qi/stream/stream.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2011 Hartmut Kaiser
0003
0004     Distributed under the Boost Software License, Version 1.0. (See accompanying
0005     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 ==============================================================================*/
0007 #if !defined(BOOST_SPIRIT_STREAM_MAY_05_2007_1228PM)
0008 #define BOOST_SPIRIT_STREAM_MAY_05_2007_1228PM
0009
0010 #if defined(_MSC_VER)
0011 #pragma once
0012 #endif
0013
0014 #include <boost/spirit/home/qi/detail/string_parse.hpp>
0015 #include <boost/spirit/home/qi/stream/detail/match_manip.hpp>
0016 #include <boost/spirit/home/support/detail/hold_any.hpp>
0017 #include <boost/proto/traits.hpp>
0018 #include <istream>
0019
0020 ///////////////////////////////////////////////////////////////////////////////
0021 namespace boost { namespace spirit
0022 {
0023     ///////////////////////////////////////////////////////////////////////////
0024     // Enablers
0025     ///////////////////////////////////////////////////////////////////////////
0026     template <>
0027     struct use_terminal<qi::domain, tag::stream> // enables stream
0028       : mpl::true_ {};
0029
0030     template <>
0031     struct use_terminal<qi::domain, tag::wstream> // enables wstream
0032       : mpl::true_ {};
0033 }}
0034
0035 ///////////////////////////////////////////////////////////////////////////////
0036 namespace boost { namespace spirit { namespace qi
0037 {
0038 #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
0039     using spirit::stream;
0040     using spirit::wstream;
0041 #endif
0042     using spirit::stream_type;
0043     using spirit::wstream_type;
0044
0045 namespace detail
0046 {
0047 #ifdef _MSC_VER
0048 #  pragma warning(push)
0049 #  pragma warning(disable: 4512) // assignment operator could not be generated.
0050 #endif
0051     template <typename Iterator>
0052     struct psbuf
0053       : std::basic_streambuf<typename std::iterator_traits<Iterator>::value_type>
0054     {
0055         psbuf(Iterator first_, Iterator const& last_)
0056           : first(first_), last(last_) {}
0057
0058     protected:
0059         typename psbuf::int_type underflow() BOOST_OVERRIDE
0060         {
0061             return first == last ? psbuf::traits_type::eof()
0062                                  : psbuf::traits_type::to_int_type(*first);
0063         }
0064
0065         typename psbuf::int_type uflow() BOOST_OVERRIDE
0066         {
0067             return first == last ? psbuf::traits_type::eof()
0068                                  : psbuf::traits_type::to_int_type(*first++);
0069         }
0070
0071     public:
0072         Iterator first;
0073         Iterator const& last;
0074     };
0075 #ifdef _MSC_VER
0076 #  pragma warning(pop)
0077 #endif
0078 }
0079
0080     template <typename Char = char, typename T = spirit::basic_hold_any<char> >
0081     struct stream_parser
0082       : primitive_parser<stream_parser<Char, T> >
0083     {
0084         template <typename Context, typename Iterator>
0085         struct attribute
0086         {
0087             typedef T type;
0088         };
0089
0090         template <typename Iterator, typename Context
0091           , typename Skipper, typename Attribute>
0092         bool parse(Iterator& first, Iterator const& last
0093           , Context& /*context*/, Skipper const& skipper
0094           , Attribute& attr_) const
0095         {
0096             qi::skip_over(first, last, skipper);
0097
0098             detail::psbuf<Iterator> pseudobuf(first, last);
0099             std::basic_istream<Char> in(&pseudobuf);
0100             in >> attr_;                        // use existing operator>>()
0101
0102             // advance the iterator if everything is ok
0103             if (in) {
0104                 first = pseudobuf.first;
0105                 return true;
0106             }
0107
0108             return false;
0109         }
0110
0111         template <typename Context>
0112         info what(Context& /*context*/) const
0113         {
0114             return info("stream");
0115         }
0116     };
0117
0118     template <typename T, typename Char = char>
0119     struct typed_stream
0120       : proto::terminal<stream_parser<Char, T> >::type
0121     {
0122     };
0123
0124     ///////////////////////////////////////////////////////////////////////////
0125     // Parser generators: make_xxx function (objects)
0126     ///////////////////////////////////////////////////////////////////////////
0127     template <typename Char>
0128     struct make_stream
0129     {
0130         typedef stream_parser<Char> result_type;
0131         result_type operator()(unused_type, unused_type) const
0132         {
0133             return result_type();
0134         }
0135     };
0136
0137     template <typename Modifiers>
0138     struct make_primitive<tag::stream, Modifiers> : make_stream<char> {};
0139
0140     template <typename Modifiers>
0141     struct make_primitive<tag::wstream, Modifiers> : make_stream<wchar_t> {};
0142 }}}
0143
0144 #endif