boost/spirit/home/qi/operator/plus.hpp
/*=============================================================================
Copyright (c) 2001-2011 Joel de Guzman
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_QI_OPERATOR_PLUS_HPP
#define BOOST_SPIRIT_QI_OPERATOR_PLUS_HPP
#if defined(_MSC_VER)
#pragma once
#endif
#include <boost/spirit/home/qi/meta_compiler.hpp>
#include <boost/spirit/home/qi/parser.hpp>
#include <boost/spirit/home/support/container.hpp>
#include <boost/spirit/home/qi/detail/attributes.hpp>
#include <boost/spirit/home/qi/detail/fail_function.hpp>
#include <boost/spirit/home/qi/detail/pass_container.hpp>
#include <boost/spirit/home/support/has_semantic_action.hpp>
#include <boost/spirit/home/support/handles_container.hpp>
#include <boost/spirit/home/support/info.hpp>
#include <boost/proto/operators.hpp>
#include <boost/proto/tags.hpp>
namespace boost { namespace spirit
{
///////////////////////////////////////////////////////////////////////////
// Enablers
///////////////////////////////////////////////////////////////////////////
template <>
struct use_operator<qi::domain, proto::tag::unary_plus> // enables +p
: mpl::true_ {};
}}
namespace boost { namespace spirit { namespace qi
{
template <typename Subject>
struct plus : unary_parser<plus<Subject> >
{
typedef Subject subject_type;
template <typename Context, typename Iterator>
struct attribute
{
// Build a std::vector from the subject's attribute. Note
// that build_std_vector may return unused_type if the
// subject's attribute is an unused_type.
typedef typename
traits::build_std_vector<
typename traits::attribute_of<
Subject, Context, Iterator>::type
>::type
type;
};
plus(Subject const& subject_)
: subject(subject_) {}
template <typename F>
bool parse_container(F f) const
{
// in order to succeed we need to match at least one element
if (f (subject))
return false;
while (!f (subject))
;
return true;
}
template <typename Iterator, typename Context
, typename Skipper, typename Attribute>
bool parse(Iterator& first, Iterator const& last
, Context& context, Skipper const& skipper
, Attribute& attr_) const
{
typedef detail::fail_function<Iterator, Context, Skipper>
fail_function;
// ensure the attribute is actually a container type
traits::make_container(attr_);
Iterator iter = first;
fail_function f(iter, last, context, skipper);
if (!parse_container(detail::make_pass_container(f, attr_)))
return false;
first = f.first;
return true;
}
template <typename Context>
info what(Context& context) const
{
return info("plus", subject.what(context));
}
Subject subject;
};
///////////////////////////////////////////////////////////////////////////
// Parser generators: make_xxx function (objects)
///////////////////////////////////////////////////////////////////////////
template <typename Elements, typename Modifiers>
struct make_composite<proto::tag::unary_plus, Elements, Modifiers>
: make_unary_composite<Elements, plus>
{};
}}}
namespace boost { namespace spirit { namespace traits
{
///////////////////////////////////////////////////////////////////////////
template <typename Subject>
struct has_semantic_action<qi::plus<Subject> >
: unary_has_semantic_action<Subject> {};
///////////////////////////////////////////////////////////////////////////
template <typename Subject, typename Attribute, typename Context
, typename Iterator>
struct handles_container<qi::plus<Subject>, Attribute, Context
, Iterator>
: mpl::true_ {};
}}}
#endif