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/spirit/home/x3.hpp>
20
21#include <iostream>
22#include <string>
23#include <vector>
24
25namespace client
26{
27 namespace x3 = boost::spirit::x3;
28 namespace ascii = boost::spirit::x3::ascii;
29
30 ///////////////////////////////////////////////////////////////////////////
31 // Our number list compiler
32 ///////////////////////////////////////////////////////////////////////////
33 //[tutorial_numlist4
34 template <typename Iterator>
35 bool parse_numbers(Iterator first, Iterator last, std::vector<double>& v)
36 {
37 using x3::double_;
38 using x3::phrase_parse;
39 using ascii::space;
40
41 bool r = phrase_parse(first, last,
42
43 // Begin grammar
44 (
45 double_ % ','
46 )
47 ,
48 // End grammar
49
50 space, v);
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////////////////////////////////////////////////////////////////////////////
60// Main program
61////////////////////////////////////////////////////////////////////////////
62int
63main()
64{
65 std::cout << "/////////////////////////////////////////////////////////\n\n";
66 std::cout << "\t\tA comma separated list parser for Spirit...\n\n";
67 std::cout << "/////////////////////////////////////////////////////////\n\n";
68
69 std::cout << "Give me a comma separated list of numbers.\n";
70 std::cout << "The numbers will be inserted in a vector of numbers\n";
71 std::cout << "Type [q or Q] to quit\n\n";
72
73 std::string str;
74 while (getline(is&: std::cin, str&: str))
75 {
76 if (str.empty() || str[0] == 'q' || str[0] == 'Q')
77 break;
78
79 std::vector<double> v;
80 if (client::parse_numbers(first: str.begin(), last: str.end(), v))
81 {
82 std::cout << "-------------------------\n";
83 std::cout << "Parsing succeeded\n";
84 std::cout << str << " Parses OK: " << std::endl;
85
86 for (std::vector<double>::size_type i = 0; i < v.size(); ++i)
87 std::cout << i << ": " << v[i] << std::endl;
88
89 std::cout << "\n-------------------------\n";
90 }
91 else
92 {
93 std::cout << "-------------------------\n";
94 std::cout << "Parsing failed\n";
95 std::cout << "-------------------------\n";
96 }
97 }
98
99 std::cout << "Bye... :-) \n\n";
100 return 0;
101}
102

source code of boost/libs/spirit/example/x3/num_list/num_list4.cpp