--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/ov-class.cc	Fri Dec 28 22:32:23 2007 +0000
@@ -0,0 +1,1199 @@
+/*
+
+Copyright (C) 2007 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 2, 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, write to the Free
+Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <iostream>
+
+#include "Array-util.h"
+#include "byte-swap.h"
+
+#include "Cell.h"
+#include "defun.h"
+#include "error.h"
+#include "gripes.h"
+#include "load-path.h"
+#include "ls-hdf5.h"
+#include "ls-oct-ascii.h"
+#include "ls-oct-binary.h"
+#include "ls-utils.h"
+#include "oct-lvalue.h"
+#include "ov-class.h"
+#include "ov-fcn.h"
+#include "pager.h"
+#include "parse.h"
+#include "pr-output.h"
+#include "toplev.h"
+#include "unwind-prot.h"
+#include "variables.h"
+
+DEFINE_OCTAVE_ALLOCATOR(octave_class);
+
+int octave_class::t_id (-1);
+
+const std::string octave_class::t_name ("class");
+
+void
+octave_class::register_type (void)
+{
+  t_id = octave_value_typeinfo::register_type
+    (octave_class::t_name, "<unknown>", octave_value (new octave_class ()));
+}
+
+Cell
+octave_class::dotref (const octave_value_list& idx)
+{
+  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
+    error ("class has no member `%s'", nm.c_str ());
+
+  return retval;
+}
+
+static void
+gripe_invalid_index (void)
+{
+  error ("invalid index for class");
+}
+
+static void
+gripe_invalid_index_for_assignment (void)
+{
+  error ("invalid index for class 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 class element failed");
+}
+
+static inline octave_value_list
+sanitize (const octave_value_list& ovl)
+{
+  octave_value_list retval = ovl;
+
+  for (octave_idx_type i = 0; i < ovl.length (); i++)
+    {
+      if (retval(i).is_magic_colon ())
+	retval(i) = ":";
+    }
+
+  return retval;
+}
+
+static inline octave_value
+make_idx_args (const std::string& type,
+	       const std::list<octave_value_list>& idx,
+	       const std::string& who)
+{
+  octave_value retval;
+
+  size_t len = type.length ();
+
+  if (len == idx.size ())
+    {
+      Cell type_field (len, 1);
+      Cell subs_field (len, 1);
+
+      std::list<octave_value_list>::const_iterator p = idx.begin ();
+
+      for (size_t i = 0; i < len; i++)
+	{
+	  char t = type[i];
+
+	  switch (t)
+	    {
+	    case '(':
+	      type_field(i) = "()";
+	      subs_field(i) = Cell (sanitize (*p++));
+	      break;
+
+	    case '{':
+	      type_field(i) = "{}";
+	      subs_field(i) = Cell (sanitize (*p++));
+	      break;
+
+	    case '.':
+	      {
+		type_field(i) = ".";
+
+		octave_value_list vlist = *p++;
+
+		if (vlist.length () == 1)
+		  {
+		    octave_value val = vlist(0);
+
+		    if (val.is_string ())
+		      subs_field(i) = val;
+		    else
+		      {
+			error ("expecting character string argument for `.' index");
+			return retval;
+		      }
+		  }
+		else
+		  {
+		    error ("expecting single argument for `.' index");
+		    return retval;
+		  }
+	      }
+	      break;
+
+	    default:
+	      panic_impossible ();
+	      break;
+	    }
+	}
+
+      Octave_map m;
+
+      m.assign ("type", type_field);
+      m.assign ("subs", subs_field);
+
+      retval = m;
+    }
+  else
+    error ("invalid index for %s", who.c_str ());
+
+  return retval;
+}
+
+octave_value_list
+octave_class::subsref (const std::string& type,
+		       const std::list<octave_value_list>& idx,
+		       int nargout)
+{
+  octave_value_list retval;
+
+  if (in_class_method ())
+    {
+      // FIXME -- this block of code is the same as the body of
+      // octave_struct::subsref.  Maybe it could be shared instead of
+      // duplicated.
+
+      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;
+
+		Cell tmp = dotref (key_idx);
+
+		if (! error_state)
+		  {
+		    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)
+	      {
+		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);
+    }
+  else
+    {
+      octave_value meth = symbol_table::find_method ("subsref", class_name ());
+
+      if (meth.is_defined ())
+	{
+	  octave_value_list args;
+
+	  args(1) = make_idx_args (type, idx, "subsref");
+
+	  if (error_state)
+	    return octave_value_list ();
+
+	  count++;
+	  args(0) = octave_value (this);
+
+	  return feval (meth.function_value (), args, nargout);
+	}
+      else
+	{
+	  if (type.length () == 1 && type[0] == '(')
+	    retval(0) = octave_value (map.index (idx.front ()), class_name ());
+	  else
+	    gripe_invalid_index ();
+	}
+    }
+
+  return retval;
+}
+
+octave_value
+octave_class::numeric_conv (const Cell& val, const std::string& type)
+{
+  octave_value retval;
+
+  if (val.length () == 1)
+    {
+      retval = val(0);
+
+      if (type.length () > 0 && type[0] == '.' && ! retval.is_map ())
+	retval = Octave_map ();
+    }
+  else
+    gripe_invalid_index_for_assignment ();
+
+  return retval;
+}
+
+octave_value
+octave_class::subsasgn (const std::string& type,
+			const std::list<octave_value_list>& idx,
+			const octave_value& rhs)
+{
+  octave_value retval;
+
+  if (in_class_method ())
+    {
+      // FIXME -- this block of code is the same as the body of
+      // octave_struct::subsasgn.  Maybe it could be shared instead of
+      // duplicated.
+
+      int n = type.length ();
+
+      octave_value t_rhs = rhs;
+
+      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 ();
+
+		    octave_value u;
+
+		    if (! map.contains (key))
+		      u = octave_value::empty_conv (type.substr (2), rhs);
+		    else
+		      {
+			Cell map_val = map.contents (key);
+
+			Cell map_elt = map_val.index (idx.front (), true);
+
+			u = numeric_conv (map_elt, type.substr (2));
+		      }
+
+		    if (! error_state)
+		      {
+			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 ());
+
+			u.make_unique ();
+
+			t_rhs = u.subsasgn (type.substr (2), next_idx, rhs);
+		      }
+		  }
+		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 ();
+
+		octave_value u;
+
+		if (! map.contains (key))
+		  u = octave_value::empty_conv (type.substr (1), rhs);
+		else
+		  {
+		    Cell map_val = map.contents (key);
+
+		    u = numeric_conv (map_val, type.substr (1));
+		  }
+
+		if (! error_state)
+		  {
+		    std::list<octave_value_list> next_idx (idx);
+
+		    next_idx.erase (next_idx.begin ());
+
+		    u.make_unique ();
+
+		    t_rhs = u.subsasgn (type.substr (1), next_idx, rhs);
+		  }
+	      }
+	      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;
+
+		    assert (key_idx.length () == 1);
+
+		    std::string key = key_idx(0).string_value ();
+
+		    if (! error_state)
+		      {
+			map.assign (idx.front (), key, t_rhs);
+
+			if (! error_state)
+			  {
+			    count++;
+			    retval = octave_value (this);
+			  }
+			else
+			  gripe_failed_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 class assignment");
+		      }
+		    else
+		      {
+			if (t_rhs.is_empty()) 
+			  {
+			    map.maybe_delete_elements (idx.front());
+
+			    if (! error_state)
+			      {
+				count++;
+				retval = octave_value (this);
+			      }
+			    else
+			      gripe_failed_assignment ();
+			  }
+			else
+			  error ("invalid class assignment");
+		      }
+		  }
+	      }
+	      break;
+
+	    case '.':
+	      {
+		octave_value_list key_idx = idx.front ();
+
+		assert (key_idx.length () == 1);
+
+		std::string key = key_idx(0).string_value ();
+
+		map.assign (key, t_rhs);
+
+		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 ();
+    }
+  else
+    {
+      octave_value meth = symbol_table::find_method ("subsasgn", class_name ());
+
+      if (meth.is_defined ())
+	{
+	  octave_value_list args;
+
+	  args(2) = rhs;
+
+	  args(1) = make_idx_args (type, idx, "subsasgn");
+
+	  if (error_state)
+	    return octave_value_list ();
+
+	  count++;
+	  args(0) = octave_value (this);
+
+	  octave_value_list tmp = feval (meth.function_value (), args);
+
+	  // FIXME -- should the subsasgn method be able to return
+	  // more than one value?
+
+	  if (tmp.length () > 1)
+	    error ("expecting single return value from @%s/subsasgn",
+		   class_name().c_str ());
+	  else
+	    retval = tmp(0);
+
+	}
+      else
+	error ("no subsasgn method defined for class %s",
+	       class_name().c_str ());
+    }
+
+  return retval;
+}
+
+size_t
+octave_class::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;
+}
+
+Octave_map
+octave_class::map_value (void) const
+{
+  Octave_map retval;
+  gripe_wrong_type_arg ("octave_class::map_value()", type_name ());
+  return retval;
+}
+
+string_vector
+octave_class::map_keys (void) const
+{
+  string_vector retval;
+  gripe_wrong_type_arg ("octave_class::map_keys()", type_name ());
+  return retval;
+}
+
+void
+octave_class::print (std::ostream& os, bool) const
+{
+  print_raw (os);
+}
+
+void
+octave_class::print_raw (std::ostream& os, bool) const
+{
+  unwind_protect::begin_frame ("octave_class_print");
+
+  unwind_protect_int (Vstruct_levels_to_print);
+
+  indent (os);
+  os << "  <class " << class_name () << ">";
+  newline (os);
+
+  unwind_protect::run_frame ("octave_class_print");
+}
+
+bool
+octave_class::print_name_tag (std::ostream& os, const std::string& name) const
+{
+  bool retval = false;
+
+  indent (os);
+  os << name << " =";
+  newline (os);
+  newline (os);
+
+  return retval;
+}
+
+void
+octave_class::print_with_name (std::ostream&, const std::string& name, 
+			       bool) const
+{
+  if (! (evaluating_function_body && Vsilent_functions))
+    {
+      octave_value fcn = symbol_table::find_method ("display", class_name ());
+
+      if (fcn.is_defined ())
+	{
+	  octave_value_list args;
+
+	  args(0) = octave_value (clone (), 1);
+      
+	  string_vector arg_names (1);
+
+	  arg_names[0] = name;
+
+	  args.stash_name_tags (arg_names);
+
+	  feval (fcn.function_value (), args);
+	}
+    }
+}
+
+bool 
+octave_class::save_ascii (std::ostream&, bool&)
+{
+  gripe_wrong_type_arg ("octave_class::save_ascii()", type_name ());
+  return false;
+}
+
+bool 
+octave_class::load_ascii (std::istream&)
+{
+  gripe_wrong_type_arg ("octave_class::load_ascii()", type_name ());
+  return false;
+}
+
+bool 
+octave_class::save_binary (std::ostream&, bool&)
+{
+  gripe_wrong_type_arg ("octave_class::save_binary()", type_name ());
+  return false;
+}
+
+bool 
+octave_class::load_binary (std::istream&, bool,
+				oct_mach_info::float_format)
+{
+  gripe_wrong_type_arg ("octave_class::load_binary()", type_name ());
+  return false;
+}
+
+#if defined (HAVE_HDF5)
+
+bool
+octave_class::save_hdf5 (hid_t, const char *, bool)
+{
+  gripe_wrong_type_arg ("octave_class::save_binary()", type_name ());
+
+  return false;
+}
+
+bool 
+octave_class::load_hdf5 (hid_t, const char *, bool)
+{
+  gripe_wrong_type_arg ("octave_class::load_binary()", type_name ());
+
+  return false;
+}
+
+#endif
+
+#if 0
+bool
+octave_class::save_ascii (std::ostream& os, bool& infnan_warned)
+{
+  Octave_map m = map_value ();
+  os << "# length: " << m.length () << "\n";
+
+  Octave_map::iterator i = m.begin ();
+  while (i != m.end ())
+    {
+      octave_value val = map.contents (i);
+
+      bool b = save_ascii_data (os, val, m.key (i), infnan_warned, false, 0);
+      
+      if (! b)
+	return os;
+
+      i++;
+    }
+
+  return true;
+}
+
+bool 
+octave_class::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 class elements");
+		  return false;
+		}
+
+	      m.assign (nm, tcell);
+	    }
+
+	  if (is) 
+	    map = m;
+	  else
+	    {
+	      error ("load: failed to load class");
+	      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 class");
+    success = false;
+  }
+
+  return success;
+}
+
+bool 
+octave_class::save_binary (std::ostream& os, bool& save_as_floats)
+{
+  Octave_map m = map_value ();
+
+  int32_t len = m.length();
+  os.write (reinterpret_cast<char *> (&len), 4);
+  
+  Octave_map::iterator i = m.begin ();
+  while (i != m.end ())
+    {
+      octave_value val = map.contents (i);
+
+      bool b = save_binary_data (os, val, m.key (i), "", 0, save_as_floats);
+      
+      if (! b)
+	return os;
+
+      i++;
+    }
+
+  return true;
+}
+
+bool 
+octave_class::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 class elements");
+	      return false;
+	    }
+
+	  m.assign (nm, tcell);
+	}
+
+      if (is) 
+	map = m;
+      else
+	{
+	  error ("load: failed to load class");
+	  success = false;
+	}
+    }
+  else if (len == 0 )
+    map = Octave_map (dim_vector (1, 1));
+  else
+    panic_impossible ();
+
+  return success;
+}
+
+#if defined (HAVE_HDF5)
+
+bool
+octave_class::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 class to this group
+  Octave_map m = map_value ();
+  Octave_map::iterator i = m.begin ();
+  while (i != m.end ())
+    {
+      octave_value val = map.contents (i);
+
+      bool retval2 = add_hdf5_data (data_hid, val, m.key (i), "", false, 
+				    save_as_floats);
+
+      if (! retval2)
+	break;
+
+      i++;
+    }
+
+  H5Gclose (data_hid);
+
+  return true;
+}
+
+bool 
+octave_class::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);
+
+  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 class 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
+
+#endif
+
+mxArray *
+octave_class::as_mxArray (void) const
+{
+  gripe_wrong_type_arg ("octave_class::as_mxArray ()", type_name ());
+
+  return 0;
+}
+
+bool
+octave_class::in_class_method (void) const
+{
+  octave_function *fcn = octave_call_stack::current ();
+
+  return (fcn
+	  && (fcn->is_class_method () || fcn->is_class_constructor ())
+	  && fcn->dispatch_class () == class_name ());
+}
+
+DEFUN (class, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {} class (@var{expr})\n\
+@deftypefnx {Built-in Function} {} class (@var{s}, @var{id})\n\
+\n\
+Return the class of the expression @var{expr}, as a string or\n\
+create a class object from the structure @var{s} with name @var{id}.\n\
+@end deftypefn")
+{
+  octave_value retval;
+
+  int nargin = args.length ();
+
+  if (nargin == 1)
+    retval = args(0).class_name ();
+  else if (nargin == 2)
+    {
+      Octave_map m = args(0).map_value ();
+
+      if (! error_state)
+	{
+	  std::string id = args(1).string_value ();
+
+	  if (! error_state)
+	    {
+	      octave_function *fcn = octave_call_stack::caller ();
+
+	      if (fcn && fcn->is_class_constructor ())
+		retval = octave_value (new octave_class (m, id));
+	      else
+		error ("class: invalid call from outside class constructor");
+	    }
+	  else
+	    error ("class: expecting character string as second argument");
+	}
+      else
+	error ("class: expecting structure as first argument");
+    }
+  else
+    print_usage ();
+
+  return retval;
+}
+
+
+DEFUN (isobject, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {} isobject (@var{x})\n\
+Return true if @var{x} is a class object.\n\
+@end deftypefn")
+{
+  octave_value retval;
+
+  if (args.length () == 1)
+    retval = args(0).is_object ();
+  else
+    print_usage ();
+
+  return retval;
+}
+
+DEFCMD (methods, args, nargout,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {} methods (@var{x})\n\
+@deftypefnx {Built-in Function} {} methods (\"classname\")\n\
+Return a cell array containing the names of the methods for the\n\
+object @var{x} or the named class.\n\
+@end deftypefn")
+{
+  octave_value retval;
+
+  if (args.length () == 1)
+    {
+      octave_value arg = args(0);
+
+      std::string class_name;
+
+      if (arg.is_object ())
+	class_name = arg.class_name ();
+      else if (arg.is_string ())
+	class_name = arg.string_value ();
+      else
+	error ("methods: expecting object or class name as argument");
+
+      if (! error_state)
+	{
+	  string_vector sv = load_path::methods (class_name);
+
+	  if (nargout == 0)
+	    {
+	      octave_stdout << "Methods for class " << class_name << ":\n\n";
+
+	      sv.list_in_columns (octave_stdout);
+
+	      octave_stdout << std::endl;
+	    }
+	  else
+	    retval = sv;
+	}	  
+    }
+  else
+    print_usage ();
+
+  return retval;
+}
+
+static bool
+is_built_in_class (const std::string& cn)
+{
+  static std::set<std::string> built_in_class_names;
+
+  if (built_in_class_names.empty ())
+    {
+      built_in_class_names.insert ("double");
+      built_in_class_names.insert ("single");
+      built_in_class_names.insert ("cell");
+      built_in_class_names.insert ("struct");
+      built_in_class_names.insert ("logical");
+      built_in_class_names.insert ("char");
+      built_in_class_names.insert ("function handle");
+      built_in_class_names.insert ("int8");
+      built_in_class_names.insert ("uint8");
+      built_in_class_names.insert ("int16");
+      built_in_class_names.insert ("uint16");
+      built_in_class_names.insert ("int32");
+      built_in_class_names.insert ("uint32");
+      built_in_class_names.insert ("int64");
+      built_in_class_names.insert ("uint64");
+    }
+
+  return built_in_class_names.find (cn) != built_in_class_names.end ();
+}
+
+static void
+set_class_relationship (const std::string& sup_class,
+			const std::string& inf_class)
+{
+  // FIXME
+
+  warning ("class precedence not implemented");
+}
+
+DEFUN (superiorto, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {} superiorto (@var{class_name})\n\
+When called from a class constructor, mark the object currently\n\
+constructed as having a higher precedence than @var{class_name}.\n\
+This function may only be called from a class constructor.\n\
+@end deftypefn")
+{
+  octave_value retval;
+
+  octave_function *fcn = octave_call_stack::caller ();
+
+  if (fcn && fcn->is_class_constructor ())
+    {
+      if (args.length () == 1)
+	{
+	  std::string class_name = args(0).string_value ();
+
+	  if (! error_state)
+	    {
+	      if (! is_built_in_class (class_name))
+		{
+		  std::string this_class_name = fcn->name ();
+
+		  set_class_relationship (this_class_name, class_name);
+		}
+	      else
+		{
+		  // User defined classes always have higher precedence
+		  // than built-in classes.
+		}
+	    }
+	  else
+	    error ("superiorto: expecting argument to be class name");
+	}
+      else
+	print_usage ();
+    }
+  else
+    error ("superiorto: invalid call from outside class constructor");
+
+  return retval;
+}
+
+DEFUN (inferiorto, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {} inferiorto (@var{class_name})\n\
+When called from a class constructor, mark the object currently\n\
+constructed as having a lower precedence than @var{class_name}.\n\
+This function may only be called from a class constructor.\n\
+@end deftypefn")
+{
+  octave_value retval;
+
+  octave_function *fcn = octave_call_stack::caller ();
+
+  if (fcn && fcn->is_class_constructor ())
+    {
+      if (args.length () == 1)
+	{
+	  std::string class_name = args(0).string_value ();
+
+	  if (! error_state)
+	    {
+	      if (! is_built_in_class (class_name))
+		{
+		  std::string this_class_name = fcn->name ();
+
+		  set_class_relationship (class_name, this_class_name);
+		}
+	      else
+		error ("inferiorto: cannot give user-defined class lower precedence than built-in class");
+	    }
+	  else
+	    error ("inferiorto: expecting argument to be class name");
+	}
+      else
+	print_usage ();
+    }
+  else
+    error ("inferiorto: invalid call from outside class constructor");
+
+  return retval;
+}
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; End: ***
+*/