/*------------------------------------------------------------------------*
 *    programm : S T A C K . C P P                                        *
 *        date : 05.11.1992                                               *
 *  created by : (fa)                                                     *
 *               Projekt MEE                                              *
 *                                                                        *
 *------------------------------------------------------------------------*/
//
// Contents -------------------------------------------------
// 
//      Stack
//
//      Member functions:
//      
//	Stack::Stack
//	Stack::~Stack
//	Stack::Push
//	Stack::Pop
//	Stack::Top
//	Stack::isNotEmpty
//	Stack::forEach
//      
// End ------------------------------------------------------
//
// Implementation Dependencies ------------------------------

#include "stack.hpp"

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

// Implementation -------------------------------------------

Stack::Stack(){
   top = NULL;
   itemsInStack = NULL;
}

//-----------------------------------------------------------

void Stack::Push(Element &element){
   if(itemsInStack==NULL){               // 0 ... 1 element
      top = new Stack_element;
      top->object=&element;
   }
   else{
      Stack_element *p=new Stack_element(top);
      p->object=&element;
      top=p;
   }
   itemsInStack++;
}

//-----------------------------------------------------------

Element& Stack::Pop(){
  Stack_element *se_tmp;
  Element        *ob_tmp;

  ob_tmp = top->object;
  se_tmp = top;
  top = top->next;

  delete se_tmp;
  itemsInStack--; 
  return *ob_tmp;  
}

//-----------------------------------------------------------

Element& Stack::Top(){
   return *(top->object);
}

//-----------------------------------------------------------

int Stack::isNotEmpty(){
   return itemsInStack;
}

//-----------------------------------------------------------

void Stack::forEach(    void (Element::*fun)() ){
   Stack_element *se_tmp =top;
   if(itemsInStack!=NULL){
      do{
         (Top().*fun)(); 
         top=top->next;
        }while(!(top==(Stack_element*)NULL)); 
   }   
   top=se_tmp;
}

//-----------------------------------------------------------

Stack::~Stack(){
   while(isNotEmpty()) Pop();
   }
   
// End of implementation -----------------------------------