deblank and empty arguments

[John W. Eaton]

On 29-Jan-2008, H. Wziontek wrote:

| Hello,
| 
| I'd like to propose, that the function deblank should return
| the argument itself instead of an error message if an empty
| value is provided. Sometimes it can happen, that a value is
| not defined, but for some reason, all values are "deblanked"
| inside a loop. A script should not stop in such a case with
| an error. Below my suggestion to change the code.
| 
| Hartmut
| 
| 
| *** deblank.m.orig      Tue Jan 22 17:54:13 2008
| --- deblank.m   Tue Jan 29 09:16:10 2008
| *************** function s = deblank (s)
| *** 34,39 ****
| --- 34,41 ----
|         print_usage ();
|       endif
| 
| +   if (!isempty (s))
| +
|         if (ischar (s))
| 
|           k = find (! isspace (s) & s != "\0");
| *************** function s = deblank (s)
| *** 51,54 ****
| --- 53,58 ----
|           error ("deblank: expecting string argument");
|         endif
| 
| +   endif
| +
|     endfunction

I checked in the following change instead.

It's best to report bugs to the address@hidden list.

Thanks,

jwe


scripts/ChangeLog:

2008-01-30  John W. Eaton  <address@hidden>

        * strings/deblank.m: Improve compatibility.


Index: scripts/strings/deblank.m
===================================================================
RCS file: /cvs/octave/scripts/strings/deblank.m,v
retrieving revision 1.25
diff -u -u -r1.25 deblank.m
--- scripts/strings/deblank.m   22 Jan 2008 21:52:26 -0000      1.25
+++ scripts/strings/deblank.m   30 Jan 2008 07:36:11 -0000
@@ -34,13 +34,23 @@
     print_usage ();
   endif
 
-  if (ischar (s))
+  char_arg = ischar (s);
 
-    k = find (! isspace (s) & s != "\0");
-    if (isempty (s) || isempty (k))
-      s = "";
-    else
-      s = s(:,1:ceil (max (k) / rows (s)));
+  if (char_arg || isnumeric (s))
+
+    if (! isempty (s))
+      if (char_arg)
+       k = find (! isspace (s) & s != "\0");
+      else
+       warning ("deblank: expecting character string argument")
+       k = find (s != 0);
+      endif
+
+      if (isempty (k))
+       s = resize (s, 0, 0);
+      else
+       s = s(:,1:ceil (max (k) / rows (s)));
+      endif
     endif
 
   elseif (iscell(s))
@@ -48,16 +58,29 @@
     s = cellfun (@deblank, s, "UniformOutput", false);
 
   else
-    error ("deblank: expecting string argument");
+    error ("deblank: expecting character string argument");
   endif
 
 endfunction
 
-%!assert(strcmp (deblank (" f o o  "), " f o o"));
+%!assert (strcmp (deblank (" f o o  "), " f o o"));
 
-%!error deblank ();
+%!assert (deblank ([]), [])
+%!assert (deblank ({}), {})
+%!assert (deblank (""), "")
 
-%!error deblank ("foo", "bar");
+%!assert (deblank ([0,0,0]), [])
+%!assert (deblank ('   '), '')
+%!assert (deblank ("   "), "")
+
+%!assert (typeinfo (deblank ("   ")), "string")
+%!assert (typeinfo (deblank ('   ')), "sq_string")
 
-%!error deblank (1);
+%!assert (deblank ([1,2,0]), [1,2])
+%!assert (deblank ([1,2,0,32]), [1,2,0,32])
 
+%!assert (deblank (int8 ([1,2,0])), int8 ([1,2]))
+
+%!error deblank ();
+
+%!error deblank ("foo", "bar");