1// Copyright (c) 2001-2011 Hartmut Kaiser
2// Copyright (c) 2001-2011 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#ifndef BOOST_SPIRIT_KARMA_OPERATOR_SEQUENCE_HPP
8#define BOOST_SPIRIT_KARMA_OPERATOR_SEQUENCE_HPP
9
10#if defined(_MSC_VER)
11#pragma once
12#endif
13
14#include <boost/spirit/home/karma/domain.hpp>
15#include <boost/spirit/home/karma/generator.hpp>
16#include <boost/spirit/home/karma/meta_compiler.hpp>
17#include <boost/spirit/home/karma/detail/fail_function.hpp>
18#include <boost/spirit/home/karma/detail/pass_container.hpp>
19#include <boost/spirit/home/karma/detail/get_stricttag.hpp>
20#include <boost/spirit/home/support/info.hpp>
21#include <boost/spirit/home/support/detail/what_function.hpp>
22#include <boost/spirit/home/karma/detail/attributes.hpp>
23#include <boost/spirit/home/karma/detail/indirect_iterator.hpp>
24#include <boost/spirit/home/support/algorithm/any_if.hpp>
25#include <boost/spirit/home/support/unused.hpp>
26#include <boost/spirit/home/support/sequence_base_id.hpp>
27#include <boost/spirit/home/support/has_semantic_action.hpp>
28#include <boost/spirit/home/support/handles_container.hpp>
29#include <boost/spirit/home/support/attributes.hpp>
30#include <boost/fusion/include/vector.hpp>
31#include <boost/fusion/include/as_vector.hpp>
32#include <boost/fusion/include/for_each.hpp>
33#include <boost/type_traits/is_same.hpp>
34#include <boost/mpl/bitor.hpp>
35#include <boost/mpl/int.hpp>
36#include <boost/mpl/and.hpp>
37#include <boost/mpl/not.hpp>
38#include <boost/fusion/include/transform.hpp>
39#include <boost/mpl/accumulate.hpp>
40#include <boost/proto/operators.hpp>
41#include <boost/proto/tags.hpp>
42#include <boost/config.hpp>
43
44///////////////////////////////////////////////////////////////////////////////
45namespace boost { namespace spirit
46{
47 ///////////////////////////////////////////////////////////////////////////
48 // Enablers
49 ///////////////////////////////////////////////////////////////////////////
50 template <>
51 struct use_operator<karma::domain, proto::tag::shift_left> // enables <<
52 : mpl::true_ {};
53
54 template <>
55 struct flatten_tree<karma::domain, proto::tag::shift_left> // flattens <<
56 : mpl::true_ {};
57}}
58
59///////////////////////////////////////////////////////////////////////////////
60namespace boost { namespace spirit { namespace traits
61{
62 // specialization for sequences
63 template <typename Elements>
64 struct sequence_properties
65 {
66 struct element_properties
67 {
68 template <typename T>
69 struct result;
70
71 template <typename F, typename Element>
72 struct result<F(Element)>
73 {
74 typedef properties_of<Element> type;
75 };
76
77 // never called, but needed for decltype-based result_of (C++0x)
78#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
79 template <typename Element>
80 typename result<element_properties(Element)>::type
81 operator()(Element&&) const;
82#endif
83 };
84
85 typedef typename mpl::accumulate<
86 typename fusion::result_of::transform<
87 Elements, element_properties>::type
88 , mpl::int_<karma::generator_properties::no_properties>
89 , mpl::bitor_<mpl::_2, mpl::_1>
90 >::type type;
91 };
92}}}
93
94///////////////////////////////////////////////////////////////////////////////
95namespace boost { namespace spirit { namespace karma
96{
97 template <typename Elements, typename Strict, typename Derived>
98 struct base_sequence : nary_generator<Derived>
99 {
100 typedef typename traits::sequence_properties<Elements>::type properties;
101
102 base_sequence(Elements const& elements)
103 : elements(elements) {}
104
105 typedef Elements elements_type;
106 struct sequence_base_id;
107
108 template <typename Context, typename Iterator = unused_type>
109 struct attribute
110 {
111 // Put all the element attributes in a tuple
112 typedef typename traits::build_attribute_sequence<
113 Elements, Context, traits::sequence_attribute_transform
114 , Iterator, karma::domain
115 >::type all_attributes;
116
117 // Now, build a fusion vector over the attributes. Note
118 // that build_fusion_vector 1) removes all unused attributes
119 // and 2) may return unused_type if all elements have
120 // unused_type(s).
121 typedef typename
122 traits::build_fusion_vector<all_attributes>::type
123 type_;
124
125 // Finally, strip single element vectors into its
126 // naked form: vector1<T> --> T
127 typedef typename
128 traits::strip_single_element_vector<type_>::type
129 type;
130 };
131
132 // standard case. Attribute is a fusion tuple
133 template <
134 typename OutputIterator, typename Context, typename Delimiter
135 , typename Attribute, typename Pred1, typename Pred2>
136 bool generate_impl(OutputIterator& sink, Context& ctx
137 , Delimiter const& d, Attribute& attr_, Pred1, Pred2) const
138 {
139 typedef detail::fail_function<
140 OutputIterator, Context, Delimiter> fail_function;
141 typedef traits::attribute_not_unused<Context> predicate;
142
143 // wrap the attribute in a tuple if it is not a tuple or if the
144 // attribute of this sequence is a single element tuple
145 typedef typename attribute<Context>::type_ attr_type_;
146 typename traits::wrap_if_not_tuple<Attribute
147 , typename mpl::and_<
148 traits::one_element_sequence<attr_type_>
149 , mpl::not_<traits::one_element_sequence<Attribute> >
150 >::type
151 >::type attr(attr_);
152
153 // return false if *any* of the generators fail
154 bool r = spirit::any_if(elements, attr
155 , fail_function(sink, ctx, d), predicate());
156
157 typedef typename traits::attribute_size<Attribute>::type size_type;
158
159 // fail generating if sequences have not the same (logical) length
160 return !r && (!Strict::value ||
161 // This ignores container element count (which is not good),
162 // but allows valid attributes to succeed. This will lead to
163 // false positives (failing generators, even if they shouldn't)
164 // if the embedded component is restricting the number of
165 // container elements it consumes (i.e. repeat). This solution
166 // is not optimal but much better than letting _all_ repetitive
167 // components fail.
168 Pred1::value ||
169 size_type(traits::sequence_size<attr_type_>::value) == traits::size(attr_));
170 }
171
172 // Special case when Attribute is an stl container and the sequence's
173 // attribute is not a one element sequence
174 template <
175 typename OutputIterator, typename Context, typename Delimiter
176 , typename Attribute>
177 bool generate_impl(OutputIterator& sink, Context& ctx
178 , Delimiter const& d, Attribute const& attr_
179 , mpl::true_, mpl::false_) const
180 {
181 // return false if *any* of the generators fail
182 typedef detail::fail_function<
183 OutputIterator, Context, Delimiter> fail_function;
184
185 typedef typename traits::container_iterator<
186 typename add_const<Attribute>::type
187 >::type iterator_type;
188
189 typedef
190 typename traits::make_indirect_iterator<iterator_type>::type
191 indirect_iterator_type;
192 typedef detail::pass_container<
193 fail_function, Attribute, indirect_iterator_type, mpl::true_>
194 pass_container;
195
196 iterator_type begin = traits::begin(attr_);
197 iterator_type end = traits::end(attr_);
198
199 pass_container pass(fail_function(sink, ctx, d),
200 indirect_iterator_type(begin), indirect_iterator_type(end));
201 bool r = fusion::any(elements, pass);
202
203 // fail generating if sequences have not the same (logical) length
204 return !r && (!Strict::value || begin == end);
205 }
206
207 // main generate function. Dispatches to generate_impl depending
208 // on the Attribute type.
209 template <
210 typename OutputIterator, typename Context, typename Delimiter
211 , typename Attribute>
212 bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d
213 , Attribute const& attr) const
214 {
215 typedef typename traits::is_container<Attribute>::type
216 is_container;
217
218 typedef typename attribute<Context>::type_ attr_type_;
219 typedef typename traits::one_element_sequence<attr_type_>::type
220 is_one_element_sequence;
221
222 return generate_impl(sink, ctx, d, attr, is_container()
223 , is_one_element_sequence());
224 }
225
226 template <typename Context>
227 info what(Context& context) const
228 {
229 info result("sequence");
230 fusion::for_each(elements,
231 spirit::detail::what_function<Context>(result, context));
232 return result;
233 }
234
235 Elements elements;
236 };
237
238 template <typename Elements>
239 struct sequence
240 : base_sequence<Elements, mpl::false_, sequence<Elements> >
241 {
242 typedef base_sequence<Elements, mpl::false_, sequence> base_sequence_;
243
244 sequence(Elements const& subject)
245 : base_sequence_(subject) {}
246 };
247
248 template <typename Elements>
249 struct strict_sequence
250 : base_sequence<Elements, mpl::true_, strict_sequence<Elements> >
251 {
252 typedef base_sequence<Elements, mpl::true_, strict_sequence>
253 base_sequence_;
254
255 strict_sequence(Elements const& subject)
256 : base_sequence_(subject) {}
257 };
258
259 ///////////////////////////////////////////////////////////////////////////
260 // Generator generators: make_xxx function (objects)
261 ///////////////////////////////////////////////////////////////////////////
262 namespace detail
263 {
264 template <typename Elements, bool strict_mode = false>
265 struct make_sequence
266 : make_nary_composite<Elements, sequence>
267 {};
268
269 template <typename Elements>
270 struct make_sequence<Elements, true>
271 : make_nary_composite<Elements, strict_sequence>
272 {};
273 }
274
275 template <typename Elements, typename Modifiers>
276 struct make_composite<proto::tag::shift_left, Elements, Modifiers>
277 : detail::make_sequence<Elements, detail::get_stricttag<Modifiers>::value>
278 {};
279
280 ///////////////////////////////////////////////////////////////////////////
281 // Helper template allowing to get the required container type for a rule
282 // attribute, which is part of a sequence.
283 template <typename Iterator>
284 struct make_sequence_iterator_range
285 {
286 typedef iterator_range<detail::indirect_iterator<Iterator> > type;
287 };
288}}}
289
290namespace boost { namespace spirit { namespace traits
291{
292 ///////////////////////////////////////////////////////////////////////////
293 template <typename Elements>
294 struct has_semantic_action<karma::sequence<Elements> >
295 : nary_has_semantic_action<Elements> {};
296
297 template <typename Elements>
298 struct has_semantic_action<karma::strict_sequence<Elements> >
299 : nary_has_semantic_action<Elements> {};
300
301 ///////////////////////////////////////////////////////////////////////////
302 template <typename Elements, typename Attribute, typename Context
303 , typename Iterator>
304 struct handles_container<karma::sequence<Elements>, Attribute, Context
305 , Iterator>
306 : mpl::true_ {};
307
308 template <typename Elements, typename Attribute, typename Context
309 , typename Iterator>
310 struct handles_container<karma::strict_sequence<Elements>, Attribute
311 , Context, Iterator>
312 : mpl::true_ {};
313}}}
314
315#endif
316

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