From bug-octave-request at bevo dot che dot wisc dot edu  Fri Nov  6 12:20:17 1998
Subject: octave-2.1.8 bug: empty string bug
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Joao Cardoso <jcardoso at inescn dot pt>
Cc: bug-octave <bug-octave at bevo dot che dot wisc dot edu>
Date: Fri, 6 Nov 1998 12:19:08 -0600 (CST)

On  6-Nov-1998, Joao Cardoso <jcardoso at inescn dot pt> wrote:

| octave-2.1.8:1> a=""
| a = 
| octave-2.1.8:2> isempty (a)
| ans = 0
| 
| isempty (x): return nonzero if x is an empty matrix or empty list
| 
| this does not apply to strings?

It should.  Please try the following patch.

Thanks,

jwe


Fri Nov  6 12:14:29 1998  John W. Eaton  <jwe at bevo dot che dot wisc dot edu>

	* data.cc (Fisempty): Also return true for empty strings.


Index: data.cc
===================================================================
RCS file: /home/jwe/src/master/octave/src/data.cc,v
retrieving revision 1.61
diff -c -r1.61 data.cc
*** data.cc	1998/11/05 04:24:45	1.61
--- data.cc	1998/11/06 18:14:27
***************
*** 782,788 ****
  }
  
  DEFUN (isempty, args, ,
!   "isempty (x): return nonzero if x is an empty matrix or empty list")
  {
    double retval = 0.0;
  
--- 782,788 ----
  }
  
  DEFUN (isempty, args, ,
!   "isempty (x): return nonzero if x is an empty matrix, string, or list")
  {
    double retval = 0.0;
  
***************
*** 792,798 ****
  
        if (arg.is_matrix_type ())
  	retval = static_cast<double> (arg.rows () == 0 || arg.columns () == 0);
!       else if (arg.is_list ())
  	retval = static_cast<double> (arg.length () == 0);
      }
    else
--- 792,798 ----
  
        if (arg.is_matrix_type ())
  	retval = static_cast<double> (arg.rows () == 0 || arg.columns () == 0);
!       else if (arg.is_list () || arg.is_string ())
  	retval = static_cast<double> (arg.length () == 0);
      }
    else