metaparse/example/meta_hs/semantic.hpp

116 lines
2.3 KiB
C++

#ifndef META_HS_SEMANTIC_HPP
#define META_HS_SEMANTIC_HPP
// Copyright Abel Sinkovics (abel@sinkovics.hu) 2012.
// 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)
#include <ast.hpp>
#include <curry.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/apply_wrap.hpp>
#include <boost/mpl/front.hpp>
#include <boost/mpl/back.hpp>
#include <boost/mpl/at.hpp>
#include <boost/mpl/pair.hpp>
namespace semantic
{
struct ref
{
typedef ref type;
template <class Name>
struct apply : ast::ref<Name> {};
};
struct value
{
typedef value type;
template <class V>
struct apply : ast::value<V> {};
};
struct lambda
{
typedef lambda type;
template <class F, class ArgName>
struct apply : ast::lambda<F, ArgName> {};
};
struct application
{
typedef application type;
template <class F, class Arg>
struct apply : ast::application<F, Arg> {};
};
class if_
{
private:
template <class C, class T, class F>
struct lazy_if : boost::mpl::if_<typename C::type, T, F> {};
public:
typedef if_ type;
template <class Seq>
struct apply :
boost::mpl::apply_wrap2<
application,
typename boost::mpl::apply_wrap2<
application,
typename boost::mpl::apply_wrap2<
application,
ast::value<curry3<lazy_if> >,
typename boost::mpl::at_c<Seq, 0>::type
>::type,
typename boost::mpl::at_c<Seq, 1>::type
>::type,
typename boost::mpl::at_c<Seq, 2>::type
>
{};
};
struct binary_op
{
typedef binary_op type;
template <class Exp, class C>
struct apply :
boost::mpl::apply_wrap2<
application,
typename boost::mpl::apply_wrap2<
application,
typename boost::mpl::apply_wrap1<
ref,
typename boost::mpl::front<C>::type
>::type,
Exp
>::type,
typename boost::mpl::back<C>::type
>
{};
};
struct pair
{
typedef pair type;
template <class Seq>
struct apply :
boost::mpl::pair<
typename boost::mpl::front<Seq>::type,
ast::top_bound<typename boost::mpl::back<Seq>::type>
>
{};
};
}
#endif