Re: Are we losing out because of grammars?

[Dan Brickley <Daniel.Brickley@bristol.ac.uk>]

On Sat, 27 Jan 2001, Eric van der Vlist wrote:
> For instance, despite many qualities, there are combinations that W3C
> XML Schema cannot describe and/or constrain.

And that's no fault of the XML Schema language. Once we have XML Query,
many of the applications that folk have looked to XML schema languages
to support will be rather easily implentable on top of a query
processor. Schematron IMHO leads the way on this. Any state of affairs
one can characterise to a query engine for the sake of finding stuff
out, one can also supply to a data validity checker for the sake of
making sure ones data is in the right shape. To overload Schema languages with
all this work is imho a mistake, since we risk confusion between
constraints from the core structures of an XML-based data format and the
(often tighter) constraints we wish to apply when using that data format
in practical applications. Same goes for RDF of course.

Dan