// File:	TCollection_Stack.gxx
// Created:	Mon Jan 18 14:30:12 1993
// Author:	Remi LEQUETTE
//		<rle@phylox>

#include <Standard_NoSuchObject.hxx>

//=======================================================================
//function : TCollection_Stack
//purpose  : 
//=======================================================================

TCollection_Stack::TCollection_Stack() :
       myTop(NULL),
       myDepth(0)
{
}

//=======================================================================
//function : TCollection_Stack
//purpose  : 
//=======================================================================

TCollection_Stack::TCollection_Stack(const TCollection_Stack& Other)
{
  if (!Other.IsEmpty()) {
    cout << "WARNING copy constructor of non empty stack !"<<endl;
  }
  TCollection_StackNode* p = (TCollection_StackNode*) Other.myTop;
  TCollection_StackNode* q;
  TCollection_StackNode* r = NULL;
  myTop = NULL;
  while (p) {
    q = new TCollection_StackNode(p->Value(),(TCollection_MapNode*)0L);
    if (r) r->Next() = q;
    else   myTop   = q;
    r = q;
    p = (TCollection_StackNode*)p->Next();
  }
  myDepth = Other.myDepth;
}

//=======================================================================
//function : Assign
//purpose  : 
//=======================================================================

const TCollection_Stack& TCollection_Stack::Assign
  (const TCollection_Stack& Other)
{
  if (this == &Other) return *this;
  Clear();
  TCollection_StackNode* p = (TCollection_StackNode*) Other.myTop;
  TCollection_StackNode* q;
  TCollection_StackNode* r = NULL;
  while (p) {
    q = new TCollection_StackNode(p->Value(),(TCollection_MapNode*)0L);
    if (r) r->Next() = q;
    else   myTop   = q;
    r = q;
    p = (TCollection_StackNode*)p->Next();
  }
  myDepth = Other.myDepth;
  return *this;
}


//=======================================================================
//function : Top
//purpose  : 
//=======================================================================

const Item& TCollection_Stack::Top() const
{
  Standard_NoSuchObject_Raise_if(IsEmpty(),"TCollection_Stack");
  return ((TCollection_StackNode*)myTop)->Value();
}

//=======================================================================
//function : Push
//purpose  : 
//=======================================================================

void TCollection_Stack::Push(const Item& I)
{
  myTop = new TCollection_StackNode(I,(TCollection_StackNode*)myTop);
  myDepth++;
}

//=======================================================================
//function : Pop
//purpose  : 
//=======================================================================

void TCollection_Stack::Pop()
{
  Standard_NoSuchObject_Raise_if(IsEmpty(),"TCollection_Stack");
  TCollection_StackNode* p = (TCollection_StackNode*) myTop;
  myTop = p->Next();
  delete p;
  myDepth--;
}

//=======================================================================
//function : Clear
//purpose  : 
//=======================================================================

void TCollection_Stack::Clear()
{
  TCollection_StackNode* p = (TCollection_StackNode*) myTop;
  TCollection_StackNode* q;
  while(p) {
    q = (TCollection_StackNode*)p->Next();
    delete p;
    p = q;
  }
  myDepth = 0;
  myTop = NULL;
}

//=======================================================================
//function : ChangeTop
//purpose  : 
//=======================================================================

Item& TCollection_Stack::ChangeTop()
{
  Standard_NoSuchObject_Raise_if(IsEmpty(),"TCollection_Stack");
  return ((TCollection_StackNode*)myTop)->Value();
}

//=======================================================================
//function : Next
//purpose  : 
//=======================================================================

void TCollection_StackIterator::Next()
{
  current = ((TCollection_StackNode*)current)->Next();
}

//=======================================================================
//function : Value
//purpose  : 
//=======================================================================

const Item& TCollection_StackIterator::Value() const
{
  Standard_NoSuchObject_Raise_if(current == NULL,
				 "TCollection_StackIterator");
  return ((TCollection_StackNode*)current)->Value();
}