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

   1 /*
   2  *
   3  * Copyright (c) 1998-2002
   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_search_example.cpp
  15   *   VERSION      see <boost/version.hpp>
  16   *   DESCRIPTION: regex_search example: searches a cpp file for class definitions.
  17   */
  18
  19 #include <string>
  20 #include <map>
  21 #include <boost/regex.hpp>
  22
  23 // purpose:
  24 // takes the contents of a file in the form of a string
  25 // and searches for all the C++ class definitions, storing
  26 // their locations in a map of strings/int's
  27
  28 typedef std::map<std::string, std::string::difference_type, std::less<std::string> > map_type;
  29
  30 const char* re =
  31    // possibly leading whitespace:
  32    "^[[:space:]]*"
  33    // possible template declaration:
  34    "(template[[:space:]]*<[^;:{]+>[[:space:]]*)?"
  35    // class or struct:
  36    "(class|struct)[[:space:]]*"
  37    // leading declspec macros etc:
  38    "("
  39       "\\<\\w+\\>"
  40       "("
  41          "[[:blank:]]*\\([^)]*\\)"
  42       ")?"
  43       "[[:space:]]*"
  44    ")*"
  45    // the class name
  46    "(\\<\\w*\\>)[[:space:]]*"
  47    // template specialisation parameters
  48    "(<[^;:{]+>)?[[:space:]]*"
  49    // terminate in { or :
  50    "(\\{|:[^;\\{()]*\\{)";
  51
  52
  53 boost::regex expression(re);
  54
  55 void IndexClasses(map_type& m, const std::string& file)
  56 {
  57    std::string::const_iterator start, end;
  58    start = file.begin();
  59    end = file.end();
  60    boost::match_results<std::string::const_iterator> what;
  61    boost::match_flag_type flags = boost::match_default;
  62    while(boost::regex_search(start, end, what, expression, flags))
  63    {
  64       // what[0] contains the whole string
  65       // what[5] contains the class name.
  66       // what[6] contains the template specialisation if any.
  67       // add class name and position to map:
  68       m[std::string(what[5].first, what[5].second) + std::string(what[6].first, what[6].second)] =
  69                what[5].first - file.begin();
  70       // update search position:
  71       start = what[0].second;
  72       // update flags:
  73       flags |= boost::match_prev_avail;
  74       flags |= boost::match_not_bob;
  75    }
  76 }
  77
  78
  79 #include <iostream>
  80 #include <fstream>
  81
  82 using namespace std;
  83
  84 void load_file(std::string& s, std::istream& is)
  85 {
  86    s.erase();
  87    if(is.bad()) return;
  88    s.reserve(static_cast<std::string::size_type>(is.rdbuf()->in_avail()));
  89    char c;
  90    while(is.get(c))
  91    {
  92       if(s.capacity() == s.size())
  93          s.reserve(s.capacity() * 3);
  94       s.append(1, c);
  95    }
  96 }
  97
  98 int main(int argc, const char** argv)
  99 {
 100    std::string text;
 101    for(int i = 1; i < argc; ++i)
 102    {
 103       cout << "Processing file " << argv[i] << endl;
 104       map_type m;
 105       std::ifstream fs(argv[i]);
 106       load_file(text, fs);
 107       fs.close();
 108       IndexClasses(m, text);
 109       cout << m.size() << " matches found" << endl;
 110       map_type::iterator c, d;
 111       c = m.begin();
 112       d = m.end();
 113       while(c != d)
 114       {
 115          cout << "class \"" << (*c).first << "\" found at index: " << (*c).second << endl;
 116          ++c;
 117       }
 118    }
 119    return 0;
 120 }
 121
 122
 123
 124
 125
 126
 127
 128
 129