an unfilled need

Sean Mc Grath digitome at
Tue Sep 7 11:16:17 BST 1999

>David Megginson wrote:
>: Perhaps an example would help.  Here's an XML document (without
>: Namespaces for now):
>:   <bllrp zata="-1">
>:    <poiuk>112</poiuk>
>:    <pppzzz>g</pppzzz>
>:    <ttt>xxx<rte w="3"/></ttt>
>:   </bllrp>
>: Now, imagine that my XML application has just received this piece of
>: XML and knows nothing about the markup language used.  What kind of
>: information should it be able to discover automatically, so that it
>: can process this document usefully?
[Brendan McKenna]
>	I would say that that depended on the application. 

Precisely! But the number of potential applications is infinite. The
amount of stuff you would need to "discover" is infinite. That
is why inventing declarative syntaxes for discoverable knowledge
such as rendering semantics, interactive behaviour, computation
etc. will always be a sandwich short of the full picnic.

The most general way to deal with the fact that so much depends
on the application, is to soft-code the application. In browser
land, this is like saying that we should take out
the hardwired rendering engine and download it along with the
data. The PostScript printer approach.

It is as Nicklaus Wirth put it : "Algorithms + Data Structures = Programs".
In the XML world we can re-phrase this as "Java + XML = Programs"
or "Perl + XML = Programs" or (my personal favourite) "Python + XML = 
Programs". A truly general solution needs both algorithm and
data. The headling rush into XML seems to have caused people
to loose sight of this and put all their faith in XML syntaxes
doing *everything*.

Whatever way you cut it, to truly general-purposify a "browser"
you need to soft-code its algorithms. In some alternative
universe you can write this:-

 <program language="Python">
  Bank.Debit ( (bllrp.zata * rte.w )/ GoldenRatio )
 <bllrp zata="-1">
  <ttt>xxx<rte w="3"/></ttt>

This approach will get you there a lot faster than
waiting for the "bank debit golden ratio rte interest group"
to finalize their declarative syntax for what the bllrp
element really means...


<Sean URI="">
Developers Day Co-Chair, 9th International World Wide Web Conference
16-19, May, 2000, Amsterdam, The Netherlands

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