Re: Personal reply to Edd Dumbill's XML Hack Article wrt W3C XML Schema

["Clark C. Evans" <cce@clarkevans.com>]

On Mon, 12 Mar 2001, Thomas B. Passin wrote:
> I ask again, why are we using markup?  

1) The XML syntax brings process auditability.  

   In many cases, having a binary format (be it application
   specific or  generic like ASN.1) is perfectly fine since the 
   generating or consuming process most likely uses its own internal 
   structure with a reader/writer pair as the gateway to the
   outside world and a visual, GUI for the user. In these cases, 
   under normal circumstances, a human is not involved and it 
   matters little if XML is used.

   However, under "unusual" circumstances, where the functioning
   of a process must be examined, XML enables the time-tested
   technique of watching the *raw* input/output streams! 

2) The XML information model allows for common tool-sets.

   Specific instances involve: tree transformation to build 
   process adapters, input and output validation to verify
   information integrety, standardized storage both memory 
   and disk variants.  

   In general, tree structures are traditionally poorly supported
   in most programming languages.  And when one moves from one
   language to another the libraries for tree minipulation were
   often very specific and/or limited.  XML tool-sets solve this
   problem... as long as they can remain language/platform independent.

> 2) Does xml-schemas move us farther along the path started by HTTP and HTML,
> or not?  Why? And is that a GOOD THING?

  HTTP has a clear function, to get and post inforamation to
       a particular URL.

  HTML has a clear function, a standard user interface for 
       relatively-static documents.

  XML  has a clear function (IMHO), a standard textual representation
       of tree like structures.

  XSLT did have a clear function, a standard way to describe
       transformations from XML to XML.  This clear function is
       being whittled away with the addition of xsl:script.

I'm not sure what W3C XML Schema's purpose is.  Validation 
would be a good purpose, but so far it is fuzzy to me...

...

What is interesting about HTTP, HTML, XML, XSLT is that they
were all very good tools that filled a clear vaccuum.  But
more importantly, they had predicessors to learn from.  
HTTP had ftp (and gopher?) XML had SGML and object oriented
data models, HTML had eqn, LaTex, etc.  XSLT had DSSSL.  In 
each of these cases, the marketplace had developed a variety 
of solutions, and the corresponding W3C solution could more
or less cherry-pick the best features (with some backard-
compatibility issues).

I have a question... What _did_ xml-schemas had to learn from?
Would it be fair to say that it was started a bit prematurely?
If this is the case then I certainly could not find any fault
with the WG members.

What is all the rush for anyway?

Best,

Clark