reworked regex directory structure to match boost requirements.

[SVN r9752]

example/snippets/regex_grep_example_4.cpp

@@ -0,0 +1,121 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+ /*
+  *   LOCATION:    see http://www.boost.org for most recent version.
+  *   FILE         regex_grep_example_4.cpp
+  *   VERSION      3.00
+  *   DESCRIPTION: regex_grep example 4: searches a cpp file for class definitions,
+  *                using a C++ Builder closure as a callback.
+  */
+
+#include <string>
+#include <map>
+#include <boost/regex.hpp>
+#include <functional>
+
+// 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;
+
+class class_index
+{
+   boost::regex expression;
+   map_type index;
+   std::string::const_iterator base;
+   typedef boost::match_results<std::string::const_iterator, boost::regex::allocator_type> arg_type;
+
+   bool grep_callback(const boost::match_results<std::string::const_iterator, boost::regex::allocator_type>& what);
+public:
+   map_type& get_map() { return index; }
+   typedef bool (__closure* grep_callback_type)(const arg_type&);
+   void IndexClasses(const std::string& file);
+   class_index()
+      : index(),
+        expression("^(template[[:space:]]*<[^;:{]+>[[:space:]]*)?(class|struct)[[:space:]]*(\\<\\w+\\>([[:blank:]]*\\([^)]*\\))?[[:space:]]*)*(\\<\\w*\\>)[[:space:]]*(<[^;:{]+>)?[[:space:]]*(\\{|:[^;\\{()]*\\{)")
+        {}
+};
+
+bool class_index::grep_callback(const boost::match_results<std::string::const_iterator, boost::regex::allocator_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:
+   index[std::string(what[5].first, what[5].second) + std::string(what[6].first, what[6].second)] =
+               what[5].first - base;
+   return true;
+}
+
+void class_index::IndexClasses(const std::string& file)
+{
+   std::string::const_iterator start, end;
+   start = file.begin();
+   end = file.end();
+   base = start;
+   class_index::grep_callback_type cl = &(this->grep_callback);
+   boost::regex_grep(cl,
+            start,
+            end,
+            expression);
+}
+
+
+#include <fstream>
+#include <iostream>
+
+using namespace std;
+
+void load_file(std::string& s, std::istream& is)
+{
+   s.erase();
+   s.reserve(is.rdbuf()->in_avail());
+   char c;
+   while(is.get(c))
+   {
+      if(s.capacity() == s.size())
+         s.reserve(s.capacity() * 3);
+      s.append(1, c);
+   }
+}
+
+int main(int argc, const char** argv)
+{
+   std::string text;
+   for(int i = 1; i < argc; ++i)
+   {
+      cout << "Processing file " << argv[i] << endl;
+      std::ifstream fs(argv[i]);
+      load_file(text, fs);
+      class_index i;
+      i.IndexClasses(text);
+      cout << i.get_map().size() << " matches found" << endl;
+      map_type::iterator c, d;
+      c = i.get_map().begin();
+      d = i.get_map().end();
+      while(c != d)
+      {
+         cout << "class \"" << (*c).first << "\" found at index: " << (*c).second << endl;
+         ++c;
+      }
+   }
+   return 0;
+}
+
+
+