NCBI C++ Toolkit Cross Reference

   // Copyright (c) 2005, Google Inc.
   // All rights reserved.
   //
   // Redistribution and use in source and binary forms, with or without
   // modification, are permitted provided that the following conditions are
   // met:
   //
   //     * Redistributions of source code must retain the above copyright
   // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  //
  // Author: Sanjay Ghemawat
  
  #ifdef HAVE_CONFIG_H
  #include "config.h"
  #endif
  
  #include <vector>
  #include <assert.h>
  
  #include "pcrecpp_internal.h"
  #include "pcre_scanner.h"
  
  using std::vector;
  
  namespace pcrecpp {
  
  Scanner::Scanner()
    : data_(),
      input_(data_),
      skip_(NULL),
      should_skip_(false),
      skip_repeat_(false),
      save_comments_(false),
      comments_(NULL),
      comments_offset_(0) {
  }
  
  Scanner::Scanner(const string& in)
    : data_(in),
      input_(data_),
      skip_(NULL),
      should_skip_(false),
      skip_repeat_(false),
      save_comments_(false),
      comments_(NULL),
      comments_offset_(0) {
  }
  
  Scanner::~Scanner() {
    delete skip_;
    delete comments_;
  }
  
  void Scanner::SetSkipExpression(const char* re) {
    delete skip_;
    if (re != NULL) {
      skip_ = new RE(re);
      should_skip_ = true;
      skip_repeat_ = true;
      ConsumeSkip();
    } else {
      skip_ = NULL;
      should_skip_ = false;
      skip_repeat_ = false;
    }
  }
  
  void Scanner::Skip(const char* re) {
    delete skip_;
    if (re != NULL) {
      skip_ = new RE(re);
      should_skip_ = true;
      skip_repeat_ = false;
      ConsumeSkip();
    } else {
      skip_ = NULL;
      should_skip_ = false;
      skip_repeat_ = false;
    }
  }
 
 void Scanner::DisableSkip() {
   assert(skip_ != NULL);
   should_skip_ = false;
 }
 
 void Scanner::EnableSkip() {
   assert(skip_ != NULL);
   should_skip_ = true;
   ConsumeSkip();
 }
 
 int Scanner::LineNumber() const {
   // TODO: Make it more efficient by keeping track of the last point
   // where we computed line numbers and counting newlines since then.
   // We could use std:count, but not all systems have it. :-(
   int count = 1;
   for (const char* p = data_.data(); p < input_.data(); ++p)
     if (*p == '\n')
       ++count;
   return count;
 }
 
 int Scanner::Offset() const {
   return input_.data() - data_.c_str();
 }
 
 bool Scanner::LookingAt(const RE& re) const {
   int consumed;
   return re.DoMatch(input_, RE::ANCHOR_START, &consumed, 0, 0);
 }
 
 
 bool Scanner::Consume(const RE& re,
                       const Arg& arg0,
                       const Arg& arg1,
                       const Arg& arg2) {
   const bool result = re.Consume(&input_, arg0, arg1, arg2);
   if (result && should_skip_) ConsumeSkip();
   return result;
 }
 
 // helper function to consume *skip_ and honour save_comments_
 void Scanner::ConsumeSkip() {
   const char* start_data = input_.data();
   while (skip_->Consume(&input_)) {
     if (!skip_repeat_) {
       // Only one skip allowed.
       break;
     }
   }
   if (save_comments_) {
     if (comments_ == NULL) {
       comments_ = new vector<StringPiece>;
     }
     // already pointing one past end, so no need to +1
     int length = input_.data() - start_data;
     if (length > 0) {
       comments_->push_back(StringPiece(start_data, length));
     }
   }
 }
 
 
 void Scanner::GetComments(int start, int end, vector<StringPiece> *ranges) {
   // short circuit out if we've not yet initialized comments_
   // (e.g., when save_comments is false)
   if (!comments_) {
     return;
   }
   // TODO: if we guarantee that comments_ will contain StringPieces
   // that are ordered by their start, then we can do a binary search
   // for the first StringPiece at or past start and then scan for the
   // ones contained in the range, quit early (use equal_range or
   // lower_bound)
   for (vector<StringPiece>::const_iterator it = comments_->begin();
        it != comments_->end(); ++it) {
     if ((it->data() >= data_.c_str() + start &&
          it->data() + it->size() <= data_.c_str() + end)) {
       ranges->push_back(*it);
     }
   }
 }
 
 
 void Scanner::GetNextComments(vector<StringPiece> *ranges) {
   // short circuit out if we've not yet initialized comments_
   // (e.g., when save_comments is false)
   if (!comments_) {
     return;
   }
   for (vector<StringPiece>::const_iterator it =
          comments_->begin() + comments_offset_;
        it != comments_->end(); ++it) {
     ranges->push_back(*it);
     ++comments_offset_;
   }
 }
 
 }   // namespace pcrecpp