/*

Copyright (C) 1996, 1997, 1998, 2000, 2002, 2003, 2004, 2005, 2006,
              2007, 2008, 2009 John W. Eaton

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/>.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <iostream>

#include "Cell.h"
#include "defun.h"
#include "error.h"
#include "gripes.h"
#include "oct-lvalue.h"
#include "ov-list.h"
#include "ov-struct.h"
#include "unwind-prot.h"
#include "utils.h"
#include "variables.h"

#include "Array-util.h"
#include "oct-locbuf.h"

#include "byte-swap.h"
#include "ls-oct-ascii.h"
#include "ls-oct-binary.h"
#include "ls-hdf5.h"
#include "ls-utils.h"
#include "pr-output.h"

DEFINE_OCTAVE_ALLOCATOR(octave_struct);

DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA(octave_struct, "struct", "struct");

Cell
octave_struct::dotref (const octave_value_list& idx, bool auto_add)
{
  Cell retval;

  assert (idx.length () == 1);

  std::string nm = idx(0).string_value ();

  Octave_map::const_iterator p = map.seek (nm);

  if (p != map.end ())
    retval = map.contents (p);
  else if (auto_add)
    retval = (numel () == 0) ? Cell (dim_vector (1)) : Cell (dims ());
  else 
    error ("structure has no member `%s'", nm.c_str ());

  return retval;
}

#if 0
static void
gripe_invalid_index (void)
{
  error ("invalid index for structure array");
}
#endif

static void
gripe_invalid_index_for_assignment (void)
{
  error ("invalid index for structure array assignment");
}

static void
gripe_invalid_index_type (const std::string& nm, char t)
{
  error ("%s cannot be indexed with %c", nm.c_str (), t);
}

static void
gripe_failed_assignment (void)
{
  error ("assignment to structure element failed");
}

octave_value_list
octave_struct::subsref (const std::string& type,
			const std::list<octave_value_list>& idx,
			int nargout)
{
  octave_value_list retval;

  int skip = 1;

  switch (type[0])
    {
    case '(':
      {
	if (type.length () > 1 && type[1] == '.')
	  {
	    std::list<octave_value_list>::const_iterator p = idx.begin ();
	    octave_value_list key_idx = *++p;

	    const Cell tmp = dotref (key_idx);

	    if (! error_state)
	      {
		const Cell t = tmp.index (idx.front ());

		retval(0) = (t.length () == 1) ? t(0) : octave_value (t, true);

		// We handled two index elements, so tell
		// next_subsref to skip both of them.

		skip++;
	      }
	  }
	else
	  retval(0) = map.index (idx.front ());
      }
      break;

    case '.':
      {
	if (map.numel() > 0)
	  {
	    const Cell t = dotref (idx.front ());

	    retval(0) = (t.length () == 1) ? t(0) : octave_value (t, true);
	  }
      }
      break;

    case '{':
      gripe_invalid_index_type (type_name (), type[0]);
      break;

    default:
      panic_impossible ();
    }

  // FIXME -- perhaps there should be an
  // octave_value_list::next_subsref member function?  See also
  // octave_user_function::subsref.

  if (idx.size () > 1)
    retval = retval(0).next_subsref (nargout, type, idx, skip);

  return retval;
}

octave_value
octave_struct::subsref (const std::string& type,
			const std::list<octave_value_list>& idx,
			bool auto_add)
{
  octave_value retval;

  int skip = 1;

  switch (type[0])
    {
    case '(':
      {
	if (type.length () > 1 && type[1] == '.')
	  {
	    std::list<octave_value_list>::const_iterator p = idx.begin ();
	    octave_value_list key_idx = *++p;

	    const Cell tmp = dotref (key_idx, auto_add);

	    if (! error_state)
	      {
		const Cell t = tmp.index (idx.front (), auto_add);

		retval = (t.length () == 1) ? t(0) : octave_value (t, true);

		// We handled two index elements, so tell
		// next_subsref to skip both of them.

		skip++;
	      }
	  }
	else
	  retval = map.index (idx.front (), auto_add);
      }
      break;

    case '.':
      {
	if (map.numel() > 0)
	  {
	    const Cell t = dotref (idx.front (), auto_add);

	    retval = (t.length () == 1) ? t(0) : octave_value (t, true);
	  }
      }
      break;

    case '{':
      gripe_invalid_index_type (type_name (), type[0]);
      break;

    default:
      panic_impossible ();
    }

  // FIXME -- perhaps there should be an
  // octave_value_list::next_subsref member function?  See also
  // octave_user_function::subsref.

  if (idx.size () > 1)
    retval = retval.next_subsref (auto_add, type, idx, skip);

  return retval;
}

/*
%!test
%! x(1).a.a = 1; x(2).a.a = 2;
%! assert (size (x), [1, 2]);
%! assert (x(1).a.a, 1);
%! assert (x(2).a.a, 2);
*/

octave_value
octave_struct::numeric_conv (const octave_value& val,
			     const std::string& type)
{
  octave_value retval;

  if (type.length () > 0 && type[0] == '.' && ! val.is_map ())
    retval = Octave_map ();
  else
    retval = val;

  return retval;
}

octave_value
octave_struct::subsasgn (const std::string& type,
			 const std::list<octave_value_list>& idx,
			 const octave_value& rhs)
{
  octave_value retval;

  int n = type.length ();

  octave_value t_rhs = rhs;

  // This is handy for calling const methods of map.
  const Octave_map& cmap = const_cast<const Octave_map &> (map);

  if (n > 1 && ! (type.length () == 2 && type[0] == '(' && type[1] == '.'))
    {
      switch (type[0])
	{
	case '(':
	  {
	    if (type.length () > 1 && type[1] == '.')
	      {
		std::list<octave_value_list>::const_iterator p = idx.begin ();
		octave_value_list t_idx = *p;

		octave_value_list key_idx = *++p;

		assert (key_idx.length () == 1);

		std::string key = key_idx(0).string_value ();

                std::list<octave_value_list> next_idx (idx);

                // We handled two index elements, so subsasgn to
                // needs to skip both of them.

                next_idx.erase (next_idx.begin ());
                next_idx.erase (next_idx.begin ());

                std::string next_type = type.substr (2);

                // cast map to const reference to avoid forced key insertion.
                Cell tmpc = cmap.contents (key).index (idx.front (), true);

                // FIXME: better code reuse? cf. octave_cell::subsasgn and the case below.
		if (! error_state)
		  {
                    if (tmpc.numel () == 1)
                      {
                        octave_value tmp = tmpc(0);
                        tmpc = Cell ();

                        if (! tmp.is_defined () || tmp.is_zero_by_zero ())
                          {
                            tmp = octave_value::empty_conv (next_type, rhs);
                            tmp.make_unique (); // probably a no-op.
                          }
                        else
                          // optimization: ignore the copy still stored inside our map.
                          tmp.make_unique (1);

                        if (! error_state)
                          t_rhs = tmp.subsasgn (next_type, next_idx, rhs);
                      }
                    else
                      gripe_indexed_cs_list ();
		  }
	      }
	    else
	      gripe_invalid_index_for_assignment ();
	  }
	  break;

	case '.':
	  {
	    octave_value_list key_idx = idx.front ();

	    assert (key_idx.length () == 1);

	    std::string key = key_idx(0).string_value ();

            std::list<octave_value_list> next_idx (idx);

            next_idx.erase (next_idx.begin ());

            std::string next_type = type.substr (1);

            Cell tmpc (1, 1);
            if (map.contains (key)) tmpc = cmap.contents (key);

            // FIXME: better code reuse?
            if (! error_state)
              {
                if (tmpc.numel () == 1)
                  {
                    octave_value tmp = tmpc(0);
                    tmpc = Cell ();

                    if (! tmp.is_defined () || tmp.is_zero_by_zero ())
                      {
                        tmp = octave_value::empty_conv (next_type, rhs);
                        tmp.make_unique (); // probably a no-op.
                      }
                    else
                      // optimization: ignore the copy still stored inside our map.
                      tmp.make_unique (1);

                    if (! error_state)
                      t_rhs = tmp.subsasgn (next_type, next_idx, rhs);
                  }
                else
                  gripe_indexed_cs_list ();
              }
	  }
	  break;

	case '{':
	  gripe_invalid_index_type (type_name (), type[0]);
	  break;

	default:
	  panic_impossible ();
	}
    }

  if (! error_state)
    {
      switch (type[0])
	{
	case '(':
	  {
	    if (n > 1 && type[1] == '.')
	      {
		std::list<octave_value_list>::const_iterator p = idx.begin ();
		octave_value_list key_idx = *++p;
                octave_value_list idxf = idx.front ();

		assert (key_idx.length () == 1);

		std::string key = key_idx(0).string_value ();

		if (! error_state)
		  {
                    if (t_rhs.is_cs_list ())
                      {
                        Cell tmp_cell = Cell (t_rhs.list_value ());

                        // Inquire the proper shape of the RHS.

                        dim_vector didx = dims ().redim (idxf.length ());
                        for (octave_idx_type k = 0; k < idxf.length (); k++)
                          if (! idxf(k).is_magic_colon ()) didx(k) = idxf(k).numel ();

                        if (didx.numel () == tmp_cell.numel ())
                          tmp_cell = tmp_cell.reshape (didx);


                        map.assign (idxf, key, tmp_cell);

                        if (! error_state)
                          {
                            count++;
                            retval = octave_value (this);
                          }
                        else
                          gripe_failed_assignment ();
                      }
                    else 
                      {
                        // cast map to const reference to avoid forced key insertion.
                        if (idxf.all_scalars () 
                            || cmap.contents (key).index (idxf, true).numel () == 1)
                          {
                            map.assign (idxf, key, t_rhs.storable_value ());
                            if (! error_state)
                              {
                                count++;
                                retval = octave_value (this);
                              }
                            else
                              gripe_failed_assignment ();
                          }
                        else if (! error_state)
                          error ("invalid assignment to cs-list outside multiple assignment.");
                      }
		  }
		else
		  gripe_failed_assignment ();
	      }
	    else
	      {
		if (t_rhs.is_map())
		  {
		    Octave_map rhs_map = t_rhs.map_value ();

		    if (! error_state)
		      {
			map.assign (idx.front (), rhs_map);

			if (! error_state)
			  {
			    count++;
			    retval = octave_value (this);
			  }
			else
			  gripe_failed_assignment ();
		      }
		    else
		      error ("invalid structure assignment");
		  }
		else
		  {
		    if (t_rhs.is_null_value()) 
		      {
			map.maybe_delete_elements (idx.front());

			if (! error_state)
			  {
			    count++;
			    retval = octave_value (this);
			  }
			else
			  gripe_failed_assignment ();
		      }
		    else
		      error ("invalid structure assignment");
		  }
	      }
	  }
	  break;

	case '.':
	  {
	    octave_value_list key_idx = idx.front ();

	    assert (key_idx.length () == 1);

	    std::string key = key_idx(0).string_value ();

	    if (t_rhs.is_cs_list ())
	      {
		Cell tmp_cell = Cell (t_rhs.list_value ());

		// The shape of the RHS is irrelevant, we just want
		// the number of elements to agree and to preserve the
		// shape of the left hand side of the assignment.

		if (numel () == tmp_cell.numel ())
		  tmp_cell = tmp_cell.reshape (dims ());

		map.assign (key, tmp_cell);
	      }
	    else
              // Regularize a null matrix if stored into a struct component.
	      map.assign (key, t_rhs.storable_value ());

	    if (! error_state)
	      {
		count++;
		retval = octave_value (this);
	      }
	    else
	      gripe_failed_assignment ();
	  }
	  break;

	case '{':
	  gripe_invalid_index_type (type_name (), type[0]);
	  break;

	default:
	  panic_impossible ();
	}
    }
  else
    gripe_failed_assignment ();

  return retval;
}

octave_value
octave_struct::do_index_op (const octave_value_list& idx, bool resize_ok)
{
  // Octave_map handles indexing itself.
  return map.index (idx, resize_ok);
}

size_t
octave_struct::byte_size (void) const
{
  // Neglect the size of the fieldnames.

  size_t retval = 0;

  for (Octave_map::const_iterator p = map.begin (); p != map.end (); p++)
    {
      std::string key = map.key (p);

      octave_value val = octave_value (map.contents (p));

      retval += val.byte_size ();
    }

  return retval;
}

void
octave_struct::print (std::ostream& os, bool) const
{
  print_raw (os);
}

void
octave_struct::print_raw (std::ostream& os, bool) const
{
  unwind_protect::begin_frame ("octave_struct_print");

  unwind_protect_int (Vstruct_levels_to_print);

  if (Vstruct_levels_to_print >= 0)
    {
      bool print_keys_only = Vstruct_levels_to_print-- == 0;

      indent (os);
      os << "{";
      newline (os);

      increment_indent_level ();

      octave_idx_type n = map.numel ();

      if (n != 1 || print_keys_only)
	{
	  indent (os);
	  dim_vector dv = dims ();
	  os << dv.str () << " struct array containing the fields:";
	  newline (os);
	  newline (os);

	  increment_indent_level ();
	}

      string_vector key_list = map.keys ();

      for (octave_idx_type i = 0; i < key_list.length (); i++)
	{
	  std::string key = key_list[i];

	  Cell val = map.contents (key);

	  octave_value tmp = (n == 1) ? val(0) : octave_value (val, true);

	  if (n != 1 || print_keys_only)
	    {
	      indent (os);
	      os << key;
	      if (n == 1)
		{
		  dim_vector dv = tmp.dims ();
		  os << ": " << dv.str () << " " << tmp.type_name ();
		}
	      newline (os);
	    }
	  else
	    tmp.print_with_name (os, key);
	}

      if (n != 1 || print_keys_only)
	decrement_indent_level ();

      decrement_indent_level ();

      indent (os);
      os << "}";
      newline (os);
    }
  else
    {
      indent (os);
      os << "<structure>";
      newline (os);
    }

  unwind_protect::run_frame ("octave_struct_print");
}

bool
octave_struct::print_name_tag (std::ostream& os, const std::string& name) const
{
  bool retval = false;

  indent (os);

  if (Vstruct_levels_to_print < 0)
    os << name << " = ";
  else
    {
      os << name << " =";
      newline (os);
      retval = true;
    }

  return retval;
}

static bool 
scalar (const dim_vector& dims) 
{
  return dims.length () == 2 && dims (0) == 1 && dims (1) == 1;
}

/*
%!shared x
%! x(1).a=1; x(2).a=2; x(1).b=3; x(2).b=3;
%!assert(struct('a',1,'b',3),x(1))
%!assert(isempty(x([])))
%!assert(isempty(struct('a',{},'b',{})))
%!assert(struct('a',{1,2},'b',{3,3}),x)
%!assert(struct('a',{1,2},'b',3),x)
%!assert(struct('a',{1,2},'b',{3}),x)
%!assert(struct('b',3,'a',{1,2}),x)
%!assert(struct('b',{3},'a',{1,2}),x) 
%!test x=struct([]);
%!assert(size(x),[0,0]);
%!assert(isstruct(x));
%!assert(isempty(fieldnames(x)));
%!fail("struct('a',{1,2},'b',{1,2,3})","dimensions of parameter 2 do not match those of parameter 4")
%!fail("struct(1,2,3,4)","struct expects alternating \"field\", VALUE pairs");
%!fail("struct('1',2,'3')","struct expects alternating \"field\", VALUE pairs");
*/

DEFUN (struct, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} struct (\"field\", @var{value}, \"field\", @var{value}, @dots{})\n\
\n\
Create a structure and initialize its value.\n\
\n\
If the values are cell arrays, create a structure array and initialize\n\
its values.  The dimensions of each cell array of values must match.\n\
Singleton cells and non-cell values are repeated so that they fill\n\
the entire array.  If the cells are empty, create an empty structure\n\
array with the specified field names.\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  // struct ([]) returns an empty struct.

  // struct (empty_matrix) returns an empty struct with the same
  // dimensions as the empty matrix.

  // Note that struct () creates a 1x1 struct with no fields for
  // compatibility with Matlab.

  if ((nargin == 1 || nargin == 2)
      && args(0).is_empty () && args(0).is_real_matrix ())
    {
      Cell fields;

      if (nargin == 2)
	{
	  if (args(1).is_cellstr ())
	    retval = Octave_map (args(0).dims (), args(1).cell_value ());
	  else
	    error ("struct: expecting cell array of field names as second argument");
	}
      else
	retval = Octave_map (args(0).dims ());

      return retval;
    }
    
  // Check for "field", VALUE pairs.

  for (int i = 0; i < nargin; i += 2) 
    {
      if (! args(i).is_string () || i + 1 >= nargin)
	{
	  error ("struct expects alternating \"field\", VALUE pairs");
	  return retval;
	}
    }

  // Check that the dimensions of the values correspond.

  dim_vector dims (1, 1);

  int first_dimensioned_value = 0;

  for (int i = 1; i < nargin; i += 2) 
    {
      if (args(i).is_cell ()) 
	{
	  dim_vector argdims (args(i).dims ());

	  if (! scalar (argdims))
	    {
	      if (! first_dimensioned_value)
		{
		  dims = argdims;
		  first_dimensioned_value = i + 1;
		}
	      else if (dims != argdims)
		{
		  error ("struct: dimensions of parameter %d do not match those of parameter %d",
			 first_dimensioned_value, i+1);
		  return retval;
		}
	    }
	}
    }

  // Create the return value.

  Octave_map map (dims);

  for (int i = 0; i < nargin; i+= 2) 
    {
      // Get key.

      std::string key (args(i).string_value ());

      if (error_state)
	return retval;

      if (! valid_identifier (key))
	{
	  error ("struct: invalid structure field name `%s'", key.c_str ());
	  return retval;
	}

      // Value may be v, { v }, or { v1, v2, ... }
      // In the first two cases, we need to create a cell array of
      // the appropriate dimensions filled with v.  In the last case, 
      // the cell array has already been determined to be of the
      // correct dimensions.

      if (args(i+1).is_cell ()) 
	{
	  const Cell c (args(i+1).cell_value ());

	  if (error_state)
	    return retval;

	  if (scalar (c.dims ())) 
	    map.assign (key, Cell (dims, c(0)));
	  else 
	    map.assign (key, c);
	}
      else 
	map.assign (key, Cell (dims, args(i+1)));

      if (error_state)
	return retval;
    }

  return octave_value (map);
}

DEFUN (isstruct, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} isstruct (@var{expr})\n\
Return 1 if the value of the expression @var{expr} is a structure.\n\
@end deftypefn")
{
  octave_value retval;

  if (args.length () == 1)
    retval = args(0).is_map ();
  else
    print_usage ();

  return retval;
}

DEFUN (fieldnames, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} fieldnames (@var{struct})\n\
Return a cell array of strings naming the elements of the structure\n\
@var{struct}.  It is an error to call @code{fieldnames} with an\n\
argument that is not a structure.\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 1)
    {
      octave_value arg = args(0);

      if (arg.is_map () || arg.is_object ())
	{
	  Octave_map m = arg.map_value ();

	  string_vector keys = m.keys ();

	  if (keys.length () == 0)
	    retval = Cell (0, 1);
	  else
	    retval = Cell (m.keys ());
	}
      else
	gripe_wrong_type_arg ("fieldnames", args(0));
    }
  else
    print_usage ();

  return retval;
}

DEFUN (isfield, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} isfield (@var{expr}, @var{name})\n\
Return true if the expression @var{expr} is a structure and it includes an\n\
element named @var{name}.  The first argument must be a structure and\n\
the second must be a string.\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 2)
    {
      retval = false;

      // FIXME -- should this work for all types that can do
      // structure reference operations?

      if (args(0).is_map () && args(1).is_string ())
	{
	  std::string key = args(1).string_value ();

	  Octave_map m = args(0).map_value ();

	  retval = m.contains (key) != 0;
	}
    }
  else
    print_usage ();

  return retval;
}

// Check that the dimensions of the input arguments are correct.

static bool
cell2struct_check_args (const dim_vector& c_dv, const dim_vector& f_dv,
			bool is_cell, int dim)
{
  bool retval = true;

  if (dim >= 0 && dim < c_dv.length ())
    {
      if (is_cell)
	{
	  if (f_dv.numel () != c_dv(dim))
	    {
	      error ("cell2struct: numel (FIELD) != size (CELL, DIM)");

	      retval = false;
	    }
	}
      else
	{
	  if (f_dv.length () > 2)
	    {
	      error ("cell2struct: field array must be a 2-d matrix");

	      retval = false;
	    }
	  else if (f_dv(0) != c_dv(dim))
	    {
	      error ("cell2struct: size (FIELD, 1) != length (C, DIM)");

	      retval = false;
	    }
	}
    }
  else
    {
      error ("cell2struct: DIM out of range");

      retval = false;
    }

  return retval;
}

static void
cell2struct_construct_idx (Array<octave_idx_type>& ra_idx1,
			   const Array<octave_idx_type>& ra_idx2,
			   octave_idx_type dim, octave_idx_type fill_value)
{
  octave_idx_type iidx = 0;

  for (octave_idx_type idx = 0; idx < ra_idx1.length (); idx++)
    {
      if (idx == dim)
	ra_idx1.elem (idx) = fill_value;
      else
	ra_idx1.elem (idx) = ra_idx2(iidx++);
    }
}

DEFUN (cell2struct, args, ,
       "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} cell2struct (@var{cell}, @var{fields}, @var{dim})\n\
Convert @var{cell} to a structure. The number of fields in @var{fields}\n\
must match the number of elements in @var{cell} along dimension @var{dim},\n\
that is @code{numel (@var{fields}) == size (@var{cell}, @var{dim})}.\n\
\n\
@example\n\
@group\n\
A = cell2struct (@{'Peter', 'Hannah', 'Robert';\n\
                   185, 170, 168@},\n\
                 @{'Name','Height'@}, 1);\n\
A(1)\n\
@result{} ans =\n\
      @{\n\
        Height = 185\n\
        Name   = Peter\n\
      @}\n\
\n\
@end group\n\
@end example\n\
@end deftypefn")
{
  octave_value retval;

  if (args.length () == 3)
    {
      Cell c = args(0).cell_value ();

      if (! error_state)
	{
	  octave_value field = args(1);

	  // Field is either cell or character matrix.

	  // FIXME -- this could be simplified if we had
	  // cellstr and iscellstr functions available.

	  bool field_is_cell = field.is_cell ();

	  Cell field_cell;
	  charMatrix field_char;

	  if (field_is_cell)
	    field_cell = field.cell_value ();
	  else
	    field_char = field.char_matrix_value ();

	  if (! error_state)
	    {
	      // Retrieve the dimension value.

	      // FIXME --  int_value () should print out the
	      // conversions it does to be Matlab compatible.

	      octave_idx_type dim = args(2).int_value () - 1;

	      if (! error_state)
		{
		  dim_vector c_dv = c.dims ();
		  dim_vector field_dv = field.dims ();

		  if (cell2struct_check_args (c_dv, field_dv, field_is_cell,
					      dim))
		    {
		      octave_idx_type c_dv_length = c_dv.length ();

		      // Dimension vector for the Cell arrays to be
		      // put into the structure.

		      dim_vector value_dv;

		      // Initialize c_value_dv.

		      if (c_dv_length == 2)
			value_dv = dim_vector (1, 1);
		      else
			value_dv.resize (c_dv_length - 1);

		      octave_idx_type idx_tmp = 0;

		      for (octave_idx_type i = 0; i < c_dv_length; i++)
			{
			  if (i != dim)
			    value_dv.elem (idx_tmp++) = c_dv.elem (i);
			}

		      // All initializing is done, we can start moving
		      // values.

		      Octave_map map;

		      // If field is a cell array then we use all
		      // elements in array, on the other hand when
		      // field is a character array the number of
		      // elements is equals the number of rows.

		      octave_idx_type field_numel
			= field_is_cell ? field_dv.numel (): field_dv(0);

		      // For matlab compatibility.

		      if (field_numel == 0)
			map.reshape (dim_vector (0, 1));

		      for (octave_idx_type i = 0; i < field_numel; i++)
			{
			  // Construct cell array which goes into the
			  // structure together with the appropriate
			  // field name.

			  Cell c_value (value_dv);

			  Array<octave_idx_type> value_idx (value_dv.length (), 0);
			  Array<octave_idx_type> c_idx (c_dv_length, 0);

			  for (octave_idx_type j = 0; j < value_dv.numel (); j++)
			    {
			      // Need to do this to construct the
			      // appropriate idx for getting elements
			      // from the original cell array.

			      cell2struct_construct_idx (c_idx, value_idx,
							 dim, i);

			      c_value.elem (value_idx) = c.elem (c_idx);

			      increment_index (value_idx, value_dv);
			    }

			  std::string field_str;

			  if (field_is_cell)
			    {
			      // Matlab retrieves the field values
			      // column by column.

			      octave_value field_tmp = field_cell.elem (i);

			      field_str = field_tmp.string_value ();

			      if (error_state)
				{
				  error ("cell2struct: fields have to be of type string");
				  break;
				}
			    }
			  else
			    {
			      field_str = field_char.row_as_string (i);

			      if (error_state)
				return retval;
			    }

			  if (! valid_identifier (field_str))
			    {
			      error ("cell2struct: invalid field name `%s'",
				     field_str.c_str ());
			      break;
			    }

			  map.reshape (value_dv);

			  map.assign (field_str, c_value);
			}

		      if (! error_state)
			retval = map;
		    }
		}
	      else
		error ("cell2struct: expecting third argument to be an integer");
	    }
	  else
	    error ("cell2struct: expecting second argument to be a cell or character array");
	}
      else
	error ("cell2struct: expecting first argument to be a cell array");
    }
  else
    print_usage ();

  return retval;
}

// So we can call Fcellstr directly.
extern octave_value_list Fcellstr (const octave_value_list& args, int);

DEFUN (rmfield, args, ,
       "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} rmfield (@var{s}, @var{f})\n\
Remove field @var{f} from the structure @var{s}.  If @var{f} is a\n\
cell array of character strings or a character array, remove the\n\
named fields.\n\
@seealso{cellstr, iscellstr, setfield}\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 2)
    {
      Octave_map m = args(0).map_value ();

      octave_value_list fval = Fcellstr (args(1), 1);

      if (! error_state)
	{
	  Cell fcell = fval(0).cell_value ();

	  for (int i = 0; i < fcell.numel (); i++)
	    {
	      std::string key = fcell(i).string_value ();

	      if (m.contains (key))
		m.del (key);
	      else
		{
		  error ("rmfield: structure does not contain field %s",
			 key.c_str ());

		  break;
		}
	    }

	  if (! error_state)
	    retval = m;
	}
    }
  else
    print_usage ();

  return retval;
}

bool
octave_struct::save_ascii (std::ostream& os)
{
  Octave_map m = map_value ();

  octave_idx_type nf = m.nfields ();

  os << "# length: " << nf << "\n";

  // Iterating over the list of keys will preserve the order of the
  // fields.
  string_vector keys = m.keys ();

  for (octave_idx_type i = 0; i < nf; i++)
    {
      std::string key = keys(i);

      octave_value val = map.contents (key);

      bool b = save_ascii_data (os, val, key, false, 0);
      
      if (! b)
	return os;
    }

  return true;
}

bool 
octave_struct::load_ascii (std::istream& is)
{
  octave_idx_type len = 0;
  bool success = true;

  if (extract_keyword (is, "length", len) && len >= 0)
    {
      if (len > 0)
	{
	  Octave_map m (map);

	  for (octave_idx_type j = 0; j < len; j++)
	    {
	      octave_value t2;
	      bool dummy;

	      // recurse to read cell elements
	      std::string nm
		= read_ascii_data (is, std::string (), dummy, t2, j);

	      if (!is)
		break;

	      Cell tcell = t2.is_cell () ? t2.cell_value () : Cell (t2);

	      if (error_state)
		{
		  error ("load: internal error loading struct elements");
		  return false;
		}

	      m.assign (nm, tcell);
	    }

	  if (is) 
	    map = m;
	  else
	    {
	      error ("load: failed to load structure");
	      success = false;
	    }
	}
      else if (len == 0 )
	map = Octave_map (dim_vector (1, 1));
      else
	panic_impossible ();
    }
  else {
    error ("load: failed to extract number of elements in structure");
    success = false;
  }

  return success;
}

bool 
octave_struct::save_binary (std::ostream& os, bool& save_as_floats)
{
  Octave_map m = map_value ();

  octave_idx_type nf = m.nfields ();

  int32_t len = nf;
  os.write (reinterpret_cast<char *> (&len), 4);

  // Iterating over the list of keys will preserve the order of the
  // fields.
  string_vector keys = m.keys ();

  for (octave_idx_type i = 0; i < nf; i++)
    {
      std::string key = keys(i);

      octave_value val = map.contents (key);

      bool b = save_binary_data (os, val, key, "", 0, save_as_floats);
      
      if (! b)
	return os;
    }

  return true;
}

bool 
octave_struct::load_binary (std::istream& is, bool swap,
			    oct_mach_info::float_format fmt)
{
  bool success = true;
  int32_t len;
  if (! is.read (reinterpret_cast<char *> (&len), 4))
    return false;
  if (swap)
    swap_bytes<4> (&len);

  if (len > 0)
    {
      Octave_map m (map);

      for (octave_idx_type j = 0; j < len; j++)
	{
	  octave_value t2;
	  bool dummy;
	  std::string doc;

	  // recurse to read cell elements
	  std::string nm = read_binary_data (is, swap, fmt, std::string (), 
					     dummy, t2, doc);

	  if (!is)
	    break;

	  Cell tcell = t2.is_cell () ? t2.cell_value () : Cell (t2);
 
	  if (error_state)
	    {
	      error ("load: internal error loading struct elements");
	      return false;
	    }

	  m.assign (nm, tcell);
	}

      if (is) 
	map = m;
      else
	{
	  error ("load: failed to load structure");
	  success = false;
	}
    }
  else if (len == 0 )
    map = Octave_map (dim_vector (1, 1));
  else
    panic_impossible ();

  return success;
}

#if defined (HAVE_HDF5)

bool
octave_struct::save_hdf5 (hid_t loc_id, const char *name, bool save_as_floats)
{
  hid_t data_hid = -1;

  data_hid = H5Gcreate (loc_id, name, 0);
  if (data_hid < 0) return false;

  // recursively add each element of the structure to this group
  Octave_map m = map_value ();

  octave_idx_type nf = m.nfields ();

  // Iterating over the list of keys will preserve the order of the
  // fields.
  string_vector keys = m.keys ();

  for (octave_idx_type i = 0; i < nf; i++)
    {
      std::string key = keys(i);

      octave_value val = map.contents (key);

      bool retval2 = add_hdf5_data (data_hid, val, key, "", false, 
				    save_as_floats);

      if (! retval2)
	break;
    }

  H5Gclose (data_hid);

  return true;
}

bool 
octave_struct::load_hdf5 (hid_t loc_id, const char *name,
			  bool have_h5giterate_bug)
{
  bool retval = false;

  hdf5_callback_data dsub;

  herr_t retval2 = 0;
  Octave_map m (dim_vector (1, 1));
  int current_item = 0;
#ifdef HAVE_H5GGET_NUM_OBJS
  hsize_t num_obj = 0;
  hid_t group_id = H5Gopen (loc_id, name); 
  H5Gget_num_objs (group_id, &num_obj);
  H5Gclose (group_id);

  // FIXME -- fields appear to be sorted alphabetically on loading.
  // Why is that happening?

  while (current_item < static_cast<int> (num_obj)
	 && (retval2 = H5Giterate (loc_id, name, &current_item,
				   hdf5_read_next_data, &dsub)) > 0)
#else
  while ((retval2 = H5Giterate (loc_id, name, &current_item,
				hdf5_read_next_data, &dsub)) > 0)
#endif
    {
      octave_value t2 = dsub.tc;

      Cell tcell = t2.is_cell () ? t2.cell_value () : Cell (t2);
 
      if (error_state)
	{
	  error ("load: internal error loading struct elements");
	  return false;
	}

      m.assign (dsub.name, tcell);

      if (have_h5giterate_bug)
	current_item++;  // H5Giterate returned the last index processed
    }

  if (retval2 >= 0)
    {
      map = m;
      retval = true;
    }
  
  return retval;
}

#endif

mxArray *
octave_struct::as_mxArray (void) const
{
  int nf = nfields ();
  string_vector kv = map_keys ();

  OCTAVE_LOCAL_BUFFER (const char *, f, nf);

  for (int i = 0; i < nf; i++)
    f[i] = kv[i].c_str ();

  mxArray *retval = new mxArray (dims (), nf, f);

  mxArray **elts = static_cast<mxArray **> (retval->get_data ());

  mwSize nel = numel ();

  mwSize ntot = nf * nel;

  for (int i = 0; i < nf; i++)
    {
      Cell c = map.contents (kv[i]);

      const octave_value *p = c.data ();

      mwIndex k = 0;
      for (mwIndex j = i; j < ntot; j += nf)
	elts[j] = new mxArray (p[k++]);
    }

  return retval;
}

/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/