x3/operator/not_predicate.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2014 Joel de Guzman
0003     Copyright (c) 2017 wanghan02
0004     Copyright (c) 2024 Nana Sakisaka
0005
0006     Distributed under the Boost Software License, Version 1.0. (See accompanying
0007     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0008 =============================================================================*/
0009 #if !defined(BOOST_SPIRIT_X3_NOT_PREDICATE_MARCH_23_2007_0618PM)
0010 #define BOOST_SPIRIT_X3_NOT_PREDICATE_MARCH_23_2007_0618PM
0011
0012 #include <boost/spirit/home/x3/core/parser.hpp>
0013 #include <boost/spirit/home/x3/support/expectation.hpp>
0014
0015 namespace boost { namespace spirit { namespace x3
0016 {
0017     template <typename Subject>
0018     struct not_predicate : unary_parser<Subject, not_predicate<Subject>>
0019     {
0020         typedef unary_parser<Subject, not_predicate<Subject>> base_type;
0021
0022         typedef unused_type attribute_type;
0023         static bool const has_attribute = false;
0024
0025         constexpr not_predicate(Subject const& subject)
0026           : base_type(subject) {}
0027
0028         template <typename Iterator, typename Context
0029           , typename RContext, typename Attribute>
0030         bool parse(Iterator& first, Iterator const& last
0031           , Context const& context, RContext& rcontext, Attribute& /*attr*/) const
0032         {
0033             Iterator i = first;
0034             return !this->subject.parse(i, last, context, rcontext, unused)
0035               && !has_expectation_failure(context);
0036         }
0037     };
0038
0039     template <typename Subject>
0040     constexpr not_predicate<typename extension::as_parser<Subject>::value_type>
0041     operator!(Subject const& subject)
0042     {
0043         return { as_parser(subject) };
0044     }
0045 }}}
0046
0047 #endif