Sprout/sprout/weed/parser/directive/as_tuple.hpp
2013-03-25 12:43:47 +09:00

91 lines
2.8 KiB
C++

#ifndef SPROUT_WEED_PARSER_DIRECTIVE_AS_TUPLE_HPP
#define SPROUT_WEED_PARSER_DIRECTIVE_AS_TUPLE_HPP
#include <cstddef>
#include <sprout/config.hpp>
#include <sprout/tuple/tuple.hpp>
#include <sprout/type_traits/identity.hpp>
#include <sprout/weed/parser_result.hpp>
#include <sprout/weed/expr/make_terminal_or_expr.hpp>
#include <sprout/weed/expr/eval.hpp>
#include <sprout/weed/parser/parser_base.hpp>
#include <sprout/weed/traits/type/is_unused.hpp>
#include <sprout/weed/traits/expr/terminal_or_expr_of.hpp>
#include <sprout/weed/traits/parser/attribute_of.hpp>
namespace sprout {
namespace weed {
//
// as_tuple_p
//
template<typename Parser>
struct as_tuple_p
: public sprout::weed::parser_base
{
public:
template<typename Context, typename Iterator>
struct attribute {
private:
typedef typename sprout::weed::traits::attribute_of<Parser, Iterator, Context>::type attr_type;
private:
static_assert(!sprout::weed::traits::is_unused<attr_type>::value, "invalid attribute : unused");
public:
typedef sprout::tuples::tuple<attr_type> type;
};
template<typename Context, typename Iterator>
struct result
: public sprout::identity<sprout::weed::parser_result<Iterator, typename attribute<Context, Iterator>::type> >
{};
private:
typedef typename sprout::weed::traits::terminal_or_expr_of<Parser>::type expr_type;
private:
expr_type expr_;
private:
template<typename Context, typename Iterator, typename Result>
SPROUT_CONSTEXPR typename result<Context, Iterator>::type call(
Iterator first,
Result const& res
) const
{
typedef typename result<Context, Iterator>::type result_type;
typedef typename attribute<Context, Iterator>::type attribute_type;
return res.success()
? result_type(true, res.current(), attribute_type(res.attr()))
: result_type(false, first, attribute_type())
;
}
public:
as_tuple_p() = default;
explicit SPROUT_CONSTEXPR as_tuple_p(
Parser const& p
)
: expr_(sprout::weed::make_terminal_or_expr(p))
{}
template<typename Context, typename Iterator>
SPROUT_CONSTEXPR typename result<Context, Iterator>::type operator()(
Iterator first,
Iterator last,
Context const& ctx
) const
{
return call<Context>(first, sprout::weed::eval(expr_, ctx));
}
};
//
// as_tuple_d
//
struct as_tuple_d {
public:
template<typename Parser>
SPROUT_CONSTEXPR sprout::weed::as_tuple_p<Parser> operator[](Parser const& p) const {
return sprout::weed::as_tuple_p<Parser>(p);
}
};
//
// as_tuple
//
SPROUT_CONSTEXPR sprout::weed::as_tuple_d as_tuple = sprout::weed::as_tuple_d();
} // namespace weed
} // namespace sprout
#endif // #ifndef SPROUT_WEED_PARSER_DIRECTIVE_AS_TUPLE_HPP