// 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_BUFFER_AUG_03_2009_0949AM) | |
#define SPIRIT_KARMA_BUFFER_AUG_03_2009_0949AM | |
#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/karma/detail/output_iterator.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/support/has_semantic_action.hpp> | |
#include <boost/spirit/home/support/handles_container.hpp> | |
#include <boost/spirit/home/karma/detail/attributes.hpp> | |
namespace boost { namespace spirit | |
{ | |
/////////////////////////////////////////////////////////////////////////// | |
// Enablers | |
/////////////////////////////////////////////////////////////////////////// | |
template <> | |
struct use_directive<karma::domain, tag::buffer> // enables buffer | |
: mpl::true_ {}; | |
}} | |
namespace boost { namespace spirit { namespace karma | |
{ | |
using spirit::buffer; | |
using spirit::buffer_type; | |
/////////////////////////////////////////////////////////////////////////// | |
// buffer_directive buffers all generated output of the embedded generator | |
// and flushes it only if the whole embedded generator succeeds | |
/////////////////////////////////////////////////////////////////////////// | |
template <typename Subject> | |
struct buffer_directive : unary_generator<buffer_directive<Subject> > | |
{ | |
typedef Subject subject_type; | |
typedef mpl::int_< | |
subject_type::properties::value | | |
generator_properties::countingbuffer | |
> properties; | |
buffer_directive(Subject const& subject) | |
: subject(subject) {} | |
template <typename Context, typename Iterator> | |
struct attribute | |
: traits::attribute_of<subject_type, Context, Iterator> | |
{}; | |
template <typename OutputIterator, typename Context, typename Delimiter | |
, typename Attribute> | |
bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d | |
, Attribute const& attr) const | |
{ | |
// wrap the given output iterator to avoid output as long as the | |
// embedded generator (subject) fails | |
detail::enable_buffering<OutputIterator> buffering(sink); | |
bool r = false; | |
{ | |
detail::disable_counting<OutputIterator> nocounting(sink); | |
r = subject.generate(sink, ctx, d, attr); | |
} | |
if (r) | |
buffering.buffer_copy(); | |
return r; | |
} | |
template <typename Context> | |
info what(Context& context) const | |
{ | |
return info("buffer", subject.what(context)); | |
} | |
Subject subject; | |
}; | |
/////////////////////////////////////////////////////////////////////////// | |
// Generator generators: make_xxx function (objects) | |
/////////////////////////////////////////////////////////////////////////// | |
template <typename Subject, typename Modifiers> | |
struct make_directive<tag::buffer, Subject, Modifiers> | |
{ | |
typedef buffer_directive<Subject> result_type; | |
result_type operator()(unused_type, Subject const& subject | |
, unused_type) const | |
{ | |
return result_type(subject); | |
} | |
}; | |
// make sure buffer[buffer[...]] does not result in double buffering | |
template <typename Subject, typename Modifiers> | |
struct make_directive<tag::buffer, buffer_directive<Subject>, Modifiers> | |
{ | |
typedef buffer_directive<Subject> result_type; | |
result_type operator()(unused_type | |
, buffer_directive<Subject> const& subject, unused_type) const | |
{ | |
return subject; | |
} | |
}; | |
}}} | |
namespace boost { namespace spirit { namespace traits | |
{ | |
/////////////////////////////////////////////////////////////////////////// | |
template <typename Subject> | |
struct has_semantic_action<karma::buffer_directive<Subject> > | |
: unary_has_semantic_action<Subject> {}; | |
/////////////////////////////////////////////////////////////////////////// | |
template <typename Subject, typename Attribute, typename Context | |
, typename Iterator> | |
struct handles_container<karma::buffer_directive<Subject>, Attribute | |
, Context, Iterator> | |
: unary_handles_container<Subject, Attribute, Context, Iterator> {}; | |
}}} | |
#endif |