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Paul Prescod wrote:
> Tim Bray wrote:
>> The problem with that wordview is that Xpath/Xquery are clearly mostly
>> going to be used at application run-time. I think the proportion of
>> cases where XMLSchema validation happens at application run-time is
>> going to be way short of 100%. I personally think's actually going to
>> be way short of 25%, it's useful for design support and debugging but
>> it's just not at the right level for business-logic validation.
> There is a faith out there that schemas are the right way to bootstrap
> from the world of dynamically typed XML to the world of statically typed
> C# and Java. It is thought that this will enhance, rather than degrade
> performance by pushing type conversion from application logic down into
> infrastructure. I don't personally believe this myself but I think that
> you need to understand it to understand the schema mindset.
I don't believe that either and I'd add that it takes a pretty narrow
view on XML but I can in fact see use cases for having access to types
in XPath. For instance when I see an XSLT processor chew for several
minutes on a very predictable document (granted, it's Java based, but
still) I think that if it had access to schema information it could
optimize a lot of what it's doing by skipping entire subtrees.
My issue here is that typing should be an option, available to those
that want it but not enforced upon others. XML Schema has too many
issues to be enforced upon anyone wishing to implement simple XPath.
Robin Berjon <email@example.com>
Research Engineer, Expway
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