Re: Namespace: what's the correct usage?

[John Cowan <cowan@mercury.ccil.org>]

W. E. Perry scripsit:

> In fact, I have designed a system, now in *production*, which happens
> to correspond to your example.

Ah, good.

[details snipped]

> So,
> in this example, the element which you, as sender, intended to convey
> 'counterparty' was, in the salient point of my processing, the very basis
> for instantiating 'settlement price',

Ah, but this obscures a distinction that is fundamental.  It is one
thing to *use* the counterparty data to establish the settlement price,
and it is quite another thing to *interpret* the counterparty data
*as* the settlement price.  The one is a matter of authority (who
gets to say what the true settlement price was?) and the latter is
a matter of denotation (who gets to say that the "foo" element contains a
counterparty and the "bar" element contains a settlement price?)

> My simple
> point is this:  my processor is autonomous and may be immune to your
> 'intent'. What we share is the syntax of a document.

If you really depended only on the *syntax* of the document, then
your process would continue to work even if I inserted a man-in-the-middle
which unsystematically changed all the element names, attribute names, and order
of document elements, since XML *syntax* is quite indifferent
to any of these.

Left horn:  If you can do that just fine, I'd like to hear about it.

Right horn:  If not, then you are attaching a significance to parts of the
document which are not purely syntactic.

> If I can--for my
> own autonomous purposes--do something useful by processing that document
> in a way which you never expected, I am not only free to do so, but
> doing so is the perfect expression of my expertise in my own particular
> (processing) specialty.

I have never doubted that you can act on a document as you please,
provided you have shared understanding of the meaning (*not* necessarily
the authority) of at least parts of the document.

-- 
John Cowan                                   cowan@ccil.org
One art/there is/no less/no more/All things/to do/with sparks/galore
	--Douglas Hofstadter