1 /*=============================================================================
2 Copyright (c) 2003 Hartmut Kaiser
3 http://spirit.sourceforge.net/
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_SELECT_HPP
9 #define BOOST_SPIRIT_SELECT_HPP
11 #include <boost/preprocessor/repeat.hpp>
12 #include <boost/preprocessor/enum.hpp>
13 #include <boost/preprocessor/enum_params.hpp>
14 #include <boost/preprocessor/enum_params_with_defaults.hpp>
15 #include <boost/preprocessor/inc.hpp>
16 #include <boost/preprocessor/cat.hpp>
17 #include <boost/preprocessor/facilities/intercept.hpp>
19 #include <boost/spirit/home/classic/namespace.hpp>
20 #include <boost/spirit/home/classic/core/parser.hpp>
22 #include <boost/spirit/home/classic/phoenix/tuples.hpp>
24 ///////////////////////////////////////////////////////////////////////////////
26 // Spirit predefined maximum number of possible embedded select_p parsers.
27 // It should NOT be greater than PHOENIX_LIMIT!
29 ///////////////////////////////////////////////////////////////////////////////
30 #if !defined(BOOST_SPIRIT_SELECT_LIMIT)
31 #define BOOST_SPIRIT_SELECT_LIMIT PHOENIX_LIMIT
32 #endif // !defined(BOOST_SPIRIT_SELECT_LIMIT)
34 ///////////////////////////////////////////////////////////////////////////////
36 // ensure BOOST_SPIRIT_SELECT_LIMIT <= PHOENIX_LIMIT and
37 // BOOST_SPIRIT_SELECT_LIMIT > 0
38 // BOOST_SPIRIT_SELECT_LIMIT <= 15
40 // [Pushed this down a little to make CW happy with BOOST_STATIC_ASSERT]
41 // [Otherwise, it complains: 'boost_static_assert_test_42' redefined]
43 ///////////////////////////////////////////////////////////////////////////////
44 BOOST_STATIC_ASSERT(BOOST_SPIRIT_SELECT_LIMIT <= PHOENIX_LIMIT);
45 BOOST_STATIC_ASSERT(BOOST_SPIRIT_SELECT_LIMIT > 0);
46 BOOST_STATIC_ASSERT(BOOST_SPIRIT_SELECT_LIMIT <= 15);
48 ///////////////////////////////////////////////////////////////////////////////
50 // Calculate the required amount of tuple members rounded up to the nearest
51 // integer dividable by 3
53 ///////////////////////////////////////////////////////////////////////////////
54 #if BOOST_SPIRIT_SELECT_LIMIT > 12
55 #define BOOST_SPIRIT_SELECT_LIMIT_A 15
56 #elif BOOST_SPIRIT_SELECT_LIMIT > 9
57 #define BOOST_SPIRIT_SELECT_LIMIT_A 12
58 #elif BOOST_SPIRIT_SELECT_LIMIT > 6
59 #define BOOST_SPIRIT_SELECT_LIMIT_A 9
60 #elif BOOST_SPIRIT_SELECT_LIMIT > 3
61 #define BOOST_SPIRIT_SELECT_LIMIT_A 6
63 #define BOOST_SPIRIT_SELECT_LIMIT_A 3
66 ///////////////////////////////////////////////////////////////////////////////
67 namespace boost { namespace spirit {
69 BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
71 ///////////////////////////////////////////////////////////////////////////////
73 // The select_default_no_fail and select_default_fail structs are used to
74 // distinguish two different behaviours for the select_parser in case that not
75 // any of the given sub-parsers match.
77 // If the select_parser is used with the select_default_no_fail behaviour,
78 // then in case of no matching sub-parser the whole select_parser returns an
79 // empty match and the value -1.
81 // If the select_parser is used with the select_default_fail behaviour, then
82 // in case of no matching sub-parser the whole select_parser fails to match at
85 ///////////////////////////////////////////////////////////////////////////////
86 struct select_default_no_fail {};
87 struct select_default_fail {};
89 BOOST_SPIRIT_CLASSIC_NAMESPACE_END
91 }} // namespace BOOST_SPIRIT_CLASSIC_NS
93 ///////////////////////////////////////////////////////////////////////////////
94 #include <boost/spirit/home/classic/dynamic/impl/select.ipp>
96 ///////////////////////////////////////////////////////////////////////////////
97 namespace boost { namespace spirit {
99 BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
101 ///////////////////////////////////////////////////////////////////////////////
102 template <typename TupleT, typename BehaviourT, typename T>
104 : public parser<select_parser<TupleT, BehaviourT, T> >
106 typedef select_parser<TupleT, BehaviourT, T> self_t;
108 select_parser(TupleT const &t_)
112 template <typename ScannerT>
115 typedef typename match_result<ScannerT, T>::type type;
118 template <typename ScannerT>
119 typename parser_result<self_t, ScannerT>::type
120 parse(ScannerT const& scan) const
122 typedef typename parser_result<self_t, ScannerT>::type result_t;
124 if (!scan.at_end()) {
125 return impl::parse_tuple_element<
126 TupleT::length, result_t, TupleT, BehaviourT>::do_(t, scan);
128 return impl::select_match_gen<result_t, BehaviourT>::do_(scan);
134 ///////////////////////////////////////////////////////////////////////////////
135 template <typename BehaviourT, typename T = int>
136 struct select_parser_gen {
138 ///////////////////////////////////////////////////////////////////////////
140 // This generates different select_parser_gen::operator()() functions with
141 // an increasing number of parser parameters:
143 // template <typename ParserT0, ...>
146 // typename impl::as_embedded_parser<ParserT0>::type,
152 // operator()(ParserT0 const &p0, ...) const
154 // typedef impl::as_embedded_parser<ParserT0> parser_t0;
157 // typedef ::phoenix::tuple<
161 // typedef select_parser<tuple_t, BehaviourT, T> result_t;
163 // return result_t(tuple_t(
164 // parser_t0::convert(p0),
169 // The number of generated functions depends on the maximum tuple member
170 // limit defined by the PHOENIX_LIMIT pp constant.
172 ///////////////////////////////////////////////////////////////////////////
173 #define BOOST_SPIRIT_SELECT_EMBEDDED(z, N, _) \
174 typename impl::as_embedded_parser<BOOST_PP_CAT(ParserT, N)>::type \
176 #define BOOST_SPIRIT_SELECT_EMBEDDED_TYPEDEF(z, N, _) \
177 typedef impl::as_embedded_parser<BOOST_PP_CAT(ParserT, N)> \
178 BOOST_PP_CAT(parser_t, N); \
180 #define BOOST_SPIRIT_SELECT_CONVERT(z, N, _) \
181 BOOST_PP_CAT(parser_t, N)::convert(BOOST_PP_CAT(p, N)) \
184 #define BOOST_SPIRIT_SELECT_PARSER(z, N, _) \
186 BOOST_PP_ENUM_PARAMS_Z(z, BOOST_PP_INC(N), typename ParserT) \
190 BOOST_PP_ENUM_ ## z(BOOST_PP_INC(N), \
191 BOOST_SPIRIT_SELECT_EMBEDDED, _) \
197 BOOST_PP_ENUM_BINARY_PARAMS_Z(z, BOOST_PP_INC(N), \
201 BOOST_PP_REPEAT_ ## z(BOOST_PP_INC(N), \
202 BOOST_SPIRIT_SELECT_EMBEDDED_TYPEDEF, _) \
204 typedef ::phoenix::tuple< \
205 BOOST_PP_ENUM_BINARY_PARAMS_Z(z, BOOST_PP_INC(N), \
206 typename parser_t, ::type BOOST_PP_INTERCEPT) \
208 typedef select_parser<tuple_t, BehaviourT, T> result_t; \
210 return result_t(tuple_t( \
211 BOOST_PP_ENUM_ ## z(BOOST_PP_INC(N), \
212 BOOST_SPIRIT_SELECT_CONVERT, _) \
217 BOOST_PP_REPEAT(BOOST_SPIRIT_SELECT_LIMIT_A,
218 BOOST_SPIRIT_SELECT_PARSER, _)
220 #undef BOOST_SPIRIT_SELECT_PARSER
221 #undef BOOST_SPIRIT_SELECT_CONVERT
222 #undef BOOST_SPIRIT_SELECT_EMBEDDED_TYPEDEF
223 #undef BOOST_SPIRIT_SELECT_EMBEDDED
224 ///////////////////////////////////////////////////////////////////////////
227 ///////////////////////////////////////////////////////////////////////////////
229 // Predefined parser generator helper objects
231 ///////////////////////////////////////////////////////////////////////////////
232 select_parser_gen<select_default_no_fail> const select_p =
233 select_parser_gen<select_default_no_fail>();
235 select_parser_gen<select_default_fail> const select_fail_p =
236 select_parser_gen<select_default_fail>();
238 #undef BOOST_SPIRIT_SELECT_LIMIT_A
240 ///////////////////////////////////////////////////////////////////////////////
241 BOOST_SPIRIT_CLASSIC_NAMESPACE_END
243 }} // namespace BOOST_SPIRIT_CLASSIC_NS
245 #endif // BOOST_SPIRIT_SELECT_HPP