From bug-octave-request at bevo dot che dot wisc dot edu  Wed Apr 18 03:07:13 2001
Subject: Re: Unidentified subject!
From: Christoph Spiel <cspiel at hammersmith-consulting dot com>
To: bug-octave at bevo dot che dot wisc dot edu
Date: Wed, 18 Apr 2001 09:18:23 +0200

On Tue, Apr 17, 2001 at 10:03:29PM -0500, John W. Eaton wrote:
> On 17-Apr-2001, Christoph Spiel <cspiel at hammersmith-consulting dot com> wrote:
> 
> | To: bug-octave at bevo dot che dot wisc dot edu
> | Cc: cspiel
> | Subject: __error_text__ keeps value of first error
> | 
> | Description:
> | -----------
> | 
> | __error_text__ only stores the error message of the first error ever
> | encountered.  This behavior is independed whether
> | 'try-catch-end_try_catch' or 'eval' is used, neither does it depend on
> | whether the error has been triggered implicitely, e.g., 'clear a; a'
> | or explicitely 'error("snafu")'.
> 
> Please try the following patch.

Applied the patch -- works perfectly!

I have made the code a bit clearer by removing the local
variable 'retval' in define_builtin_const() and define().  No
change in functionality.  See following cdiff.

The only one -- as far as I can see -- to spoil our party is a
user defining '__error_text__', which introduces the symbol as a
local variable shadowing the "built-in constant" of the same
name.  But the problem of shadowing exists with all constants,
not only with '__error_text__'.



*** symtab.cc.orig	Wed Apr 18 08:42:12 2001
--- symtab.cc	Wed Apr 18 08:58:00 2001
***************
*** 235,267 ****
  bool
  symbol_record::define_builtin_const (const octave_value& v)
  {
!   bool retval = false;
! 
!   if (! read_only_error ("redefine"))
      {
!       replace_all_defs (new symbol_def (v, symbol_record::BUILTIN_CONSTANT));
  
!       retval = true;
      }
- 
-   return retval;
  }
  
  bool
  symbol_record::define (octave_function *f, unsigned int sym_type)
  {
!   bool retval = false;
! 
!   if (! read_only_error ("redefine"))
      {
        octave_value tmp (f);
  
        replace_all_defs (new symbol_def (tmp, sym_type));
  
!       retval = true;
      }
- 
-   return retval;
  }
  
  void
--- 235,263 ----
  bool
  symbol_record::define_builtin_const (const octave_value& v)
  {
!   if (read_only_error ("redefine"))
!       return false;
!   else
      {
!       definition->define (v, symbol_record::BUILTIN_CONSTANT);
  
!       return true;
      }
  }
  
  bool
  symbol_record::define (octave_function *f, unsigned int sym_type)
  {
!   if (read_only_error ("redefine"))
!       return false;
!   else
      {
        octave_value tmp (f);
  
        replace_all_defs (new symbol_def (tmp, sym_type));
  
!       return true;
      }
  }
  
  void



Thanks a lot!

-Chris

-- 
Christoph L. Spiel  <cspiel at hammersmith-consulting dot com>
Hammersmith Consulting,  web: www.hammersmith-consulting.com
Phone: +49-8022-662908, fax: +49-8022-662909



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