ceph/src/boost/libs/spirit/example/x3/num_list/num_list4.cpp

   1 /*=============================================================================
   2     Copyright (c) 2002-2015 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 //  This time, the numbers are automatically collected into the attribute by
  11 //  the parser itself using the full power of attribute grammars.
  12 //
  13 //  [ JDG May 10, 2002 ]    spirit1
  14 //  [ JDG March 24, 2007 ]  spirit2
  15 //  [ JDG May 12, 2015 ]    spirit X3
  16 //
  17 ///////////////////////////////////////////////////////////////////////////////
  18
  19 #include <boost/config/warning_disable.hpp>
  20 #include <boost/spirit/home/x3.hpp>
  21
  22 #include <iostream>
  23 #include <string>
  24 #include <vector>
  25
  26 namespace client
  27 {
  28     namespace x3 = boost::spirit::x3;
  29     namespace ascii = boost::spirit::x3::ascii;
  30
  31     ///////////////////////////////////////////////////////////////////////////
  32     //  Our number list compiler
  33     ///////////////////////////////////////////////////////////////////////////
  34     //[tutorial_numlist4
  35     template <typename Iterator>
  36     bool parse_numbers(Iterator first, Iterator last, std::vector<double>& v)
  37     {
  38         using x3::double_;
  39         using x3::phrase_parse;
  40         using x3::_attr;
  41         using ascii::space;
  42
  43         bool r = phrase_parse(first, last,
  44
  45             //  Begin grammar
  46             (
  47                 double_ % ','
  48             )
  49             ,
  50             //  End grammar
  51
  52             space, v);
  53
  54         if (first != last) // fail if we did not get a full match
  55             return false;
  56         return r;
  57     }
  58     //]
  59 }
  60
  61 ////////////////////////////////////////////////////////////////////////////
  62 //  Main program
  63 ////////////////////////////////////////////////////////////////////////////
  64 int
  65 main()
  66 {
  67     std::cout << "/////////////////////////////////////////////////////////\n\n";
  68     std::cout << "\t\tA comma separated list parser for Spirit...\n\n";
  69     std::cout << "/////////////////////////////////////////////////////////\n\n";
  70
  71     std::cout << "Give me a comma separated list of numbers.\n";
  72     std::cout << "The numbers will be inserted in a vector of numbers\n";
  73     std::cout << "Type [q or Q] to quit\n\n";
  74
  75     std::string str;
  76     while (getline(std::cin, str))
  77     {
  78         if (str.empty() || str[0] == 'q' || str[0] == 'Q')
  79             break;
  80
  81         std::vector<double> v;
  82         if (client::parse_numbers(str.begin(), str.end(), v))
  83         {
  84             std::cout << "-------------------------\n";
  85             std::cout << "Parsing succeeded\n";
  86             std::cout << str << " Parses OK: " << std::endl;
  87
  88             for (std::vector<double>::size_type i = 0; i < v.size(); ++i)
  89                 std::cout << i << ": " << v[i] << std::endl;
  90
  91             std::cout << "\n-------------------------\n";
  92         }
  93         else
  94         {
  95             std::cout << "-------------------------\n";
  96             std::cout << "Parsing failed\n";
  97             std::cout << "-------------------------\n";
  98         }
  99     }
 100
 101     std::cout << "Bye... :-) \n\n";
 102     return 0;
 103 }