package Defined;

use strict;
use warnings;

sub TIESCALAR { 
	my $class = shift;
	my $name = shift;
	my $self = { 'NAME' => $name,
		     'DEFINED' => undef, };
	return bless ($self, $class);
}

sub FETCH {
	my $self = shift; 
	my $name = $self->{'NAME'}; 
	my @caller = caller; 
	if (defined $self->{'DEFINED'}) {
	       print STDERR "@caller -> $name defined\n";
        } else {
 		print STDERR "@caller -> $name undefined\n";
	}		
}

sub STORE {
	my $self = shift;
	my $value = shift;
	my $name = $self->{'NAME'};
	my @caller = caller;
	$self->{'DEFINED'} = $value;
	print STDERR "@caller -> $name defined with value $value\n";
}

1;