RE: XSCH-DM-02: Further comment on the Data Model vis a vis the Infoset REC

There are several problems with such an approach:

1. Often, the Infoset is considered an abstract description of parser
output. Thus an extension with the necessary informations may be not
acceptable for this camp. 

2. The data model is based on the XPath 1.0 data model that uses most of
the terminology (in particular "node"). The XPath/XQuery community has
repeatedly expressed disdain on using the Infoset terminology to
describe the data model.

3. There are a couple of properties that are not that easy to add to the
Infoset. Examples: Notion of nodeid (mainly philosophical issues when to
instantiate such a concept on the infoset), atomic values, even some of
the PSVI abstractions.

4. There are issues with the relationship of typed values, comments,
PIs, character information items and text nodes.

5. This comment has a very large impact on the data model document and
other documents and is therefore of high risk to the specification and
progressing. Since it has mainly definitional impact and would not
change the semantics, I feel this is too risky an undertaking before we
progress into Recommendation.

Having said all of that, I can see the value of a general evaluation of
the notion of the Infoset, PSVI and data model and would support an
effort inside the W3C to get to a single model AFTER XQuery 1.0 has been
released.

Best regards
Michael (speaking for myself)

> -----Original Message-----
> From: public-qt-comments-request@w3.org [mailto:public-qt-comments-
> request@w3.org] On Behalf Of Henry S. Thompson
> Sent: Thursday, March 04, 2004 9:33 AM
> To: public-qt-comments@w3.org
> Subject: XSCH-DM-02: Further comment on the Data Model vis a vis the
> Infoset REC
> 
> 
> We have observed a welcome trajectory over drafts of the Data Model to
> reduce the distance between its core and the W3C Infoset
> Recommendation.  We actually see no remaining impediment to completing
> this and actually identifying the Data Model explicitly as an
> extension of the Infoset.  This would probably need to be done on two
> levels: the first, in the spirit of the PSVI, adding new properties
> and possibly new information items, the second adding accessors.
> 
> Although in one way this might seem to be a purely editorial request,
> or at best a rhetorical one, we actually think participating in the
> use of the Infoset abstraction in this way will actually make the
> Query specs stronger and simpler.
> 
> A major advantage of adopting this suggestion, connected to our
> previous comment XSCH-QL-018 [1] about 'validate' expressions, is that
> the need for serialization in the definition of validation goes away
> -- infosets are by definition validatable as such.
> 
> Henry Thompson
> By and on behalf of the W3C XML Schema WG
> --
>  Henry S. Thompson, HCRC Language Technology Group, University of
> Edinburgh
>                      Half-time member of W3C Team
>     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131
650-4440
>             Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk
>                    URL: http://www.ltg.ed.ac.uk/~ht/
> [mail really from me _always_ has this .sig -- mail without it is
forged
> spam]

Received on Thursday, 4 March 2004 13:39:16 UTC