Andreas Raab wrote:

> > Or why would you accept parameterisation in one case, but not
> > the other?
>
> Because in the one case the complexity is hidden in a single place (have
> you ever had the need to reimplement #respondsTo:?) whereas in the other
> there is a _common_ need to extend the properties in question and
> therefore, simplicity of implementation is definitely worth a few extra
> methods.

Thank you, Andreas, I think you made it a lot clearer to me what the trouble 
with my proposed approach is.

-- Lothar

"Walk this world with me"