How do you delete an unwanted object?

jettero has asked for the wisdom of the Perl Monks concerning the following question:

How do you delete an unwanted object? Is there a generic way to do it?

Not that you'd ever need to do something like this, but could you?

use Gtk;
    Gtk->init;
    Gtk->set_locale;

  for(1..200) {
    my $o = new Gtk::Window;
    undef $o;
    sleep 1;
    print "$_\n";
  }
[download]

Load up top, hit 'M', and watch the thing grow evilly... I tried using delete instead of undef, but it didn't help.

I actually have a very good reason for this. I need to generate Gtk::CList's on the fly, but I realized I have no way to delete the old ones... I could really use some help here. Actually, a solution to changing the number of columns in a Gtk::CList would be equally helpful. ;)

How do you delete an unwanted object in perl?

Comment on How do you delete an unwanted object? Download Code

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Re: How do you delete an unwanted object? by m_turner (Sexton) on Nov 13, 2000 at 04:33 UTC
undef does indeed invoke garbage destruction as can be shown in the following code. `#!/usr/bin/perl -w use strict; my $foo = new stuff; my $bar = new stuff; print $foo,"\n"; $foo = undef; print STDERR "foo gone\n"; exit; package stuff; sub new { my $self = []; bless $self; return $self; } sub DESTROY { my ($self) = @_; print STDERR "destroying...\n"; } 1;` [download] The output is: stuff=ARRAY(0x80cb9c8) destroying... foo gone destroying... As you can see: $foo gets undef'ed DESTROY gets called for $foo program exits, begins garbage collection DESTROY gets called for $bar program exits The real question is do Gtk::CList objects get refrenced anywhere else or have circluar data structures that will prevent them from getting destroyed with the undef?	[reply] [d/l]

Replies are listed 'Best First'.

Re: How do you delete an unwanted object?
by m_turner (Sexton) on Nov 13, 2000 at 04:33 UTC

#!/usr/bin/perl -w
use strict;

my $foo = new stuff;
my $bar = new stuff;
print $foo,"\n";
$foo = undef;
print STDERR "foo gone\n";
exit;

package stuff;
sub new
{
  my $self = [];
  bless $self;
  return $self;
}

sub DESTROY
{
  my ($self) = @_;
  print STDERR "destroying...\n";
}

1;
[download]

stuff=ARRAY(0x80cb9c8)
destroying...
foo gone
destroying...

$foo gets undef'ed
DESTROY gets called for $foo
program exits, begins garbage collection
DESTROY gets called for $bar
program exits

circluar data structures

[reply]
[d/l]