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Re: Comment on XSD 1.1

From: Rick Jelliffe <rjelliffe@allette.com.au>
Date: Wed, 20 May 2009 22:52:27 +1000
Message-ID: <4A13FD0B.6060904@allette.com.au>
To: www-tag@w3.org
CC: www-xml-schema-comments@w3.org


Mukul Gandhi wrote:
>  But I can read following response to the text you cited, by Henry S. 
> Thompson:
> <quote>
> With all
> respect to the advocates of various light-weight reduced-aspiration
> alternatives, XML Schema is the _only_ design which covers the range
> of functionality required by the diverse communities eager for an
> XML-based alternative to DTDs.
>   
With all respect to Henry's hypes and hopes 8 years ago, XSD design 
covers the range of functionality in a way that has caused 
implementations to each implement different subsets: the design is a 
Phyrric victory.

(In any case, Henry was writing before RELAX NG and several other schema 
languages which were developed in the light of and in response to XSD.)
> What has pleasantly surprised _me_ over the last few months is how
> many people in the XML community are using XML Schema and evidently
> getting value from it and finding it straightforward. 
Mukul, are you really sure you want to defend XSD 1.n as being 
"straightforward"?  Gosh, things are worse than I thought  ;-)   

I have taught commercial courses in XSD for many years to hundreds of 
users from different backgrounds, and I do not recall XSD every being 
accused of straightforwardness.

> It's also true, in my opinion and that of many in the community, that
> XML Schema as it stands will be an incredibly valuable move forward:
> not perfect, but the right first step. I'm looking forward to seeing
> it deployed, to using it, and to starting work to integrate all we've
> learned from the experience and from external input as we begin work
> on the next version.
> </quote>
>   
...so lets learn from experience and external input then!: while it may 
serve some users well, or well enough, it is serving others extremely 
poorly.  That XSD 1.0 is an unprecedented disaster on the implementation 
front does not mean it is a total disaster that needs to go away or that 
cannot be salvaged by its closer stakeholders. But on the other hand, 
that it is not completely unusable in many important areas is no reason 
to be defensive about it.

When I was pushing for greater modularity in 1999 or 2000, I recall Noah 
saying on a conference call something to the effect that "validity had 
to mean validity": that modules or optional bits removed the certainty 
needed for validation, and that therefore the schema language had to be 
in some sense monolithic.  I think the poor coverage of the spec 
especially by databinding tools (as documented by that W3C effort) has 
put paid to that being a credible position now. We can either close our 
eyes and pretend there is no problem, which is to say that our 
(community's) needs are more important than their (community's) needs, 
or we can break the circle.

Cheers
Rick Jelliffe
Received on Wednesday, 20 May 2009 13:05:00 GMT

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