119 lines
4.3 KiB
C++
119 lines
4.3 KiB
C++
// 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)
|
|
|
|
#ifndef BOOST_SPIRIT_KARMA_AUXILIARY_ATTR_CAST_HPP
|
|
#define BOOST_SPIRIT_KARMA_AUXILIARY_ATTR_CAST_HPP
|
|
|
|
#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
|