Re: General semantics
Date: Sat, 22 May 2010 04:44:30 -0700 (PDT)
On May 22, 1:15 am, Erwin <e.sm..._at_myonline.be> wrote:
> On 22 mei, 00:20, Nilone <rea..._at_gmail.com> wrote:
> > I would prefer to program in a pure relational model,
> That is a tall order. The closest you can get to this ideal, as
> things are today, is Rel (and that's nowhere near industrial strength)
> and Muldis D (and that's nothing more than just a spec). I won't even
> mention my own project, which I believe to give better results from
> the perspective of "industrial strength", but which doesn't really
> facilitate "programming in a pure relational model", as you call it.
> > but I must deal
> > with both OOP classes and SQL tables, so I want to understand how the
> > concepts and mechanisms fit together.
> As things stand today, only in extremely ugly ways.
> > Analyzing OOP in relational terms simply opens the way to apply
> > relational thinking in existing OOP systems.
> Dubious. If you can analyze OOP in relational terms, then that means
> that you understand relational terms, and that in turn means that you
> can already "apply relational thinking" to _just any_ kind of problem.
> So it is not the "Analyzing OOP in relational terms" that opens up to
> "apply relational thinking in existing OOP systems". What DOES open
> up to that is merely to "understand relational thinking".
I agree with your whole post. Still, I want to describe OOP in RM to make its limitations explicit. It raises questions I want answered, such as:
- Why can't I query the domain of a class?
- Why does my framework stuff numerous non-identifying attributes inside an entity class?
- Why allow programmers to override implemented methods, when interfaces and abstract classes enforce better design principles?
- Why encapsulate everything in containers when relations provide structure-preserving aggregation?
- If we can have classes, i.e. set-like relations, why can't we have other kinds of relations?
- Why do our systems still describe everything in terms of blocks of bits?