boost/spirit/home/karma/operator/list.hpp
// Copyright (c) 2001-2010 Hartmut Kaiser
// Copyright (c) 2001-2010 Joel de Guzman
//
// 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_LIST_MAY_01_2007_0229PM)
#define SPIRIT_KARMA_LIST_MAY_01_2007_0229PM
#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/support/info.hpp>
#include <boost/spirit/home/support/unused.hpp>
#include <boost/spirit/home/support/container.hpp>
#include <boost/spirit/home/support/attributes.hpp>
namespace boost { namespace spirit
{
///////////////////////////////////////////////////////////////////////////
// Enablers
///////////////////////////////////////////////////////////////////////////
template <>
struct use_operator<karma::domain, proto::tag::modulus> // enables g % d
: mpl::true_ {};
}}
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit { namespace karma
{
template <typename Left, typename Right>
struct list : binary_generator<list<Left, Right> >
{
private:
// iterate over the given container until its exhausted or the embedded
// (left) generator succeeds
template <
typename OutputIterator, typename Context, typename Delimiter
, typename Iterator>
bool generate_left(OutputIterator& sink, Context& ctx
, Delimiter const& d, Iterator& it, Iterator& end) const
{
while (!traits::compare(it, end))
{
if (left.generate(sink, ctx, d, traits::deref(it)))
return true;
traits::next(it);
}
return false;
}
public:
typedef Left left_type;
typedef Right right_type;
typedef mpl::int_<
left_type::properties::value
| right_type::properties::value
| generator_properties::buffering
| generator_properties::counting
> properties;
// Build a std::vector from the LHS's 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<Left, Context, Iterator>::type>
{};
list(Left const& left, Right const& right)
: left(left), right(right)
{}
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);
if (generate_left(sink, ctx, d, it, end))
{
for (traits::next(it); !traits::compare(it, end); traits::next(it))
{
// wrap the given output iterator as generate_left might fail
detail::enable_buffering<OutputIterator> buffering(sink);
{
detail::disable_counting<OutputIterator> nocounting(sink);
if (!right.generate(sink, ctx, d, unused))
return false; // shouldn't happen
if (!generate_left(sink, ctx, d, it, end))
break; // return true as one item succeeded
}
buffering.buffer_copy();
}
return true;
}
return false;
}
template <typename Context>
info what(Context& context) const
{
return info("list",
std::make_pair(left.what(context), right.what(context)));
}
Left left;
Right right;
};
///////////////////////////////////////////////////////////////////////////
// Generator generators: make_xxx function (objects)
///////////////////////////////////////////////////////////////////////////
template <typename Elements, typename Modifiers>
struct make_composite<proto::tag::modulus, Elements, Modifiers>
: make_binary_composite<Elements, list>
{};
}}}
namespace boost { namespace spirit { namespace traits
{
template <typename Left, typename Right>
struct has_semantic_action<karma::list<Left, Right> >
: binary_has_semantic_action<Left, Right> {};
}}}
#endif