karma/operator/and_predicate.hpp

0001 //  Copyright (c) 2001-2011 Hartmut Kaiser
0002 //  Copyright (c) 2001-2011 Joel de Guzman
0003 //
0004 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006
0007 #ifndef BOOST_SPIRIT_KARMA_OPERATOR_AND_PREDICATE_HPP
0008 #define BOOST_SPIRIT_KARMA_OPERATOR_AND_PREDICATE_HPP
0009
0010 #if defined(_MSC_VER)
0011 #pragma once
0012 #endif
0013
0014 #include <boost/spirit/home/karma/domain.hpp>
0015 #include <boost/spirit/home/karma/meta_compiler.hpp>
0016 #include <boost/spirit/home/karma/generator.hpp>
0017 #include <boost/spirit/home/karma/detail/output_iterator.hpp>
0018 #include <boost/spirit/home/karma/detail/attributes.hpp>
0019 #include <boost/spirit/home/support/info.hpp>
0020 #include <boost/spirit/home/support/has_semantic_action.hpp>
0021 #include <boost/spirit/home/support/handles_container.hpp>
0022 #include <boost/proto/operators.hpp>
0023 #include <boost/proto/tags.hpp>
0024
0025 namespace boost { namespace spirit
0026 {
0027     ///////////////////////////////////////////////////////////////////////////
0028     // Enablers
0029     ///////////////////////////////////////////////////////////////////////////
0030     template <>
0031     struct use_operator<karma::domain, proto::tag::address_of> // enables &g
0032       : mpl::true_ {};
0033 }}
0034
0035 namespace boost { namespace spirit { namespace karma
0036 {
0037     template <typename Subject>
0038     struct and_predicate : unary_generator<and_predicate<Subject> >
0039     {
0040         typedef Subject subject_type;
0041         typedef mpl::int_<
0042             generator_properties::disabling | subject_type::properties::value
0043         > properties;
0044
0045         template <typename Context, typename Iterator>
0046         struct attribute
0047           : traits::attribute_of<subject_type, Context, Iterator>
0048         {};
0049
0050         and_predicate(Subject const& subject)
0051           : subject(subject) {}
0052
0053         template <
0054             typename OutputIterator, typename Context, typename Delimiter
0055           , typename Attribute>
0056         bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d
0057           , Attribute const& attr) const
0058         {
0059             // inhibits output
0060             detail::disable_output<OutputIterator> disable(sink);
0061             return subject.generate(sink, ctx, d, attr);
0062         }
0063
0064         template <typename Context>
0065         info what(Context& context) const
0066         {
0067             return info("and-predicate", subject.what(context));
0068         }
0069
0070         Subject subject;
0071     };
0072
0073     ///////////////////////////////////////////////////////////////////////////
0074     // Generator generators: make_xxx function (objects)
0075     ///////////////////////////////////////////////////////////////////////////
0076     template <typename Elements, typename Modifiers>
0077     struct make_composite<proto::tag::address_of, Elements, Modifiers>
0078       : make_unary_composite<Elements, and_predicate> {};
0079
0080 }}}
0081
0082 namespace boost { namespace spirit { namespace traits
0083 {
0084     ///////////////////////////////////////////////////////////////////////////
0085     template <typename Subject>
0086     struct has_semantic_action<karma::and_predicate<Subject> >
0087       : unary_has_semantic_action<Subject> {};
0088
0089     ///////////////////////////////////////////////////////////////////////////
0090     template <typename Subject, typename Attribute, typename Context
0091       , typename Iterator>
0092     struct handles_container<karma::and_predicate<Subject>, Attribute
0093       , Context, Iterator>
0094       : unary_handles_container<Subject, Attribute, Context, Iterator> {};
0095 }}}
0096
0097 #endif