diff -r 000000000000 -r 1918ee327afb util/qlalr/examples/qparser/qparser.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/util/qlalr/examples/qparser/qparser.h Mon Jan 11 14:00:40 2010 +0000 @@ -0,0 +1,152 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** 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 +#include + +template +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 stateStack; + QVarLengthArray<_Value, DefaultStackSize> parseStack; + int stackSize; + int tos; + + void reallocateStack() { + stackSize <<= 1; + stateStack.resize(stackSize); + parseStack.resize(stackSize); + } + }; + + QSharedDataPointer d; +}; + +template +inline _Value &QParser<_Parser, _Table, _Value>::sym(int n) +{ + return d->parseStack [d->tos + n - 1]; +} + +template +QParser<_Parser, _Table, _Value>::QParser(): + d(new Data()) +{ +} + +template +QParser<_Parser, _Table, _Value>::~QParser() +{ +} + +template +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