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 // A parser for summing a comma-separated list of numbers using phoenix.
10 //
11 // [ JDG June 28, 2002 ] spirit1
12 // [ JDG March 24, 2007 ] spirit2
13 //
14 ///////////////////////////////////////////////////////////////////////////////
15
16 #include <boost/config/warning_disable.hpp>
17 //[tutorial_adder_includes
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 <iostream>
22 #include <string>
23 //]
24
25 namespace client
26 {
27 //[tutorial_adder_using
28 namespace qi = boost::spirit::qi;
29 namespace ascii = boost::spirit::ascii;
30 namespace phoenix = boost::phoenix;
31
32 using qi::double_;
33 using qi::_1;
34 using ascii::space;
35 using phoenix::ref;
36 //]
37
38 ///////////////////////////////////////////////////////////////////////////
39 // Our adder
40 ///////////////////////////////////////////////////////////////////////////
41
42 //[tutorial_adder
43 template <typename Iterator>
adder(Iterator first,Iterator last,double & n)44 bool adder(Iterator first, Iterator last, double& n)
45 {
46 bool r = qi::phrase_parse(first, last,
47
48 // Begin grammar
49 (
50 double_[ref(n) = _1] >> *(',' >> double_[ref(n) += _1])
51 )
52 ,
53 // End grammar
54
55 space);
56
57 if (first != last) // fail if we did not get a full match
58 return false;
59 return r;
60 }
61 //]
62 }
63
64 ////////////////////////////////////////////////////////////////////////////
65 // Main program
66 ////////////////////////////////////////////////////////////////////////////
67 int
main()68 main()
69 {
70 std::cout << "/////////////////////////////////////////////////////////\n\n";
71 std::cout << "\t\tA parser for summing a list of numbers...\n\n";
72 std::cout << "/////////////////////////////////////////////////////////\n\n";
73
74 std::cout << "Give me a comma separated list of numbers.\n";
75 std::cout << "The numbers are added using Phoenix.\n";
76 std::cout << "Type [q or Q] to quit\n\n";
77
78 std::string str;
79 while (getline(std::cin, str))
80 {
81 if (str.empty() || str[0] == 'q' || str[0] == 'Q')
82 break;
83
84 double n;
85 if (client::adder(str.begin(), str.end(), n))
86 {
87 std::cout << "-------------------------\n";
88 std::cout << "Parsing succeeded\n";
89 std::cout << str << " Parses OK: " << std::endl;
90
91 std::cout << "sum = " << n;
92 std::cout << "\n-------------------------\n";
93 }
94 else
95 {
96 std::cout << "-------------------------\n";
97 std::cout << "Parsing failed\n";
98 std::cout << "-------------------------\n";
99 }
100 }
101
102 std::cout << "Bye... :-) \n\n";
103 return 0;
104 }
105
106
107