summaryrefslogtreecommitdiffstats
blob: 7d1cb1433d0fd3668ed02d5ac5e43248cb925564 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
/*=============================================================================
    Copyright (c) 1998-2003 Joel de Guzman
    Copyright (c) 2001 Daniel Nuffer
    Copyright (c) 2002 Hartmut Kaiser
    http://spirit.sourceforge.net/

  Distributed under the Boost Software License, Version 1.0. (See accompanying
  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#if !defined(BOOST_SPIRIT_DIFFERENCE_HPP)
#define BOOST_SPIRIT_DIFFERENCE_HPP

#include <boost/spirit/home/classic/namespace.hpp>
#include <boost/spirit/home/classic/core/parser.hpp>
#include <boost/spirit/home/classic/core/primitives/primitives.hpp>
#include <boost/spirit/home/classic/core/composite/composite.hpp>
#include <boost/spirit/home/classic/meta/as_parser.hpp>

namespace boost { namespace spirit {

BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN

    ///////////////////////////////////////////////////////////////////////////
    //
    //  difference: a - b; Matches a but not b
    //
    //      Handles expressions of the form:
    //
    //          a - b
    //
    //      where a and b are parsers. The expression returns a composite
    //      parser that matches a but not b. One (not both) of the operands
    //      may be a literal char, wchar_t or a primitive string char const*,
    //      wchar_t const*.
    //
    ///////////////////////////////////////////////////////////////////////////
    struct difference_parser_gen;

#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
#pragma warning(push)
#pragma warning(disable:4512) //assignment operator could not be generated
#endif

    template <typename A, typename B>
    struct difference
    :   public binary<A, B, parser<difference<A, B> > >
    {
        typedef difference<A, B>                self_t;
        typedef binary_parser_category          parser_category_t;
        typedef difference_parser_gen           parser_generator_t;
        typedef binary<A, B, parser<self_t> >   base_t;
    
        difference(A const& a, B const& b)
        : base_t(a, b) {}
    
        template <typename ScannerT>
        typename parser_result<self_t, ScannerT>::type
        parse(ScannerT const& scan) const
        {
            typedef typename parser_result<self_t, ScannerT>::type result_t;
            typedef typename ScannerT::iterator_t iterator_t;
            iterator_t save = scan.first;
            if (result_t hl = this->left().parse(scan))
            {
                std::swap(save, scan.first);
                result_t hr = this->right().parse(scan);
                if (!hr || (hr.length() < hl.length()))
                {
                    scan.first = save;
                    return hl;
                }
            }
    
            return scan.no_match();
        }
    };

#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
#pragma warning(pop)
#endif
    
    struct difference_parser_gen
    {
        template <typename A, typename B>
        struct result 
        {
            typedef 
                difference<
                    typename as_parser<A>::type
                  , typename as_parser<B>::type
                > 
            type;
        };
    
        template <typename A, typename B>
        static difference<
            typename as_parser<A>::type
          , typename as_parser<B>::type
        >
        generate(A const& a, B const& b)
        {
            return difference<BOOST_DEDUCED_TYPENAME as_parser<A>::type,
                BOOST_DEDUCED_TYPENAME as_parser<B>::type>
                    (as_parser<A>::convert(a), as_parser<B>::convert(b));
        }
    };
    
    template <typename A, typename B>
    difference<A, B>
    operator-(parser<A> const& a, parser<B> const& b);
    
    template <typename A>
    difference<A, chlit<char> >
    operator-(parser<A> const& a, char b);
    
    template <typename B>
    difference<chlit<char>, B>
    operator-(char a, parser<B> const& b);
    
    template <typename A>
    difference<A, strlit<char const*> >
    operator-(parser<A> const& a, char const* b);
    
    template <typename B>
    difference<strlit<char const*>, B>
    operator-(char const* a, parser<B> const& b);
    
    template <typename A>
    difference<A, chlit<wchar_t> >
    operator-(parser<A> const& a, wchar_t b);
    
    template <typename B>
    difference<chlit<wchar_t>, B>
    operator-(wchar_t a, parser<B> const& b);
    
    template <typename A>
    difference<A, strlit<wchar_t const*> >
    operator-(parser<A> const& a, wchar_t const* b);
    
    template <typename B>
    difference<strlit<wchar_t const*>, B>
    operator-(wchar_t const* a, parser<B> const& b);

BOOST_SPIRIT_CLASSIC_NAMESPACE_END

}} // namespace BOOST_SPIRIT_CLASSIC_NS

#endif

#include <boost/spirit/home/classic/core/composite/impl/difference.ipp>