ceph/src/boost/libs/regex/example/snippets/regex_grep_example_1.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_grep_example_1.cpp
  15   *   VERSION      see <boost/version.hpp>
  16   *   DESCRIPTION: regex_grep example 1: searches a cpp file for class definitions.
  17   */
  18
  19 #include <boost/regex.hpp>
  20 #include <string>
  21 #include <map>
  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 boost::regex expression(re);
  53
  54 class IndexClassesPred
  55 {
  56    map_type& m;
  57    std::string::const_iterator base;
  58 public:
  59    IndexClassesPred(map_type& a, std::string::const_iterator b) : m(a), base(b) {}
  60    bool operator()(const boost::match_results<std::string::const_iterator>& what)
  61    {
  62       // what[0] contains the whole string
  63       // what[5] contains the class name.
  64       // what[6] contains the template specialisation if any.
  65       // add class name and position to map:
  66       m[std::string(what[5].first, what[5].second) + std::string(what[6].first, what[6].second)] =
  67                what[5].first - base;
  68       return true;
  69    }
  70 private:
  71    IndexClassesPred& operator=(const IndexClassesPred&);
  72 };
  73
  74 void IndexClasses(map_type& m, const std::string& file)
  75 {
  76    std::string::const_iterator start, end;
  77    start = file.begin();
  78    end = file.end();
  79    boost::regex_grep(IndexClassesPred(m, start), start, end, expression);
  80 }
  81
  82
  83 #include <fstream>
  84 #include <iostream>
  85
  86 using namespace std;
  87
  88 void load_file(std::string& s, std::istream& is)
  89 {
  90    s.erase();
  91    if(is.bad()) return;
  92    s.reserve(static_cast<std::string::size_type>(is.rdbuf()->in_avail()));
  93    char c;
  94    while(is.get(c))
  95    {
  96       if(s.capacity() == s.size())
  97          s.reserve(s.capacity() * 3);
  98       s.append(1, c);
  99    }
 100 }
 101
 102 int main(int argc, const char** argv)
 103 {
 104    std::string text;
 105    for(int i = 1; i < argc; ++i)
 106    {
 107       cout << "Processing file " << argv[i] << endl;
 108       map_type m;
 109       std::ifstream fs(argv[i]);
 110       load_file(text, fs);
 111       fs.close();
 112       IndexClasses(m, text);
 113       cout << m.size() << " matches found" << endl;
 114       map_type::iterator c, d;
 115       c = m.begin();
 116       d = m.end();
 117       while(c != d)
 118       {
 119          cout << "class \"" << (*c).first << "\" found at index: " << (*c).second << endl;
 120          ++c;
 121       }
 122    }
 123    return 0;
 124 }
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