Re: global variable question

[Paul Kienzle]

On Dec 8, 2003, at 10:31 AM, John W. Eaton wrote:

> On  8-Dec-2003, Geraint Paul Bevan <address@hidden> wrote:
>
> | Upgrading to 2.1.50 doesn't fix the problem with subsequent global
> | declarations
> |
> | GNU Octave, version 2.1.50 (i386-pc-linux-gnu).
> |
> | octave:1> global n = 10
> | octave:2> n
> | n = 10
> | octave:3> global n = 100
> | octave:4> n
> | n = 10
>
> There is nothing to fix.  As I said before, this behavior is
> intentional, though perhaps Octave should print a warning for
> subsequent initializations in global statements.

If octave did print a warning, then the following couldn't be used:

   function myfunc()
      global myfunc_val = 'default value';
      printf("myfunc_val is %s", myfunc_val);
   endfunction

Incidentally, I stopped using globals for edit.m because
global variables get saved automatically whenever you save
a variable to a file.  Is there a way to suppress this?

Instead I use persistent variables, and provide a calling sequence
to update them:

   function edit(file,state)
      persistent FUNCTION_EDITOR = [EDITOR, " %s"];
      ...
      if (nargin == 2)
         switch file
         case 'EDITOR', FUNCTION_EDITOR=state;
         ...
         end
         return
     end
     ...
   endfunction

Paul Kienzle
address@hidden



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