boost/xpressive/detail/core/matcher/action_matcher.hpp
///////////////////////////////////////////////////////////////////////////////
// action_matcher.hpp
//
// Copyright 2008 Eric Niebler.
// Copyright 2008 David Jenkins.
//
// 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)
#ifndef BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_ACTION_MATCHER_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_ACTION_MATCHER_HPP_EAN_10_04_2005
// MS compatible compilers support #pragma once
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/config.hpp>
#include <boost/version.hpp>
#include <boost/ref.hpp>
#include <boost/assert.hpp>
#include <boost/mpl/if.hpp>
#include <boost/throw_exception.hpp>
#include <boost/utility/result_of.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/core/quant_style.hpp>
#include <boost/xpressive/detail/core/action.hpp>
#include <boost/xpressive/detail/core/state.hpp>
#include <boost/proto/core.hpp>
#include <boost/proto/context.hpp>
#include <boost/xpressive/match_results.hpp> // for type_info_less
#include <boost/xpressive/detail/static/transforms/as_action.hpp> // for 'read_attr'
#if BOOST_VERSION >= 103500
# include <boost/proto/fusion.hpp>
# include <boost/fusion/include/transform_view.hpp>
# include <boost/fusion/include/invoke.hpp>
# include <boost/fusion/include/push_front.hpp>
# include <boost/fusion/include/pop_front.hpp>
#endif
#if BOOST_MSVC
#pragma warning(push)
#pragma warning(disable : 4510) // default constructor could not be generated
#pragma warning(disable : 4512) // assignment operator could not be generated
#pragma warning(disable : 4610) // can never be instantiated - user defined constructor required
#endif
namespace boost { namespace xpressive { namespace detail
{
#if BOOST_VERSION >= 103500
struct DataMember
: proto::mem_ptr<proto::_, proto::terminal<proto::_> >
{};
template<typename Expr, long N>
struct child_
: remove_reference<
typename proto::result_of::child_c<Expr &, N>::type
>
{};
///////////////////////////////////////////////////////////////////////////////
// mem_ptr_eval
// Rewrites expressions of the form x->*foo(a) into foo(x, a) and then
// evaluates them.
template<typename Expr, typename Context, bool IsDataMember = proto::matches<Expr, DataMember>::value>
struct mem_ptr_eval
{
typedef typename child_<Expr, 0>::type left_type;
typedef typename child_<Expr, 1>::type right_type;
typedef
typename proto::result_of::value<
typename proto::result_of::child_c<right_type, 0>::type
>::type
function_type;
typedef
fusion::transform_view<
typename fusion::result_of::push_front<
typename fusion::result_of::pop_front<right_type>::type const
, reference_wrapper<left_type>
>::type const
, proto::eval_fun<Context>
>
evaluated_args;
typedef
typename fusion::result_of::invoke<function_type, evaluated_args>::type
result_type;
result_type operator()(Expr &expr, Context &ctx) const
{
return fusion::invoke<function_type>(
proto::value(proto::child_c<0>(proto::right(expr)))
, evaluated_args(
fusion::push_front(fusion::pop_front(proto::right(expr)), boost::ref(proto::left(expr)))
, proto::eval_fun<Context>(ctx)
)
);
}
};
///////////////////////////////////////////////////////////////////////////////
// mem_ptr_eval
// Rewrites expressions of the form x->*foo into foo(x) and then
// evaluates them.
template<typename Expr, typename Context>
struct mem_ptr_eval<Expr, Context, true>
{
typedef typename child_<Expr, 0>::type left_type;
typedef typename child_<Expr, 1>::type right_type;
typedef
typename proto::result_of::value<right_type>::type
function_type;
typedef typename boost::result_of<
function_type(typename proto::result_of::eval<left_type, Context>::type)
>::type result_type;
result_type operator()(Expr &expr, Context &ctx) const
{
return proto::value(proto::right(expr))(
proto::eval(proto::left(expr), ctx)
);
}
};
#endif
struct attr_with_default_tag
{};
template<typename T>
struct opt;
///////////////////////////////////////////////////////////////////////////////
// action_context
//
struct action_context
{
explicit action_context(action_args_type *action_args)
: action_args_(action_args)
{}
action_args_type const &args() const
{
return *this->action_args_;
}
// eval_terminal
template<typename Expr, typename Arg>
struct eval_terminal
: proto::default_eval<Expr, action_context const>
{};
template<typename Expr, typename Arg>
struct eval_terminal<Expr, reference_wrapper<Arg> >
{
typedef Arg &result_type;
result_type operator()(Expr &expr, action_context const &) const
{
return proto::value(expr).get();
}
};
template<typename Expr, typename Arg>
struct eval_terminal<Expr, opt<Arg> >
{
typedef Arg const &result_type;
result_type operator()(Expr &expr, action_context const &) const
{
return proto::value(expr);
}
};
template<typename Expr, typename Type, typename Int>
struct eval_terminal<Expr, action_arg<Type, Int> >
{
typedef typename action_arg<Type, Int>::reference result_type;
result_type operator()(Expr &expr, action_context const &ctx) const
{
action_args_type::const_iterator where_ = ctx.args().find(&typeid(proto::value(expr)));
if(where_ == ctx.args().end())
{
BOOST_THROW_EXCEPTION(
regex_error(
regex_constants::error_badarg
, "An argument to an action was unspecified"
)
);
}
return proto::value(expr).cast(where_->second);
}
};
// eval
template<typename Expr, typename Tag = typename Expr::proto_tag>
struct eval
: proto::default_eval<Expr, action_context const>
{};
template<typename Expr>
struct eval<Expr, proto::tag::terminal>
: eval_terminal<Expr, typename proto::result_of::value<Expr>::type>
{};
// Evaluate attributes like a1|42
template<typename Expr>
struct eval<Expr, attr_with_default_tag>
{
typedef
typename proto::result_of::value<
typename proto::result_of::left<
typename proto::result_of::child<
Expr
>::type
>::type
>::type
temp_type;
typedef typename temp_type::type result_type;
result_type operator ()(Expr const &expr, action_context const &ctx) const
{
return proto::value(proto::left(proto::child(expr))).t_
? *proto::value(proto::left(proto::child(expr))).t_
: proto::eval(proto::right(proto::child(expr)), ctx);
}
};
#if BOOST_VERSION >= 103500
template<typename Expr>
struct eval<Expr, proto::tag::mem_ptr>
: mem_ptr_eval<Expr, action_context const>
{};
#endif
private:
action_args_type *action_args_;
};
///////////////////////////////////////////////////////////////////////////////
// action
//
template<typename Actor>
struct action
: actionable
{
action(Actor const &actor)
: actionable()
, actor_(actor)
{
}
virtual void execute(action_args_type *action_args) const
{
action_context const ctx(action_args);
proto::eval(this->actor_, ctx);
}
private:
Actor actor_;
};
///////////////////////////////////////////////////////////////////////////////
// subreg_transform
//
struct subreg_transform : proto::transform<subreg_transform>
{
template<typename Expr, typename State, typename Data>
struct impl : proto::transform_impl<Expr, State, Data>
{
typedef typename impl::state state_type;
typedef
typename proto::terminal<sub_match<typename state_type::iterator> >::type
result_type;
result_type operator ()(
typename impl::expr_param
, typename impl::state_param state
, typename impl::data_param data
) const
{
return result_type::make(state.sub_matches_[ data ]);
}
};
};
///////////////////////////////////////////////////////////////////////////////
// mark_transform
//
struct mark_transform : proto::transform<mark_transform>
{
template<typename Expr, typename State, typename Data>
struct impl : proto::transform_impl<Expr, State, Data>
{
typedef typename impl::state state_type;
typedef
typename proto::terminal<sub_match<typename state_type::iterator> >::type
result_type;
result_type operator ()(
typename impl::expr_param expr
, typename impl::state_param state
, typename impl::data_param
) const
{
return result_type::make(state.sub_matches_[ proto::value(expr).mark_number_ ]);
}
};
};
///////////////////////////////////////////////////////////////////////////////
// opt
//
template<typename T>
struct opt
{
typedef T type;
typedef T const &reference;
opt(T const *t)
: t_(t)
{}
operator reference() const
{
BOOST_XPR_ENSURE_(0 != this->t_, regex_constants::error_badattr, "Use of uninitialized regex attribute");
return *this->t_;
}
T const *t_;
};
///////////////////////////////////////////////////////////////////////////////
// attr_transform
//
struct attr_transform : proto::transform<attr_transform>
{
template<typename Expr, typename State, typename Data>
struct impl : proto::transform_impl<Expr, State, Data>
{
typedef typename impl::expr expr_type;
typedef
typename expr_type::proto_child0::matcher_type::value_type::second_type
attr_type;
typedef
typename proto::terminal<opt<attr_type> >::type
result_type;
result_type operator ()(
typename impl::expr_param
, typename impl::state_param state
, typename impl::data_param
) const
{
int slot = typename expr_type::proto_child0::nbr_type();
attr_type const *attr = static_cast<attr_type const *>(state.attr_context_.attr_slots_[slot-1]);
return result_type::make(opt<attr_type>(attr));
}
};
};
///////////////////////////////////////////////////////////////////////////////
// attr_with_default_transform
//
template<typename Grammar, typename Callable = proto::callable>
struct attr_with_default_transform : proto::transform<attr_with_default_transform<Grammar, Callable> >
{
template<typename Expr, typename State, typename Data>
struct impl : proto::transform_impl<Expr, State, Data>
{
typedef
typename proto::unary_expr<
attr_with_default_tag
, typename Grammar::template impl<Expr, State, Data>::result_type
>::type
result_type;
result_type operator ()(
typename impl::expr_param expr
, typename impl::state_param state
, typename impl::data_param data
) const
{
result_type that = {
typename Grammar::template impl<Expr, State, Data>()(expr, state, data)
};
return that;
}
};
};
///////////////////////////////////////////////////////////////////////////////
// by_ref_transform
//
struct by_ref_transform : proto::transform<by_ref_transform>
{
template<typename Expr, typename State, typename Data>
struct impl : proto::transform_impl<Expr, State, Data>
{
typedef
typename proto::result_of::value<typename impl::expr_param>::type
reference;
typedef
typename proto::terminal<reference>::type
result_type;
result_type operator ()(
typename impl::expr_param expr
, typename impl::state_param
, typename impl::data_param
) const
{
return result_type::make(proto::value(expr));
}
};
};
///////////////////////////////////////////////////////////////////////////////
// BindActionArgs
//
struct BindActionArgs
: proto::or_<
proto::when<proto::terminal<any_matcher>, subreg_transform>
, proto::when<proto::terminal<mark_placeholder>, mark_transform>
, proto::when<proto::terminal<read_attr<proto::_, proto::_> >, attr_transform>
, proto::when<proto::terminal<proto::_>, by_ref_transform>
, proto::when<
proto::bitwise_or<proto::terminal<read_attr<proto::_, proto::_> >, BindActionArgs>
, attr_with_default_transform<proto::bitwise_or<attr_transform, BindActionArgs> >
>
, proto::otherwise<proto::nary_expr<proto::_, proto::vararg<BindActionArgs> > >
>
{};
///////////////////////////////////////////////////////////////////////////////
// action_matcher
//
template<typename Actor>
struct action_matcher
: quant_style<quant_none, 0, false>
{
int sub_;
Actor actor_;
action_matcher(Actor const &actor, int sub)
: sub_(sub)
, actor_(actor)
{
}
template<typename BidiIter, typename Next>
bool match(match_state<BidiIter> &state, Next const &next) const
{
// Bind the arguments
typedef
typename boost::result_of<BindActionArgs(
Actor const &
, match_state<BidiIter> &
, int const &
)>::type
action_type;
action<action_type> actor(BindActionArgs()(this->actor_, state, this->sub_));
// Put the action in the action list
actionable const **action_list_tail = state.action_list_tail_;
*state.action_list_tail_ = &actor;
state.action_list_tail_ = &actor.next;
// Match the rest of the pattern
if(next.match(state))
{
return true;
}
BOOST_ASSERT(0 == actor.next);
// remove action from list
*action_list_tail = 0;
state.action_list_tail_ = action_list_tail;
return false;
}
};
}}}
#if BOOST_MSVC
#pragma warning(pop)
#endif
#endif