I was recently trying to explain OOP to my dad, who's an old fortran programmer. One of the things I said was, "it's a way to have global variables without the danger."

I wouldn't recommend making your object by hand the old fashioned way. I'd try one of the nifty packages that do a lot of the grunt work. The only one that pops into my head right now is Moose, but I know there are others.

Re: singleton,

{
  my $foo;
  sub set_foo {
     $foo = shift;
  }
  sub get_foo {
     return $foo;
  }
}
[download]

Is that a singleton? If so, I never knew the name.

How would closures fit in this conversation? It seem like they'd be a middle-point between a singleton and an object.

sub make_accessor {
  my $foo;
  return sub {
     my $in = shift;
     if defined($in) {
        $foo = $in;
     }
     return $foo;
   }
}
[download]

Thanks
--Pileofrogs