1// Copyright (c) 2001-2011 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#if !defined(BOOST_SPIRIT_KARMA_AUTO_NOV_29_2009_0339PM)
7#define BOOST_SPIRIT_KARMA_AUTO_NOV_29_2009_0339PM
8
9#if defined(_MSC_VER)
10#pragma once
11#endif
12
13#include <boost/spirit/home/support/common_terminals.hpp>
14#include <boost/spirit/home/support/info.hpp>
15#include <boost/spirit/home/support/container.hpp>
16#include <boost/spirit/home/support/assert_msg.hpp>
17#include <boost/spirit/home/support/detail/hold_any.hpp>
18#include <boost/spirit/home/karma/domain.hpp>
19#include <boost/spirit/home/karma/meta_compiler.hpp>
20#include <boost/spirit/home/karma/delimit_out.hpp>
21#include <boost/spirit/home/karma/generator.hpp>
22#include <boost/spirit/home/karma/auto/create_generator.hpp>
23#include <boost/mpl/bool.hpp>
24
25///////////////////////////////////////////////////////////////////////////////
26namespace boost { namespace spirit
27{
28 ///////////////////////////////////////////////////////////////////////////
29 // Enablers
30 ///////////////////////////////////////////////////////////////////////////
31 template <>
32 struct use_terminal<karma::domain, tag::auto_> // enables auto_
33 : mpl::true_ {};
34
35 template <typename A0>
36 struct use_terminal<karma::domain // enables auto_(...)
37 , terminal_ex<tag::auto_, fusion::vector1<A0> >
38 > : mpl::true_ {};
39
40 template <> // enables auto_(f)
41 struct use_lazy_terminal<
42 karma::domain, tag::auto_, 1 /*arity*/
43 > : mpl::true_ {};
44
45}}
46
47///////////////////////////////////////////////////////////////////////////////
48namespace boost { namespace spirit { namespace karma
49{
50#ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
51 using spirit::auto_;
52#endif
53 using spirit::auto_type;
54
55 ///////////////////////////////////////////////////////////////////////////
56 template <typename Modifiers>
57 struct auto_generator
58 : generator<auto_generator<Modifiers> >
59 {
60 typedef mpl::int_<generator_properties::all_properties> properties;
61
62 template <typename Context, typename Unused>
63 struct attribute
64 {
65 typedef spirit::basic_hold_any<char> type;
66 };
67
68 auto_generator(Modifiers const& modifiers)
69 : modifiers_(modifiers) {}
70
71 // auto_generator has an attached attribute
72 template <
73 typename OutputIterator, typename Context, typename Delimiter
74 , typename Attribute>
75 bool generate(OutputIterator& sink, Context& context
76 , Delimiter const& d, Attribute const& attr) const
77 {
78 return compile<karma::domain>(create_generator<Attribute>(), modifiers_)
79 .generate(sink, context, d, attr);
80 }
81
82 // this auto_generator has no attribute attached, it needs to have been
83 // initialized from a value/variable
84 template <typename OutputIterator, typename Context
85 , typename Delimiter>
86 static bool
87 generate(OutputIterator&, Context&, Delimiter const&, unused_type)
88 {
89 // It is not possible (doesn't make sense) to use auto_ generators
90 // without providing any attribute, as the generator doesn't 'know'
91 // what to output. The following assertion fires if this situation
92 // is detected in your code.
93 BOOST_SPIRIT_ASSERT_FAIL(OutputIterator, auto_not_usable_without_attribute, ());
94 return false;
95 }
96
97 template <typename Context>
98 info what(Context& /*context*/) const
99 {
100 return info("auto_");
101 }
102
103 Modifiers modifiers_;
104 };
105
106 ///////////////////////////////////////////////////////////////////////////
107 template <typename T, typename Modifiers>
108 struct lit_auto_generator
109 : generator<lit_auto_generator<T, Modifiers> >
110 {
111 typedef mpl::int_<generator_properties::all_properties> properties;
112
113 template <typename Context, typename Unused>
114 struct attribute
115 {
116 typedef unused_type type;
117 };
118
119 lit_auto_generator(typename add_reference<T>::type t, Modifiers const& modifiers)
120 : t_(t)
121 , generator_(compile<karma::domain>(create_generator<T>(), modifiers))
122 {}
123
124 // auto_generator has an attached attribute
125 template <
126 typename OutputIterator, typename Context, typename Delimiter
127 , typename Attribute>
128 bool generate(OutputIterator& sink, Context& context
129 , Delimiter const& d, Attribute const&) const
130 {
131 return generator_.generate(sink, context, d, t_);
132 }
133
134 template <typename Context>
135 info what(Context& /*context*/) const
136 {
137 return info("auto_");
138 }
139
140 typedef typename spirit::result_of::create_generator<T>::type
141 generator_type;
142
143 typedef typename spirit::result_of::compile<
144 karma::domain, generator_type, Modifiers>::type generator_impl_type;
145
146 T t_;
147 generator_impl_type generator_;
148 };
149
150 ///////////////////////////////////////////////////////////////////////////
151 // Generator generators: make_xxx function (objects)
152 ///////////////////////////////////////////////////////////////////////////
153
154 // auto_
155 template <typename Modifiers>
156 struct make_primitive<tag::auto_, Modifiers>
157 {
158 typedef auto_generator<Modifiers> result_type;
159
160 result_type operator()(unused_type, Modifiers const& modifiers) const
161 {
162 return result_type(modifiers);
163 }
164 };
165
166 // auto_(...)
167 template <typename Modifiers, typename A0>
168 struct make_primitive<
169 terminal_ex<tag::auto_, fusion::vector1<A0> >, Modifiers>
170 {
171 typedef typename add_const<A0>::type const_attribute;
172
173 typedef lit_auto_generator<const_attribute, Modifiers> result_type;
174
175 template <typename Terminal>
176 result_type operator()(Terminal const& term, Modifiers const& modifiers) const
177 {
178 return result_type(fusion::at_c<0>(term.args), modifiers);
179 }
180 };
181
182}}}
183
184#endif
185

source code of boost/libs/spirit/include/boost/spirit/home/karma/auto/auto.hpp