[topicmapmail] XTM Datatypes [Was: Adding weigths to associations]

[Kal Ahmed]

On Tuesday 10 December 2002 17:01, Murray Altheim wrote:
> Lars Marius Garshol wrote:
<snip>
> > Kal's approach of allowing <resourceData> to contain XML, which can
> > then be typed as desired using XML Schema/RELAX-NG is rather
> > different, and has different implications for the stack of standards.
> > I don't agree with it myself, but we should settle this discussion in
> > favour of one of the approaches so that we can proceed.
>
> I think if Kal reconsidered simply pointing at those resources
> outside of the <topicMap> element but within the same document,
> he'd not need to do something so ugly. :-)
>

My suggestion is not so much in response to the proposal for mixing XTM a=
nd=20
other namespaces - although I think that it has a role to play in that, b=
ut a=20
suggestion of a more XML-friendly way of supporting datatypes in the topi=
c=20
map model.=20

I fail to see why TMCL/TMQL should define yet another set of datatypes wh=
en=20
there is already at least one widely implemented set of data types with a=
=20
defined lexical representation and an XML serialisation syntax (W3C Schem=
a=20
datatypes). Simple datatyping could be addressed with the approach you=20
propose, but not complex datatypes - do the TMCL/TMQL committees feel tha=
t it=20
is worth spending their time reinventing this particular wheel ? Or is it=
=20
proposed that they should define just a set of "simple" types and we shou=
ld=20
all live with that ?

> > The issue of data typing strongly affects TMQL, of course. Data types
> > will change how values are compared and sorted, which means that we
> > have to keep all of XTM, SAM, TMCL, and TMQL in mind when discussing
> > this.

The principles of typed value ordering are also covered to some extent by=
 W3C=20
Schema (I expect that XSLT2.0/XPath 2.0 probably has more to say on that,=
 but=20
I haven't checked yet).

Cheers,

Kal
--=20
Kal Ahmed, techquila.com
XML and Topic Map Consultancy

e: kal@techquila.com
p: +44 7968 529531
w: www.techquila.com