/*------------------------------------------------------------------------*
 *    programm : S T A C K . H P P                                        *
 *        date : 05.11.1992                                               *
 *  created by : (fa)                                                     *
 *               Projekt MEE                                              *
 *                                                                        *
 *------------------------------------------------------------------------*/
//
// Contents -------------------------------------------------
// 
//      Stack
//
// Description
// 
//      Defines the class Stack for general use
//
// End ------------------------------------------------------
//
// Implementation Dependencies ------------------------------

#include <element.hpp>
#include <stream.hpp>
#ifndef __STACK_H
#define __STACK_H

// End ------------------------------------------------------


// Class //

class Stack;                       // forward deklaration

class Stack_element{
   friend Stack;
   protected:
   Stack_element *next;
   Element * object;
   Stack_element( Stack_element *_next=NULL){
      next=_next;
   }
};

class Stack{
   protected:
   int       itemsInStack;         // number of stack items 1...n
   Stack_element *top;
 public:
   Stack();
  ~Stack(); 
   void      Push( Element & );     
   Element&   Pop();                
   Element&   Top();                
   int       isNotEmpty();
   void      forEach(void (Element::*)());
};

// Description ----------------------------------------------
// 
// Public Members
//     
//      Push
//            Pushes an object on the stack
//
//      Pop
//            Pops an object from the stack 
//
//      Top
//            Returns a refrence to the object on the top of the stack
//
//      isNotEmpty
//            Returns NULL when stack is empty, other number of objects
//            in stack
//
//      forEach
//
// End ------------------------------------------------------

#endif // ifndef __STACK_H