Chris@102: /*=============================================================================
Chris@102:     Copyright (c) 2001-2014 Joel de Guzman
Chris@102:     Copyright (c) 2013-2014 Agustin Berge
Chris@102: 
Chris@102:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@102:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@102: ==============================================================================*/
Chris@102: #if !defined(BOOST_SPIRIT_X3_AUXILIARY_ANY_PARSER_APR_09_2014_1145PM)
Chris@102: #define BOOST_SPIRIT_X3_AUXILIARY_ANY_PARSER_APR_09_2014_1145PM
Chris@102: 
Chris@102: #if defined(_MSC_VER)
Chris@102: #pragma once
Chris@102: #endif
Chris@102: 
Chris@102: #include <boost/spirit/home/x3/core/parser.hpp>
Chris@102: #include <boost/spirit/home/x3/support/context.hpp>
Chris@102: #include <boost/spirit/home/x3/support/subcontext.hpp>
Chris@102: #include <boost/spirit/home/x3/support/unused.hpp>
Chris@102: #include <boost/spirit/home/x3/support/traits/container_traits.hpp>
Chris@102: #include <boost/spirit/home/x3/support/traits/has_attribute.hpp>
Chris@102: #include <boost/spirit/home/x3/support/traits/move_to.hpp>
Chris@102: #include <boost/spirit/home/x3/support/traits/is_parser.hpp>
Chris@102: #include <memory>
Chris@102: #include <string>
Chris@102: 
Chris@102: namespace boost { namespace spirit { namespace x3
Chris@102: {
Chris@102:     template <
Chris@102:         typename Iterator
Chris@102:       , typename Attribute = unused_type
Chris@102:       , typename Context = subcontext<>>
Chris@102:     struct any_parser : parser<any_parser<Iterator, Attribute, Context>>
Chris@102:     {
Chris@102:         typedef Attribute attribute_type;
Chris@102: 
Chris@102:         static bool const has_attribute =
Chris@102:             !is_same<unused_type, attribute_type>::value;
Chris@102:         static bool const handles_container =
Chris@102:             traits::is_container<Attribute>::value;
Chris@102: 
Chris@102:     public:
Chris@102:         any_parser()
Chris@102:           : _content(nullptr) {}
Chris@102: 
Chris@102:         template <typename Expr,
Chris@102:             typename Enable = typename enable_if<traits::is_parser<Expr>>::type>
Chris@102:         any_parser(Expr const& expr)
Chris@102:           : _content(new holder<Expr>(expr)) {}
Chris@102: 
Chris@102:         any_parser(any_parser const& other)
Chris@102:           : _content(other._content ? other._content->clone() : nullptr) {}
Chris@102: 
Chris@102:         any_parser(any_parser&& other) = default;
Chris@102: 
Chris@102:         any_parser& operator=(any_parser const& other)
Chris@102:         {
Chris@102:             _content.reset(other._content ? other._content->clone() : nullptr);
Chris@102:             return *this;
Chris@102:         }
Chris@102: 
Chris@102:         any_parser& operator=(any_parser&& other) = default;
Chris@102: 
Chris@102:         template <typename Iterator_, typename Context_>
Chris@102:         bool parse(Iterator_& first, Iterator_ const& last
Chris@102:           , Context_ const& context, unused_type, Attribute& attr) const
Chris@102:         {
Chris@102:             BOOST_STATIC_ASSERT_MSG(
Chris@102:                 (is_same<Iterator, Iterator_>::value)
Chris@102:               , "Incompatible iterator used"
Chris@102:             );
Chris@102: 
Chris@102:             BOOST_ASSERT_MSG(
Chris@102:                 (_content != nullptr)
Chris@102:               , "Invalid use of uninitialized any_parser"
Chris@102:             );
Chris@102: 
Chris@102:             return _content->parse(first, last, context, attr);
Chris@102:         }
Chris@102: 
Chris@102:         template <typename Iterator_, typename Context_, typename Attribute_>
Chris@102:         bool parse(Iterator_& first, Iterator_ const& last
Chris@102:           , Context_ const& context, unused_type, Attribute_& attr_) const
Chris@102:         {
Chris@102:             Attribute attr;
Chris@102:             if (parse(first, last, context, unused, attr))
Chris@102:             {
Chris@102:                 traits::move_to(attr, attr_);
Chris@102:                 return true;
Chris@102:             }
Chris@102:             return false;
Chris@102:         }
Chris@102: 
Chris@102:         std::string get_info() const
Chris@102:         {
Chris@102:             return _content ? _content->get_info() : "";
Chris@102:         }
Chris@102: 
Chris@102:     private:
Chris@102: 
Chris@102:         struct placeholder
Chris@102:         {
Chris@102:             virtual placeholder* clone() const = 0;
Chris@102: 
Chris@102:             virtual bool parse(Iterator& first, Iterator const& last
Chris@102:               , Context const& context, Attribute& attr) const = 0;
Chris@102: 
Chris@102:             virtual std::string get_info() const = 0;
Chris@102: 
Chris@102:             virtual ~placeholder() {}
Chris@102:         };
Chris@102: 
Chris@102:         template <typename Expr>
Chris@102:         struct holder : placeholder
Chris@102:         {
Chris@102:             typedef typename extension::as_parser<Expr>::value_type parser_type;
Chris@102: 
Chris@102:             explicit holder(Expr const& p)
Chris@102:               : _parser(as_parser(p)) {}
Chris@102: 
Chris@102:             holder* clone() const override
Chris@102:             {
Chris@102:                 return new holder(*this);
Chris@102:             }
Chris@102: 
Chris@102:             bool parse(Iterator& first, Iterator const& last
Chris@102:               , Context const& context, Attribute& attr) const override
Chris@102:             {
Chris@102:                 return _parser.parse(first, last, context, unused, attr);
Chris@102:             }
Chris@102: 
Chris@102:             std::string get_info() const override
Chris@102:             {
Chris@102:                 return x3::what(_parser);
Chris@102:             }
Chris@102: 
Chris@102:             parser_type _parser;
Chris@102:         };
Chris@102: 
Chris@102:     private:
Chris@102:         std::unique_ptr<placeholder> _content;
Chris@102:     };
Chris@102: 
Chris@102:     template <typename Iterator, typename Attribute, typename Context>
Chris@102:     struct get_info<any_parser<Iterator, Attribute, Context>>
Chris@102:     {
Chris@102:         typedef std::string result_type;
Chris@102:         std::string operator()(
Chris@102:             any_parser<Iterator, Attribute, Context> const& p) const
Chris@102:         {
Chris@102:             return p.get_info();
Chris@102:         }
Chris@102:     };
Chris@102: }}}
Chris@102: 
Chris@102: #endif