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/*
* This file is part of the KDE libraries
* Copyright (C) 2003 Apple Computer, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef KJS_SCOPE_CHAIN_H
#define KJS_SCOPE_CHAIN_H
#include "global.h"
namespace KJS {
class ObjectImp;
/**
* A scope chain node.
*/
class KJS_EXPORT ScopeChainNode {
public:
ScopeChainNode(ScopeChainNode *n, ObjectImp *o)
: next(n), object(o), refCount(1) { }
ScopeChainNode *next;
ObjectImp *object;
int refCount;
};
/**
* A scope chain object.
*/
class KJS_EXPORT ScopeChain {
public:
ScopeChain() : _node(0) { }
~ScopeChain() { deref(); }
ScopeChain(const ScopeChain &c) : _node(c._node)
{ if (_node) ++_node->refCount; }
ScopeChain &operator=(const ScopeChain &);
bool isEmpty() const { return !_node; }
ObjectImp *top() const { return _node->object; }
ObjectImp *bottom() const { const ScopeChainNode *n = _node;
while (n->next) n = n->next;
return n->object; }
void clear() { deref(); _node = 0; }
void push(ObjectImp *);
void pop();
void mark();
private:
ScopeChainNode *_node;
void deref() { if (_node && --_node->refCount == 0) release(); }
void ref() const;
void release();
};
} // namespace KJS
#endif // KJS_SCOPE_CHAIN_H
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