repl.link = function(obj) {
    if (! repl.linkedVars) {
        repl.linkedVars = {};
        repl.linkedIdNext = 1;
    };
    
    if (obj) {
        repl.linkedVars[ repl.linkedIdNext ] = obj;
        return repl.linkedIdNext++;
    } else {
        return undefined
    }

##</code><code>##

sub link {
    my ($repl,$obj) = @_;
    if (! $repl->{linkedVars}) {
        $repl->{linkedVars} = {};
        $repl->{linkedIdNext} = 1;
    };
    
    if (defined $obj) {
        $repl->{linkedVars}->{ $repl->{linkedIdNext} } = obj;
        return $repl->{linkedIdNext}++;
    } else {
        return undef
    };
};

##</code><code>##

package MozRepl::RemoteObject;
sub new {
    my ($class, $id) = @_;
    my $self = {
        id => $id,
    };
    bless $self, $class;
};

sub expr {
    my ($class, $js) = @_;
    return $class->new( javascript_eval($js)); # assuming that it returns an object
};

##</code><code>##

sub DESTROY {
    my ($self) = @_;
    if ($self->{id}) {
        $self->expr("repl.breakLink($self->{id})");
    };
};

##</code><code>##

repl.breakLink = function(id) {
    delete repl.linkedVars[ id ];
}

##</code><code>##

sub breakLink {
    my ($repl,$id) = @_;
    delete $repl->{linkedVars}->{id};
    
};

##</code><code>##

my $doc_a = MozRepl::RemoteObject->expr('window.document'); # id 42
my $doc_b = MozRepl::RemoteObject->expr('window.document'); # id 43