boost/spirit/home/classic/dynamic/select.hpp
/*=============================================================================
Copyright (c) 2003 Hartmut Kaiser
http://spirit.sourceforge.net/
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)
=============================================================================*/
#ifndef BOOST_SPIRIT_SELECT_HPP
#define BOOST_SPIRIT_SELECT_HPP
#include <boost/preprocessor/repeat.hpp>
#include <boost/preprocessor/enum.hpp>
#include <boost/preprocessor/enum_params.hpp>
#include <boost/preprocessor/enum_params_with_defaults.hpp>
#include <boost/preprocessor/inc.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/facilities/intercept.hpp>
#include <boost/spirit/home/classic/namespace.hpp>
#include <boost/spirit/home/classic/core/parser.hpp>
#include <boost/spirit/home/classic/phoenix/tuples.hpp>
///////////////////////////////////////////////////////////////////////////////
//
// Spirit predefined maximum number of possible embedded select_p parsers.
// It should NOT be greater than PHOENIX_LIMIT!
//
///////////////////////////////////////////////////////////////////////////////
#if !defined(BOOST_SPIRIT_SELECT_LIMIT)
#define BOOST_SPIRIT_SELECT_LIMIT PHOENIX_LIMIT
#endif // !defined(BOOST_SPIRIT_SELECT_LIMIT)
///////////////////////////////////////////////////////////////////////////////
//
// ensure BOOST_SPIRIT_SELECT_LIMIT <= PHOENIX_LIMIT and
// BOOST_SPIRIT_SELECT_LIMIT > 0
// BOOST_SPIRIT_SELECT_LIMIT <= 15
//
// [Pushed this down a little to make CW happy with BOOST_STATIC_ASSERT]
// [Otherwise, it complains: 'boost_static_assert_test_42' redefined]
//
///////////////////////////////////////////////////////////////////////////////
BOOST_STATIC_ASSERT(BOOST_SPIRIT_SELECT_LIMIT <= PHOENIX_LIMIT);
BOOST_STATIC_ASSERT(BOOST_SPIRIT_SELECT_LIMIT > 0);
BOOST_STATIC_ASSERT(BOOST_SPIRIT_SELECT_LIMIT <= 15);
///////////////////////////////////////////////////////////////////////////////
//
// Calculate the required amount of tuple members rounded up to the nearest
// integer dividable by 3
//
///////////////////////////////////////////////////////////////////////////////
#if BOOST_SPIRIT_SELECT_LIMIT > 12
#define BOOST_SPIRIT_SELECT_LIMIT_A 15
#elif BOOST_SPIRIT_SELECT_LIMIT > 9
#define BOOST_SPIRIT_SELECT_LIMIT_A 12
#elif BOOST_SPIRIT_SELECT_LIMIT > 6
#define BOOST_SPIRIT_SELECT_LIMIT_A 9
#elif BOOST_SPIRIT_SELECT_LIMIT > 3
#define BOOST_SPIRIT_SELECT_LIMIT_A 6
#else
#define BOOST_SPIRIT_SELECT_LIMIT_A 3
#endif
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit {
BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
///////////////////////////////////////////////////////////////////////////////
//
// The select_default_no_fail and select_default_fail structs are used to
// distinguish two different behaviours for the select_parser in case that not
// any of the given sub-parsers match.
//
// If the select_parser is used with the select_default_no_fail behaviour,
// then in case of no matching sub-parser the whole select_parser returns an
// empty match and the value -1.
//
// If the select_parser is used with the select_default_fail behaviour, then
// in case of no matching sub-parser the whole select_parser fails to match at
// all.
//
///////////////////////////////////////////////////////////////////////////////
struct select_default_no_fail {};
struct select_default_fail {};
BOOST_SPIRIT_CLASSIC_NAMESPACE_END
}} // namespace BOOST_SPIRIT_CLASSIC_NS
///////////////////////////////////////////////////////////////////////////////
#include <boost/spirit/home/classic/dynamic/impl/select.ipp>
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit {
BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
///////////////////////////////////////////////////////////////////////////////
template <typename TupleT, typename BehaviourT, typename T>
struct select_parser
: public parser<select_parser<TupleT, BehaviourT, T> >
{
typedef select_parser<TupleT, BehaviourT, T> self_t;
select_parser(TupleT const &t_)
: t(t_)
{}
template <typename ScannerT>
struct result
{
typedef typename match_result<ScannerT, T>::type type;
};
template <typename ScannerT>
typename parser_result<self_t, ScannerT>::type
parse(ScannerT const& scan) const
{
typedef typename parser_result<self_t, ScannerT>::type result_t;
if (!scan.at_end()) {
return impl::parse_tuple_element<
TupleT::length, result_t, TupleT, BehaviourT>::do_(t, scan);
}
return impl::select_match_gen<result_t, BehaviourT>::do_(scan);
}
TupleT const t;
};
///////////////////////////////////////////////////////////////////////////////
template <typename BehaviourT, typename T = int>
struct select_parser_gen {
///////////////////////////////////////////////////////////////////////////
//
// This generates different select_parser_gen::operator()() functions with
// an increasing number of parser parameters:
//
// template <typename ParserT0, ...>
// select_parser<
// ::phoenix::tuple<
// typename impl::as_embedded_parser<ParserT0>::type,
// ...
// >,
// BehaviourT,
// T
// >
// operator()(ParserT0 const &p0, ...) const
// {
// typedef impl::as_embedded_parser<ParserT0> parser_t0;
// ...
//
// typedef ::phoenix::tuple<
// parser_t0::type,
// ...
// > tuple_t;
// typedef select_parser<tuple_t, BehaviourT, T> result_t;
//
// return result_t(tuple_t(
// parser_t0::convert(p0),
// ...
// ));
// }
//
// The number of generated functions depends on the maximum tuple member
// limit defined by the PHOENIX_LIMIT pp constant.
//
///////////////////////////////////////////////////////////////////////////
#define BOOST_SPIRIT_SELECT_EMBEDDED(z, N, _) \
typename impl::as_embedded_parser<BOOST_PP_CAT(ParserT, N)>::type \
/**/
#define BOOST_SPIRIT_SELECT_EMBEDDED_TYPEDEF(z, N, _) \
typedef impl::as_embedded_parser<BOOST_PP_CAT(ParserT, N)> \
BOOST_PP_CAT(parser_t, N); \
/**/
#define BOOST_SPIRIT_SELECT_CONVERT(z, N, _) \
BOOST_PP_CAT(parser_t, N)::convert(BOOST_PP_CAT(p, N)) \
/**/
#define BOOST_SPIRIT_SELECT_PARSER(z, N, _) \
template < \
BOOST_PP_ENUM_PARAMS_Z(z, BOOST_PP_INC(N), typename ParserT) \
> \
select_parser< \
::phoenix::tuple< \
BOOST_PP_ENUM_ ## z(BOOST_PP_INC(N), \
BOOST_SPIRIT_SELECT_EMBEDDED, _) \
>, \
BehaviourT, \
T \
> \
operator()( \
BOOST_PP_ENUM_BINARY_PARAMS_Z(z, BOOST_PP_INC(N), \
ParserT, const &p) \
) const \
{ \
BOOST_PP_REPEAT_ ## z(BOOST_PP_INC(N), \
BOOST_SPIRIT_SELECT_EMBEDDED_TYPEDEF, _) \
\
typedef ::phoenix::tuple< \
BOOST_PP_ENUM_BINARY_PARAMS_Z(z, BOOST_PP_INC(N), \
typename parser_t, ::type BOOST_PP_INTERCEPT) \
> tuple_t; \
typedef select_parser<tuple_t, BehaviourT, T> result_t; \
\
return result_t(tuple_t( \
BOOST_PP_ENUM_ ## z(BOOST_PP_INC(N), \
BOOST_SPIRIT_SELECT_CONVERT, _) \
)); \
} \
/**/
BOOST_PP_REPEAT(BOOST_SPIRIT_SELECT_LIMIT_A,
BOOST_SPIRIT_SELECT_PARSER, _)
#undef BOOST_SPIRIT_SELECT_PARSER
#undef BOOST_SPIRIT_SELECT_CONVERT
#undef BOOST_SPIRIT_SELECT_EMBEDDED_TYPEDEF
#undef BOOST_SPIRIT_SELECT_EMBEDDED
///////////////////////////////////////////////////////////////////////////
};
///////////////////////////////////////////////////////////////////////////////
//
// Predefined parser generator helper objects
//
///////////////////////////////////////////////////////////////////////////////
select_parser_gen<select_default_no_fail> const select_p =
select_parser_gen<select_default_no_fail>();
select_parser_gen<select_default_fail> const select_fail_p =
select_parser_gen<select_default_fail>();
#undef BOOST_SPIRIT_SELECT_LIMIT_A
///////////////////////////////////////////////////////////////////////////////
BOOST_SPIRIT_CLASSIC_NAMESPACE_END
}} // namespace BOOST_SPIRIT_CLASSIC_NS
#endif // BOOST_SPIRIT_SELECT_HPP
