Re: Derived private interface

[Maciej Sobczak <see.my.homepage@gmail.com>]

On Jul 27, 1:43 am, Jeffrey Carter
<spam.jrcarter....@spam.not.acm.org> wrote:

> > Others have pointed out that using case statements as you suggested is
> > essentially worthless unless you know every entity that the program is going
> > to process before the fact. And real world programs are not like that

> Yes, it's called "design", and it's part of what distinguishes S/W engineers
> from coders.

This statement is unfair and uses a very superficial argumentation.
No matter how much extensive is the "design" and how good are the S/W
engineers doing it, a complete view on the system is not always
feasible.
Software is built from components that are prepared in separation,
possibly by different vendors. They have no way to know the complete
set of types that will be used in the final system, as the final
system might not be even invented yet when the components are
produced.
Using the open/closed principle with the help of dispatching
operations is the cleanest and the least intrusive way to integrate
such components and generics are not always applicable - a canonical
example is the web server component that delivers the client request
to the layer that can handle it. I've yet to see an approach that is
cleaner and less error-prone than the dispatching call via an
interface type.

> As you note, it's an iterative process. The extra work and extra
> code is worth it

It is iterative on which side? The extra work by whom?

> for the significant improvement in ease of reading and
> understanding that results.

Did you try that with web servers?

--
Maciej Sobczak * http://www.msobczak.com * http://www.inspirel.com