ceph/src/boost/libs/spirit/example/qi/custom_string.cpp

   1 //  Copyright (c) 2001-2010 Hartmut Kaiser
   2 //
   3 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 //  This example demonstrates the steps needed to integrate a custom container
   7 //  type to be usable with Spirit.Qi. It shows how to utilize the QString data
   8 //  type as a Qi attribute.
   9
  10 //  Note: you need to have Qt4 installed on your system and you have to make
  11 //        sure your compiler finds the includes and your linker finds the
  12 //        proper libraries.
  13
  14 #include <boost/spirit/include/qi.hpp>
  15
  16 #include <Qt/qstring.h>
  17
  18 namespace boost { namespace spirit { namespace traits
  19 {
  20     // Make Qi recognize QString as a container
  21     template <> struct is_container<QString> : mpl::true_ {};
  22
  23     // Expose the container's (QString's) value_type
  24     template <> struct container_value<QString> : mpl::identity<QChar> {};
  25
  26     // Define how to insert a new element at the end of the container (QString)
  27     template <>
  28     struct push_back_container<QString, QChar>
  29     {
  30         static bool call(QString& c, QChar const& val)
  31         {
  32             c.append(val);
  33             return true;
  34         }
  35     };
  36
  37     // Test if a QString is empty (required for debug)
  38     template <>
  39     struct is_empty_container<QString>
  40     {
  41         static bool call(QString const& c)
  42         {
  43             return c.isEmpty();
  44         }
  45     };
  46
  47     // Define how to stream a QString (required for debug)
  48     template <typename Out, typename Enable>
  49     struct print_attribute_debug<Out, QString, Enable>
  50     {
  51         static void call(Out& out, QString const& val)
  52         {
  53             out << val.toStdString();
  54         }
  55     };
  56 }}}
  57
  58 ///////////////////////////////////////////////////////////////////////////////
  59 namespace client
  60 {
  61     template <typename Iterator>
  62     bool parse_qstring(Iterator first, Iterator last, QString& t)
  63     {
  64         using boost::spirit::qi::char_;
  65         using boost::spirit::ascii::space;
  66         using boost::spirit::qi::phrase_parse;
  67
  68         bool r = phrase_parse(first, last, +char_, space, t);
  69         if (!r || first != last) // fail if we did not get a full match
  70             return false;
  71
  72         return r;
  73     }
  74 }
  75
  76 ///////////////////////////////////////////////////////////////////////////////
  77 int main()
  78 {
  79     std::cout << "/////////////////////////////////////////////////////////\n\n";
  80     std::cout << "\t\tParsing into a QString from Spirit...\n\n";
  81     std::cout << "/////////////////////////////////////////////////////////\n\n";
  82
  83     std::cout << "Give me a complex number of the form r or (r) or (r,i) \n";
  84     std::cout << "Type [q or Q] to quit\n\n";
  85
  86     std::string str;
  87     while (getline(std::cin, str))
  88     {
  89         if (str.empty() || str[0] == 'q' || str[0] == 'Q')
  90             break;
  91
  92         QString t;
  93         if (client::parse_qstring(str.begin(), str.end(), t))
  94         {
  95             std::cout << "-------------------------\n";
  96             std::cout << "Parsing succeeded\n";
  97             std::cout << "got: " << t.toStdString() << std::endl;
  98             std::cout << "\n-------------------------\n";
  99         }
 100         else
 101         {
 102             std::cout << "-------------------------\n";
 103             std::cout << "Parsing failed\n";
 104             std::cout << "-------------------------\n";
 105         }
 106     }
 107
 108     std::cout << "Bye... :-) \n\n";
 109     return 0;
 110 }
 111
 112