// Created on: 1991-09-18
// Created by: Arnaud BOUZY
// Copyright (c) 1991-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#ifndef _Expr_UnknownIterator_HeaderFile
#define _Expr_UnknownIterator_HeaderFile

#include "Standard.hxx"
#include "Standard_DefineAlloc.hxx"
#include "Standard_Handle.hxx"

#include "Expr_NamedUnknown.hxx"
#include "NCollection_IndexedMap.hxx"
#include "Standard_Integer.hxx"
class Expr_GeneralExpression;
class Expr_NamedUnknown;

//! Describes an iterator on NamedUnknowns contained
//! in any GeneralExpression.
class Expr_UnknownIterator
{
public:
  DEFINE_STANDARD_ALLOC

  Standard_EXPORT Expr_UnknownIterator(const occ::handle<Expr_GeneralExpression>& exp);

  Standard_EXPORT bool More() const;

  Standard_EXPORT void Next();

  Standard_EXPORT occ::handle<Expr_NamedUnknown> Value() const;

private:
  Standard_EXPORT void Perform(const occ::handle<Expr_GeneralExpression>& exp);

  NCollection_IndexedMap<occ::handle<Expr_NamedUnknown>> myMap;
  int                                                    myCurrent;
};

#endif // _Expr_UnknownIterator_HeaderFile