Re: Datamodel Strawman (ACTION-298)

Gary Hallmark <gary.hallmark@oracle.com> writes:
> 
> Xpath expressions returns a list of nodes, and nodes can be elements, 
> attributes, and typed literal values.  So we'd need at minimum some kind 
> of list in RIF (which we've talked about quite a bit), and I don't know 
> what you do about elements and attributes.  Forbid them?  Introduce an 
> opaque nodeId?
> 
> My worry is that a big component of a data model is the relationships 
> among the types/classes.  I would expect to be able to reason about 
> those relationships using rules.  E.g. find the mothers of twins in a 
> family tree expressed in an xml document.  I don't know how to do that 
> if all I can do is pick out typed literal values (leaves) from that xml 
> document using an xpath builtin. 

I don't have an opinion in this general area, but I do want to point
out that it is out of scope for Phase 1.  (Specifically, the charter
puts it in phase 2, Data Sources, XML data.)   

The reason for that placement as I recall is that it's quite possible to
build a small core language which does not directly access XML data.
One can always translate the XML data into facts in the rule language,
so this isn't something that needs to be standardized at first.  Rather,
we can let people play with the core before we standardize this bit.

That's what I'd suggest we do....

    -- Sandro

Received on Monday, 23 July 2007 21:23:12 UTC