in reply to Re^2: Design of a global-variable storage package (string)
in thread Design of a global-variable storage package

I thought of that $p part, too, just forgot to mention it. I'm not sure, though, that this would be better-received. ;-)

As for your non-singleton approach - something like this? 

my $default;

sub new
{
  my $class = shift || __PACKAGE__;
  my $self = {};
  bless $self, $class;
  $default ||= $self;
}

sub global_instance
{
  $default ||= (shift || __PACKAGE__)->new();
}

[download]
And, perhaps, a way to change the global instance to be another one, if you really do need More Than One?

Replies are listed 'Best First'.
Re^4: Design of a global-variable storage package (Two)
by tye (Sage) on Nov 23, 2005 at 21:11 UTC

    Rather than try to detect, I'd probably do something deterministic like export functions that use the singleton: 

    package Getopt::Long::Framework;
use vars qw( @EXPORT_OK );
@EXPORT_OK= qw( Foo Bar Baz );

require Getopt::Long::Framework::Object;

my $singleton = Getopt::Long::Framework::Object->new();

sub Foo
{
    $singleton->Foo( @_ );
}

...

sub GetObjectPackage
{
    "Getopt::Long::Framework::Object";
}

sub new
{
    my $class= shift @_;
    $class = $class->GetObjectPacket()
        if $class->can("GetObjectPacket");
    ...
}

    [download]

    (in part, because I prefer to keep my class methods and object methods in separate 'package's anyway)

    - tye        

[reply]
[d/l]

In Section Seekers of Perl Wisdom