Sure, closures, the same technique that's used to make other lexicals really private, can be used for anonymous subroutines:

{
    my $private_method = { foo => sub { stuff },
                           bar => sub { mostuff },
                          };
    sub public_method {
        my @args = @_;
        $private_method->{foo}(@args);
        $private_method->{bar}(@args);
    }
}
[download]

The references within public_method keep the lexical $private_method alive after the name has gone out of scope.

After Compline,
Zaxo