boost/spirit/home/classic/meta/impl/traverse.ipp
/*=============================================================================
Copyright (c) 2002-2003 Joel de Guzman
Copyright (c) 2002-2003 Hartmut Kaiser
http://spirit.sourceforge.net/
Use, modification and distribution is subject to 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_TRAVERSE_IPP)
#define BOOST_SPIRIT_TRAVERSE_IPP
///////////////////////////////////////////////////////////////////////////////
#include <boost/spirit/home/classic/meta/fundamental.hpp>
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit {
BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
///////////////////////////////////////////////////////////////////////////////
namespace impl
{
template <typename CategoryT>
struct traverse_post_order_return_category;
} // namespace impl
///////////////////////////////////////////////////////////////////////////////
//
// Environment class for post_order_traversal
//
///////////////////////////////////////////////////////////////////////////////
template <int Level, int Node, int Index, int LastLeft>
struct traverse_post_order_env {
BOOST_STATIC_CONSTANT(int, level = Level);
BOOST_STATIC_CONSTANT(int, node = Node);
BOOST_STATIC_CONSTANT(int, index = Index);
BOOST_STATIC_CONSTANT(int, lastleft = LastLeft);
};
///////////////////////////////////////////////////////////////////////////////
//
// traverse_post_order_return template
//
// This template is a helper for dispatching the calculation of a parser
// type result for a traversal level to the corresponding parser_category
// based specialization.
//
///////////////////////////////////////////////////////////////////////////////
template <typename MetaT, typename ParserT, typename EnvT>
struct traverse_post_order_return {
typedef typename ParserT::parser_category_t parser_category_t;
typedef typename impl::traverse_post_order_return_category<parser_category_t>
::template result<MetaT, ParserT, EnvT>::type type;
};
///////////////////////////////////////////////////////////////////////////////
//
// parser_traversal_..._result templates
//
// These are metafunctions, which calculate the resulting parser type
// for all subparsers and feed these types to the user supplied
// metafunctions to get back the resulting parser type of this traversal
// level.
//
///////////////////////////////////////////////////////////////////////////////
template <typename MetaT, typename ParserT, typename EnvT>
struct parser_traversal_plain_result {
typedef typename MetaT::template plain_result<ParserT, EnvT>::type type;
};
///////////////////////////////////////////////////////////////////////////////
template <typename MetaT, typename UnaryT, typename SubjectT, typename EnvT>
struct parser_traversal_unary_result {
typedef typename MetaT
::template unary_result<UnaryT, SubjectT, EnvT>::type type;
};
///////////////////////////////////////////////////////////////////////////////
template <typename MetaT, typename ActionT, typename SubjectT, typename EnvT>
struct parser_traversal_action_result {
typedef typename MetaT
::template action_result<ActionT, SubjectT, EnvT>::type type;
};
///////////////////////////////////////////////////////////////////////////////
template <
typename MetaT, typename BinaryT, typename LeftT,
typename RightT, typename EnvT
>
struct parser_traversal_binary_result {
BOOST_STATIC_CONSTANT(int,
thisnum = (node_count<BinaryT>::value + EnvT::lastleft-1));
BOOST_STATIC_CONSTANT(int,
leftnum = (node_count<LeftT>::value + EnvT::lastleft-1));
BOOST_STATIC_CONSTANT(int,
leafnum = (leaf_count<LeftT>::value + EnvT::index));
typedef parser_traversal_binary_result self_t;
// left traversal environment and resulting parser type
typedef traverse_post_order_env<
(EnvT::level+1), (self_t::leftnum), (EnvT::index), (EnvT::lastleft)
> left_sub_env_t;
typedef typename traverse_post_order_return<
MetaT, LeftT, left_sub_env_t
>::type
left_t;
// right traversal environment and resulting parser type
typedef traverse_post_order_env<
(EnvT::level+1), (self_t::thisnum-1), (self_t::leafnum), (self_t::leftnum+1)
> right_sub_env_t;
typedef typename traverse_post_order_return<
MetaT, RightT, right_sub_env_t
>::type
right_t;
typedef typename MetaT::template binary_result<
BinaryT, left_t, right_t, EnvT
>::type
type;
};
///////////////////////////////////////////////////////////////////////////////
namespace impl
{
///////////////////////////////////////////////////////////////////////////
//
// Meta functions, which dispatch the calculation of the return type of
// of the post_order traverse function to the result template of the
// corresponding parser_category based metafunction template.
//
///////////////////////////////////////////////////////////////////////////
template <typename CategoryT>
struct traverse_post_order_return_category;
template <>
struct traverse_post_order_return_category<plain_parser_category> {
template <typename MetaT, typename ParserT, typename EnvT>
struct result {
typedef typename parser_traversal_plain_result<
MetaT, ParserT, EnvT
>::type
type;
};
};
template <>
struct traverse_post_order_return_category<unary_parser_category> {
template <typename MetaT, typename ParserT, typename EnvT>
struct result {
typedef typename parser_traversal_unary_result<
MetaT, ParserT, typename ParserT::subject_t, EnvT
>::type
type;
};
};
template <>
struct traverse_post_order_return_category<action_parser_category> {
template <typename MetaT, typename ParserT, typename EnvT>
struct result {
typedef typename parser_traversal_action_result<
MetaT, ParserT, typename ParserT::subject_t, EnvT
>::type
type;
};
};
template <>
struct traverse_post_order_return_category<binary_parser_category> {
template <typename MetaT, typename ParserT, typename EnvT>
struct result {
typedef typename parser_traversal_binary_result<
MetaT, ParserT, typename ParserT::left_t,
typename ParserT::right_t, EnvT
>::type
type;
};
};
///////////////////////////////////////////////////////////////////////////
//
// Post-order parser traversal
//
// The following templates contain the parser_category based code for
//
// - calculating the type of the resulting parser, which is to be
// returned from a level of traversal
// - traversing down the composite parser structure, this traversal
// returnes a new parser object
//
// Both tasks are delegated to the MetaT metafunction supplied by the
// user.
//
///////////////////////////////////////////////////////////////////////////
template <typename CategoryT>
struct traverse_post_order;
template <>
struct traverse_post_order<plain_parser_category> {
template <typename MetaT, typename ParserT, typename EnvT>
struct result {
typedef
typename parser_traversal_plain_result<MetaT, ParserT, EnvT>::type
type;
};
template <typename MetaT, typename ParserT, typename EnvT>
static
typename parser_traversal_plain_result<MetaT, ParserT, EnvT>::type
generate(MetaT const &meta_, ParserT const &parser_, EnvT const &env)
{
return meta_.generate_plain(parser_, env);
}
};
template <>
struct traverse_post_order<unary_parser_category> {
template <
typename MetaT, typename ParserT, typename SubjectT, typename EnvT
>
struct result {
typedef typename parser_traversal_unary_result<
MetaT, ParserT, SubjectT, EnvT
>::type
type;
};
template <typename MetaT, typename ParserT, typename EnvT>
static
typename parser_traversal_unary_result<
MetaT, ParserT,
typename traverse_post_order_return<
MetaT, typename ParserT::subject_t, EnvT
>::type,
EnvT
>::type
generate(MetaT const &meta_, ParserT const &unary_, EnvT const &env)
{
typedef typename ParserT::subject_t subject_t;
typedef typename subject_t::parser_category_t subject_category_t;
return meta_.generate_unary(
unary_,
traverse_post_order<subject_category_t>::generate(meta_,
unary_.subject(),
traverse_post_order_env<
EnvT::level+1, EnvT::node-1, EnvT::index, EnvT::lastleft
>()
),
env
);
}
};
template <>
struct traverse_post_order<action_parser_category> {
template <
typename MetaT, typename ParserT, typename SubjectT, typename EnvT
>
struct result {
typedef typename parser_traversal_action_result<
MetaT, ParserT, SubjectT, EnvT
>::type
type;
};
template <typename MetaT, typename ParserT, typename EnvT>
static
typename parser_traversal_action_result<
MetaT, ParserT,
typename traverse_post_order_return<
MetaT, typename ParserT::subject_t, EnvT
>::type,
EnvT
>::type
generate(MetaT const &meta_, ParserT const &action_, EnvT const &env)
{
typedef typename ParserT::subject_t subject_t;
typedef typename subject_t::parser_category_t subject_category_t;
return meta_.generate_action(
action_,
traverse_post_order<subject_category_t>::generate(meta_,
action_.subject(),
traverse_post_order_env<
EnvT::level+1, EnvT::node-1, EnvT::index, EnvT::lastleft
>()
),
env
);
}
};
template <>
struct traverse_post_order<binary_parser_category> {
template <
typename MetaT, typename ParserT, typename LeftT,
typename RightT, typename EnvT
>
struct result {
typedef typename parser_traversal_binary_result<
MetaT, ParserT, LeftT, RightT, EnvT
>::type
type;
};
template <typename MetaT, typename ParserT, typename EnvT>
static
typename parser_traversal_binary_result<
MetaT, ParserT,
typename traverse_post_order_return<
MetaT, typename ParserT::left_t, EnvT
>::type,
typename traverse_post_order_return<
MetaT, typename ParserT::right_t, EnvT
>::type,
EnvT
>::type
generate(MetaT const &meta_, ParserT const &binary_, EnvT const& /*env*/)
{
typedef typename ParserT::left_t left_t;
typedef typename ParserT::right_t right_t;
typedef typename left_t::parser_category_t left_category_t;
typedef typename right_t::parser_category_t right_category_t;
enum {
leftnum = (node_count<left_t>::value + EnvT::lastleft-1),
thisnum = (node_count<ParserT>::value + EnvT::lastleft-1),
rightnum = (thisnum-1),
leafnum = (leaf_count<left_t>::value + EnvT::index)
};
return meta_.generate_binary(
binary_,
traverse_post_order<left_category_t>::generate(
meta_, binary_.left(),
traverse_post_order_env<
EnvT::level+1, leftnum, EnvT::index, EnvT::lastleft
>()
),
traverse_post_order<right_category_t>::generate(
meta_, binary_.right(),
traverse_post_order_env<
EnvT::level+1, rightnum, leafnum, leftnum+1
>()
),
traverse_post_order_env<
EnvT::level, thisnum, EnvT::index, EnvT::lastleft
>()
);
}
};
} // namespace impl
///////////////////////////////////////////////////////////////////////////////
BOOST_SPIRIT_CLASSIC_NAMESPACE_END
}} // namespace boost::spirit
#endif // !defined(BOOST_SPIRIT_TRAVERSE_IPP)
