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
151
152
|
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QLALR module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.1, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef QPARSER_H
#define QPARSER_H
#include <QtCore/QSharedDataPointer>
#include <QtCore/QVarLengthArray>
template <typename _Parser, typename _Table, typename _Value = int>
class QParser: protected _Table
{
public:
QParser();
~QParser();
bool parse();
inline _Value &sym(int index);
private:
inline int nextToken()
{
return static_cast<_Parser*> (this)->nextToken();
}
inline void consumeRule(int rule)
{
static_cast<_Parser*> (this)->consumeRule(rule);
}
enum { DefaultStackSize = 128 };
struct Data: public QSharedData
{
Data(): stackSize (DefaultStackSize), tos (0) {}
QVarLengthArray<int, DefaultStackSize> stateStack;
QVarLengthArray<_Value, DefaultStackSize> parseStack;
int stackSize;
int tos;
void reallocateStack() {
stackSize <<= 1;
stateStack.resize(stackSize);
parseStack.resize(stackSize);
}
};
QSharedDataPointer<Data> d;
};
template <typename _Parser, typename _Table, typename _Value>
inline _Value &QParser<_Parser, _Table, _Value>::sym(int n)
{
return d->parseStack [d->tos + n - 1];
}
template <typename _Parser, typename _Table, typename _Value>
QParser<_Parser, _Table, _Value>::QParser():
d(new Data())
{
}
template <typename _Parser, typename _Table, typename _Value>
QParser<_Parser, _Table, _Value>::~QParser()
{
}
template <typename _Parser, typename _Table, typename _Value>
bool QParser<_Parser, _Table, _Value>::parse()
{
const int INITIAL_STATE = 0;
d->tos = 0;
d->reallocateStack();
int act = d->stateStack[++d->tos] = INITIAL_STATE;
int token = -1;
forever {
if (token == -1 && - _Table::TERMINAL_COUNT != _Table::action_index[act])
token = nextToken();
act = _Table::t_action(act, token);
if (d->stateStack[d->tos] == _Table::ACCEPT_STATE)
return true;
else if (act > 0) {
if (++d->tos == d->stackSize)
d->reallocateStack();
d->parseStack[d->tos] = d->parseStack[d->tos - 1];
d->stateStack[d->tos] = act;
token = -1;
}
else if (act < 0) {
int r = - act - 1;
d->tos -= _Table::rhs[r];
act = d->stateStack[d->tos++];
consumeRule(r);
act = d->stateStack[d->tos] = _Table::nt_action(act, _Table::lhs[r] - _Table::TERMINAL_COUNT);
}
else break;
}
return false;
}
#endif // QPARSER_H
|
