Re: relations aren't types?

"Bob Badour" <bbadour_at_golden.net> wrote in message news:<xMudnTkkUJU2D2qiRVn-uA_at_golden.net>...

> > No, it is not a possible representation of a relation, it is a
> > description of the structure of a relation.
>
> In what way do those THE_ operators fail to represent a relation?

Operators don't make a representation. A representation is defined by its components.

But you can encapsulate relations into a scalar.

For instance:

type T possrep { Header relation { ... }, Body relation { ... } };

Now T is a scalar type with a possrep called T which has two components "Header" and "Body".

BTW "encapsulate" means nothing but "scalarize".

But it is evident that there are logical differences between T and a relation type. For instance:

var a T;
var b T;
...
a := a join b; // ERROR

Regards
  Alfredo Received on Sun Jan 04 2004 - 20:27:22 CET