Re: relations aren't types?

"John Jacob" <jingleheimerschmitt_at_hotmail.com> wrote in message news:72f08f6c.0401050954.2aec066e_at_posting.google.com...
> > From a language grammar perspective, they may have named a production or
two
> > using "scalar", but I do not see any logical distinction.
>
> Try right around 20 in Tutorial D. An industrial D would have many
> more. Out of 26 prescriptions in TTM, 8 deal specifically with scalar
> types, values, variables and operators. That's almost one third of
> the specification. Scalar is treated at least as much, if not more,
> than relation and tuple types combined. There is an entire chapter
> devoted to explaining the difference between scalar types (domains)
> and relations.

Well, duh! Of course there is a logical difference between a type (domain) and a value (relation). I never compared types with values; I compared types with types. The relation value has a type, and I see no use in calling one type scalar and another type non-scalar. In fact, I have seen no useful definition of scalar at all.

The important concepts are generic types vs. specific types. The relation type generator defines a generic type and instantiates specific types as necessary. Likewise, the tuple type generator defines a generic type and instantiates specific types as necessary. Similarly for interval types. Received on Mon Jan 05 2004 - 21:57:59 CET