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Re: import functions and operators from MathML rather than XPath/XQuery? (valueTesting)

From: Eric Prud'hommeaux <eric@w3.org>
Date: Mon, 6 Jun 2005 02:56:43 -0400
To: Dan Connolly <connolly@w3.org>
Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Message-ID: <20050606065643.GB29143@w3.org>
On Thu, Jun 02, 2005 at 09:12:08AM -0500, Dan Connolly wrote:
> 
> We currently import our functions and operators
> from
>  http://www.w3.org/TR/xpath-functions/
> 
> The normative reference on that and
> on http://www.w3.org/TR/xquery continue to concern
> me, w.r.t. our schedule.
> 
> At the rules workshop, somebody pointed out to me
> that MathML has URIs for functions an operators,
> e.g.
> 
>   http://www.w3.org/TR/MathML2/appendixc.html#cedef.factorial

Factorial was a funny choice, but perhaps you could use tendsTo
  http://www.w3.org/TR/MathML2/appendixc.html#cedef.tendsto
to describe our assymptotic approach towards Last Call.

> I don't think it has all the ones we need; regex,
> in particular.
> 
> But MathML2 is already a REC, and I played around with
> it (http://www.w3.org/2001/sw/DataAccess/mathml-rules.xml )
> and found it integrates with the Semantic Web pretty well,
> so I have been thinking about importing our functions
> and operators from there instead of XQuery, and I thought
> I'd share the thought with the WG and see if it goes
> anywhere.

One benefit to using XQuery F&O is the dream of re-using libraries to
supply SPARQL functionality. Also, the MathML defns are more syntactic.
Specifically, they don't have type errors, which are pretty crucial to
our "can't say one way or the other" approach to the open world of
datatype relationships.

I didn't see any handy join operators to help us with the graph
patterh. To get extra geeky, I considered defining bNodes in CONSTRUCT
patterns as compositional functions.
  http://www.w3.org/TR/MathML2/appendixc.html#cedef.compose

From what I've considered, MathML doesn't offer us much beyond
notation. If we want to time-out on XQuery, it seems like we could
take a snapshot of the parts of it that we use and Recommend that.

> This might involve a charter change... er... hmm...
> I thought there was something explicit about using XQuery
> functions and operators in our charter, but I don't see it
> now.
>   http://www.w3.org/2003/12/swa/dawg-charter

I think the word "maybe" sums up our obligations pretty well:

[[
While the data model of the query language of this protocol is
dissimilar to that of XQuery, a non-XML concrete syntax might reuse
syntactic elements from XQuery to aid learning time, even if XQuery is
not chosen as the strawman.
]]


-- 
-eric

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Received on Monday, 6 June 2005 06:56:46 GMT

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