Chris@16: //  Copyright (c) 2001-2011 Hartmut Kaiser
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: #if !defined(BOOST_SPIRIT_KARMA_ACTION_MAR_07_2007_0851AM)
Chris@16: #define BOOST_SPIRIT_KARMA_ACTION_MAR_07_2007_0851AM
Chris@16: 
Chris@16: #if defined(_MSC_VER)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/spirit/home/karma/detail/attributes.hpp>
Chris@16: #include <boost/spirit/home/support/argument.hpp>
Chris@16: #include <boost/spirit/home/support/context.hpp>
Chris@16: #include <boost/spirit/home/support/unused.hpp>
Chris@16: #include <boost/spirit/home/support/info.hpp>
Chris@16: #include <boost/spirit/home/support/action_dispatch.hpp>
Chris@16: #include <boost/spirit/home/support/has_semantic_action.hpp>
Chris@16: #include <boost/spirit/home/support/handles_container.hpp>
Chris@16: #include <boost/spirit/home/karma/domain.hpp>
Chris@16: #include <boost/spirit/home/karma/meta_compiler.hpp>
Chris@16: #include <boost/spirit/home/karma/generator.hpp>
Chris@16: 
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/type_traits/remove_const.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace karma
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     BOOST_PP_REPEAT(SPIRIT_ARGUMENTS_LIMIT, SPIRIT_USING_ARGUMENT, _)
Chris@16: 
Chris@16:     template <typename Subject, typename Action>
Chris@16:     struct action : unary_generator<action<Subject, Action> >
Chris@16:     {
Chris@16:         typedef Subject subject_type;
Chris@16:         typedef typename subject_type::properties properties;
Chris@16: 
Chris@16:         template <typename Context, typename Iterator>
Chris@16:         struct attribute
Chris@16:           : traits::attribute_of<Subject, Context, Iterator>
Chris@16:         {};
Chris@16: 
Chris@16:         action(Subject const& subject, Action f)
Chris@16:           : subject(subject), f(f) {}
Chris@16: 
Chris@16:         template <
Chris@16:             typename OutputIterator, typename Context, typename Delimiter
Chris@16:           , typename Attribute>
Chris@16:         bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d
Chris@16:           , Attribute const& attr_) const
Chris@16:         {
Chris@16:             typedef typename attribute<Context, unused_type>::type attr_type;
Chris@16:             typedef traits::make_attribute<attr_type, Attribute> make_attribute;
Chris@16: 
Chris@16:             // create a attribute if none is supplied
Chris@16:             // this creates a _copy_ of the attribute because the semantic
Chris@16:             // action will likely change parts of this
Chris@16:             typedef traits::transform_attribute<
Chris@16:                 typename make_attribute::type, attr_type, domain> transform;
Chris@16: 
Chris@16:             typename transform::type attr = 
Chris@16:                 traits::pre_transform<domain, attr_type>(make_attribute::call(attr_));
Chris@16: 
Chris@16:             // call the function, passing the attribute, the context and a bool 
Chris@16:             // flag that the client can set to false to fail generating.
Chris@16:             return traits::action_dispatch<Subject>()(f, attr, ctx) && 
Chris@16:                    subject.generate(sink, ctx, d, attr);
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Context>
Chris@16:         info what(Context& context) const
Chris@16:         {
Chris@16:             // the action is transparent (does not add any info)
Chris@16:             return subject.what(context);
Chris@16:         }
Chris@16: 
Chris@16:         subject_type subject;
Chris@16:         Action f;
Chris@16:     };
Chris@16: 
Chris@16: }}}
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace spirit
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     // Karma action meta-compiler
Chris@16:     template <>
Chris@16:     struct make_component<karma::domain, tag::action>
Chris@16:     {
Chris@16:         template <typename Sig>
Chris@16:         struct result;
Chris@16: 
Chris@16:         template <typename This, typename Elements, typename Modifiers>
Chris@16:         struct result<This(Elements, Modifiers)>
Chris@16:         {
Chris@16:             typedef typename
Chris@16:                 remove_const<typename Elements::car_type>::type
Chris@16:             subject_type;
Chris@16: 
Chris@16:             typedef typename
Chris@16:                 remove_const<typename Elements::cdr_type::car_type>::type
Chris@16:             action_type;
Chris@16: 
Chris@16:             typedef karma::action<subject_type, action_type> type;
Chris@16:         };
Chris@16: 
Chris@16:         template <typename Elements>
Chris@16:         typename result<make_component(Elements, unused_type)>::type
Chris@16:         operator()(Elements const& elements, unused_type) const
Chris@16:         {
Chris@16:             typename result<make_component(Elements, unused_type)>::type
Chris@16:                 result(elements.car, elements.cdr.car);
Chris@16:             return result;
Chris@16:         }
Chris@16:     };
Chris@16: }}
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace traits
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject, typename Action>
Chris@16:     struct has_semantic_action<karma::action<Subject, Action> >
Chris@16:       : mpl::true_ {};
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject, typename Action, typename Attribute
Chris@16:       , typename Context, typename Iterator>
Chris@16:     struct handles_container<karma::action<Subject, Action>, Attribute
Chris@16:       , Context, Iterator>
Chris@16:       : unary_handles_container<Subject, Attribute, Context, Iterator> {};
Chris@16: }}}
Chris@16: 
Chris@16: #endif