URI as sort v. URI as spelling for constants

Since I didn't manage to express my comment very clearly on the telecon 
here's another attempt ...

Recap:
   We started out discussing issue 30: what is the definition of rif:uri?

   That turned into: do we really want a rif:uri sort at all?

   Which led to: but what is the alternative?

The point I was trying to make is that the alternative is to hardwire 
use of URIs to denote individuals, functions and predicates into the 
syntax as lexical forms rather than using sorts.

Thus instead of the current asn:

[[[
...
class TERM

     subclass Var
         property name: xsd:string

     subclass Const
         property name: xsd:string

     subclass Uniterm
         property op: Const
         property arg: list of TERM
]]]

One would have the asn:

[[[
...
class TERM

     subclass Var
         property name: xsd:string

     subclass Const
         subclass Literal
             property lexicalForm: xsd:string
             property sort: xsd:anyURI [*]

         subclass Symbol [**]
             property uri: xsd:anyURI

     subclass Uniterm
         property op: Symbol
         property arg: list of TERM
]]]

It seems to me that what we set out to do was to find a way of saying
"you can use URIs to denote symbolic constants such as predicates, 
functions and individuals".

The original argument for using sorts for this was to permit other 
things to also be used as to denote these. Which is why I asked (well 
tried to ask) "so what are these other things?". I'm not yet convinced 
we do need anything else, especially for RIF Core.

Does this make sense?

Dave

[*] Note that this is not a sort this is a lexical form. Note also that 
xsd:anyURI includes both relative an absolute URIs so that the URI as 
written in a RIF document might be spelt "foo" or "#bar" and might not 
look like "http://example.com/foo#bar".

[**] I use "Symbol" here rather than "Individual" (as used in Adrian's 
version [1]) since it can be used to as a predicate and function symbol 
as well as an individual.

[1] http://lists.w3.org/Archives/Public/public-rif-wg/2007Mar/0009.html

Received on Tuesday, 20 March 2007 17:07:59 UTC