ceph/src/boost/libs/spirit/example/qi/num_list3.cpp

   1 /*=============================================================================
   2     Copyright (c) 2002-2010 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/spirit/include/qi.hpp>
  18 #include <boost/phoenix/core.hpp>
  19 #include <boost/phoenix/operator.hpp>
  20 #include <boost/phoenix/stl.hpp>
  21
  22 #include <iostream>
  23 #include <string>
  24 #include <vector>
  25
  26 namespace client
  27 {
  28     namespace qi = boost::spirit::qi;
  29     namespace ascii = boost::spirit::ascii;
  30     namespace phoenix = boost::phoenix;
  31
  32     ///////////////////////////////////////////////////////////////////////////////
  33     //  Our number list compiler
  34     ///////////////////////////////////////////////////////////////////////////////
  35     //[tutorial_numlist3
  36     template <typename Iterator>
  37     bool parse_numbers(Iterator first, Iterator last, std::vector<double>& v)
  38     {
  39         using qi::double_;
  40         using qi::phrase_parse;
  41         using qi::_1;
  42         using ascii::space;
  43         using phoenix::push_back;
  44
  45         bool r = phrase_parse(first, last,
  46
  47             //  Begin grammar
  48             (
  49                 double_[push_back(phoenix::ref(v), _1)] % ','
  50             )
  51             ,
  52             //  End grammar
  53
  54             space);
  55
  56         if (first != last) // fail if we did not get a full match
  57             return false;
  58         return r;
  59     }
  60     //]
  61 }
  62
  63 ////////////////////////////////////////////////////////////////////////////
  64 //  Main program
  65 ////////////////////////////////////////////////////////////////////////////
  66 int
  67 main()
  68 {
  69     std::cout << "/////////////////////////////////////////////////////////\n\n";
  70     std::cout << "\t\tA comma separated list parser for Spirit...\n\n";
  71     std::cout << "/////////////////////////////////////////////////////////\n\n";
  72
  73     std::cout << "Give me a comma separated list of numbers.\n";
  74     std::cout << "The numbers will be inserted in a vector of numbers\n";
  75     std::cout << "Type [q or Q] to quit\n\n";
  76
  77     std::string str;
  78     while (getline(std::cin, str))
  79     {
  80         if (str.empty() || str[0] == 'q' || str[0] == 'Q')
  81             break;
  82
  83         std::vector<double> v;
  84         if (client::parse_numbers(str.begin(), str.end(), v))
  85         {
  86             std::cout << "-------------------------\n";
  87             std::cout << "Parsing succeeded\n";
  88             std::cout << str << " Parses OK: " << std::endl;
  89
  90             for (std::vector<double>::size_type i = 0; i < v.size(); ++i)
  91                 std::cout << i << ": " << v[i] << std::endl;
  92
  93             std::cout << "\n-------------------------\n";
  94         }
  95         else
  96         {
  97             std::cout << "-------------------------\n";
  98             std::cout << "Parsing failed\n";
  99             std::cout << "-------------------------\n";
 100         }
 101     }
 102
 103     std::cout << "Bye... :-) \n\n";
 104     return 0;
 105 }
 106
 107