| // 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(SPIRIT_KARMA_ATTR_CAST_SEP_26_2009_0348PM) |
| #define SPIRIT_KARMA_ATTR_CAST_SEP_26_2009_0348PM |
| |
| #if defined(_MSC_VER) |
| #pragma once |
| #endif |
| |
| #include <boost/spirit/home/karma/meta_compiler.hpp> |
| #include <boost/spirit/home/karma/generator.hpp> |
| #include <boost/spirit/home/karma/domain.hpp> |
| #include <boost/spirit/home/support/unused.hpp> |
| #include <boost/spirit/home/support/info.hpp> |
| #include <boost/spirit/home/support/common_terminals.hpp> |
| #include <boost/spirit/home/karma/detail/attributes.hpp> |
| #include <boost/spirit/home/support/auxiliary/attr_cast.hpp> |
| |
| namespace boost { namespace spirit |
| { |
| /////////////////////////////////////////////////////////////////////////// |
| // enables attr_cast<>() pseudo generator |
| template <typename Expr, typename Exposed, typename Transformed> |
| struct use_terminal<karma::domain |
| , tag::stateful_tag<Expr, tag::attr_cast, Exposed, Transformed> > |
| : mpl::true_ {}; |
| }} |
| |
| namespace boost { namespace spirit { namespace karma |
| { |
| using spirit::attr_cast; |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // attr_cast_generator consumes the attribute of subject generator without |
| // generating anything |
| /////////////////////////////////////////////////////////////////////////// |
| template <typename Exposed, typename Transformed, typename Subject> |
| struct attr_cast_generator |
| : unary_generator<attr_cast_generator<Exposed, Transformed, Subject> > |
| { |
| typedef typename result_of::compile<karma::domain, Subject>::type |
| subject_type; |
| |
| typedef mpl::int_<subject_type::properties::value> properties; |
| |
| typedef typename mpl::eval_if< |
| traits::not_is_unused<Transformed> |
| , mpl::identity<Transformed> |
| , traits::attribute_of<subject_type> >::type |
| transformed_attribute_type; |
| |
| attr_cast_generator(Subject const& subject) |
| : subject(subject) |
| { |
| // If you got an error_invalid_expression error message here, |
| // then the expression (Subject) is not a valid spirit karma |
| // expression. |
| BOOST_SPIRIT_ASSERT_MATCH(karma::domain, Subject); |
| } |
| |
| // If Exposed is given, we use the given type, otherwise all we can do |
| // is to guess, so we expose our inner type as an attribute and |
| // deal with the passed attribute inside the parse function. |
| template <typename Context, typename Unused> |
| struct attribute |
| : mpl::if_<traits::not_is_unused<Exposed>, Exposed |
| , transformed_attribute_type> |
| {}; |
| |
| template <typename OutputIterator, typename Context, typename Delimiter |
| , typename Attribute> |
| bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d |
| , Attribute const& attr) const |
| { |
| typedef traits::transform_attribute< |
| Attribute const, transformed_attribute_type, domain> |
| transform; |
| |
| return compile<karma::domain>(subject).generate( |
| sink, ctx, d, transform::pre(attr)); |
| } |
| |
| template <typename Context> |
| info what(Context& context) const |
| { |
| return info("attr_cast" |
| , compile<karma::domain>(subject).what(context)); |
| } |
| |
| Subject subject; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Generator generator: make_xxx function (objects) |
| /////////////////////////////////////////////////////////////////////////// |
| template <typename Expr, typename Exposed, typename Transformed |
| , typename Modifiers> |
| struct make_primitive< |
| tag::stateful_tag<Expr, tag::attr_cast, Exposed, Transformed>, Modifiers> |
| { |
| typedef attr_cast_generator<Exposed, Transformed, Expr> result_type; |
| |
| template <typename Terminal> |
| result_type operator()(Terminal const& term, unused_type) const |
| { |
| typedef tag::stateful_tag< |
| Expr, tag::attr_cast, Exposed, Transformed> tag_type; |
| using spirit::detail::get_stateful_data; |
| return result_type(get_stateful_data<tag_type>::call(term)); |
| } |
| }; |
| |
| }}} |
| |
| #endif |