Chris@16: /*==============================================================================
Chris@16:     Copyright (c) 2001-2010 Joel de Guzman
Chris@16:     Copyright (c) 2010 Thomas Heller
Chris@16: 
Chris@16:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: ==============================================================================*/
Chris@16: #ifndef BOOST_PHOENIX_STATEMENT_SWITCH_HPP
Chris@16: #define BOOST_PHOENIX_STATEMENT_SWITCH_HPP
Chris@16: 
Chris@16: #include <boost/phoenix/core/limits.hpp>
Chris@16: #include <boost/fusion/iterator/advance.hpp>
Chris@16: #include <boost/phoenix/core/call.hpp>
Chris@16: #include <boost/phoenix/core/expression.hpp>
Chris@16: #include <boost/phoenix/core/meta_grammar.hpp>
Chris@16: #include <boost/phoenix/core/is_nullary.hpp>
Chris@16: #include <boost/phoenix/support/iterate.hpp>
Chris@16: #include <boost/proto/make_expr.hpp>
Chris@16: #include <boost/proto/fusion.hpp>
Chris@16: 
Chris@16: #ifdef _MSC_VER
Chris@16: #pragma warning(push)
Chris@16: #pragma warning(disable: 4065) // switch statement contains 'default' but no 'case' labels
Chris@16: #endif
Chris@16: 
Chris@16: BOOST_PHOENIX_DEFINE_EXPRESSION(
Chris@16:     (boost)(phoenix)(switch_case)
Chris@16:   , (proto::terminal<proto::_>)
Chris@16:     (meta_grammar)
Chris@16: )
Chris@16: 
Chris@16: BOOST_PHOENIX_DEFINE_EXPRESSION(
Chris@16:     (boost)(phoenix)(switch_default_case)
Chris@16:   , (meta_grammar)
Chris@16: )
Chris@16: 
Chris@16: namespace boost { namespace phoenix
Chris@16: {
Chris@16:     namespace detail
Chris@16:     {
Chris@16:         struct switch_case_grammar;
Chris@16:         struct switch_case_with_default_grammar;
Chris@16:         struct switch_grammar
Chris@16:             : proto::or_<
Chris@16:                 proto::when<
Chris@16:                     detail::switch_case_grammar
Chris@16:                   , mpl::false_()
Chris@16:                 >
Chris@16:               , proto::when<
Chris@16:                     detail::switch_case_with_default_grammar
Chris@16:                   , mpl::true_()
Chris@16:                 >
Chris@16:             >
Chris@16:         {};
Chris@16:     }
Chris@16: 
Chris@16:     namespace detail
Chris@16:     {
Chris@16:         struct switch_case_is_nullary
Chris@16:             : proto::or_<
Chris@16:                 proto::when<
Chris@16:                     proto::comma<
Chris@16:                         switch_case_is_nullary
Chris@16:                       , proto::or_<phoenix::rule::switch_default_case, phoenix::rule::switch_case>
Chris@16:                     >
Chris@16:                   , mpl::and_<
Chris@16:                         switch_case_is_nullary(
Chris@16:                             proto::_child_c<0>
Chris@16:                           , proto::_state
Chris@16:                         )
Chris@16:                       , switch_case_is_nullary(
Chris@16:                             proto::_child_c<1>
Chris@16:                           , proto::_state
Chris@16:                         )
Chris@16:                     >()
Chris@16:                 >
Chris@16:               , proto::when<
Chris@16:                     proto::or_<phoenix::rule::switch_default_case, phoenix::rule::switch_case>
Chris@16:                   , evaluator(proto::_child_c<0>, proto::_state)
Chris@16:                 >
Chris@16:             >
Chris@16:         {};
Chris@16: 
Chris@16:         struct switch_case_grammar
Chris@16:             : proto::or_<
Chris@16:                 proto::comma<switch_case_grammar, phoenix::rule::switch_case>
Chris@16:               , proto::when<phoenix::rule::switch_case, proto::_>
Chris@16:             >
Chris@16:         {};
Chris@16: 
Chris@16:         struct switch_case_with_default_grammar
Chris@16:             : proto::or_<
Chris@16:                 proto::comma<switch_case_grammar, phoenix::rule::switch_default_case>
Chris@16:               , proto::when<phoenix::rule::switch_default_case, proto::_>
Chris@16:             >
Chris@16:         {};
Chris@16: 
Chris@16:         struct switch_size
Chris@16:             : proto::or_<
Chris@16:                 proto::when<
Chris@16:                     proto::comma<switch_size, proto::_>
Chris@16:                   , mpl::next<switch_size(proto::_left)>()
Chris@16:                 >
Chris@16:               , proto::when<proto::_, mpl::int_<1>()>
Chris@16:             >
Chris@16:         {};
Chris@16:     }
Chris@16: }}
Chris@16: 
Chris@16: BOOST_PHOENIX_DEFINE_EXPRESSION(
Chris@16:     (boost)(phoenix)(switch_)
Chris@16:   , (meta_grammar)           // Cond
Chris@16:     (detail::switch_grammar) // Cases
Chris@16: )
Chris@16: 
Chris@16: namespace boost { namespace phoenix {
Chris@16: 
Chris@16:     template <typename Dummy>
Chris@16:     struct is_nullary::when<rule::switch_, Dummy>
Chris@16:         : proto::and_<
Chris@16:             evaluator(proto::_child_c<0>, _context)
Chris@16:           , detail::switch_case_is_nullary(proto::_child_c<1>, _context)
Chris@16:         >
Chris@16:     {};
Chris@16: 
Chris@16:     struct switch_eval
Chris@16:     {
Chris@16:         typedef void result_type;
Chris@16:         
Chris@16:         template <typename Context>
Chris@16:         result_type
Chris@16:         operator()(Context const &) const
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Cond, typename Cases, typename Context>
Chris@16:         result_type
Chris@16:         operator()(Cond const & cond, Cases const & cases, Context const & ctx) const
Chris@16:         {
Chris@16:             this->evaluate(
Chris@16:                     ctx
Chris@16:                   , cond
Chris@16:                   , cases
Chris@16:                   , typename detail::switch_size::impl<Cases, int, proto::empty_env>::result_type()
Chris@16:                   , typename detail::switch_grammar::impl<Cases, int, proto::empty_env>::result_type()
Chris@16:                 );
Chris@16:         }
Chris@16: 
Chris@16:         private:
Chris@16:             template <typename Context, typename Cond, typename Cases>
Chris@16:             result_type
Chris@16:             evaluate(
Chris@16:                 Context const & ctx
Chris@16:               , Cond const & cond
Chris@16:               , Cases const & cases
Chris@16:               , mpl::int_<1>
Chris@16:               , mpl::false_
Chris@16:             ) const
Chris@16:             {
Chris@16:                 typedef
Chris@16:                     typename proto::result_of::value<
Chris@16:                         typename proto::result_of::child_c<
Chris@16:                             Cases
Chris@16:                           , 0
Chris@16:                         >::type
Chris@16:                     >::type
Chris@16:                     case_label;
Chris@16: 
Chris@16:                 switch(boost::phoenix::eval(cond, ctx))
Chris@16:                 {
Chris@16:                     case case_label::value:
Chris@16:                         boost::phoenix::eval(proto::child_c<1>(cases), ctx);
Chris@16:                 }
Chris@16:             }
Chris@16:             
Chris@16:             template <typename Context, typename Cond, typename Cases>
Chris@16:             result_type
Chris@16:             evaluate(
Chris@16:                 Context const & ctx
Chris@16:               , Cond const & cond
Chris@16:               , Cases const & cases
Chris@16:               , mpl::int_<1>
Chris@16:               , mpl::true_
Chris@16:             ) const
Chris@16:             {
Chris@16:                 switch(boost::phoenix::eval(cond, ctx))
Chris@16:                 {
Chris@16:                     default:
Chris@16:                         boost::phoenix::eval(proto::child_c<0>(cases), ctx);
Chris@16:                 }
Chris@16:             }
Chris@16: 
Chris@16:             // Bring in the evaluation functions
Chris@16:             #include <boost/phoenix/statement/detail/switch.hpp>
Chris@16:     };
Chris@16:     
Chris@16:     template <typename Dummy>
Chris@16:     struct default_actions::when<rule::switch_, Dummy>
Chris@16:         : call<switch_eval>
Chris@16:     {};
Chris@16: 
Chris@16:     template <int N, typename A>
Chris@16:     inline
Chris@16:     typename proto::result_of::make_expr<
Chris@16:         tag::switch_case
Chris@16:       , proto::basic_default_domain
Chris@16:       , mpl::int_<N>
Chris@16:       , A
Chris@16:     >::type const
Chris@16:     case_(A const & a)
Chris@16:     {
Chris@16:         return
Chris@16:             proto::make_expr<
Chris@16:                 tag::switch_case
Chris@16:               , proto::basic_default_domain
Chris@16:             >(
Chris@16:                 mpl::int_<N>()
Chris@16:               , a
Chris@16:             );
Chris@16:     }
Chris@16: 
Chris@16:     template <typename A>
Chris@16:     inline
Chris@16:     typename proto::result_of::make_expr<
Chris@16:         tag::switch_default_case
Chris@16:       , proto::basic_default_domain
Chris@16:       , A
Chris@16:     >::type const
Chris@16:     default_(A const& a)
Chris@16:     {
Chris@16:         return
Chris@16:             proto::make_expr<
Chris@16:                 tag::switch_default_case
Chris@16:               , proto::basic_default_domain
Chris@16:             >(a);
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Cond>
Chris@16:     struct switch_gen
Chris@16:     {
Chris@101:         switch_gen(Cond const& cond_) : cond(cond_) {}
Chris@16: 
Chris@16:         template <typename Cases>
Chris@16:         typename expression::switch_<
Chris@16:             Cond
Chris@16:           , Cases
Chris@16:         >::type
Chris@16:         operator[](Cases const& cases) const
Chris@16:         {
Chris@16:             return
Chris@16:                 this->generate(
Chris@16:                     cases
Chris@16:                   , proto::matches<Cases, detail::switch_grammar>()
Chris@16:                 );
Chris@16:         }
Chris@16: 
Chris@16:         private:
Chris@16:             Cond const& cond;
Chris@16: 
Chris@16:             template <typename Cases>
Chris@16:             typename expression::switch_<
Chris@16:                 Cond
Chris@16:               , Cases
Chris@16:             >::type
Chris@16:             generate(Cases const & cases, mpl::true_) const
Chris@16:             {
Chris@16:                 return expression::switch_<Cond, Cases>::make(cond, cases);
Chris@16:             }
Chris@16:             
Chris@16:             template <typename Cases>
Chris@16:             typename expression::switch_<
Chris@16:                 Cond
Chris@16:               , Cases
Chris@16:             >::type
Chris@16:             generate(Cases const &, mpl::false_) const
Chris@16:             {
Chris@16:                 BOOST_MPL_ASSERT_MSG(
Chris@16:                     false
Chris@16:                   , INVALID_SWITCH_CASE_STATEMENT
Chris@16:                   , (Cases)
Chris@16:                 );
Chris@16:             }
Chris@16:     };
Chris@16: 
Chris@16:     template <typename Cond>
Chris@16:     inline
Chris@16:     switch_gen<Cond> const
Chris@16:     switch_(Cond const& cond)
Chris@16:     {
Chris@16:         return switch_gen<Cond>(cond);
Chris@16:     }
Chris@16: 
Chris@16: }}
Chris@16: 
Chris@16: #ifdef _MSC_VER
Chris@16: #pragma warning(pop)
Chris@16: #endif
Chris@16: 
Chris@16: #endif
Chris@16: