ceph/src/boost/libs/spirit/example/qi/reorder_struct.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 //  The main purpose of this example is to show how a single fusion sequence
   7 //  can be filled from a parsed input of the elements in different sequences
   8
   9 #include <boost/config/warning_disable.hpp>
  10 #include <boost/mpl/print.hpp>
  11 #include <boost/spirit/include/qi.hpp>
  12 #include <boost/fusion/include/struct.hpp>
  13 #include <boost/fusion/include/nview.hpp>
  14 #include <boost/foreach.hpp>
  15
  16 namespace fusion = boost::fusion;
  17 namespace qi = boost::spirit::qi;
  18
  19 ///////////////////////////////////////////////////////////////////////////////
  20 namespace client
  21 {
  22     //  Our employee struct
  23     struct employee
  24     {
  25         std::string surname;
  26         std::string forename;
  27         int age;
  28         double salary;
  29         std::string department;
  30     };
  31
  32     // define iterator type
  33     typedef std::string::const_iterator iterator_type;
  34
  35     // This is the output routine taking a format description and the data to
  36     // print
  37     template <typename Parser, typename Sequence>
  38     bool parse(std::string const& input, Parser const& p, Sequence& s)
  39     {
  40         iterator_type begin = input.begin();
  41         return qi::parse(begin, input.end(), p, s);
  42     }
  43 }
  44
  45 // We need to tell fusion about our employee struct to make it a first-class
  46 // fusion citizen. This has to be in global scope. Note that we don't need to
  47 // list the members of our struct in the same sequence a they are defined
  48 BOOST_FUSION_ADAPT_STRUCT(
  49     client::employee,
  50     (int, age)
  51     (std::string, surname)
  52     (std::string, forename)
  53     (std::string, department)
  54     (double, salary)
  55 )
  56
  57 ///////////////////////////////////////////////////////////////////////////////
  58 // that's the different types we need to reorder the attributes
  59 typedef fusion::result_of::as_nview<client::employee, 2, 0>::type name_and_age;
  60 typedef fusion::result_of::as_nview<client::employee, 1, 2, 4>::type names_and_salary;
  61 typedef fusion::result_of::as_nview<client::employee, 2, 0, 3>::type name_age_and_department;
  62
  63 ///////////////////////////////////////////////////////////////////////////////
  64 int main()
  65 {
  66     std::string str;
  67
  68     // some employees
  69     client::employee john;
  70     client::employee mary;
  71     client::employee tom;
  72
  73     // print data about employees in different formats
  74     {
  75         // parse forename and age only
  76         name_and_age johnview(fusion::as_nview<2, 0>(john));
  77         bool r = client::parse(
  78             "John, 25",
  79             *(qi::char_ - ',') >> ", " >> qi::int_,
  80             johnview);
  81         if (r) {
  82             std::cout << "Parsed: " << john.forename << ", " << john.age
  83                       << std::endl;
  84         }
  85
  86         // parse surname, forename, and salary
  87         names_and_salary maryview(fusion::as_nview<1, 2, 4>(mary));
  88         r = client::parse(
  89             "Higgins, Mary: 2200.36",
  90             *(qi::char_ - ',') >> ", " >> *(qi::char_ - ':') >> ": " >> qi::double_,
  91             maryview);
  92         if (r) {
  93             std::cout << "Parsed: " << mary.forename << ", " << mary.surname
  94                       << ", " << mary.salary << std::endl;
  95         }
  96
  97         // parse forename, age, and department
  98         name_age_and_department tomview(fusion::as_nview<2, 0, 3>(tom));
  99         client::parse(
 100             "Tom: 48 (Boss)",
 101             *(qi::char_ - ':') >> ": " >> qi::int_ >> " (" >> *(qi::char_ - ')') >> ')',
 102             tomview);
 103         if (r) {
 104             std::cout << "Parsed: " << tom.forename << ", " << tom.age
 105                       << ", " << tom.department << std::endl;
 106         }
 107     }
 108
 109     // now parse a list of several employees and print them all
 110     std::vector<client::employee> employees;
 111
 112     // parse surname, forename, and salary for all employees
 113     {
 114         qi::rule<client::iterator_type, names_and_salary()> r =
 115             *(qi::char_ - ',') >> ", " >> *(qi::char_ - ',') >> ", " >> qi::double_;
 116
 117         bool result = client::parse(
 118             "John, Smith, 2000.50\n" "Mary, Higgins, 2200.36\n" "Tom, Taylor, 3200.00\n",
 119             r % qi::eol, employees);
 120
 121         std::cout << "Parsed: " << std::endl;
 122         BOOST_FOREACH(client::employee const& e, employees)
 123         {
 124             std::cout << e.forename << ", " << e.surname << ", " << e.salary
 125                       << std::endl;
 126         }
 127     }
 128     return 0;
 129 }
 130