1 /*=============================================================================
2     Copyright (c) 2001-2011 Joel de Guzman
3 
4     Distributed under the Boost Software License, Version 1.0. (See accompanying
5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 =============================================================================*/
7 #ifndef BOOST_SPIRIT_QI_OPERATOR_NOT_PREDICATE_HPP
8 #define BOOST_SPIRIT_QI_OPERATOR_NOT_PREDICATE_HPP
9 
10 #if defined(_MSC_VER)
11 #pragma once
12 #endif
13 
14 #include <boost/spirit/home/qi/domain.hpp>
15 #include <boost/spirit/home/qi/meta_compiler.hpp>
16 #include <boost/spirit/home/qi/parser.hpp>
17 #include <boost/spirit/home/qi/detail/attributes.hpp>
18 #include <boost/spirit/home/support/has_semantic_action.hpp>
19 #include <boost/spirit/home/support/handles_container.hpp>
20 #include <boost/spirit/home/support/info.hpp>
21 #include <boost/proto/operators.hpp>
22 #include <boost/proto/tags.hpp>
23 
24 namespace boost { namespace spirit
25 {
26     ///////////////////////////////////////////////////////////////////////////
27     // Enablers
28     ///////////////////////////////////////////////////////////////////////////
29     template <>
30     struct use_operator<qi::domain, proto::tag::logical_not> // enables !p
31       : mpl::true_ {};
32 }}
33 
34 namespace boost { namespace spirit { namespace qi
35 {
36     template <typename Subject>
37     struct not_predicate : unary_parser<not_predicate<Subject> >
38     {
39         typedef Subject subject_type;
40 
41         template <typename Context, typename Iterator>
42         struct attribute
43         {
44             typedef unused_type type;
45         };
46 
not_predicateboost::spirit::qi::not_predicate47         not_predicate(Subject const& subject_)
48           : subject(subject_) {}
49 
50         template <typename Iterator, typename Context
51           , typename Skipper, typename Attribute>
parseboost::spirit::qi::not_predicate52         bool parse(Iterator& first, Iterator const& last
53           , Context& context, Skipper const& skipper
54           , Attribute& /*attr*/) const
55         {
56             Iterator i = first;
57             return !subject.parse(i, last, context, skipper, unused);
58         }
59 
60         template <typename Context>
whatboost::spirit::qi::not_predicate61         info what(Context& context) const
62         {
63             return info("not-predicate", subject.what(context));
64         }
65 
66         Subject subject;
67     };
68 
69     ///////////////////////////////////////////////////////////////////////////
70     // Parser generators: make_xxx function (objects)
71     ///////////////////////////////////////////////////////////////////////////
72     template <typename Elements, typename Modifiers>
73     struct make_composite<proto::tag::logical_not, Elements, Modifiers>
74       : make_unary_composite<Elements, not_predicate>
75     {};
76 }}}
77 
78 namespace boost { namespace spirit { namespace traits
79 {
80     ///////////////////////////////////////////////////////////////////////////
81     template <typename Subject>
82     struct has_semantic_action<qi::not_predicate<Subject> >
83       : unary_has_semantic_action<Subject> {};
84 
85     ///////////////////////////////////////////////////////////////////////////
86     template <typename Subject, typename Attribute, typename Context
87         , typename Iterator>
88     struct handles_container<qi::not_predicate<Subject>, Attribute
89         , Context, Iterator>
90       : unary_handles_container<Subject, Attribute, Context, Iterator> {};
91 }}}
92 
93 #endif
94