boost/spirit/home/x3/nonterminal/rule.hpp
/*=============================================================================
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(BOOST_SPIRIT_X3_RULE_JAN_08_2012_0326PM)
#define BOOST_SPIRIT_X3_RULE_JAN_08_2012_0326PM
#include <boost/spirit/home/x3/nonterminal/detail/rule.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/spirit/home/x3/support/context.hpp>
#include <boost/preprocessor/variadic/to_seq.hpp>
#include <boost/preprocessor/variadic/elem.hpp>
#include <boost/preprocessor/seq/for_each.hpp>
#include <type_traits>
#if !defined(BOOST_SPIRIT_X3_NO_RTTI)
#include <typeinfo>
#endif
namespace boost { namespace spirit { namespace x3
{
// default parse_rule implementation
template <typename ID, typename Iterator
, typename Context, typename ActualAttribute>
inline detail::default_parse_rule_result
parse_rule(
detail::rule_id<ID>
, Iterator& first, Iterator const& last
, Context const& context, ActualAttribute& attr)
{
static_assert(!is_same<decltype(x3::get<ID>(context)), unused_type>::value,
"BOOST_SPIRIT_DEFINE undefined for this rule.");
return x3::get<ID>(context).parse(first, last, context, unused, attr);
}
template <typename ID, typename RHS, typename Attribute, bool force_attribute_, bool skip_definition_injection = false>
struct rule_definition : parser<rule_definition<ID, RHS, Attribute, force_attribute_, skip_definition_injection>>
{
typedef rule_definition<ID, RHS, Attribute, force_attribute_, skip_definition_injection> this_type;
typedef ID id;
typedef RHS rhs_type;
typedef rule<ID, Attribute, force_attribute_> lhs_type;
typedef Attribute attribute_type;
static bool const has_attribute =
!is_same<Attribute, unused_type>::value;
static bool const handles_container =
traits::is_container<Attribute>::value;
static bool const force_attribute =
force_attribute_;
constexpr rule_definition(RHS const& rhs, char const* name)
: rhs(rhs), name(name) {}
template <typename Iterator, typename Context, typename Attribute_>
bool parse(Iterator& first, Iterator const& last
, Context const& context, unused_type, Attribute_& attr) const
{
return detail::rule_parser<attribute_type, ID, skip_definition_injection>
::call_rule_definition(
rhs, name, first, last
, context
, attr
, mpl::bool_<force_attribute>());
}
RHS rhs;
char const* name;
};
template <typename ID, typename Attribute, bool force_attribute_>
struct rule : parser<rule<ID, Attribute, force_attribute_>>
{
static_assert(!std::is_reference<Attribute>::value,
"Reference qualifier on rule attribute type is meaningless");
typedef ID id;
typedef Attribute attribute_type;
static bool const has_attribute =
!std::is_same<std::remove_const_t<Attribute>, unused_type>::value;
static bool const handles_container =
traits::is_container<Attribute>::value;
static bool const force_attribute = force_attribute_;
#if !defined(BOOST_SPIRIT_X3_NO_RTTI)
rule() : name(typeid(rule).name()) {}
#else
constexpr rule() : name("unnamed") {}
#endif
constexpr rule(char const* name)
: name(name) {}
constexpr rule(rule const& r)
: name(r.name)
{
// Assert that we are not copying an unitialized static rule. If
// the static is in another TU, it may be initialized after we copy
// it. If so, its name member will be nullptr.
BOOST_ASSERT_MSG(r.name, "uninitialized rule"); // static initialization order fiasco
}
template <typename RHS>
constexpr rule_definition<
ID, typename extension::as_parser<RHS>::value_type, Attribute, force_attribute_>
operator=(RHS const& rhs) const&
{
return { as_parser(rhs), name };
}
template <typename RHS>
constexpr rule_definition<
ID, typename extension::as_parser<RHS>::value_type, Attribute, true>
operator%=(RHS const& rhs) const&
{
return { as_parser(rhs), name };
}
// When a rule placeholder constructed and immediately consumed it cannot be used recursively,
// that's why the rule definition injection into a parser context can be skipped.
// This optimization has a huge impact on compile times because immediate rules are commonly
// used to cast an attribute like `as`/`attr_cast` does in Qi.
template <typename RHS>
constexpr rule_definition<
ID, typename extension::as_parser<RHS>::value_type, Attribute, force_attribute_, true>
operator=(RHS const& rhs) const&&
{
return { as_parser(rhs), name };
}
template <typename RHS>
constexpr rule_definition<
ID, typename extension::as_parser<RHS>::value_type, Attribute, true, true>
operator%=(RHS const& rhs) const&&
{
return { as_parser(rhs), name };
}
template <typename Iterator, typename Context, typename Attribute_>
bool parse(Iterator& first, Iterator const& last
, Context const& context, unused_type, Attribute_& attr) const
{
static_assert(has_attribute,
"The rule does not have an attribute. Check your parser.");
using transform = traits::transform_attribute<
Attribute_, attribute_type, parser_id>;
using transform_attr = typename transform::type;
transform_attr attr_ = transform::pre(attr);
if (parse_rule(detail::rule_id<ID>{}, first, last, context, attr_)) {
transform::post(attr, std::forward<transform_attr>(attr_));
return true;
}
return false;
}
template <typename Iterator, typename Context>
bool parse(Iterator& first, Iterator const& last
, Context const& context, unused_type, unused_type) const
{
// make sure we pass exactly the rule attribute type
attribute_type no_attr{};
return parse_rule(detail::rule_id<ID>{}, first, last, context, no_attr);
}
char const* name;
};
namespace traits
{
template <typename T, typename Enable = void>
struct is_rule : mpl::false_ {};
template <typename ID, typename Attribute, bool force_attribute>
struct is_rule<rule<ID, Attribute, force_attribute>> : mpl::true_ {};
template <typename ID, typename Attribute, typename RHS, bool force_attribute, bool skip_definition_injection>
struct is_rule<rule_definition<ID, RHS, Attribute, force_attribute, skip_definition_injection>> : mpl::true_ {};
}
template <typename T>
struct get_info<T, typename enable_if<traits::is_rule<T>>::type>
{
typedef std::string result_type;
std::string operator()(T const& r) const
{
BOOST_ASSERT_MSG(r.name, "uninitialized rule"); // static initialization order fiasco
return r.name? r.name : "uninitialized";
}
};
#define BOOST_SPIRIT_DECLARE_(r, data, rule_type) \
template <typename Iterator, typename Context> \
bool parse_rule( \
::boost::spirit::x3::detail::rule_id<rule_type::id> \
, Iterator& first, Iterator const& last \
, Context const& context, rule_type::attribute_type& attr); \
/***/
#define BOOST_SPIRIT_DECLARE(...) BOOST_PP_SEQ_FOR_EACH( \
BOOST_SPIRIT_DECLARE_, _, BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__)) \
/***/
#if BOOST_WORKAROUND(BOOST_MSVC, < 1910)
#define BOOST_SPIRIT_DEFINE_(r, data, rule_name) \
using BOOST_PP_CAT(rule_name, _synonym) = decltype(rule_name); \
template <typename Iterator, typename Context> \
inline bool parse_rule( \
::boost::spirit::x3::detail::rule_id<BOOST_PP_CAT(rule_name, _synonym)::id> \
, Iterator& first, Iterator const& last \
, Context const& context, BOOST_PP_CAT(rule_name, _synonym)::attribute_type& attr) \
{ \
using rule_t = BOOST_JOIN(rule_name, _synonym); \
return ::boost::spirit::x3::detail \
::rule_parser<typename rule_t::attribute_type, rule_t::id, true> \
::call_rule_definition( \
BOOST_JOIN(rule_name, _def), rule_name.name \
, first, last, context, attr \
, ::boost::mpl::bool_<rule_t::force_attribute>()); \
} \
/***/
#else
#define BOOST_SPIRIT_DEFINE_(r, data, rule_name) \
template <typename Iterator, typename Context> \
inline bool parse_rule( \
::boost::spirit::x3::detail::rule_id<decltype(rule_name)::id> \
, Iterator& first, Iterator const& last \
, Context const& context, decltype(rule_name)::attribute_type& attr) \
{ \
using rule_t = decltype(rule_name); \
return ::boost::spirit::x3::detail \
::rule_parser<typename rule_t::attribute_type, rule_t::id, true> \
::call_rule_definition( \
BOOST_JOIN(rule_name, _def), rule_name.name \
, first, last, context, attr \
, ::boost::mpl::bool_<rule_t::force_attribute>()); \
} \
/***/
#endif
#define BOOST_SPIRIT_DEFINE(...) BOOST_PP_SEQ_FOR_EACH( \
BOOST_SPIRIT_DEFINE_, _, BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__)) \
/***/
#define BOOST_SPIRIT_INSTANTIATE(rule_type, Iterator, Context) \
template bool parse_rule<Iterator, Context>( \
::boost::spirit::x3::detail::rule_id<rule_type::id> \
, Iterator& first, Iterator const& last \
, Context const& context, rule_type::attribute_type&); \
/***/
}}}
#endif
