State variables (was: Re: Bug in pixbuf->copy ?)

[Torsten Schoenfeld <kaffeetisch gmx de>]

On Tue, 2006-04-18 at 19:36 +0200, Thierry Vignaud wrote:

> > This is actually an undocumented and not future-proof way of getting
> > static variables.  The "glitches" that make it work are described in
> > [1].  There was also an entry about this on of the p5p digests, but the
> > original site[2] doesn't seem to have it anymore -- probably to not
> > further publicize the trick.  Anyway, the Google cache[3] still has it.
>
> well, until state variables are availlable (perl-5.9.x ???), that's
> the only way to have static variables, that do be usefull in some
> cases.

Not really.  If you put a block around a sub, you can declare a lexical
variable in that scope but outside the sub.  It will then behave like a
state variable:

  {
    my $state = 0;
    sub bla {
      print $state++, "\n";
    }
  }
  bla(); # 0
  bla(); # 1
  bla(); # 2

-- 
Bye,
-Torsten