sub process {
    my ( $choice, $book ) = @_;

    my $dispatch = {
        1   => \&search_menu,
        2   => sub { return \&edit_name($book)  },
        3   => sub { return add_entry($book)    },
        4   => sub { return delete_entry($book) },
        5   => \&save_default,
        6   => \sub{ print "Goodbye!\n"; die; },
        e   => \sub{ print "Goodbye!\n"; die; },
    };

    print &{ $dispatch->{ $choice } };
}