boost/spirit/home/qi/directive/as.hpp
/*=============================================================================
Copyright (c) 2001-2011 Joel de Guzman
Copyright (c) 2001-2011 Hartmut Kaiser
Copyright (c) 2010 Bryce Lelbach
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_AS_DECEMBER_6_2010_1013AM)
#define SPIRIT_AS_DECEMBER_6_2010_1013AM
#if defined(_MSC_VER)
#pragma once
#endif
#include <boost/spirit/home/qi/meta_compiler.hpp>
#include <boost/spirit/home/qi/skip_over.hpp>
#include <boost/spirit/home/qi/parser.hpp>
#include <boost/spirit/home/qi/detail/assign_to.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/unused.hpp>
#include <boost/spirit/home/support/has_semantic_action.hpp>
#include <boost/spirit/home/support/handles_container.hpp>
#include <boost/spirit/home/support/assert_msg.hpp>
#include <boost/spirit/home/support/container.hpp>
#include <boost/range/iterator_range.hpp>
#include <string>
namespace boost { namespace spirit { namespace qi
{
template <typename T>
struct as
: stateful_tag_type<T, tag::as>
{
//~ BOOST_SPIRIT_ASSERT_MSG(
//~ (traits::is_container<T>::type::value),
//~ error_type_must_be_a_container,
//~ (T));
};
}}}
namespace boost { namespace spirit
{
///////////////////////////////////////////////////////////////////////////
// Enablers
///////////////////////////////////////////////////////////////////////////
// enables as_string[...]
template <>
struct use_directive<qi::domain, tag::as_string>
: mpl::true_ {};
// enables as_wstring[...]
template <>
struct use_directive<qi::domain, tag::as_wstring>
: mpl::true_ {};
// enables as<T>[...]
template <typename T>
struct use_directive<qi::domain, tag::stateful_tag<T, tag::as> >
: mpl::true_
{};
}}
namespace boost { namespace spirit { namespace qi
{
#ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
using spirit::as_string;
using spirit::as_wstring;
#endif
using spirit::as_string_type;
using spirit::as_wstring_type;
template <typename Subject, typename T>
struct as_directive : unary_parser<as_directive<Subject, T> >
{
typedef Subject subject_type;
as_directive(Subject const& subject_)
: subject(subject_) {}
template <typename Context, typename Iterator>
struct attribute
{
typedef T type;
};
template <typename Iterator, typename Context
, typename Skipper, typename Attribute>
bool parse(Iterator& first, Iterator const& last
, Context& context, Skipper const& skipper, Attribute& attr_) const
{
Iterator i = first;
T as_attr;
if (subject.parse(i, last, context, skipper, as_attr))
{
spirit::traits::assign_to(as_attr, attr_);
first = i;
return true;
}
return false;
}
template <typename Iterator, typename Context, typename Skipper>
bool parse(Iterator& first, Iterator const& last
, Context& context, Skipper const& skipper, T& attr_) const
{
Iterator i = first;
if (subject.parse(i, last, context, skipper, attr_))
{
first = i;
return true;
}
return false;
}
template <typename Context>
info what(Context& context) const
{
return info("as", subject.what(context));
}
Subject subject;
};
///////////////////////////////////////////////////////////////////////////
// Parser generators: make_xxx function (objects)
///////////////////////////////////////////////////////////////////////////
template <typename Subject, typename Modifiers>
struct make_directive<tag::as_string, Subject, Modifiers>
{
typedef as_directive<Subject, std::string> result_type;
result_type operator()(unused_type, Subject const& subject
, unused_type) const
{
return result_type(subject);
}
};
template <typename Subject, typename Modifiers>
struct make_directive<tag::as_wstring, Subject, Modifiers>
{
typedef as_directive<Subject, std::basic_string<wchar_t> > result_type;
result_type operator()(unused_type, Subject const& subject
, unused_type) const
{
return result_type(subject);
}
};
template <typename T, typename Subject, typename Modifiers>
struct make_directive<tag::stateful_tag<T, tag::as>, Subject, Modifiers>
{
typedef as_directive<Subject, T> result_type;
result_type operator()(unused_type, Subject const& subject
, unused_type) const
{
return result_type(subject);
}
};
}}}
namespace boost { namespace spirit { namespace traits
{
///////////////////////////////////////////////////////////////////////////
template <typename Subject, typename T>
struct has_semantic_action<qi::as_directive<Subject, T> >
: unary_has_semantic_action<Subject> {};
///////////////////////////////////////////////////////////////////////////
template <typename Subject, typename T, typename Attribute
, typename Context, typename Iterator>
struct handles_container<qi::as_directive<Subject, T>, Attribute
, Context, Iterator>
: mpl::false_ {};
}}}
#endif