Re: A Logical Model for Lists as Relations

Bob Badour wrote:
> Marshall Spight wrote:
> >>
> >>>What about imperative operations? This is a bit more complicated.
> >>
> >>Not really. The only imperative operations in an RDBMS map to relation
> >>variable assignment. Lists, if you have them at all, are necessarily
> >>just values.
> >
> > I'm not convinced that "there is only assignment" is the right design.
>
> Since I never said there is only assignment, I wonder why you would
> bother mentioning your lack of convincement. The issue is the RM
> proscription against imperative operations on things other than relation
> variables.

Apparently I misread your original statement.

> > I hate to respond with such a generic answer, but "for ordered data"
> > is as specific as I can get. Character strings are a good example.
>
> I have yet to see a character string implemented as a list except in
> list-only languages.

I believe python and icon are examples of languages which treat character strings as lists, but also contain other generic containers such as maps. I'm not aware of any languages (outside of sql) that has anything like a first class treatment for relations, though.  

Marshall Received on Fri May 12 2006 - 19:23:32 CEST