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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
|
/****************************************************************************
**
** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** 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, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
#ifndef Patternist_XsdStateMachine_H
#define Patternist_XsdStateMachine_H
#include <private/qnamepool_p.h>
#include <QtCore/QHash>
#include <QtCore/QSet>
#include <QtCore/QTextStream>
QT_BEGIN_HEADER
QT_BEGIN_NAMESPACE
class QIODevice;
namespace QPatternist
{
/**
* @short A state machine used for evaluation.
*
* @ingroup Patternist_schema
* @author Tobias Koenig <tobias.koenig@nokia.com>
*/
template <typename TransitionType>
class XsdStateMachine
{
public:
typedef qint32 StateId;
/**
* Describes the type of state.
*/
enum StateType
{
StartState, ///< The state the machine will start with.
StartEndState, ///< The state the machine will start with, can be end state as well.
InternalState, ///< Any state that is not start or end state.
EndState ///< Any state where the machine is allowed to stop.
};
/**
* Creates a new state machine object.
*/
XsdStateMachine();
/**
* Creates a new state machine object.
*
* The name pool to use for accessing object names.
*/
XsdStateMachine(const NamePool::Ptr &namePool);
/**
* Adds a new state of the given @p type to the state machine.
*
* @return The id of the new state.
*/
StateId addState(StateType type);
/**
* Adds a new @p transition to the state machine.
*
* @param start The start state.
* @param transition The transition to come from the start to the end state.
* @param end The end state.
*/
void addTransition(StateId start, TransitionType transition, StateId end);
/**
* Adds a new epsilon @p transition to the state machine.
*
* @param start The start state.
* @param end The end state.
*/
void addEpsilonTransition(StateId start, StateId end);
/**
* Resets the machine to the start state.
*/
void reset();
/**
* Removes all states and transitions from the state machine.
*/
void clear();
/**
* Continues execution of the machine with the given input @p transition.
*
* @return @c true if the transition was successful, @c false otherwise.
*/
bool proceed(TransitionType transition);
/**
* Returns the list of transitions that are reachable from the current
* state.
*/
QList<TransitionType> possibleTransitions() const;
/**
* Continues execution of the machine with the given @p input.
*
* @note To use this method, inputEqualsTransition must be implemented
* to find the right transition to use.
*
* @return @c true if the transition was successful, @c false otherwise.
*/
template <typename InputType>
bool proceed(InputType input);
/**
* Returns whether the given @p input matches the given @p transition.
*/
template <typename InputType>
bool inputEqualsTransition(InputType input, TransitionType transition) const;
/**
* Returns whether the machine is in an allowed end state.
*/
bool inEndState() const;
/**
* Returns the last transition that was taken.
*/
TransitionType lastTransition() const;
/**
* Returns the start state of the machine.
*/
StateId startState() const;
/**
* This method should be redefined by template specialization for every
* concret TransitionType.
*/
QString transitionTypeToString(TransitionType type) const;
/**
* Outputs the state machine in DOT format to the given
* output @p device.
*/
bool outputGraph(QIODevice *device, const QString &graphName) const;
/**
* Returns a DFA that is equal to the NFA of the state machine.
*/
XsdStateMachine<TransitionType> toDFA() const;
/**
* Returns the information of all states of the state machine.
*/
QHash<StateId, StateType> states() const;
/**
* Returns the information of all transitions of the state machine.
*/
QHash<StateId, QHash<TransitionType, QVector<StateId> > > transitions() const;
private:
/**
* Returns the DFA state for the given @p nfaStat from the given @p stateTable.
* If there is no corresponding DFA state yet, a new one is created.
*/
StateId dfaStateForNfaState(QSet<StateId> nfaState, QList< QPair< QSet<StateId>, StateId> > &stateTable, XsdStateMachine<TransitionType> &dfa) const;
/**
* Returns the set of all states that can be reached from the set of @p input states
* by the epsilon transition.
*
* The implementation is inlined in order to workaround a compiler
* bug on Symbian/winscw.
*/
QSet<StateId> epsilonClosure(const QSet<StateId> &input) const
{
// every state can reach itself by epsilon transition, so include the input states
// in the result as well
QSet<StateId> result = input;
// add the input states to the list of to be processed states
QList<StateId> workStates = input.toList();
while (!workStates.isEmpty()) { // while there are states to be processed left...
// dequeue one state from list
const StateId state = workStates.takeFirst();
// get the list of states that can be reached by the epsilon transition
// from the current 'state'
const QVector<StateId> targetStates = m_epsilonTransitions.value(state);
for (int i = 0; i < targetStates.count(); ++i) {
// if we have this target state not in our result set yet...
if (!result.contains(targetStates.at(i))) {
// ... add it to the result set
result.insert(targetStates.at(i));
// add the target state to the list of to be processed states as well,
// as we want to have the epsilon transitions not only for the first
// level of following states
workStates.append(targetStates.at(i));
}
}
}
return result;
}
/**
* Returns the set of all states that can be reached from the set of given @p states
* by the given @p input.
*
* The implementation is inlined in order to workaround a compiler
* bug on Symbian/winscw.
*/
QSet<StateId> move(const QSet<StateId> &states, TransitionType input) const
{
QSet<StateId> result;
QSetIterator<StateId> it(states);
while (it.hasNext()) { // iterate over all given states
const StateId state = it.next();
// get the transition table for the current state
const QHash<TransitionType, QVector<StateId> > transitions = m_transitions.value(state);
// get the target states for the given input
const QVector<StateId> targetStates = transitions.value(input);
// add all target states to the result
for (int i = 0; i < targetStates.size(); ++i)
result.insert(targetStates.at(i));
}
return result;
}
NamePool::Ptr m_namePool;
QHash<StateId, StateType> m_states;
QHash<StateId, QHash<TransitionType, QVector<StateId> > > m_transitions;
QHash<StateId, QVector<StateId> > m_epsilonTransitions;
StateId m_currentState;
qint32 m_counter;
TransitionType m_lastTransition;
};
#include "qxsdstatemachine_tpl_p.h"
}
QT_END_NAMESPACE
QT_END_HEADER
#endif
|
