x3/core/parse.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2014 Joel de Guzman
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_X3_PARSE_APRIL_16_2006_0442PM)
0008 #define BOOST_SPIRIT_X3_PARSE_APRIL_16_2006_0442PM
0009
0010 #include <boost/spirit/home/x3/support/context.hpp>
0011 #include <boost/spirit/home/x3/core/parser.hpp>
0012 #include <boost/spirit/home/x3/core/skip_over.hpp>
0013 #include <boost/iterator/iterator_concepts.hpp>
0014
0015 namespace boost { namespace spirit { namespace x3
0016 {
0017     ///////////////////////////////////////////////////////////////////////////
0018     template <typename Iterator, typename Parser, typename Attribute>
0019     inline bool
0020     parse_main(
0021         Iterator& first
0022       , Iterator last
0023       , Parser const& p
0024       , Attribute& attr)
0025     {
0026         // Make sure the iterator is at least a readable forward traversal iterator.
0027         // If you got a compilation error here, then you are using a weaker iterator
0028         // while calling this function, you need to supply a readable forward traversal
0029         // iterator instead.
0030         BOOST_CONCEPT_ASSERT((boost_concepts::ReadableIteratorConcept<Iterator>));
0031         BOOST_CONCEPT_ASSERT((boost_concepts::ForwardTraversalConcept<Iterator>));
0032
0033         // If you get an error no matching function for call to 'as_parser'
0034         // here, then p is not a parser or there is no suitable conversion
0035         // from p to a parser.
0036         return as_parser(p).parse(first, last, unused, unused, attr);
0037     }
0038
0039     ///////////////////////////////////////////////////////////////////////////
0040     template <typename Iterator, typename Parser, typename Attribute>
0041     inline bool
0042     parse(
0043         Iterator& first
0044       , Iterator last
0045       , Parser const& p
0046       , Attribute& attr)
0047     {
0048         return parse_main(first, last, p, attr);
0049     }
0050
0051     ///////////////////////////////////////////////////////////////////////////
0052     template <typename Iterator, typename Parser, typename Attribute>
0053     inline bool
0054     parse(
0055         Iterator const& first_
0056       , Iterator last
0057       , Parser const& p
0058       , Attribute& attr)
0059     {
0060         Iterator first = first_;
0061         return parse_main(first, last, p, attr);
0062     }
0063
0064     ///////////////////////////////////////////////////////////////////////////
0065     template <typename Iterator, typename Parser>
0066     inline bool
0067     parse(
0068         Iterator& first
0069       , Iterator last
0070       , Parser const& p)
0071     {
0072         return parse_main(first, last, p, unused);
0073     }
0074
0075     ///////////////////////////////////////////////////////////////////////////
0076     template <typename Iterator, typename Parser>
0077     inline bool
0078     parse(
0079         Iterator const& first_
0080       , Iterator last
0081       , Parser const& p)
0082     {
0083         Iterator first = first_;
0084         return parse_main(first, last, p, unused);
0085     }
0086
0087     ///////////////////////////////////////////////////////////////////////////
0088     enum class skip_flag
0089     {
0090         post_skip,      // force post-skipping in phrase_parse()
0091         dont_post_skip  // inhibit post-skipping in phrase_parse()
0092     };
0093
0094     ///////////////////////////////////////////////////////////////////////////
0095     template <typename Iterator, typename Parser, typename Skipper, typename Attribute>
0096     inline bool
0097     phrase_parse_main(
0098         Iterator& first
0099       , Iterator last
0100       , Parser const& p
0101       , Skipper const& s
0102       , Attribute& attr
0103       , skip_flag post_skip = skip_flag::post_skip)
0104     {
0105         // Make sure the iterator is at least a readable forward traversal iterator.
0106         // If you got a compilation error here, then you are using a weaker iterator
0107         // while calling this function, you need to supply a readable forward traversal
0108         // iterator instead.
0109         BOOST_CONCEPT_ASSERT((boost_concepts::ReadableIteratorConcept<Iterator>));
0110         BOOST_CONCEPT_ASSERT((boost_concepts::ForwardTraversalConcept<Iterator>));
0111
0112         static_assert(!std::is_same<Skipper, unused_type>::value,
0113             "Error! Skipper cannot be unused_type.");
0114
0115         // If you get an error no matching function for call to 'as_parser'
0116         // here, for either p or s, then p or s is not a parser or there is
0117         // no suitable conversion from p to a parser.
0118         auto skipper_ctx = make_context<skipper_tag>(as_parser(s));
0119         bool r = as_parser(p).parse(first, last, skipper_ctx, unused, attr);
0120         if (post_skip == skip_flag::post_skip)
0121             x3::skip_over(first, last, skipper_ctx);
0122         return r;
0123     }
0124
0125     ///////////////////////////////////////////////////////////////////////////
0126     template <typename Iterator, typename Parser, typename Skipper, typename Attribute>
0127     inline bool
0128     phrase_parse(
0129         Iterator& first
0130       , Iterator last
0131       , Parser const& p
0132       , Skipper const& s
0133       , Attribute& attr
0134       , skip_flag post_skip = skip_flag::post_skip)
0135     {
0136         return phrase_parse_main(first, last, p, s, attr, post_skip);
0137     }
0138
0139     ///////////////////////////////////////////////////////////////////////////
0140     template <typename Iterator, typename Parser, typename Skipper, typename Attribute>
0141     inline bool
0142     phrase_parse(
0143         Iterator const& first_
0144       , Iterator last
0145       , Parser const& p
0146       , Skipper const& s
0147       , Attribute& attr
0148       , skip_flag post_skip = skip_flag::post_skip)
0149     {
0150         Iterator first = first_;
0151         return phrase_parse_main(first, last, p, s, attr, post_skip);
0152     }
0153
0154     ///////////////////////////////////////////////////////////////////////////
0155     template <typename Iterator, typename Parser, typename Skipper>
0156     inline bool
0157     phrase_parse(
0158         Iterator& first
0159       , Iterator last
0160       , Parser const& p
0161       , Skipper const& s
0162       , skip_flag post_skip = skip_flag::post_skip)
0163     {
0164         return phrase_parse_main(first, last, p, s, unused, post_skip);
0165     }
0166
0167     ///////////////////////////////////////////////////////////////////////////
0168     template <typename Iterator, typename Parser, typename Skipper>
0169     inline bool
0170     phrase_parse(
0171         Iterator const& first_
0172       , Iterator last
0173       , Parser const& p
0174       , Skipper const& s
0175       , skip_flag post_skip = skip_flag::post_skip)
0176     {
0177         Iterator first = first_;
0178         return phrase_parse_main(first, last, p, s, unused, post_skip);
0179     }
0180
0181     ///////////////////////////////////////////////////////////////////////////
0182     template <typename Skipper>
0183     struct phrase_parse_context
0184     {
0185         typedef decltype(
0186             make_context<skipper_tag>(as_parser(std::declval<Skipper>())))
0187         type;
0188     };
0189 }}}
0190
0191 #endif