Re: Are we losing out because of grammars?

[Rick Jelliffe <ricko@allette.com.au>]

 ±H¥óªÌ: Eric van der Vlist <vdv@dyomedea.com>

>Yes, that would be really great to have schema languages that let you
>describe the links within and also between documents.

Prof Anthony Finkelstein's  XLinkit language (not sure of current name or
reference)  was designed to help this kind of thing. It is like Schematron
except much more sophisticated--it uses XPointers where Schematron uses
XPaths and has more datatypes and its own expression language.

In Schematron you can traverse a link and navigate around the other end. We
use it for things like controlled vocabularies, but it can also check link
integrity. But this is just a side-effect of using XPath technology, not a
systematic attempt to address that problem (which I think XLinkit is more
targetted to.)

> XML Schema languages seem to focus on single documents and this looks
> also like a necessary extension !

XML Schemas does not really even get up to the document level--it
concentrates on local branches formed by namespace changes.  This may
suggest to some that it can scale up to infosets that are too large to
consider sending: databases rather than pages.

Rick Jelliffe

P.S. If anyone knows any good website on term rewriting that list rules for
regular expressions -> paths of some kind, I would be very interested.