snip5.cpp

正则表达式源代码

/*
 *
 * Copyright (c) 1998-2000
 * Dr John Maddock
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Dr John Maddock makes no representations
 * about the suitability of this software for any purpose.
 * It is provided "as is" without express or implied warranty.
 *
 */

#include <string>
#include <map>
#include <regex>

// purpose:
// takes the contents of a file in the form of a string
// and searches for all the C++ class definitions, storing
// their locations in a map of strings/int's

typedef std::map<std::string, int, std::less<std::string> > map_type;

regex expression("^(template[[:space:]]*<[^;:{]+>[[:space:]]*)?(class|struct)[[:space:]]*(\\<\\w+\\>([[:blank:]]*\\([^)]*\\))?[[:space:]]*)*(\\<\\w*\\>)[[:space:]]*(<[^;:{]+>[[:space:]]*)?(\\{|:[^;\\{()]*\\{)");
map_type class_index;
std::string::const_iterator base;

bool grep_callback(const reg_match<std::string::const_iterator, regex::alloc_type>& what)
{
   // what[0] contains the whole string
   // what[5] contains the class name.
   // what[6] contains the template specialisation if any.
   // add class name and position to map:
   class_index[std::string(what[5].first, what[5].second) + std::string(what[6].first, what[6].second)] = 
               what[5].first - base;
   return true;
}

void IndexClasses(const std::string& file)
{
   std::string::const_iterator start, end;
   start = file.begin();
   end = file.end();
   base = start;
   reg_grep(grep_callback, start, end, expression, match_default);
}