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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> | |
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 | |
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 |