Chris@16: //  Copyright (c) 2001-2011 Joel de Guzman
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_POSITIVE_MAR_03_2007_0945PM)
Chris@16: #define BOOST_SPIRIT_KARMA_POSITIVE_MAR_03_2007_0945PM
Chris@16: 
Chris@16: #if defined(_MSC_VER)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
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/karma/detail/indirect_iterator.hpp>
Chris@16: #include <boost/spirit/home/karma/detail/output_iterator.hpp>
Chris@16: #include <boost/spirit/home/karma/detail/get_stricttag.hpp>
Chris@16: #include <boost/spirit/home/karma/detail/pass_container.hpp>
Chris@16: #include <boost/spirit/home/karma/detail/fail_function.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/container.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/detail/attributes.hpp>
Chris@16: 
Chris@16: #include <boost/type_traits/add_const.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::unary_plus> // enables +g
Chris@16:       : mpl::true_ {};
Chris@16: }}
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace spirit { namespace karma
Chris@16: {
Chris@16:     template <typename Subject, typename Strict, typename Derived>
Chris@16:     struct base_plus : unary_generator<Derived>
Chris@16:     {
Chris@16:     private:
Chris@16:         // Ignore return value in relaxed mode (failing subject generators 
Chris@16:         // are just skipped). This allows to selectively generate items in 
Chris@16:         // the provided attribute.
Chris@16:         template <typename F, typename Attribute>
Chris@16:         bool generate_subject(F f, Attribute const&, bool& result, mpl::false_) const
Chris@16:         {
Chris@16:             bool r = !f(subject);
Chris@16:             if (r) 
Chris@16:                 result = true;
Chris@16:             else if (!f.is_at_end())
Chris@16:                 f.next();
Chris@16:             return true;
Chris@16:         }
Chris@16: 
Chris@16:         template <typename F, typename Attribute>
Chris@16:         bool generate_subject(F f, Attribute const&, bool& result, mpl::true_) const
Chris@16:         {
Chris@16:             bool r = !f(subject);
Chris@16:             if (r)
Chris@16:                 result = true;
Chris@16:             return r;
Chris@16:         }
Chris@16: 
Chris@16:         // There is no way to distinguish a failed generator from a 
Chris@16:         // generator to be skipped. We assume the user takes responsibility
Chris@16:         // for ending the loop if no attribute is specified.
Chris@16:         template <typename F>
Chris@16:         bool generate_subject(F f, unused_type, bool& result, mpl::false_) const
Chris@16:         {
Chris@16:             bool r = f(subject);
Chris@16:             if (!r)
Chris@16:                 result = true;
Chris@16:             return !r;
Chris@16:         }
Chris@16: 
Chris@16: //         template <typename F>
Chris@16: //         bool generate_subject(F f, unused_type, bool& result, mpl::true_) const
Chris@16: //         {
Chris@16: //             bool r = f(subject);
Chris@16: //             if (!r)
Chris@16: //                 result = true;
Chris@16: //             return !r;
Chris@16: //         }
Chris@16: 
Chris@16:     public:
Chris@16:         typedef Subject subject_type;
Chris@16:         typedef typename subject_type::properties properties;
Chris@16: 
Chris@16:         // Build a std::vector from the subjects attribute. Note
Chris@16:         // that build_std_vector may return unused_type if the
Chris@16:         // subject's attribute is an unused_type.
Chris@16:         template <typename Context, typename Iterator>
Chris@16:         struct attribute
Chris@16:           : traits::build_std_vector<
Chris@16:                 typename traits::attribute_of<subject_type, Context, Iterator>::type
Chris@16:             >
Chris@16:         {};
Chris@16: 
Chris@16:         base_plus(Subject const& subject)
Chris@16:           : subject(subject) {}
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::fail_function<
Chris@16:                 OutputIterator, Context, Delimiter> fail_function;
Chris@16: 
Chris@16:             typedef typename traits::container_iterator<
Chris@16:                 typename add_const<Attribute>::type
Chris@16:             >::type iterator_type;
Chris@16: 
Chris@16:             typedef 
Chris@16:                 typename traits::make_indirect_iterator<iterator_type>::type 
Chris@16:             indirect_iterator_type;
Chris@16:             typedef detail::pass_container<
Chris@16:                 fail_function, Attribute, indirect_iterator_type, mpl::false_>
Chris@16:             pass_container;
Chris@16: 
Chris@16:             iterator_type it = traits::begin(attr);
Chris@16:             iterator_type end = traits::end(attr);
Chris@16: 
Chris@16:             // plus fails if the parameter is empty
Chris@16:             if (traits::compare(it, end))
Chris@16:                 return false;
Chris@16: 
Chris@16:             pass_container pass(fail_function(sink, ctx, d), 
Chris@16:                 indirect_iterator_type(it), indirect_iterator_type(end));
Chris@16: 
Chris@16:             // from now on plus fails if the underlying output fails or overall
Chris@16:             // no subject generators succeeded
Chris@16:             bool result = false;
Chris@16:             while (!pass.is_at_end())
Chris@16:             {
Chris@16:                 if (!generate_subject(pass, attr, result, Strict()))
Chris@16:                     break;
Chris@16:             }
Chris@16:             return result && detail::sink_is_good(sink);
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Context>
Chris@16:         info what(Context& context) const
Chris@16:         {
Chris@16:             return info("plus", subject.what(context));
Chris@16:         }
Chris@16: 
Chris@16:         Subject subject;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename Subject>
Chris@16:     struct plus 
Chris@16:       : base_plus<Subject, mpl::false_, plus<Subject> >
Chris@16:     {
Chris@16:         typedef base_plus<Subject, mpl::false_, plus> base_plus_;
Chris@16: 
Chris@16:         plus(Subject const& subject)
Chris@16:           : base_plus_(subject) {}
Chris@16:     };
Chris@16: 
Chris@16:     template <typename Subject>
Chris@16:     struct strict_plus 
Chris@16:       : base_plus<Subject, mpl::true_, strict_plus<Subject> >
Chris@16:     {
Chris@16:         typedef base_plus<Subject, mpl::true_, strict_plus> base_plus_;
Chris@16: 
Chris@16:         strict_plus(Subject const& subject)
Chris@16:           : base_plus_(subject) {}
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_plus 
Chris@16:           : make_unary_composite<Elements, plus>
Chris@16:         {};
Chris@16: 
Chris@16:         template <typename Elements>
Chris@16:         struct make_plus<Elements, true> 
Chris@16:           : make_unary_composite<Elements, strict_plus>
Chris@16:         {};
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Elements, typename Modifiers>
Chris@16:     struct make_composite<proto::tag::unary_plus, Elements, Modifiers>
Chris@16:       : detail::make_plus<Elements, detail::get_stricttag<Modifiers>::value>
Chris@16:     {};
Chris@16: }}}
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace traits
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject>
Chris@16:     struct has_semantic_action<karma::plus<Subject> >
Chris@16:       : unary_has_semantic_action<Subject> {};
Chris@16: 
Chris@16:     template <typename Subject>
Chris@16:     struct has_semantic_action<karma::strict_plus<Subject> >
Chris@16:       : unary_has_semantic_action<Subject> {};
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject, typename Attribute, typename Context
Chris@16:       , typename Iterator>
Chris@16:     struct handles_container<karma::plus<Subject>, Attribute
Chris@16:           , Context, Iterator>
Chris@16:       : mpl::true_ {};
Chris@16: 
Chris@16:     template <typename Subject, typename Attribute, typename Context
Chris@16:       , typename Iterator>
Chris@16:     struct handles_container<karma::strict_plus<Subject>, Attribute
Chris@16:           , Context, Iterator>
Chris@16:       : mpl::true_ {};
Chris@16: }}}
Chris@16: 
Chris@16: #endif