/*! \file seriesstepper.h
 * \brief a stepper class for aff::Series (prototypes)
 * 
 * ----------------------------------------------------------------------------
 * 
 * $Id: seriesstepper.h,v 1.1 2002-12-20 10:18:43 forbrig Exp $
 * \author Thomas Forbriger
 * \date 20/12/2002
 * 
 * a stepper class for aff::Series (prototypes)
 *
 * \note 
 * This file is automatically included through aff/series.h
 * 
 * Copyright (c) 2002 by Thomas Forbriger (IMG Frankfurt) 
 * 
 * REVISIONS and CHANGES 
 *  - 20/12/2002   V1.0   Thomas Forbriger
 * 
 * ============================================================================
 */

// include guard
#ifndef AFF_SERIESSTEPPER_H_VERSION

#define AFF_SERIESSTEPPER_H_VERSION \
  "AFF_SERIESSTEPPER_H   V1.0"
#define AFF_SERIESSTEPPER_H_CVSID \
  "$Id: seriesstepper.h,v 1.1 2002-12-20 10:18:43 forbrig Exp $"

#include<aff/lib/types.h>

namespace aff {
namespace util {

  /*! \brief A stepper for aff::Series
   *
   * If we provide a stepper class, The aff::Iterator template can work with
   * the aff::Series. 
   *
   * This class cycles through the offset range of an aff::Series. It is used
   * internally within aff::Series::operator=() for value assignment. And it
   * is used within the aff::Iterator and aff::Browser classes. You normally
   * will not use it directly.
   */
  class SeriesStepper 
  {
    //! only non-copy constructor
    SeriesStepper(const Tsubscript& first,
                  const Tsubscript& last,
                  const Tsize& base):
      Mfirst_offset(first-base), Mlast_offset(last-base),
      Mbase(base), Mcurrent(first-base), Mvalid(true) { }
    //! return current index value for Representation access
    const Tsubscript& current() const { return(Mcurrent); }
    //! return current index vector for array access
    Tsubscript index() const { return(Mcurrent+Mbase); }
    //! increment offset - return reference to itself
    SeriesStepper& incr();
    //! decrement offset - return reference to itself
    SeriesStepper& decr();
    //! returns true if there are more elements in incr-direction
    bool more() const
    { return(Mcurrent<Mlast_offset); }
    //! returns true if there are more elements in decr-direction
    bool less() const
    { return(Mcurrent>Mfirst_offset); }
    //! valid if not passed end or beginning
    const bool& valid() const
    { return(Mvalid); }
    //! set current element index to the first - return reference to itself
    SeriesStepper& tofirst();
    //! set current element index to the last - return reference to itself
    SeriesStepper& tolast();
  private:
    //! store current bounds to reduce execution time 
    Tsubscript Mfirst_offset, Mlast_offset;
    //! hold reference to shape
    Tsize Mbase;
    //! hold current position offset to memory
    Tsubscript Mcurrent;
    //! true while not passed start or end
    bool Mvalid;
  }; // class SeriesStepper

} // namespace util
} // namespace aff

#endif // AFF_SERIESSTEPPER_H_VERSION (includeguard)

/* ----- END OF seriesstepper.h ----- */