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