RE: [xml-dev] 2007 Predictions

[noah_mendelsohn@us.ibm.com]

Mike Champion wrote:

> From: Len Bullard [mailto:cbullard@hiwaay.net] 
> Sent: Tuesday, January 16, 2007 1:58 PM
> To: 'Kurt Cagle'
> Cc: 'Nathan Young -X (natyoung - Artizen at Cisco)'; 'XML Developers 
List'
> Subject: RE: [xml-dev] 2007 Predictions
> 
> [...]
>  
> > On the other hand, I wonder about everything becoming declarative.  It
> seems reasonable 
> > to those of us who are old enough to remember ...
> 
> Agreed. The declarative vs procedural discussion has been hot on and off
> since at least the 1970s 
> 
> 
http://search.live.com/results.aspx?FORM=&q=declarative+procedural+controver
> sy 
> http://www.google.com/search?q=declarative+procedural+controversy 
> 
> Web 1.0 pushed the pendulum toward the declarative (SQL + XSLT) side, 
Web
> 2.0 made the world safe for imperative Javascript, now XQueryP is 
proposed
> to nudge XQuery in the imperative direction and LINQ is moving C# and VB 
in
> the declarative direction.  That thing isn't going to stop swinging 
anytime
> soon.

A key point is that information captured in declarative form is typically 
much easier to extract and repurpose than information encoded 
procedurally.  Get me a table of stock quotes, and I can easily and 
probably securely import it into charting tools, database, AJAX clients, 
etc.  Give me instead a Javascript program which, it is asserted, will 
produce stock quotes as output and for many purposes I'm in much worse 
shape.  I need a runtime for Javascript, but worse, we know that there is 
no way to tell whether an arbitrary Javascript program will produce any 
output in bounded time.  Running Javascript or other imperative languages 
tends also to raise more security concerns than parsing a declarative 
file.

These points are all made somewhat more carefully in the recent TAG 
finding titled: "The Rule of Least Power"[1].  Although my name is on it 
as co-editor, my role was primarily to help Tim Berners-Lee package for 
widespread publication a note [2] he had written on the same subject many 
years ago.

Noah

[1] http://www.w3.org/2001/tag/doc/leastPower.html
[2] http://www.w3.org/DesignIssues/Principles.html#PLP



--------------------------------------
Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
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