Re: relations aren't types?

"Marshall Spight" <mspight_at_dnai.com> wrote in message <news:cNKHb.64146$VB2.125134_at_attbi_s51>...

> "Bob Badour" <bbadour_at_golden.net> wrote in message news:MPOdnepoTvzeP3OiRVn-hA_at_golden.net...
> >
> > Sorry. Time is just as atomic as any other type including relation types.
>
> I'm not clear on why types have to be atomic. I have not seen a
> reason for it.
>
> For example, consider the TimeOfDay type. Perhaps it has
> logical components hour, minute, and second, and possibly
> something to decide whether it's currently AM or PM. The
> AM/PM operator need be defined only in terms of the hour
> attribute.
>
> Now a given implementation of TimeOfDay may well use
> a single long or some such, but that still doesn't make
> the *type* atomic, only that specific implementation of
> the type.
>
> I can imagine that one could have a kind of "type project"
> operator that gives me just the Hour attribute from the TimeOfDay,
> and that brought along the AM/PM operator, since it was
> defined only in terms of attributes that remained after the
> project.
>
> If one had these operators on (some) types, I don't think one
> could continue to call those types "atomic." I do believe that
> the system will necessarily have some atomic types, but I don't
> see that there has to be very many of them; say, less than ten.

The type is "scalar" or "atomic" if you cannot bypass the operators defined for that type. If the available operators are rich enough, Bob's your uncle.

--
Joe Foster <mailto:jlfoster%40znet.com>     Got Thetans? <http://www.xenu.net/>
WARNING: I cannot be held responsible for the above        They're   coming  to
because  my cats have  apparently  learned to type.        take me away, ha ha!