Boost_1_39_0/libs/spirit/example/qi/num_list2.cpp

   1 /*=============================================================================
   2     Copyright (c) 2002-2007 Joel de Guzman
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 =============================================================================*/
   7 ///////////////////////////////////////////////////////////////////////////////
   8 //
   9 //  This sample demontrates a parser for a comma separated list of numbers.
  10 //  The numbers are inserted in a vector using phoenix.
  11 //
  12 //  [ JDG May 10, 2002 ]    spirit1
  13 //  [ JDG March 24, 2007 ]  spirit2
  14 //
  15 ///////////////////////////////////////////////////////////////////////////////
  16
  17 #include <boost/config/warning_disable.hpp>
  18 #include <boost/spirit/include/qi.hpp>
  19 #include <boost/spirit/include/phoenix_core.hpp>
  20 #include <boost/spirit/include/phoenix_operator.hpp>
  21 #include <boost/spirit/include/phoenix_stl.hpp>
  22
  23 #include <iostream>
  24 #include <string>
  25 #include <vector>
  26
  27 using namespace boost::phoenix;
  28 using namespace boost::spirit;
  29 using namespace boost::spirit::qi;
  30 using namespace boost::spirit::ascii;
  31 using namespace boost::spirit::arg_names;
  32
  33 ///////////////////////////////////////////////////////////////////////////////
  34 //  Our number list compiler
  35 ///////////////////////////////////////////////////////////////////////////////
  36 //[tutorial_numlist2
  37 template <typename Iterator>
  38 bool parse_numbers(Iterator first, Iterator last, std::vector<double>& v)
  39 {
  40     bool r = phrase_parse(first, last,
  41
  42         //  Begin grammar
  43         (
  44             double_[push_back(ref(v), _1)]
  45                 >> *(',' >> double_[push_back(ref(v), _1)])
  46         )
  47         ,
  48         //  End grammar
  49
  50         space);
  51
  52     if (first != last) // fail if we did not get a full match
  53         return false;
  54     return r;
  55 }
  56 //]
  57
  58 ////////////////////////////////////////////////////////////////////////////
  59 //  Main program
  60 ////////////////////////////////////////////////////////////////////////////
  61 int
  62 main()
  63 {
  64     std::cout << "/////////////////////////////////////////////////////////\n\n";
  65     std::cout << "\t\tA comma separated list parser for Spirit...\n\n";
  66     std::cout << "/////////////////////////////////////////////////////////\n\n";
  67
  68     std::cout << "Give me a comma separated list of numbers.\n";
  69     std::cout << "The numbers will be inserted in a vector of numbers\n";
  70     std::cout << "Type [q or Q] to quit\n\n";
  71
  72     std::string str;
  73     while (getline(std::cin, str))
  74     {
  75         if (str.empty() || str[0] == 'q' || str[0] == 'Q')
  76             break;
  77
  78         std::vector<double> v;
  79         if (parse_numbers(str.begin(), str.end(), v))
  80         {
  81             std::cout << "-------------------------\n";
  82             std::cout << "Parsing succeeded\n";
  83             std::cout << str << " Parses OK: " << std::endl;
  84
  85             for (std::vector<double>::size_type i = 0; i < v.size(); ++i)
  86                 std::cout << i << ": " << v[i] << std::endl;
  87
  88             std::cout << "\n-------------------------\n";
  89         }
  90         else
  91         {
  92             std::cout << "-------------------------\n";
  93             std::cout << "Parsing failed\n";
  94             std::cout << "-------------------------\n";
  95         }
  96     }
  97
  98     std::cout << "Bye... :-) \n\n";
  99     return 0;
 100 }
 101
 102