qtbase-opensource-src/util/lexgen/nfa.h

115 lines
3.3 KiB
C++

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the utils of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL-EXCEPT$
** 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 The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef NFA_H
#define NFA_H
#include <QMap>
#include <QHash>
#include <QString>
#include <QVector>
#include <QDebug>
#include <QStack>
#include <QByteArray>
#include "global.h"
typedef QHash<InputType, int> TransitionMap;
struct State
{
QString symbol;
TransitionMap transitions;
};
inline QDataStream &operator<<(QDataStream &stream, const State &state)
{
return stream << state.symbol << state.transitions;
}
inline QDataStream &operator>>(QDataStream &stream, State &state)
{
return stream >> state.symbol >> state.transitions;
}
struct DFA : public QVector<State>
{
void debug() const;
DFA minimize() const;
};
class NFA
{
public:
static NFA createSingleInputNFA(InputType input);
static NFA createSymbolNFA(const QString &symbol);
static NFA createAlternatingNFA(const NFA &a, const NFA &b);
static NFA createConcatenatingNFA(const NFA &a, const NFA &b);
static NFA createOptionalNFA(const NFA &a);
// convenience
static NFA createStringNFA(const QByteArray &str);
static NFA createSetNFA(const QSet<InputType> &set);
static NFA createZeroOrOneNFA(const NFA &a);
static NFA applyQuantity(const NFA &a, int minOccurrences, int maxOccurrences);
void setTerminationSymbol(const QString &symbol);
DFA toDFA() const;
inline bool isEmpty() const { return states.isEmpty(); }
inline int stateCount() const { return states.count(); }
void debug();
private:
void initialize(int size);
void addTransition(int from, InputType input, int to);
void copyFrom(const NFA &other, int baseState);
void initializeFromPair(const NFA &a, const NFA &b,
int *initialA, int *finalA,
int *initialB, int *finalB);
QSet<int> epsilonClosure(const QSet<int> &initialClosure) const;
inline void assertValidState(int state)
{ Q_UNUSED(state); Q_ASSERT(state >= 0); Q_ASSERT(state < states.count()); }
#if defined(AUTOTEST)
public:
#endif
int initialState;
int finalState;
QVector<State> states;
};
#endif // NFA_H