1/*=============================================================================
2 Copyright (c) 2009 Hartmut Kaiser
3 Copyright (c) 2014 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#ifndef BOOST_SPIRIT_X3_NUMERIC_BOOL_HPP
9#define BOOST_SPIRIT_X3_NUMERIC_BOOL_HPP
10
11#include <boost/spirit/home/x3/core/parser.hpp>
12#include <boost/spirit/home/x3/core/skip_over.hpp>
13#include <boost/spirit/home/x3/numeric/bool_policies.hpp>
14
15namespace boost { namespace spirit { namespace x3
16{
17 template <typename T, typename Encoding, typename BoolPolicies = bool_policies<T>>
18 struct bool_parser : parser<bool_parser<T, Encoding, BoolPolicies>>
19 {
20 typedef Encoding encoding;
21 typedef T attribute_type;
22 static bool const has_attribute = true;
23
24 constexpr bool_parser()
25 : policies() {}
26
27 constexpr bool_parser(BoolPolicies const& policies)
28 : policies(policies) {}
29
30 template <typename Iterator, typename Context>
31 bool parse(Iterator& first, Iterator const& last
32 , Context const& context, unused_type, T& attr) const
33 {
34 x3::skip_over(first, last, context);
35 return policies.parse_true(first, last, attr, get_case_compare<encoding>(context))
36 || policies.parse_false(first, last, attr, get_case_compare<encoding>(context));
37 }
38
39 template <typename Iterator, typename Context, typename Attribute>
40 bool parse(Iterator& first, Iterator const& last
41 , Context const& context, unused_type, Attribute& attr_param) const
42 {
43 // this case is called when Attribute is not T
44 T attr_;
45 if (parse(first, last, context, unused, attr_))
46 {
47 traits::move_to(attr_, attr_param);
48 return true;
49 }
50 return false;
51 }
52
53 BoolPolicies policies;
54 };
55
56 template <typename T, typename Encoding, typename BoolPolicies = bool_policies<T>>
57 struct literal_bool_parser : parser<bool_parser<T, Encoding, BoolPolicies>>
58 {
59 typedef Encoding encoding;
60 typedef T attribute_type;
61 static bool const has_attribute = true;
62
63 template <typename Value>
64 constexpr literal_bool_parser(Value const& n)
65 : policies(), n_(n) {}
66
67 template <typename Value>
68 constexpr literal_bool_parser(Value const& n, BoolPolicies const& policies)
69 : policies(policies), n_(n) {}
70
71 template <typename Iterator, typename Context>
72 bool parse_main(Iterator& first, Iterator const& last
73 , Context const& context, T& attr) const
74 {
75 x3::skip_over(first, last, context);
76 return (n_ && policies.parse_true(first, last, attr, get_case_compare<encoding>(context)))
77 || (!n_ && policies.parse_false(first, last, attr, get_case_compare<encoding>(context)));
78 }
79
80 template <typename Iterator, typename Context>
81 bool parse(Iterator& first, Iterator const& last
82 , Context const& context, unused_type, T& attr) const
83 {
84 return parse_main(first, last, context, attr);
85 }
86
87 template <typename Iterator, typename Context, typename Attribute>
88 bool parse(Iterator& first, Iterator const& last
89 , Context const& context, unused_type, Attribute& attr_param) const
90 {
91 // this case is called when Attribute is not T
92 T attr_;
93 if (parse_main(first, last, context, attr_))
94 {
95 traits::move_to(attr_, attr_param);
96 return true;
97 }
98 return false;
99 }
100
101 BoolPolicies policies;
102 T n_;
103 };
104
105 namespace standard
106 {
107 typedef bool_parser<bool, char_encoding::standard> bool_type;
108 constexpr bool_type bool_ = {};
109
110 typedef literal_bool_parser<bool, char_encoding::standard> true_type;
111 constexpr true_type true_ = { true };
112
113 typedef literal_bool_parser<bool, char_encoding::standard> false_type;
114 constexpr false_type false_ = { false };
115 }
116
117#ifndef BOOST_SPIRIT_NO_STANDARD_WIDE
118 namespace standard_wide
119 {
120 typedef bool_parser<bool, char_encoding::standard_wide> bool_type;
121 constexpr bool_type bool_ = {};
122
123 typedef literal_bool_parser<bool, char_encoding::standard_wide> true_type;
124 constexpr true_type true_ = { true };
125
126 typedef literal_bool_parser<bool, char_encoding::standard_wide> false_type;
127 constexpr false_type false_ = { false };
128 }
129#endif
130
131 namespace ascii
132 {
133 typedef bool_parser<bool, char_encoding::ascii> bool_type;
134 constexpr bool_type bool_ = {};
135
136 typedef literal_bool_parser<bool, char_encoding::ascii> true_type;
137 constexpr true_type true_ = { true };
138
139 typedef literal_bool_parser<bool, char_encoding::ascii> false_type;
140 constexpr false_type false_ = { false };
141 }
142
143 namespace iso8859_1
144 {
145 typedef bool_parser<bool, char_encoding::iso8859_1> bool_type;
146 constexpr bool_type bool_ = {};
147
148 typedef literal_bool_parser<bool, char_encoding::iso8859_1> true_type;
149 constexpr true_type true_ = { true };
150
151 typedef literal_bool_parser<bool, char_encoding::iso8859_1> false_type;
152 constexpr false_type false_ = { false };
153 }
154
155 using standard::bool_;
156 using standard::true_;
157 using standard::false_;
158
159 }}}
160
161#endif
162

source code of boost/libs/spirit/include/boost/spirit/home/x3/numeric/bool.hpp