL;
75     should_skip_ = false;
76     }
77     }
78    
79     void Scanner::DisableSkip() {
80     assert(skip_ != NULL);
81     should_skip_ = false;
82     }
83    
84     void Scanner::EnableSkip() {
85     assert(skip_ != NULL);
86     should_skip_ = true;
87     ConsumeSkip();
88     }
89    
90     int Scanner::LineNumber() const {
91     // TODO: Make it more efficient by keeping track of the last point
92     // where we computed line numbers and counting newlines since then.
93     return 1 + std::count(data_.data(), input_.data(), '\n');
94     }
95    
96     int Scanner::Offset() const {
97     return input_.data() - data_.c_str();
98     }
99    
100     bool Scanner::LookingAt(const RE& re) const {
101     int consumed;
102     return re.DoMatch(input_, RE::ANCHOR_START, &consumed, 0, 0);
103     }
104    
105    
106     bool Scanner::Consume(const RE& re,
107     const Arg& arg0,
108     const Arg& arg1,
109     const Arg& arg2) {
110     const bool result = re.Consume(&input_, arg0, arg1, arg2);
111     if (result && should_skip_) ConsumeSkip();
112     return result;
113     }
114    
115     // helper function to consume *skip_ and honour save_comments_
116     void Scanner::ConsumeSkip() {
117     if (save_comments_) {
118     if (NULL == comments_) {
119     comments_ = new vector<StringPiece>;
120     }
121     const char *start_data = input_.data();
122     skip_->Consume(&input_);
123     // already pointing one past end, so no need to +1
124     int length = input_.data() - start_data;
125     if (length > 0) {
126     comments_->push_back(StringPiece(start_data, length));
127     }
128     } else {
129     skip_->Consume(&input_);
130     }
131     }
132    
133    
134     void Scanner::GetComments(int start, int end, vector<StringPiece> *ranges) {
135     // short circuit out if we've not yet initialized comments_
136     // (e.g., when save_comments is false)
137     if (!comments_) {
138     return;
139     }
140     // TODO: if we guarantee that comments_ will contain StringPieces
141     // that are ordered by their start, then we can do a binary search
142     // for the first StringPiece at or past start and then scan for the
143     // ones contained in the range, quit early (use equal_range or
144     // lower_bound)
145     for (vector<StringPiece>::const_iterator it = comments_->begin();
146     it != comments_->end(); ++it) {
147     if ((it->data() >= data_.c_str() + start &&
148     it->data() + it->size() <= data_.c_str() + end)) {
149     ranges->push_back(*it);
150     }
151     }
152     }
153    
154    
155     void Scanner::GetNextComments(vector<StringPiece> *ranges) {
156     // short circuit out if we've not yet initialized comments_
157     // (e.g., when save_comments is false)
158     if (!comments_) {
159     return;
160     }
161     for (vector<StringPiece>::const_iterator it =
162     comments_->begin() + comments_offset_;
163     it != comments_->end(); ++it) {
164     ranges->push_back(*it);
165     ++comments_offset_;
166     }
167     }
168    
169     } // namespace pcrecpp

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