Home -> Usenet -> comp.databases.theory -> Re: Nested Relations / RVAs / NFNF

Re: Nested Relations / RVAs / NFNF

From: Marshall Spight <mspight_at_dnai.com>
Date: Thu, 28 Oct 2004 02:00:46 GMT
Message-ID: <ipYfd.324263$3l3.156622_at_attbi_s03> 






"Laconic2" <laconic2_at_comcast.net> wrote in message news:PuWdnYoANcjSbOLcRVn-qA_at_comcast.com...

>




> So,  could you have two distinct types that share a common domain?  That is,


> they both have exactly the same

> possible values,  with the same semantics,  but they don't allow the same

> operations on them?




You could, but you get more mileage if you don't. For example, if
2 feet and two meters have the same semantics, you've lost the
distinction that caused you to put the units in in the first place.



OTOH, it does make sense to have them both be, say, int32 under
the covers. The important thing to remember about static analysis
is that it's static; type checks may not happen at runtime; in fact,
type information may not even be *present* at runtime.




Marshall
Received on Thu Oct 28 2004 - 04:00:46 CEST












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