Chris@16: //  Copyright (c) 2001-2011 Hartmut Kaiser
Chris@16: //  Copyright (c) 2001-2011 Joel de Guzman
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(SPIRIT_KARMA_ALTERNATIVE_MAR_01_2007_1117AM)
Chris@16: #define SPIRIT_KARMA_ALTERNATIVE_MAR_01_2007_1117AM
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/alternative_function.hpp>
Chris@16: #include <boost/spirit/home/karma/detail/get_stricttag.hpp>
Chris@16: #include <boost/spirit/home/karma/domain.hpp>
Chris@16: #include <boost/spirit/home/karma/generator.hpp>
Chris@16: #include <boost/spirit/home/karma/meta_compiler.hpp>
Chris@16: #include <boost/spirit/home/support/info.hpp>
Chris@16: #include <boost/spirit/home/support/unused.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/support/detail/what_function.hpp>
Chris@16: #include <boost/fusion/include/any.hpp>
Chris@16: #include <boost/fusion/include/mpl.hpp>
Chris@16: #include <boost/fusion/include/for_each.hpp>
Chris@16: #include <boost/mpl/accumulate.hpp>
Chris@16: #include <boost/mpl/bitor.hpp>
Chris@16: #include <boost/config.hpp>
Chris@16: 
Chris@16: namespace boost { namespace spirit
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     // Enablers
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <>
Chris@16:     struct use_operator<karma::domain, proto::tag::bitwise_or>  // enables |
Chris@16:       : mpl::true_ {};
Chris@16: 
Chris@16:     template <>
Chris@16:     struct flatten_tree<karma::domain, proto::tag::bitwise_or>  // flattens |
Chris@16:       : mpl::true_ {};
Chris@16: 
Chris@16: }}
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace spirit { namespace traits
Chris@16: {
Chris@16:     // specialization for sequences
Chris@16:     template <typename Elements>
Chris@16:     struct alternative_properties
Chris@16:     {
Chris@16:         struct element_properties
Chris@16:         {
Chris@16:             template <typename T>
Chris@16:             struct result;
Chris@16: 
Chris@16:             template <typename F, typename Element>
Chris@16:             struct result<F(Element)>
Chris@16:             {
Chris@16:                 typedef properties_of<Element> type;
Chris@16:             };
Chris@16: 
Chris@16:             // never called, but needed for decltype-based result_of (C++0x)
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:             template <typename Element>
Chris@16:             typename result<element_properties(Element)>::type
Chris@16:             operator()(Element&&) const;
Chris@16: #endif
Chris@16:         };
Chris@16: 
Chris@16:         typedef typename mpl::accumulate<
Chris@16:             typename fusion::result_of::transform<
Chris@16:                 Elements, element_properties>::type
Chris@16:           , mpl::int_<karma::generator_properties::countingbuffer>
Chris@16:           , mpl::bitor_<mpl::_2, mpl::_1>
Chris@16:         >::type type;
Chris@16:     };
Chris@16: 
Chris@16: }}}
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace karma
Chris@16: {
Chris@16:     template <typename Elements, typename Strict, typename Derived>
Chris@16:     struct base_alternative : nary_generator<Derived>
Chris@16:     {
Chris@16:         typedef typename traits::alternative_properties<Elements>::type 
Chris@16:             properties;
Chris@16: 
Chris@16:         template <typename Context, typename Iterator = unused_type>
Chris@16:         struct attribute
Chris@16:         {
Chris@16:             // Put all the element attributes in a tuple
Chris@16:             typedef typename traits::build_attribute_sequence<
Chris@16:                 Elements, Context, traits::alternative_attribute_transform
Chris@16:               , Iterator, karma::domain
Chris@16:             >::type all_attributes;
Chris@16: 
Chris@16:             // Ok, now make a variant over the attribute sequence. Note that
Chris@16:             // build_variant makes sure that 1) all attributes in the variant
Chris@16:             // are unique 2) puts the unused attribute, if there is any, to
Chris@16:             // the front and 3) collapses single element variants, variant<T>
Chris@16:             // to T.
Chris@16:             typedef typename traits::build_variant<all_attributes>::type type;
Chris@16:         };
Chris@16: 
Chris@16:         base_alternative(Elements const& elements)
Chris@16:           : elements(elements) {}
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
Chris@16:           , Delimiter const& d, Attribute const& attr) const
Chris@16:         {
Chris@16:             typedef detail::alternative_generate_function<
Chris@16:                 OutputIterator, Context, Delimiter, Attribute, Strict
Chris@16:             > functor;
Chris@16: 
Chris@16:             // f return true if *any* of the parser succeeds
Chris@16:             functor f (sink, ctx, d, attr);
Chris@16:             return fusion::any(elements, f);
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Context>
Chris@16:         info what(Context& context) const
Chris@16:         {
Chris@16:             info result("alternative");
Chris@16:             fusion::for_each(elements,
Chris@16:                 spirit::detail::what_function<Context>(result, context));
Chris@16:             return result;
Chris@16:         }
Chris@16: 
Chris@16:         Elements elements;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename Elements>
Chris@16:     struct alternative 
Chris@16:       : base_alternative<Elements, mpl::false_, alternative<Elements> >
Chris@16:     {
Chris@16:         typedef base_alternative<Elements, mpl::false_, alternative> 
Chris@16:             base_alternative_;
Chris@16: 
Chris@16:         alternative(Elements const& elements)
Chris@16:           : base_alternative_(elements) {}
Chris@16:     };
Chris@16: 
Chris@16:     template <typename Elements>
Chris@16:     struct strict_alternative 
Chris@16:       : base_alternative<Elements, mpl::true_, strict_alternative<Elements> >
Chris@16:     {
Chris@16:         typedef base_alternative<Elements, mpl::true_, strict_alternative> 
Chris@16:             base_alternative_;
Chris@16: 
Chris@16:         strict_alternative(Elements const& elements)
Chris@16:           : base_alternative_(elements) {}
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     // Generator generators: make_xxx function (objects)
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     namespace detail
Chris@16:     {
Chris@16:         template <typename Elements, bool strict_mode = false>
Chris@16:         struct make_alternative 
Chris@16:           : make_nary_composite<Elements, alternative>
Chris@16:         {};
Chris@16: 
Chris@16:         template <typename Elements>
Chris@16:         struct make_alternative<Elements, true> 
Chris@16:           : make_nary_composite<Elements, strict_alternative>
Chris@16:         {};
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Elements, typename Modifiers>
Chris@16:     struct make_composite<proto::tag::bitwise_or, Elements, Modifiers>
Chris@16:       : detail::make_alternative<Elements
Chris@16:           , detail::get_stricttag<Modifiers>::value>
Chris@16:     {};
Chris@16: 
Chris@16: }}}
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace traits
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Elements>
Chris@16:     struct has_semantic_action<karma::alternative<Elements> >
Chris@16:       : nary_has_semantic_action<Elements> {};
Chris@16: 
Chris@16:     template <typename Elements>
Chris@16:     struct has_semantic_action<karma::strict_alternative<Elements> >
Chris@16:       : nary_has_semantic_action<Elements> {};
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Elements, typename Attribute, typename Context
Chris@16:       , typename Iterator>
Chris@16:     struct handles_container<karma::alternative<Elements>
Chris@16:           , Attribute, Context, Iterator>
Chris@16:       : nary_handles_container<Elements, Attribute, Context, Iterator> {};
Chris@16: 
Chris@16:     template <typename Elements, typename Attribute, typename Context
Chris@16:       , typename Iterator>
Chris@16:     struct handles_container<karma::strict_alternative<Elements>
Chris@16:           , Attribute, Context, Iterator>
Chris@16:       : nary_handles_container<Elements, Attribute, Context, Iterator> {};
Chris@16: }}}
Chris@16: 
Chris@16: #endif