// Copyright (c) 2001-2011 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 |