list.h

/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
 *  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_LIST_H
#define KJS_LIST_H
 
#include "value.h"
 
namespace KJS {
 
    struct ListImpBase {
        int size;
        int refCount;
    int valueRefCount;
    };
    
    class ListIterator;
 
    class KJS_EXPORT List {
    public:
        List();
    List(bool needsMarking);
        ~List() { deref(); }
 
        List(const List &b) : _impBase(b._impBase), _needsMarking(false) {
        ++_impBase->refCount; 
        if (!_impBase->valueRefCount) refValues(); 
        ++_impBase->valueRefCount; 
    }
        List &operator=(const List &);
 
        void append(const Value& val) { append(val.imp()); }
        void append(ValueImp *val);
        void clear();
 
        List copy() const;
 
        List copyTail() const;
    
        bool isEmpty() const { return _impBase->size == 0; }
        int size() const { return _impBase->size; }
        ListIterator begin() const;
        ListIterator end() const;
        
        Value at(int i) const { return Value(impAt(i)); }
        Value operator[](int i) const { return Value(impAt(i)); }
        
        ValueImp *impAt(int i) const;
    
        static const List &empty();
        
    void mark() { if (_impBase->valueRefCount == 0) markValues(); }
    private:
        ListImpBase *_impBase;
    bool _needsMarking;
        
        void deref() { if (!_needsMarking && --_impBase->valueRefCount == 0) derefValues(); if (--_impBase->refCount == 0) release(); }
 
        void release();
        void refValues();
        void derefValues();
        void markValues();
    };
  
    class ListIterator {
    public:
        ListIterator(const List &l) : _list(&l), _i(0) { }
        ListIterator(const List &l, int index) : _list(&l), _i(index) { }
        ValueImp *operator->() const { return _list->impAt(_i); }
        Value operator*() const { return Value(_list->impAt(_i)); }
        Value operator++() { return Value(_list->impAt(++_i)); }
        Value operator++(int) { return Value(_list->impAt(_i++)); }
        Value operator--() { return Value(_list->impAt(--_i)); }
        Value operator--(int) { return Value(_list->impAt(_i--)); }
        bool operator==(const ListIterator &it) const { return _i == it._i; }
        bool operator!=(const ListIterator &it) const { return _i != it._i; }
 
    private:
        const List *_list;
        int _i;
    };
 
    inline ListIterator List::begin() const { return ListIterator(*this); }
    inline ListIterator List::end() const { return ListIterator(*this, size()); }
 
    inline List &List::operator=(const List &b)
    {
        ListImpBase *bImpBase = b._impBase;
        ++bImpBase->refCount;
        deref();
        _impBase = bImpBase;
    if (!_needsMarking) {
        if (!_impBase->valueRefCount) {
        refValues();
        }
        _impBase->valueRefCount++;
    }
 
        return *this;
    }
 
 } // namespace KJS
 
#endif // KJS_LIST_H