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
|
///////////////////////////////////////////////////////////////////////////////
// optional_matcher.hpp
//
// Copyright 2008 Eric Niebler. 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)
#ifndef BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_OPTIONAL_MATCHER_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_OPTIONAL_MATCHER_HPP_EAN_10_04_2005
// MS compatible compilers support #pragma once
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
#include <boost/mpl/bool.hpp>
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/core/quant_style.hpp>
#include <boost/xpressive/detail/core/state.hpp>
namespace boost { namespace xpressive { namespace detail
{
///////////////////////////////////////////////////////////////////////////////
// optional_matcher
template<typename Xpr, typename Greedy>
struct optional_matcher
: quant_style<quant_variable_width, unknown_width::value, Xpr::pure>
{
Xpr xpr_;
explicit optional_matcher(Xpr const &xpr)
: xpr_(xpr)
{
}
template<typename BidiIter, typename Next>
bool match(match_state<BidiIter> &state, Next const &next) const
{
return this->match_(state, next, Greedy());
}
private:
template<typename BidiIter, typename Next>
bool match_(match_state<BidiIter> &state, Next const &next, mpl::true_) const // Greedy
{
return this->xpr_.BOOST_NESTED_TEMPLATE push_match<Next>(state)
|| next.match(state);
}
template<typename BidiIter, typename Next>
bool match_(match_state<BidiIter> &state, Next const &next, mpl::false_) const // Non-greedy
{
return next.match(state)
|| this->xpr_.BOOST_NESTED_TEMPLATE push_match<Next>(state);
}
optional_matcher &operator =(optional_matcher const &);
};
///////////////////////////////////////////////////////////////////////////////
// optional_mark_matcher
template<typename BidiIter, typename Next>
inline bool match_next(match_state<BidiIter> &state, Next const &next, int mark_number)
{
sub_match_impl<BidiIter> &br = state.sub_match(mark_number);
bool old_matched = br.matched;
br.matched = false;
if(next.match(state))
{
return true;
}
br.matched = old_matched;
return false;
}
///////////////////////////////////////////////////////////////////////////////
// optional_mark_matcher
template<typename Xpr, typename Greedy>
struct optional_mark_matcher
: quant_style<quant_variable_width, unknown_width::value, Xpr::pure>
{
Xpr xpr_;
int mark_number_;
explicit optional_mark_matcher(Xpr const &xpr, int mark_number)
: xpr_(xpr)
, mark_number_(mark_number)
{
}
template<typename BidiIter, typename Next>
bool match(match_state<BidiIter> &state, Next const &next) const
{
return this->match_(state, next, Greedy());
}
private:
template<typename BidiIter, typename Next>
bool match_(match_state<BidiIter> &state, Next const &next, mpl::true_) const // Greedy
{
return this->xpr_.BOOST_NESTED_TEMPLATE push_match<Next>(state)
|| match_next(state, next, this->mark_number_);
}
template<typename BidiIter, typename Next>
bool match_(match_state<BidiIter> &state, Next const &next, mpl::false_) const // Non-greedy
{
return match_next(state, next, this->mark_number_)
|| this->xpr_.BOOST_NESTED_TEMPLATE push_match<Next>(state);
}
optional_mark_matcher &operator =(optional_mark_matcher const &);
};
}}}
#endif
|
