Bummer... Of course ! shame on me... So there isn't any way around ? What do you think of this :

use strict;
use warnings;

package Child;

use Data::Dumper ;

use base 'Parent' ;

 sub data  { return { one => 1, two => 2 } };

1;
[download]

use strict;
use warnings;

package Parent;

use Data::Dumper ;

sub new {
    my $proto = shift ;
    return bless {}, $proto
}


sub show {
    my $self = shift ;
    
    my $proto = ref $self ;
    
    print $proto->data();
    
    print Dumper $proto->data() 
}


1;
[download]

The script code remains of course unchanged. Unless I... May it be possible to get it working the way I meant by using tie ?

In that example you're not actually sharing the data: you're creating a new hash every time data() is called. If you really want to share the data, you can do:

my $data = { one => 1, two => 2 }; 
sub data { return $data; }
[download]

I don't know how you'd use tie() to get the original code to work. If you really want that construct, you'll need to use symbolic references or - even more dangerous - eval.

Also note that even if it would work as you expected, the original code will break as soon as someone subclasses Child.

update: in the example you posted here, there's no need to do

my $proto = ref $self;
print $proto->data;
[download]

You can just call

print $self->data;
[download]

"What should it profit a man, if he should win a flame war, yet lose his cool?"

In that example you're not actually sharing the data: you're creating a new hash every time data() is called.

How unfortunate I am ! I can't have all my bad code reviewed by your sharp eyes, precious friend. Thanks a lot for this one :)

update: in the example you posted here, there's no need to do
my $proto = ref $self;
print $proto->data;


Yes, this one is just a hurried copy-and-paste :)