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 //
11 // [ JDG May 10, 2002 ] spirit1
12 // [ JDG March 24, 2007 ] spirit2
13 // [ JDG May 12, 2015 ] spirit X3
14 //
15 ///////////////////////////////////////////////////////////////////////////////
16
17 #include <boost/config/warning_disable.hpp>
18 #include <boost/spirit/home/x3.hpp>
19
20 #include <iostream>
21 #include <string>
22 #include <vector>
23
24 namespace client
25 {
26 namespace x3 = boost::spirit::x3;
27 namespace ascii = boost::spirit::x3::ascii;
28
29 ///////////////////////////////////////////////////////////////////////////
30 // Our number list compiler
31 ///////////////////////////////////////////////////////////////////////////
32 template <typename Iterator>
parse_numbers(Iterator first,Iterator last,std::vector<double> & v)33 bool parse_numbers(Iterator first, Iterator last, std::vector<double>& v)
34 {
35 using x3::double_;
36 using x3::phrase_parse;
37 using x3::_attr;
38 using ascii::space;
39
40 auto push_back = [&](auto& ctx){ v.push_back(_attr(ctx)); };
41
42 bool r = phrase_parse(first, last,
43
44 // Begin grammar
45 (
46 double_[push_back] >> *(',' >> double_[push_back])
47 )
48 ,
49 // End grammar
50
51 space);
52
53 if (first != last) // fail if we did not get a full match
54 return false;
55 return r;
56 }
57 }
58
59 ////////////////////////////////////////////////////////////////////////////
60 // Main program
61 ////////////////////////////////////////////////////////////////////////////
62 int
main()63 main()
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(std::cin, 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(str.begin(), 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