ceph/src/boost/libs/regex/example/snippets/regex_iterator_example.cpp

   1 /*
   2  *
   3  * Copyright (c) 2003
   4  * John Maddock
   5  *
   6  * Use, modification and distribution are subject to the
   7  * Boost Software License, Version 1.0. (See accompanying file
   8  * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9  *
  10  */
  11
  12  /*
  13   *   LOCATION:    see http://www.boost.org for most recent version.
  14   *   FILE         regex_iterator_example_2.cpp
  15   *   VERSION      see <boost/version.hpp>
  16   *   DESCRIPTION: regex_iterator example 2: searches a cpp file for class definitions,
  17   *                using global data.
  18   */
  19
  20 #include <string>
  21 #include <map>
  22 #include <fstream>
  23 #include <iostream>
  24 #include <boost/regex.hpp>
  25
  26 using namespace std;
  27
  28 // purpose:
  29 // takes the contents of a file in the form of a string
  30 // and searches for all the C++ class definitions, storing
  31 // their locations in a map of strings/int's
  32
  33 typedef std::map<std::string, std::string::difference_type, std::less<std::string> > map_type;
  34
  35 const char* re =
  36    // possibly leading whitespace:
  37    "^[[:space:]]*"
  38    // possible template declaration:
  39    "(template[[:space:]]*<[^;:{]+>[[:space:]]*)?"
  40    // class or struct:
  41    "(class|struct)[[:space:]]*"
  42    // leading declspec macros etc:
  43    "("
  44       "\\<\\w+\\>"
  45       "("
  46          "[[:blank:]]*\\([^)]*\\)"
  47       ")?"
  48       "[[:space:]]*"
  49    ")*"
  50    // the class name
  51    "(\\<\\w*\\>)[[:space:]]*"
  52    // template specialisation parameters
  53    "(<[^;:{]+>)?[[:space:]]*"
  54    // terminate in { or :
  55    "(\\{|:[^;\\{()]*\\{)";
  56
  57
  58 boost::regex expression(re);
  59 map_type class_index;
  60
  61 bool regex_callback(const boost::match_results<std::string::const_iterator>& what)
  62 {
  63    // what[0] contains the whole string
  64    // what[5] contains the class name.
  65    // what[6] contains the template specialisation if any.
  66    // add class name and position to map:
  67    class_index[what[5].str() + what[6].str()] = what.position(5);
  68    return true;
  69 }
  70
  71 void load_file(std::string& s, std::istream& is)
  72 {
  73    s.erase();
  74    if(is.bad()) return;
  75    s.reserve(static_cast<std::string::size_type>(is.rdbuf()->in_avail()));
  76    char c;
  77    while(is.get(c))
  78    {
  79       if(s.capacity() == s.size())
  80          s.reserve(s.capacity() * 3);
  81       s.append(1, c);
  82    }
  83 }
  84
  85 int main(int argc, const char** argv)
  86 {
  87    std::string text;
  88    for(int i = 1; i < argc; ++i)
  89    {
  90       cout << "Processing file " << argv[i] << endl;
  91       std::ifstream fs(argv[i]);
  92       load_file(text, fs);
  93       fs.close();
  94       // construct our iterators:
  95       boost::sregex_iterator m1(text.begin(), text.end(), expression);
  96       boost::sregex_iterator m2;
  97       std::for_each(m1, m2, &regex_callback);
  98       // copy results:
  99       cout << class_index.size() << " matches found" << endl;
 100       map_type::iterator c, d;
 101       c = class_index.begin();
 102       d = class_index.end();
 103       while(c != d)
 104       {
 105          cout << "class \"" << (*c).first << "\" found at index: " << (*c).second << endl;
 106          ++c;
 107       }
 108       class_index.erase(class_index.begin(), class_index.end());
 109    }
 110    return 0;
 111 }
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