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//
// Stack.cc
//
// Stack: This class implements a linked list of objects. It itself is also an
// object
//
// Part of the ht://Dig package <https://htdig.sourceforge.net/>
// Copyright (c) 1999-2004 The ht://Dig Group
// For copyright details, see the file COPYING in your distribution
// or the GNU Library General Public License (LGPL) version 2 or later
// <http://www.gnu.org/copyleft/lgpl.html>
//
// $Id: Stack.cc,v 1.5 2004/05/28 13:15:21 lha Exp $
//
#ifdef HAVE_CONFIG_H
#include "htconfig.h"
#endif /* HAVE_CONFIG_H */
#include "Stack.h"
struct stacknode
{
stacknode *next;
Object *obj;
};
//***************************************************************************
// Stack::Stack()
//
Stack::Stack()
{
sp = 0;
size = 0;
}
//***************************************************************************
// Stack::~Stack()
//
Stack::~Stack()
{
while (sp)
{
Object *obj = pop();
delete obj;
}
}
//***************************************************************************
// void Stack::destroy()
//
void Stack::destroy()
{
while (sp)
{
Object *obj = pop();
delete obj;
}
}
//***************************************************************************
// void Stack::push(Object *obj)
// PURPOSE:
// Push an object onto the stack.
//
void Stack::push(Object *obj)
{
stacknode *node = new stacknode;
node->obj = obj;
node->next = (stacknode *) sp;
sp = node;
size++;
}
//***************************************************************************
// Object *Stack::pop()
// PURPOSE:
// Return the object at the top of the stack and remove it from the stack.
//
Object *Stack::pop()
{
if (size == 0)
return 0;
stacknode *node = (stacknode *) sp;
Object *obj = node->obj;
sp = (void *) node->next;
delete node;
size--;
return obj;
}
//***************************************************************************
// Object *Stack::peek()
// PURPOSE:
// Return the object at the top of the stack.
//
Object *Stack::peek()
{
if (size == 0)
return 0;
return ((stacknode *)sp)->obj;
}
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