1// Copyright (c) 2001-2010 Hartmut Kaiser
2//
3// Distributed under the Boost Software License, Version 1.0. (See accompanying
4// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5
6// The main purpose of this example is to show how a single fusion sequence
7// can be filled from a parsed input of the elements in different sequences
8
9#include <boost/spirit/include/qi.hpp>
10#include <boost/fusion/include/struct.hpp>
11#include <boost/fusion/include/nview.hpp>
12#include <boost/foreach.hpp>
13
14namespace fusion = boost::fusion;
15namespace qi = boost::spirit::qi;
16
17///////////////////////////////////////////////////////////////////////////////
18namespace client
19{
20 // Our employee struct
21 struct employee
22 {
23 std::string surname;
24 std::string forename;
25 int age;
26 double salary;
27 std::string department;
28 };
29
30 // define iterator type
31 typedef std::string::const_iterator iterator_type;
32
33 // This is the output routine taking a format description and the data to
34 // print
35 template <typename Parser, typename Sequence>
36 bool parse(std::string const& input, Parser const& p, Sequence& s)
37 {
38 iterator_type begin = input.begin();
39 return qi::parse(begin, input.end(), p, s);
40 }
41}
42
43// We need to tell fusion about our employee struct to make it a first-class
44// fusion citizen. This has to be in global scope. Note that we don't need to
45// list the members of our struct in the same sequence a they are defined
46BOOST_FUSION_ADAPT_STRUCT(
47 client::employee,
48 (int, age)
49 (std::string, surname)
50 (std::string, forename)
51 (std::string, department)
52 (double, salary)
53)
54
55///////////////////////////////////////////////////////////////////////////////
56// that's the different types we need to reorder the attributes
57typedef fusion::result_of::as_nview<client::employee, 2, 0>::type name_and_age;
58typedef fusion::result_of::as_nview<client::employee, 1, 2, 4>::type names_and_salary;
59typedef fusion::result_of::as_nview<client::employee, 2, 0, 3>::type name_age_and_department;
60
61///////////////////////////////////////////////////////////////////////////////
62int main()
63{
64 std::string str;
65
66 // some employees
67 client::employee john;
68 client::employee mary;
69 client::employee tom;
70
71 // print data about employees in different formats
72 {
73 // parse forename and age only
74 name_and_age johnview(fusion::as_nview<2, 0>(s&: john));
75 bool r = client::parse(
76 input: "John, 25",
77 p: *(qi::char_ - ',') >> ", " >> qi::int_,
78 s&: johnview);
79 if (r) {
80 std::cout << "Parsed: " << john.forename << ", " << john.age
81 << std::endl;
82 }
83
84 // parse surname, forename, and salary
85 names_and_salary maryview(fusion::as_nview<1, 2, 4>(s&: mary));
86 r = client::parse(
87 input: "Higgins, Mary: 2200.36",
88 p: *(qi::char_ - ',') >> ", " >> *(qi::char_ - ':') >> ": " >> qi::double_,
89 s&: maryview);
90 if (r) {
91 std::cout << "Parsed: " << mary.forename << ", " << mary.surname
92 << ", " << mary.salary << std::endl;
93 }
94
95 // parse forename, age, and department
96 name_age_and_department tomview(fusion::as_nview<2, 0, 3>(s&: tom));
97 client::parse(
98 input: "Tom: 48 (Boss)",
99 p: *(qi::char_ - ':') >> ": " >> qi::int_ >> " (" >> *(qi::char_ - ')') >> ')',
100 s&: tomview);
101 if (r) {
102 std::cout << "Parsed: " << tom.forename << ", " << tom.age
103 << ", " << tom.department << std::endl;
104 }
105 }
106
107 // now parse a list of several employees and print them all
108 std::vector<client::employee> employees;
109
110 // parse surname, forename, and salary for all employees
111 {
112 qi::rule<client::iterator_type, names_and_salary()> r =
113 *(qi::char_ - ',') >> ", " >> *(qi::char_ - ',') >> ", " >> qi::double_;
114
115 bool result = client::parse(
116 input: "John, Smith, 2000.50\n" "Mary, Higgins, 2200.36\n" "Tom, Taylor, 3200.00\n",
117 p: r % qi::eol, s&: employees);
118
119 std::cout << "Parsed: " << std::endl;
120 BOOST_FOREACH(client::employee const& e, employees)
121 {
122 std::cout << e.forename << ", " << e.surname << ", " << e.salary
123 << std::endl;
124 }
125 }
126 return 0;
127}
128
129

source code of boost/libs/spirit/example/qi/reorder_struct.cpp