// Template array classes
/*

Copyright (C) 1996, 1997, 2000, 2002, 2003, 2004, 2005, 2006, 2007
              John W. Eaton
Copyright (C) 2008, 2009 Jaroslav Hajek
Copyright (C) 2010 VZLU Prague

This file is part of Octave.

Octave is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

Octave is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

*/

#if !defined (octave_DiagArray2_h)
#define octave_DiagArray2_h 1

#include <cassert>
#include <cstdlib>

#include "Array.h"

// Array<T> is inherited privately so that some methods, like index, don't
// produce unexpected results.

template <class T>
class
DiagArray2 : protected Array<T>
{
protected:
  octave_idx_type d1, d2;

public:

  using Array<T>::element_type;

  DiagArray2 (void) 
    : Array<T> (), d1 (0), d2 (0) { }

  DiagArray2 (octave_idx_type r, octave_idx_type c) 
    : Array<T> (std::min (r, c), 1), d1 (r), d2 (c) { }

  DiagArray2 (octave_idx_type r, octave_idx_type c, const T& val) 
    : Array<T> (std::min (r, c), 1, val), d1 (r), d2 (c) { }

  explicit DiagArray2 (const Array<T>& a) 
    : Array<T> (a.as_column ()), d1 (a.numel ()), d2 (a.numel ()) { }

  DiagArray2 (const Array<T>& a, octave_idx_type r, octave_idx_type c);

  DiagArray2 (const DiagArray2<T>& a) 
    : Array<T> (a), d1 (a.d1), d2 (a.d2) { }

  template <class U>
  DiagArray2 (const DiagArray2<U>& a) 
  : Array<T> (a.diag ()), d1 (a.dim1 ()), d2 (a.dim2 ()) { }

  ~DiagArray2 (void) { }

  DiagArray2<T>& operator = (const DiagArray2<T>& a)
    {
      if (this != &a)
        {
          Array<T>::operator = (a);
          d1 = a.d1;
          d2 = a.d2;
        }

      return *this;
    }

  octave_idx_type dim1 (void) const { return d1; }
  octave_idx_type dim2 (void) const { return d2; }

  octave_idx_type rows (void) const { return dim1 (); }
  octave_idx_type cols (void) const { return dim2 (); }
  octave_idx_type columns (void) const { return dim2 (); }

  octave_idx_type diag_length (void) const { return Array<T>::length (); }
  // FIXME: a dangerous ambiguity?
  octave_idx_type length (void) const { return Array<T>::length (); }
  octave_idx_type nelem (void) const { return dim1 () * dim2 (); }
  octave_idx_type numel (void) const { return nelem (); }

  size_t byte_size (void) const { return Array<T>::byte_size (); }

  dim_vector dims (void) const { return dim_vector (d1, d2); }

  Array<T> diag (octave_idx_type k = 0) const;

  // Warning: the non-const two-index versions will silently ignore assignments
  // to off-diagonal elements. 

  T elem (octave_idx_type r, octave_idx_type c) const
    {
      return (r == c) ? Array<T>::elem (r) : T (0);
    }

  T& elem (octave_idx_type r, octave_idx_type c)
    {
      static T zero (0);
      return (r == c) ? Array<T>::elem (r) : zero;
    }

  T dgelem (octave_idx_type i) const
    { return Array<T>::elem (i); }

  T& dgelem (octave_idx_type i) 
    { return Array<T>::elem (i); }

  T checkelem (octave_idx_type r, octave_idx_type c) const;

  T operator () (octave_idx_type r, octave_idx_type c) const
    {
#if defined (BOUNDS_CHECKING)
      return checkelem (r, c);
#else
      return elem (r, c);
#endif
    }

  // No checking.

  T xelem (octave_idx_type r, octave_idx_type c) const
    {
      return (r == c) ? Array<T>::xelem (r) : T (0);
    }

  T& dgxelem (octave_idx_type i)
    { return Array<T>::xelem (i); }

  T dgxelem (octave_idx_type i) const
    { return Array<T>::xelem (i); }

  void resize (octave_idx_type n, octave_idx_type m, 
               const T& rfv = Array<T>::resize_fill_value ());

  DiagArray2<T> transpose (void) const;
  DiagArray2<T> hermitian (T (*fcn) (const T&) = 0) const;

  Array<T> array_value (void) const;

  const T *data (void) const { return Array<T>::data (); }

  const T *fortran_vec (void) const { return Array<T>::fortran_vec (); }

  T *fortran_vec (void) { return Array<T>::fortran_vec (); }

  void print_info (std::ostream& os, const std::string& prefix) const
    { Array<T>::print_info (os, prefix); }
};

#endif