1/*=============================================================================
2 Copyright (c) 2002-2010 Hartmut Kaiser
3 Copyright (c) 2002-2010 Joel de Guzman
4
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7=============================================================================*/
8///////////////////////////////////////////////////////////////////////////////
9//
10// This sample demonstrates a generator for a comma separated list of numbers.
11// No actions. It is based on the example qi/num_lists.cpp for reading in
12// some numbers to generate.
13//
14///////////////////////////////////////////////////////////////////////////////
15
16#include <boost/spirit/include/qi.hpp>
17#include <boost/spirit/include/karma.hpp>
18
19#include <iostream>
20#include <string>
21#include <vector>
22
23namespace client
24{
25 ///////////////////////////////////////////////////////////////////////////
26 // Our number list parser, please see the example qi/numlist1.cpp for
27 // more information
28 ///////////////////////////////////////////////////////////////////////////
29 template <typename Iterator>
30 bool parse_numbers(Iterator first, Iterator last, std::vector<double>& v)
31 {
32 using boost::spirit::qi::double_;
33 using boost::spirit::qi::phrase_parse;
34 using boost::spirit::ascii::space;
35
36 bool r = phrase_parse(first, last, double_ % ',', space, v);
37 if (first != last)
38 return false;
39 return r;
40 }
41
42 //[tutorial_karma_numlist3_complex
43 // a simple complex number representation z = a + bi
44 struct complex
45 {
46 complex (double a, double b = 0.0) : a(a), b(b) {}
47
48 double a;
49 double b;
50 };
51
52 // the streaming operator for the type complex
53 std::ostream&
54 operator<< (std::ostream& os, complex const& z)
55 {
56 os << "{" << z.a << "," << z.b << "}";
57 return os;
58 }
59 //]
60
61 ///////////////////////////////////////////////////////////////////////////
62 // Our number list generator
63 ///////////////////////////////////////////////////////////////////////////
64 //[tutorial_karma_numlist3
65 template <typename OutputIterator, typename Container>
66 bool generate_numbers(OutputIterator& sink, Container const& v)
67 {
68 using boost::spirit::karma::stream;
69 using boost::spirit::karma::generate;
70 using boost::spirit::karma::eol;
71
72 bool r = generate(
73 sink, // destination: output iterator
74 stream % eol, // the generator
75 v // the data to output
76 );
77 return r;
78 }
79 //]
80}
81
82////////////////////////////////////////////////////////////////////////////
83// Main program
84////////////////////////////////////////////////////////////////////////////
85int
86main()
87{
88 std::cout << "/////////////////////////////////////////////////////////\n\n";
89 std::cout << "\tA comma separated list generator for Spirit...\n\n";
90 std::cout << "/////////////////////////////////////////////////////////\n\n";
91
92 std::cout << "Give me a comma separated list of numbers.\n";
93 std::cout << "Type [q or Q] to quit\n\n";
94
95 std::string str;
96 while (getline(is&: std::cin, str&: str))
97 {
98 if (str.empty() || str[0] == 'q' || str[0] == 'Q')
99 break;
100
101 std::vector<double> v; // here we put the data gotten from input
102 if (client::parse_numbers(first: str.begin(), last: str.end(), v))
103 {
104 // ok, we got some numbers, fill a vector of client::complex
105 // instances and print them back out
106 std::vector<client::complex> vc;
107 std::vector<double>::const_iterator end = v.end();
108 for (std::vector<double>::const_iterator it = v.begin();
109 it != end; ++it)
110 {
111 double real(*it);
112 if (++it != end)
113 vc.push_back(x: client::complex(real, *it));
114 else {
115 vc.push_back(x: client::complex(real));
116 break;
117 }
118 }
119
120 std::cout << "-------------------------\n";
121
122 std::string generated;
123 std::back_insert_iterator<std::string> sink(generated);
124 if (!client::generate_numbers(sink, v: vc))
125 {
126 std::cout << "-------------------------\n";
127 std::cout << "Generating failed\n";
128 std::cout << "-------------------------\n";
129 }
130 else
131 {
132 std::cout << "-------------------------\n";
133 std::cout << "Generated:\n" << generated << "\n";
134 std::cout << "-------------------------\n";
135 }
136 }
137 else
138 {
139 std::cout << "-------------------------\n";
140 std::cout << "Parsing failed\n";
141 std::cout << "-------------------------\n";
142 }
143 }
144
145 std::cout << "Bye... :-) \n\n";
146 return 0;
147}
148
149
150

source code of boost/libs/spirit/example/karma/num_list3.cpp