Re: Domain

"Adrian Kubala" <adrian_at_sixfingeredman.net> wrote in message news:slrnbvmav2.ba0.adrian_at_sixfingeredman.net...
> I wrote:
> What's the difference between a function "value -> current position
> within value" and a function "date -> month"?
>
> Bob Badour wrote:
> Month is a derivable value from any date value. Since values have no
> locations, a current position within a value is an absurdity.
>
> and later wrote:
> Since all values in an actual dbms are finite, I do not find this a
> useful distinction either.
>
> So:
> All values in an actual dbms also have some concrete representation,
> which have locations (or rather, within which one can name a location
> for each part of the representation, like a bit). So I still don't see
> why "current location" cannot be derived from any real value in the same
> way as month from date.

One could do that, but it would violate the principle of physical independence and tie everything to a particular artifact. This was done in the past with less than desirable results. Received on Thu Jan 08 2004 - 04:51:50 CET