Re: Datamodel Strawman (ACTION-298)

You think adding xpath to RIF is easier than adding generic lists and 
frame types?  Does xpath have a model theory?  If it did, would it be 
compatible with RIF's?

Christian de Sainte Marie wrote:
> Gary,
>
> Gary Hallmark wrote:
>
>> The statement for this action reads "Show how to use XML Schema for 
>> App Data Model".
>> This begs the question: what is an "App Data Model"?  I believe that 
>> we must define such a thing in RIF, and only then can we define a 
>> mapping between XML Schema (or relational databases, or OWL, or RDFS, 
>> etc.) and this RIF Data Model (RDM).
>
> During F2F6, in Innsbruck, there seemed to be broad agreement that RIF 
> should not invent its own data model/schema language, as Dave and Paul 
> point out.
>
> The action to "show how to use an XML schema for ADM" was seen as 
> necessary because it was felt that, although several participants 
> (including myself) contented that being able to use a data model 
> specified in an XML Schema (or DTD) was a requirement, nobody seemed 
> to have a precise idea of what it meant.
>
> As I understand it, there are basically two places where we may need 
> the reference to an external, or application data model:
>
> 1. when specifying the type of a variable beyond the builtin types 
> (and of a slot if we decide that RIF should allow type checking);
>
> 2. when navigating a data source, that is, to specify data accessors.
>
> As regards case 1, I suppose that a QName is all we need (in addition 
> to  the metadata that will tell us what this ruleset requires, e.g. a 
> data model represented by an XML schema, the URI of that schema etc).
>
> As regards case 2, as I understand it, it is the 'op' property of an 
> UNITERM that specifies the path to the data to be accessed, where the 
> 'args' give the context.
>
> E.g., suppose that the data model is specified by the XML Schema in 
> [1], and that there is a rule that says (informally) (taken from the 
> MISMO POC [2]:
>
> Forall ?R: Root()
> If ?R.division="wholesale" and ?R.occupancy="Investors"
> Then r.occupancyAdjustment = 0.95d
>
> The RIF XML could be (probably not compliant with Sandro's proposed 
> rules, but that is not the purpose):
>
> <Ruleset xmlns:mismo="(the URL in [1]">
> ...
>   <Rule>
>      <Forall>
>         <declare>
>            <Var>
>               <name>?R</name>
>               <type>mismo:root</type>
>            </Var>
>         </declare>
>      <if>
>         <And>
>            <Equal>
>               <side>
>                  (*) Here we would like something like an XPath expr 
> selecting the "division" element where the value of ?R is the context
>               </side>
>               <side>"wholesale"</side>
>  ...
>
> (*) E.g. <Uniterm><op>mismo:division</op><arg>?R</arg></Uniterm>, 
> where the arg could itself be another uniterm if we needed to navigate 
> deeper; or a single 'op' could be a complete XPath expression; etc. 
> The slotted syntax may be more appropriate for that case, btw.
>
> The question is: if there is a standard way, associated to the data 
> model, to navigate the source - e.g. XPath if the data model is an DTD 
> or XML Schema,etc -, should that be the syntax for accessors (and thus 
> the syntax for accessor 'op's or slots may vary depending on the data 
> model? Or does RIF need to define a RIF "data source navigation 
> language" that works for, e.g., XML-S, RDF-S OWL, etc?
>
> Christian
>
> [1] 
> http://anonsvn.labs.jboss.com/labs/jbossrules/contrib/apocrif/jrules/src/test/resources/xsd/mismo.xsd 
>
> [2] 
> http://anonsvn.labs.jboss.com/labs/jbossrules/contrib/apocrif/jrules/src/test/resources/irl/mismo2.irl 
>
>

Received on Friday, 20 July 2007 06:06:25 UTC