Implement some embryonic handle-classdef semantic. * libinterp/octave-value/ov-classdef.h (cdef_object_rep::subsasgn, handle_cdef_object::subsasgn, octave_classdef::subsasgn): New method declarations. (handle_cdef_object::~handle_cdef_object): New destructor declaration. (cdef_class::cdef_class_rep::handle_class): New boolean field. (cdef_class::cdef_class_rep::cdef_class_rep): Initialize it. (cdef_class::cdef_class_rep::mark_as_handle_class, cdef_class::cdef_class_rep::is_handle_class, cdef_class::mark_as_handle_class, cdef_class::is_handle_class): Manipulate it. (cdef_class::cdef_class_rep::get_name): New method. (cdef_class::get_name): Use it. (cdef_class::cdef_class_rep::initialize_object, cdef_class::cdef_class_rep::subsref_meta, cdef_class::cdef_class_rep::run_constructor, cdef_class::cdef_class_rep::construct, cdef_class:initialize_object, cdef_class::subsref_meta, cdef_class::run_constructor, cdef_class::construct): New methods. (cdef_class::cdef_class_rep::find_method, cdef_class::find_method): Add "local" argument. (cdef_class::cdef_class_rep::find_names, cdef_class::find_names): Change signature to use std::set and a boolean flag. (cdef_class::cdef_class_rep::find_methods, cdef_class::find_methods): Change signature to use a boolean flag as second argument. (cdef_class::make_meta_class): New static method. (cdef_class::get_method_function, cdef_class::get_constructor_function): New methods. (cdef_property::cdef_property_rep::set_value, cdef_property::set_value): Make cdef_object argument non const. (cdef_property::cder_property_rep::is_relative_set): New method. (cdef_property::get_get_access, cdef_property::get_set_access): Delete methods. (cdef_property::check_get_access, cdef_property::check_set_access): Remove string argument. (cdef_method::get_access): Delete method. (cdef_method::check_access): Remove string argument. * libinterp/octave-value/ov-classdef.cc (gripe_method_access, gripe_property_access): Support access specified as cell array of classes. (make_function_of_class): New static function(s). (check_access (std::string, std::string), superclass_access): Remove static functions. (lookup_class): Use symbol_table when class hasn't been loaded yet. (lookup_classes): Returns std::list<cdef_class> instead of Cell. (class_get_superclasses, class_get_inferiorclasses): Use it. (to_ov (const std::list<cdef_class>&)): New static function. (get_class_context, check_access (const cdef_class&, const octave_value&)): Likewise. (handle_cdef_object::subsref): Use new signature of access check methods. (property_get_defaultvalue): New built-in property accessor. (make_class): Change signature to support multiple inheritance. Set "Sealed" to false by default. Determine value for HandleCompatible property and handle-class representation. (make_property): Take cdef_class as first argument. Add DefaultValue and HasDefault properties. Call make_function_of_class for property accessors. (make_attribute): Take cdef_class as first argument. (make_method): Likewise. Call make_function_of_class. (make_method (octave_builtin::fcn)): Do no construct a function handle object. (octave_classdef::subsasgn, handle_cdef_object::subsasgn): New method. (class octave_classdef_proxy): New class. (cdef_class::get_method_function): Use it, new method. (handle_cdef_object::~handle_cdef_object): New destructor. (cdef_class_rep::find_method): New boolean "local" argument. When true, only look into the current class, not in superclasses. (cdef_class_rep::find_methods): New signature. (cdef_class_rep::get_methods): Use it. (cdef_class_rep::find_properties): New signature. (cdef_class_rep::get_properties): Use it. (cdef_class_rep::find_names): New signature. (cdef_class_rep::get_names): Use it. (cdef_class_rep::subsref_meta, cdef_class_rep::initialize_object, cdef_class_rep::run_constructor, cdef_class_rep::construct): New methods. (compute_attribute_value, attribute_to_string): New static functions. (cdef_class::make_meta_class): Change signature, non const argument. Implement it. (cdef_property_rep::get_value): Do not check access here. (cdef_property_rep::set_value, cdef_property_rep::is_recursive_set): New method. (cdef_property_rep::check_get_access, cdef_property_rep::check_set_access, cdef_method_rep::check_access): Use static check_access utility function. (install_classdef): Adapt to change of signature of make_class. Mark meta classes as sealed. Add HandleCompatible property to meta.class. Add DefaultValue and HasDefault properties to meta.property. * libinterp/parse-tree/pt-classdef.h (tree_classdef::make_meta_class): Change return type to (octave_function *). * libinterp/parse-tree/pt-classdef.cc (tree_classdef::make_meta_class): Likewise. Call cdef_class::get_constructor_function. * libinterp/parse-tree/oct-parse.yy (parse_fcn_file): Adapt to new signature of tree_classdef::make_meta_class. * libinterp/octave-value/ov-fcn.h (octave_function::is_classdef_constructor): New virtual method. * libinterp/octave-value/ov-usr-fcn.h (octave_user_function::class_ctor_type): New private enum. (octave_user_function::mark_as_class_constructor, octave_user_function::is_class_constructor): Use it. (octave_user_function::mark_as_classdef_constructor, octave_user_function::is_classdef_constructor): New methods. (octave_user_function::class_constructor): Turn into class_ctor_type. * libinterp/octave-value/of-usr-fcn.cc (octave_user_function::octave_user_function): Initialize class_constructor. (octave_user_function::do_multi_index_op): When function is a classdef constructor, extract the first argument and use it to populate the first output argument.

/*

Copyright (C) 1996-2012 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 "error.h"
#include "oct-obj.h"
#include "oct-lvalue.h"
#include "pager.h"
#include "pt-bp.h"
#include "pt-const.h"
#include "pt-eval.h"
#include "pt-id.h"
#include "pt-walk.h"
#include "symtab.h"
#include "utils.h"
#include "variables.h"

// Symbols from the symbol table.

void
tree_identifier::eval_undefined_error (void)
{
  int l = line ();
  int c = column ();

  maybe_missing_function_hook (name ());
  if (error_state)
    return;

  if (l == -1 && c == -1)
    ::error_with_id ("Octave:undefined-function",
                     "'%s' undefined", name ().c_str ());
  else
    ::error_with_id ("Octave:undefined-function",
                     "'%s' undefined near line %d column %d",
                     name ().c_str (), l, c);
}

octave_value_list
tree_identifier::rvalue (int nargout)
{
  octave_value_list retval;

  if (error_state)
    return retval;

  octave_value val = sym->find ();

  if (val.is_defined ())
    {
      // GAGME -- this would be cleaner if we required
      // parens to indicate function calls.
      //
      // If this identifier refers to a function, we need to know
      // whether it is indexed so that we can do the same thing
      // for 'f' and 'f()'.  If the index is present, return the
      // function object and let tree_index_expression::rvalue
      // handle indexing.  Otherwise, arrange to call the function
      // here, so that we don't return the function definition as
      // a value.

      if (val.is_function () && ! is_postfix_indexed ())
        {
          octave_value_list tmp_args;

          retval = val.do_multi_index_op (nargout, tmp_args);
        }
      else
        {
          if (print_result () && nargout == 0
              && tree_evaluator::statement_printing_enabled ())
            val.print_with_name (octave_stdout, name ());

          retval = val;
        }
    }
  else if (sym->is_added_static ())
    static_workspace_error ();
  else
    eval_undefined_error ();

  return retval;
}

octave_value
tree_identifier::rvalue1 (int nargout)
{
  octave_value retval;

  octave_value_list tmp = rvalue (nargout);

  if (! tmp.empty ())
    retval = tmp(0);

  return retval;
}

octave_lvalue
tree_identifier::lvalue (void)
{
  if (sym->is_added_static ())
    static_workspace_error ();

  return octave_lvalue (&(sym->varref ()));
}

tree_identifier *
tree_identifier::dup (symbol_table::scope_id sc,
                      symbol_table::context_id) const
{
  // The new tree_identifier object contains a symbol_record
  // entry from the duplicated scope.

  // FIXME -- is this the best way?
  symbol_table::symbol_record new_sym
    = symbol_table::find_symbol (name (), sc);

  tree_identifier *new_id
    = new tree_identifier (new_sym, line (), column ());

  new_id->copy_base (*this);

  return new_id;
}

void
tree_identifier::accept (tree_walker& tw)
{
  tw.visit_identifier (*this);
}