| // Copyright (c) 2001-2010 Joel de Guzman |
| // Copyright (c) 2001-2010 Hartmut Kaiser |
| // |
| // 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) |
| |
| #if !defined(BOOST_SPIRIT_KARMA_POSITIVE_MAR_03_2007_0945PM) |
| #define BOOST_SPIRIT_KARMA_POSITIVE_MAR_03_2007_0945PM |
| |
| #if defined(_MSC_VER) |
| #pragma once |
| #endif |
| |
| #include <boost/spirit/home/karma/domain.hpp> |
| #include <boost/spirit/home/karma/generator.hpp> |
| #include <boost/spirit/home/karma/meta_compiler.hpp> |
| #include <boost/spirit/home/karma/detail/output_iterator.hpp> |
| #include <boost/spirit/home/karma/detail/get_stricttag.hpp> |
| #include <boost/spirit/home/support/info.hpp> |
| #include <boost/spirit/home/support/unused.hpp> |
| #include <boost/spirit/home/support/container.hpp> |
| #include <boost/spirit/home/karma/detail/attributes.hpp> |
| |
| #include <boost/type_traits/add_const.hpp> |
| |
| namespace boost { namespace spirit |
| { |
| /////////////////////////////////////////////////////////////////////////// |
| // Enablers |
| /////////////////////////////////////////////////////////////////////////// |
| template <> |
| struct use_operator<karma::domain, proto::tag::unary_plus> // enables +g |
| : mpl::true_ {}; |
| }} |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| namespace boost { namespace spirit { namespace karma |
| { |
| template <typename Subject, typename Strict, typename Derived> |
| struct base_plus : unary_generator<Derived> |
| { |
| private: |
| template < |
| typename OutputIterator, typename Context, typename Delimiter |
| , typename Attribute> |
| bool generate_subject(OutputIterator& sink, Context& ctx |
| , Delimiter const& d, Attribute const& attr, bool& result) const |
| { |
| // Ignore return value, failing subject generators are just |
| // skipped. This allows to selectively generate items in the |
| // provided attribute. |
| if (subject.generate(sink, ctx, d, attr)) { |
| result = true; |
| return true; |
| } |
| return !Strict::value; |
| } |
| |
| template <typename OutputIterator, typename Context, typename Delimiter> |
| bool generate_subject(OutputIterator& sink, Context& ctx |
| , Delimiter const& d, unused_type, bool& result) const |
| { |
| // There is no way to distinguish a failed generator from a |
| // generator to be skipped. We assume the user takes responsibility |
| // for ending the loop if no attribute is specified. |
| if (subject.generate(sink, ctx, d, unused)) { |
| result = true; |
| return true; |
| } |
| return false; |
| } |
| |
| public: |
| typedef Subject subject_type; |
| typedef typename subject_type::properties properties; |
| |
| // Build a std::vector from the subjects attribute. Note |
| // that build_std_vector may return unused_type if the |
| // subject's attribute is an unused_type. |
| template <typename Context, typename Iterator> |
| struct attribute |
| : traits::build_std_vector< |
| typename traits::attribute_of<subject_type, Context, Iterator>::type |
| > |
| {}; |
| |
| base_plus(Subject const& subject) |
| : subject(subject) {} |
| |
| template < |
| typename OutputIterator, typename Context, typename Delimiter |
| , typename Attribute> |
| bool generate(OutputIterator& sink, Context& ctx |
| , Delimiter const& d, Attribute const& attr) const |
| { |
| typedef typename traits::container_iterator< |
| typename add_const<Attribute>::type |
| >::type iterator_type; |
| |
| iterator_type it = traits::begin(attr); |
| iterator_type end = traits::end(attr); |
| |
| // plus fails if the parameter is empty |
| if (traits::compare(it, end)) |
| return false; |
| |
| // from now on plus fails if the underlying output fails or overall |
| // no subject generators succeeded |
| bool result = false; |
| for (/**/; detail::sink_is_good(sink) && !traits::compare(it, end); |
| traits::next(it)) |
| { |
| if (!generate_subject(sink, ctx, d, traits::deref(it), result)) |
| break; |
| } |
| return result && detail::sink_is_good(sink); |
| } |
| |
| template <typename Context> |
| info what(Context& context) const |
| { |
| return info("plus", subject.what(context)); |
| } |
| |
| Subject subject; |
| }; |
| |
| template <typename Subject> |
| struct plus |
| : base_plus<Subject, mpl::false_, plus<Subject> > |
| { |
| typedef base_plus<Subject, mpl::false_, plus> base_plus_; |
| |
| plus(Subject const& subject) |
| : base_plus_(subject) {} |
| }; |
| |
| template <typename Subject> |
| struct strict_plus |
| : base_plus<Subject, mpl::true_, strict_plus<Subject> > |
| { |
| typedef base_plus<Subject, mpl::true_, strict_plus> base_plus_; |
| |
| strict_plus(Subject const& subject) |
| : base_plus_(subject) {} |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Generator generators: make_xxx function (objects) |
| /////////////////////////////////////////////////////////////////////////// |
| namespace detail |
| { |
| template <typename Elements, bool strict_mode = false> |
| struct make_plus |
| : make_unary_composite<Elements, plus> |
| {}; |
| |
| template <typename Elements> |
| struct make_plus<Elements, true> |
| : make_unary_composite<Elements, strict_plus> |
| {}; |
| } |
| |
| template <typename Elements, typename Modifiers> |
| struct make_composite<proto::tag::unary_plus, Elements, Modifiers> |
| : detail::make_plus<Elements, detail::get_stricttag<Modifiers>::value> |
| {}; |
| }}} |
| |
| namespace boost { namespace spirit { namespace traits |
| { |
| template <typename Subject> |
| struct has_semantic_action<karma::plus<Subject> > |
| : unary_has_semantic_action<Subject> {}; |
| |
| template <typename Subject> |
| struct has_semantic_action<karma::strict_plus<Subject> > |
| : unary_has_semantic_action<Subject> {}; |
| }}} |
| |
| #endif |