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Re: Why Are Schemas Hard?
- From: Joe English <firstname.lastname@example.org>
- To: email@example.com
- Date: Fri, 24 Aug 2001 18:07:28 -0700
Bullard, Claude L (Len) wrote:
> Just an aside. There is an excellent article from
> Donald Smith at http://www.xml.com/pub/a/2001/08/22/easyschema.html
> on the mysteries of the Schemas type tree. It doesn't take
> up the issues of namespace, binding vs validating etc. but it
> makes it much easier to understand how to do some fundamental
> work with schemas that befuddled some of us for awhile.
> Good Work, Mr. Smith!
Seconded. A good article.
It goes a long way towards anwering the question in the
Subject: line, too. When I figured out that the sample
| <complexType name="myNewNameType">
| <restriction base="anyType">
| <element name="name" type="string" />
| <element name="location" type="string" />
| <attribute name="position" type="string" />
| <element name="employee" type="dc:myNewNameType" />
<!ELEMENT employee (name, location) >
position CDATA #IMPLIED >
<!ELEMENT name (#PCDATA) >
<!ELEMENT location (#PCDATA) >
I said to myself, "complexType? That's not a complex type.
(<^>) :: P ((a -> b) -> c -> d -> e)
-> P ((f -> g) -> d -> d -> b)
-> P (((a,f) -> g) -> c -> d -> e) [*]
is a complex type!"
The 'employee' definition only *looks* complex when it's
written in W3C XML Schema notation.