RE: [relax-ng-comment] Are sequences and interleaves overloaded?

[Michael Fitzgerald <mike@wyeast.net>]

James, I think <not> in this example should be <except>. Jeff Lowry brought
this to my attention in a separate mail. -Mike

-----Original Message-----
From: James Clark [mailto:jjc@jclark.com]
Sent: Sunday, December 16, 2001 1:06 AM
To: Jeff Lowery; 'relax-ng-comment@lists.oasis-open.org'
Subject: Re: [relax-ng-comment] Are sequences and interleaves
overloaded?


You can handle your example with an interleave one of whose operands is a
group (sequence):

<element xmlns="http://relaxng.org/ns/structure/1.0"
         ns="http://www.example.com/g"
         name="foos">
  <zeroOrMore>
    <element name="foo">
      <interleave>
        <zeroOrMore>
          <choice>
            <element name="A">...</element>
            <element name="B">...</element>
            <element name="C">...</element>
            <element>
              <not>
                <nsName/>
              </not>
              ...
            </element>
          </choice>
        </zeroOrMore>
        <group>
          <element name="x">...</element>
          <element name="y">...</element>
          <element name="z">...</element>
        </group>
       </interleave>
    </element>
  </zeroOrMore>
</element>


--On 13 December 2001 11:59 -0800 Jeff Lowery <jlowery@scenicsoft.com>
wrote:

> I've been going around and around this maypole on the xml-dev and
> xmlSchema-dev lists for a couple of weeks, so I figure it's time to
> torture RELAX NG people with this:
>
> I've got a content model, unordered, which I wish to interleave with ANY
> elements of ANY other content model. I can't seem to do this in either XML
> Schema or RELAX NG without having to explicitly interleave the unordered
> elements between each and every element in each and every content model.
> For example, in XML Schema, a definition such as this works:
>
> <?xml version="1.0" encoding="UTF-8"?>
> <schema
> 	xmlns="http://www.w3.org/2001/XMLSchema"
> 	xmlns:g="http://www.example.com/g"
> 	targetNamespace="http://www.example.com/g"
> 	elementFormDefault="qualified"
>>
> 	<group name="ABC">
> 		<choice>
> 			<element name="A" minOccurs="0"
> maxOccurs="unbounded"/>
> 			<element name="B"  minOccurs="0"
> maxOccurs="unbounded"/>
> 			<element name="C" minOccurs="0"
> maxOccurs="unbounded"/>
> 			<any namespace="##other" processContents="lax"/>
> 		</choice>
> 	</group>
>
> 	<complexType name="foo">
> 		<sequence>
> 			<group ref="g:ABC" maxOccurs="unbounded"/>
> 			<element name="x"/>
> 			<group ref="g:ABC" maxOccurs="unbounded"/>
> 			<element name="y"/>
> 			<group ref="g:ABC" maxOccurs="unbounded"/>
> 			<element name="z"/>
> 			<group ref="g:ABC" maxOccurs="unbounded"/>
> 		</sequence>
> 	</complexType>
>
> 	<element name="foos">
> 		<complexType>
> 			<sequence>
> 				<element name="foo" type="g:foo"
> maxOccurs="unbounded"/>
> 			</sequence>
> 		</complexType>
> 	</element>
> </schema>
>
>
> Notice that foo has to have group refs between each element. I don't think
> RELAX NG does any better here, assuming that I want to maintain the
> ordering of x,y,z children in the foo element.
>
> To my mind, the basic problem here that both RELAX NG and XML Schema share
> is that both languages convolute the concept of "order" and "contiguity"
> in the term "sequence". Conversely, while XML Schema views <all> content
> models as unordered yet contiguous, RELAX NG choses to see interleaved
> content models as unordered and discontiguous (yet maintaining contiguity
> and order of sequence components within interleaved content models). [I'm
> basing my understanding of RELAX NG on the tutorial, not the spec, so I
> may not be fully cognizant of the capabilities of RELAX NG].
>
> The point I'm getting to is why not separate out the notion of order from
> that of contiguity? For example, why not have content models of <ordered>
> and <unordered>, with attributes of "contiguous" and "discontiguous"?
> That way, the above schema could be written as such (apologies that it's
> XML Schema syntax and not RELAX NG, but the ideas apply to both):
>
>
> <?xml version="1.0" encoding="UTF-8"?>
> <schema
> 	xmlns="http://www.w3.org/2001/XMLSchema"
> 	xmlns:g="http://www.example.com/g"
> 	targetNamespace="http://www.example.com/g"
> 	elementFormDefault="qualified"
>>
>
> 	<group name="ABC">
> 		<unordered contiguous="false">
> 			<element name="A" minOccurs="0"
> maxOccurs="unbounded"/>
> 			<element name="B"  minOccurs="0"
> maxOccurs="unbounded"/>
> 			<element name="C" minOccurs="0"
> maxOccurs="unbounded"/>
> 			<any namespace="##other" processContents="lax"/>
> 		</unordered>
> 	</group>
>
> 	<complexType name="foo">
> 		<unordered contiguous="true">
> 			<ordered contiguous="false">
> 				<element name="x"/>
> 				<element name="y"/>
> 				<element name="z"/>
> 			</ordered>
> 			<group ref="g:ABC" maxOccurs="unbounded"/>
> 		</unordered>
> 	</complexType>
>
> 	<element name="foos">
> 		<complexType>
> 			<ordered> <!-- contiguous="true" by default -->
> 				<element name="foo" type="g:foo"
> maxOccurs="unbounded"/>
> 			</ordered>
> 		</complexType>
> 	</element>
> </schema>
>
> Note that the conguity/discontiguity concept could also apply to element
> declarations with cardinality >1, probably by adding and attribute:
>
> 	<element name="foo" type="g:foo" maxOccurs="unbounded"
> contiguous="true"/>
>
> I can't be the first one who's suggested this, so there must be something
> terribly naive in this concept somewhere, or the capability is actually
> supported by RELAX NG in some other fashion.
>
> Later,
> Jeff
>
>
> ----------------------------------------------------------------
> To subscribe or unsubscribe from this elist use the subscription
> manager: <http://lists.oasis-open.org/ob/adm.pl>
>
>
>



----------------------------------------------------------------
To subscribe or unsubscribe from this elist use the subscription
manager: <http://lists.oasis-open.org/ob/adm.pl>