Mixing and matching a couple of posts....

> On Friday 23 February 2001 14:14, Stephen White wrote:
> >

> > Just a brief side-track... but I'm seeing "XML" everywhere and I
> > just don't click onto why everyone's talking about it.
> >
> > It seems to me that XML is a really weak SQL, with the difference
> > that anything is supposed to be able to parse it... but ends up
> > with everyone having to create and re-create a database in their
> > code instead of just using SQL or an external database.

XML and SQL aren't commensurate.  In fact, very broadly viewed,
they're sort of at opposite ends of things.  SQL is a mechanism for
getting at data; XML is a data storage standard (or
data-storage-standard standard).  SQL requires that there be a
database to query; XML documents require that some tool exist to query
them and process what's in them.

(That's painted with awfully broad strokes, but I think the gist is
accurate.)

XML is both a supposedly (but I'm not convinced really) "simplified"
version of its sort-of-parent, sort-of-sibling technology, SGML, and
an exponentially more powerful way to define and process documents and
data than HTML.

On Sat, 24 Feb 2001, W. Kent Starr wrote:

> It can also be thought of a a meta-language, in that, with XML you
> define customized tags and attributes for these. This 'defining' is
> done via a 'document type definition' (DTD). As long as you and I
> write to the same DTD (which can be located anywhere on the
> Internet) then we can exchange even highly customized data unique to
> our respective needs.

One addendum: XML (unlike SGML) doesn't actually require a DTD.  I
really hope people do continue to understand their value, though, in
spite of XML's wimp-out option :-)  I never found DTD-writing
particularly difficult; I'm not entirely sure how they earned their
reputation as a scary part of SGML.

ANYWAY...

A good-faith attempt to reconnect this with Ruby will now follow.

Earlier this week I was looking at the WWW Consortium site and
noticed, among other things, a newly-released working draft of XQuery,
an XML query language.  Not the first such language, but supposedly a
very comprehensive one that improves on old ones.

It occurred to me to wonder whether there might be a worthwhile
opening here for the implementation of this standard in Ruby tools
and/or libraries.  This is the vaguest possible idea -- I haven't even
really looked over the standard in detail, or thought about what would
be involved -- but it struck me as an area of potential rubification.


David

-- 
David Alan Black
home: dblack / candle.superlink.net
work: blackdav / shu.edu
Web:  http://pirate.shu.edu/~blackdav