summaryrefslogtreecommitdiff
path: root/boost/spirit/home/x3/core/detail/parse_into_container.hpp
blob: 45ecc41ae0593c8ec5392ec2136e2be76375bcaf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
/*=============================================================================
    Copyright (c) 2001-2014 Joel de Guzman

    Distributed under the Boost Software License, Version 1.0. (See accompanying
    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#if !defined(SPIRIT_PARSE_INTO_CONTAINER_JAN_15_2013_0957PM)
#define SPIRIT_PARSE_INTO_CONTAINER_JAN_15_2013_0957PM

#include <type_traits>

#include <boost/spirit/home/x3/support/traits/container_traits.hpp>
#include <boost/spirit/home/x3/support/traits/value_traits.hpp>
#include <boost/spirit/home/x3/support/traits/attribute_of.hpp>
#include <boost/spirit/home/x3/support/traits/handles_container.hpp>
#include <boost/spirit/home/x3/support/traits/has_attribute.hpp>
#include <boost/spirit/home/x3/support/traits/is_substitute.hpp>
#include <boost/spirit/home/x3/support/traits/move_to.hpp>
#include <boost/mpl/and.hpp>
#include <boost/fusion/include/front.hpp>
#include <boost/fusion/include/back.hpp>
#include <boost/variant/apply_visitor.hpp>

namespace boost { namespace spirit { namespace x3 { namespace detail
{
    template <typename Attribute, typename Value>
    struct saver_visitor;

    // save to associative fusion container where Key is simple type
    template <typename Key, typename Enable = void>
    struct save_to_assoc_attr
    {
        template <typename Value, typename Attribute>
        static void call(const Key, Value& value, Attribute& attr)
        {
            traits::move_to(value, fusion::at_key<Key>(attr));
        }
    };

/*	$$$ clang reports: warning: class template partial specialization contains
 *	a template parameter that can not be deduced; this partial specialization
 *	will never be used $$$
 *
    // save to associative fusion container where Key
    // is variant over possible keys
    template <typename ...T>
    struct save_to_assoc_attr<variant<T...> >
    {
        typedef variant<T...> variant_t;

        template <typename Value, typename Attribute>
        static void call(const variant_t key, Value& value, Attribute& attr)
        {
            apply_visitor(saver_visitor<Attribute, Value>(attr, value), key);
        }
    };
*/
    template <typename Attribute, typename Value>
    struct saver_visitor  : boost::static_visitor<void>
    {
        saver_visitor(Attribute& attr, Value& value)
            : attr(attr), value(value) {};

        Attribute& attr;
        Value& value;

        template <typename Key>
        void operator()(Key) const
        {
            save_to_assoc_attr<Key>::call(Key(), value,attr);
        }
    };

    template <typename Parser, typename Container, typename Context>
    struct parser_accepts_container
        : traits::is_substitute<
                typename traits::attribute_of<Parser, Context>::type
              , Container
            >
    {};

    template <typename Parser>
    struct parse_into_container_base_impl
    {
    private:

        // Parser has attribute (synthesize; Attribute is a container)
        template <typename Iterator, typename Context
          , typename RContext, typename Attribute>
        static bool call_synthesize_x(
            Parser const& parser
          , Iterator& first, Iterator const& last
          , Context const& context, RContext& rcontext, Attribute& attr, mpl::false_)
        {
            // synthesized attribute needs to be value initialized
            typedef typename
                traits::container_value<Attribute>::type
            value_type;
            value_type val = traits::value_initialize<value_type>::call();

            if (!parser.parse(first, last, context, rcontext, val))
                return false;

            // push the parsed value into our attribute
            traits::push_back(attr, val);
            return true;
        }

        // Parser has attribute (synthesize; Attribute is a container)
        template <typename Iterator, typename Context
          , typename RContext, typename Attribute>
        static bool call_synthesize_x(
            Parser const& parser
          , Iterator& first, Iterator const& last
          , Context const& context, RContext& rcontext, Attribute& attr, mpl::true_)
        {
            return parser.parse(first, last, context, rcontext, attr);
        }

        // Parser has attribute (synthesize; Attribute is a container)
        template <typename Iterator, typename Context
          , typename RContext, typename Attribute>
        static bool call_synthesize(
            Parser const& parser
          , Iterator& first, Iterator const& last
          , Context const& context, RContext& rcontext, Attribute& attr)
        {
            typedef
                parser_accepts_container<Parser, Attribute, Context>
            parser_accepts_container;

            return call_synthesize_x(parser, first, last, context, rcontext, attr
                , parser_accepts_container());
        }

        // Parser has attribute (synthesize; Attribute is a single element fusion sequence)
        template <typename Iterator, typename Context
          , typename RContext, typename Attribute>
        static bool call_synthesize_into_fusion_seq(Parser const& parser
          , Iterator& first, Iterator const& last, Context const& context
          , RContext& rcontext, Attribute& attr, mpl::false_ /* is_associative */)
        {
            static_assert(traits::has_size<Attribute, 1>::value,
                "Expecting a single element fusion sequence");
            return call_synthesize(parser, first, last, context, rcontext,
                fusion::front(attr));
        }

        // Parser has attribute (synthesize; Attribute is fusion map sequence)
        template <typename Iterator, typename Context, typename RContext, typename Attribute>
        static bool call_synthesize_into_fusion_seq(
            Parser const& parser
          , Iterator& first, Iterator const& last, Context const& context
          , RContext& rcontext, Attribute& attr, mpl::true_ /*is_associative*/)
        {
            using attribute_type = typename traits::attribute_of<Parser, Context>::type;
            static_assert(traits::has_size<attribute_type, 2>::value,
                "To parse directly into fusion map parser must produce 2 element attr");

            // use type of  first element of attribute as key
            using key = typename std::remove_reference<
            typename fusion::result_of::front<attribute_type>::type>::type;

            attribute_type attr_;
            if (!parser.parse(first, last, context, rcontext, attr_))
                return false;

            save_to_assoc_attr<key>::call(fusion::front(attr_), fusion::back(attr_), attr);
            return true;
        }

        template <typename Iterator, typename Context, typename RContext, typename Attribute>
        static bool call_synthesize_dispatch_by_seq(Parser const& parser
          , Iterator& first, Iterator const& last, Context const& context
          , RContext& rcontext, Attribute& attr, mpl::true_ /*is_sequence*/)
        {
            return call_synthesize_into_fusion_seq(
                parser, first, last, context, rcontext, attr
              , fusion::traits::is_associative<Attribute>());
        }

        template <typename Iterator, typename Context, typename RContext, typename Attribute>
        static bool call_synthesize_dispatch_by_seq(Parser const& parser
          , Iterator& first, Iterator const& last, Context const& context
          , RContext& rcontext, Attribute& attr, mpl::false_ /*is_sequence*/)
        {
            return call_synthesize(parser, first, last, context, rcontext, attr);
        }

        // Parser has attribute (synthesize)
        template <typename Iterator, typename Context, typename RContext, typename Attribute>
        static bool call(Parser const& parser
          , Iterator& first, Iterator const& last, Context const& context
          , RContext& rcontext, Attribute& attr, mpl::true_)
        {
            return call_synthesize_dispatch_by_seq(parser, first, last, context, rcontext, attr
                , fusion::traits::is_sequence<Attribute>());
        }

        // Parser has no attribute (pass unused)
        template <typename Iterator, typename Context, typename RContext, typename Attribute>
        static bool call(
            Parser const& parser
          , Iterator& first, Iterator const& last, Context const& context
          , RContext& rcontext, Attribute& /* attr */, mpl::false_)
        {
            return parser.parse(first, last, context, rcontext, unused);
        }


    public:

        template <typename Iterator, typename Context, typename RContext, typename Attribute>
        static bool call(Parser const& parser
          , Iterator& first, Iterator const& last, Context const& context
          , RContext& rcontext, Attribute& attr)
        {
            return call(parser, first, last, context, rcontext, attr
              , mpl::bool_<traits::has_attribute<Parser, Context>::value>());
        }
    };

    template <typename Parser, typename Context, typename RContext, typename Enable = void>
    struct parse_into_container_impl : parse_into_container_base_impl<Parser> {};

    template <typename Parser, typename Container, typename Context>
    struct parser_attr_is_substitute_for_container_value
        : traits::is_substitute<
            typename traits::attribute_of<Parser, Context>::type
          , typename traits::container_value<Container>::type
        >
    {};

    template <typename Parser, typename Context, typename RContext>
    struct parse_into_container_impl<Parser, Context, RContext,
        typename enable_if<traits::handles_container<Parser, Context>>::type>
    {
        template <typename Iterator, typename Attribute>
        static bool call(
            Parser const& parser
          , Iterator& first, Iterator const& last
          , Context const& context, RContext& rcontext, Attribute& attr, mpl::false_)
        {
            return parse_into_container_base_impl<Parser>::call(
                parser, first, last, context, rcontext, attr);
        }

        template <typename Iterator, typename Attribute>
        static bool call(
            Parser const& parser
          , Iterator& first, Iterator const& last
          , Context const& context, RContext& rcontext, Attribute& attr, mpl::true_)
        {
            if (attr.empty())
                return parser.parse(first, last, context, rcontext, attr);
            Attribute rest;
            bool r = parser.parse(first, last, context, rcontext, rest);
            if (r)
                attr.insert(attr.end(), rest.begin(), rest.end());
            return r;
        }

        template <typename Iterator, typename Attribute>
        static bool call(Parser const& parser
          , Iterator& first, Iterator const& last
          , Context const& context, RContext& rcontext, Attribute& attr)
        {
            typedef parser_accepts_container<
                    Parser, Attribute, Context>
            parser_accepts_container;

            typedef parser_attr_is_substitute_for_container_value<
                    Parser, Attribute, Context>
            parser_attr_is_substitute_for_container_value;

            typedef mpl::or_<
                parser_accepts_container
              , mpl::not_<parser_attr_is_substitute_for_container_value>>
            pass_attibute_as_is;

            return call(parser, first, last, context, rcontext, attr,
                pass_attibute_as_is());
        }
    };

    template <typename Parser, typename Iterator, typename Context
      , typename RContext, typename Attribute>
    bool parse_into_container(
        Parser const& parser
      , Iterator& first, Iterator const& last, Context const& context
      , RContext& rcontext, Attribute& attr)
    {
        return parse_into_container_impl<Parser, Context, RContext>::call(
            parser, first, last, context, rcontext, attr);
    }

}}}}

#endif