Sprout/sprout/weed/parser/lim.hpp
2011-11-13 17:54:38 +09:00

95 lines
2.9 KiB
C++

#ifndef SPROUT_WEED_PARSER_LIM_HPP
#define SPROUT_WEED_PARSER_LIM_HPP
#include <cstddef>
#include <sprout/config.hpp>
#include <sprout/weed/parser_result.hpp>
#include <sprout/weed/limited.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/expr/terminal_or_expr_of.hpp>
#include <sprout/weed/traits/parser/attribute_of.hpp>
#include <sprout/weed/traits/parser/limit_of.hpp>
namespace sprout {
namespace weed {
//
// limit_p
//
template<typename Parser, std::size_t Limit>
struct limit_p
: public sprout::weed::parser_base
{
public:
SPROUT_STATIC_CONSTEXPR std::size_t limit = Limit;
public:
template<typename Context, typename Iterator>
struct attribute {
public:
typedef typename sprout::weed::traits::attribute_of<Parser, Iterator, Context>::type type;
};
template<typename Context, typename Iterator>
struct result {
public:
typedef sprout::weed::parser_result<Iterator, typename attribute<Context, Iterator>::type> type;
};
private:
typedef typename sprout::weed::traits::terminal_or_expr_of<Parser>::type expr_type;
private:
expr_type expr_;
sprout::weed::limited::category limited_category_;
public:
limit_p() = default;
SPROUT_CONSTEXPR explicit limit_p(
Parser const& p,
sprout::weed::limited::category limited_category = sprout::weed::limited::discard
)
: expr_(sprout::weed::make_terminal_or_expr(p))
, limited_category_(limited_category)
{}
SPROUT_CONSTEXPR sprout::weed::limited::category limited_category() const {
return limited_category_;
}
template<typename Context, typename Iterator>
SPROUT_CONSTEXPR typename result<Context, Iterator>::type operator()(
Iterator first,
Iterator last,
Context const& ctx
) const
{
return sprout::weed::eval(expr_, ctx).presult();
}
};
template<typename Parser, std::size_t Limit>
SPROUT_CONSTEXPR std::size_t limit_p<Parser, Limit>::limit;
//
// lim
//
template<std::size_t Limit, typename Parser>
SPROUT_CONSTEXPR sprout::weed::limit_p<Parser, Limit> lim(Parser const& p) {
return sprout::weed::limit_p<Parser, Limit>(p);
}
template<std::size_t Limit, typename Parser>
SPROUT_CONSTEXPR sprout::weed::limit_p<Parser, Limit> lim(
Parser const& p,
sprout::weed::limited::category limited_category
)
{
return sprout::weed::limit_p<Parser, Limit>(p, limited_category);
}
namespace traits {
//
// limit_of
//
template<typename Parser, std::size_t Limit, typename Iterator, typename Context>
struct limit_of<sprout::weed::limit_p<Parser, Limit>, Iterator, Context>
: public std::integral_constant<std::size_t, Limit>
{};
} // namespace traits
} // namespace weed
} // namespace sprout
#endif // #ifndef SPROUT_WEED_PARSER_LIM_HPP