begin removal of global error_state variable * gripes.h, gripes.cc (gripe_library_execution_error): Delete. * error.cc (warning_state): Delete unused variable. (reset_error_handler): Don't set warning_state or error_state. (debug_or_throw_exception): New static function. (verror): Don't check error_state. (vmessage): Call debug_or_throw_exception instead of setting error_state. (error_1, error_2): Combine into single function, error_1 that prints error message and ultimately calls debug_or_throw_exception. (verror, verror_with_cfn, verror_with_id_cfn): Call error_1. Don't check or set warning_state. (error): Don't check error_state. (Flasterror, Flasterr): Adapt to not using error_state. (interpreter_try): Don't unwind_protect error_state. * NEWS: Update. * doc/interpreter/external.txi: Explain octave_execution_exception instead of error_state for matrix addition example. * jit-typeinfo.cc (octave_jit_gripe_nan_to_logical_conversion, octave_jit_ginvalid_index, octave_jit_gindex_range, octave_jit_paren_scalar, octave_jit_paren_scalar_subsasgn): Don't catch octave_execution_exception. * cellfun.cc (Fcellfun): Use exceptions instead of error_state. * ls-mat-ascii.cc (save_mat_ascii_data): Likewise. * mex.cc (mexCallMATLAB, mexEvalString): Likewise. * variables.cc (safe_symbol_lookup): Likewise. * svd.cc (Fsvd): Eliminate use of error_state. * __magick_read__.cc (read_file, write_file): Likewise. * variables.cc (generate_struct_completions): Eliminate use of obsolete warning_state variable. * ov-builtin.cc (octave_builtin::do_multi_index_op): Don't catch octave_execution_exception and call gripe_library_execution_error. * ov-class.cc (octave_class::reconstruct_exemplar): Eliminate use of error_state. Catch possible octave_execution_exception in do_multi_index_op. * ov-mex-fcn.cc (octave_mex_function::do_multi_index_op): Eliminate use of error_state. Catch possible octave_execution_exception in call_mex. * ov-fcn-handle.cc (octave_fcn_binder::maybe_binder): Eliminate use of error_state. * ov-oncleanup.cc (octave_oncleanup::~octave_oncleanup): Eliminate use of error_state. Propagate possible octave_execution_exception from do_multi_index_op. * ov.cc (octave_value::assign, do_binary_op, do_unary_op, octave_value::do_non_const_unary_op): Don't catch octave_execution_exception here. * oct-parse.in.yy (octave_base_parser::finish_colon_expression, octave_base_parser::finish_array_list): Eliminate use of warning_state and error_state. (Feval, Fevalin): Use exceptions instead of error_state. * pt-eval.cc, pt-eval.h (tree_evaluator::unwind_protect_exception): New static variable. * (tree_evaluator::visit_statement): Don't catch octave_execution_exception here. (tree_evaluator::visit_try_catch_command, tree_evaluator::do_unwind_protect_cleanup): Eliminate use of error_state. (tree_evaluator::visit_unwind_protect_command): Use unwind_protect_exception to track whether an exception has occurred in the try block.

/*

Copyright (C) 1996-2015 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/>.

*/

#if !defined (octave_oct_lvalue_h)
#define octave_oct_lvalue_h 1

class octave_value;
class octave_value_list;

#include <string>

#include "oct-obj.h"
#include "pt-idx.h"
#include "symtab.h"

class
octave_lvalue
{
public:

  octave_lvalue (const symbol_table::symbol_reference& s
                   = symbol_table::symbol_reference ())
    : sym (s), type (), idx (), nel (1)
  { }

  octave_lvalue (const octave_lvalue& vr)
    : sym (vr.sym), type (vr.type), idx (vr.idx), nel (vr.nel)
  { }

  octave_lvalue& operator = (const octave_lvalue& vr)
  {
    if (this != &vr)
      {
        sym = vr.sym;
        type = vr.type;
        idx = vr.idx;
        nel = vr.nel;
      }

    return *this;
  }

  ~octave_lvalue (void) { }

  bool is_black_hole (void) const { return sym.is_black_hole (); }

  bool is_defined (void) const
  {
    return ! is_black_hole () && sym->is_defined ();
  }

  bool is_undefined (void) const
  {
    return is_black_hole () || sym->is_undefined ();
  }

  bool is_map (void) const
  {
    return value().is_map ();
  }

  void define (const octave_value& v) { sym->assign (v); }

  void assign (octave_value::assign_op, const octave_value&);

  void numel (octave_idx_type n) { nel = n; }

  octave_idx_type numel (void) const { return nel; }

  void set_index (const std::string& t, const std::list<octave_value_list>& i);

  void clear_index (void) { type = std::string (); idx.clear (); }

  std::string index_type (void) const { return type; }

  bool index_is_empty (void) const;

  void do_unary_op (octave_value::unary_op op);

  octave_value value (void) const;

private:

  symbol_table::symbol_reference sym;

  std::string type;

  std::list<octave_value_list> idx;

  octave_idx_type nel;
};

#endif