/********************************************************************************* dllist.h: an include file for (doubly-)linked lists.**** Copyright (C) 1995 by Dani Lischinski **** This program is free software; you can redistribute it and/or modify** it under the terms of the GNU General Public License as published by** the Free Software Foundation; either version 2 of the License, or** (at your option) any later version.**** This program 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 General Public License for more details.**** You should have received a copy of the GNU General Public License** along with this program; if not, write to the Free Software** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.********************************************************************************/#ifndef LLIST_H#define LLIST_Htypedef void* Ldata;class Llist;class LlistNode {	friend Llist;private:	Ldata data;	LlistNode *next, *prev;	LlistNode()                         { data = 0; next = prev = this; }	LlistNode(Ldata d, LlistNode* n)    { data = d; next = n;	                                      prev = n->prev; n->prev = this; }};typedef LlistNode *LlistPos;class Llist {private:	int len;	LlistNode *node;public:	Llist()                             { node = new LlistNode; len = 0; }	Boolean empty() const               { return (node == node->next); }	Boolean isEnd(LlistPos p) const     { return (p->next == node); }	LlistPos first() const              { return node; }	LlistPos next(LlistPos p) const     { return p->next; }	LlistPos prev(LlistPos p) const     { return p->prev; }	Ldata retrieve(LlistPos p) const    { return p->next->data; }	void store(LlistPos p, Ldata d)     { p->next->data = d; }	int length() const                  { return len; }	LlistNode* insert(LlistPos, Ldata);	void remove(LlistPos);	~Llist();};inline LlistNode* Llist::insert(LlistPos p, Ldata d){	len++;	return p->next = new LlistNode(d, p->next);}inline void Llist::remove(LlistPos p){	LlistNode *t = p->next;	p->next = t->next;	t->next->prev = t->prev;	delete t;	len--;}inline Llist::~Llist(){	while (!empty()) remove(first());	delete node;}#endif