1// Copyright (c) 2001-2010 Hartmut Kaiser
2// Copyright (c) 2001-2010 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 complex number micro generator - take 3.
10//
11// Look'ma, still no semantic actions! And no explicit access to member
12// functions any more.
13//
14// [ HK April 6, 2010 ] spirit2
15//
16///////////////////////////////////////////////////////////////////////////////
17
18#include <boost/spirit/include/qi.hpp>
19#include <boost/spirit/include/karma.hpp>
20#include <boost/phoenix/core.hpp>
21#include <boost/phoenix/operator.hpp>
22#include <boost/fusion/include/std_pair.hpp>
23#include <boost/fusion/include/adapt_adt.hpp>
24#include <boost/spirit/include/support_adapt_adt_attributes.hpp>
25
26#include <iostream>
27#include <string>
28#include <complex>
29
30///////////////////////////////////////////////////////////////////////////////
31// The following macro adapts the type std::complex<double> as a fusion
32// sequence.
33//[tutorial_karma_complex_number_adapt_class
34// We can leave off the setters as Karma does not need them.
35BOOST_FUSION_ADAPT_ADT(
36 std::complex<double>,
37 (bool, bool, obj.imag() != 0, /**/)
38 (double, double, obj.real(), /**/)
39 (double, double, obj.imag(), /**/)
40)
41//]
42
43namespace client
44{
45 ///////////////////////////////////////////////////////////////////////////
46 // Our complex number parser/compiler (that's just a copy of the complex
47 // number example from Qi (see examples/qi/complex_number.cpp)
48 ///////////////////////////////////////////////////////////////////////////
49 template <typename Iterator>
50 bool parse_complex(Iterator first, Iterator last, std::complex<double>& c)
51 {
52 using boost::spirit::qi::double_;
53 using boost::spirit::qi::_1;
54 using boost::spirit::qi::phrase_parse;
55 using boost::spirit::ascii::space;
56 using boost::phoenix::ref;
57
58 double rN = 0.0;
59 double iN = 0.0;
60 bool r = phrase_parse(first, last,
61 (
62 '(' >> double_[ref(rN) = _1]
63 >> -(',' >> double_[ref(iN) = _1]) >> ')'
64 | double_[ref(rN) = _1]
65 ),
66 space);
67
68 if (!r || first != last) // fail if we did not get a full match
69 return false;
70 c = std::complex<double>(rN, iN);
71 return r;
72 }
73
74 ///////////////////////////////////////////////////////////////////////////
75 // Our complex number generator
76 ///////////////////////////////////////////////////////////////////////////
77 //[tutorial_karma_complex_number_adapt
78 template <typename OutputIterator>
79 bool generate_complex(OutputIterator sink, std::complex<double> const& c)
80 {
81 using boost::spirit::karma::double_;
82 using boost::spirit::karma::bool_;
83 using boost::spirit::karma::true_;
84 using boost::spirit::karma::omit;
85 using boost::spirit::karma::generate;
86
87 return generate(sink,
88
89 // Begin grammar
90 (
91 &true_ << '(' << double_ << ", " << double_ << ')'
92 | omit[bool_] << double_ << omit[double_]
93 ),
94 // End grammar
95
96 c // Data to output
97 );
98 }
99 //]
100}
101
102///////////////////////////////////////////////////////////////////////////////
103// Main program
104///////////////////////////////////////////////////////////////////////////////
105int main()
106{
107 std::cout << "/////////////////////////////////////////////////////////\n\n";
108 std::cout << "\t\tA complex number micro generator for Spirit...\n\n";
109 std::cout << "/////////////////////////////////////////////////////////\n\n";
110
111 std::cout << "Give me a complex number of the form r or (r) or (r,i) \n";
112 std::cout << "Type [q or Q] to quit\n\n";
113
114 std::string str;
115 while (getline(is&: std::cin, str&: str))
116 {
117 if (str.empty() || str[0] == 'q' || str[0] == 'Q')
118 break;
119
120 std::complex<double> c;
121 if (client::parse_complex(first: str.begin(), last: str.end(), c))
122 {
123 std::cout << "-------------------------\n";
124
125 std::string generated;
126 std::back_insert_iterator<std::string> sink(generated);
127 if (!client::generate_complex(sink, c))
128 {
129 std::cout << "-------------------------\n";
130 std::cout << "Generating failed\n";
131 std::cout << "-------------------------\n";
132 }
133 else
134 {
135 std::cout << "-------------------------\n";
136 std::cout << "Generated: " << generated << "\n";
137 std::cout << "-------------------------\n";
138 }
139 }
140 else
141 {
142 std::cout << "-------------------------\n";
143 std::cout << "Parsing failed\n";
144 std::cout << "-------------------------\n";
145 }
146 }
147
148 std::cout << "Bye... :-) \n\n";
149 return 0;
150}
151
152
153

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