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RE: Substitution group chains - which can be abstract?

From: Dan Vint <dvint@mindspring.com>
Date: Fri, 18 Apr 2003 09:16:25 -0700
Message-Id: <5.1.0.14.2.20030418091021.02ba3008@mail.dvint.com>
To: xmlschema-dev@w3.org

I see what you are trying to do, I'm thinking you can't get there from here.

You might want to try this approach with abstract types instead of 
elements. That gets rid of the substitutionGroup attribute problem. Or the 
solution might be a combination of the abstract types, with substitution 
groups (with or without the abstract).

..dan

At 11:54 AM 4/18/2003 -0400, Xan Gregg wrote:
> > ...You sort of have 2 head elements, but only one common set
> > of substitution elements.
>
>Not necessarily the same set of "substitution elements", but usually a
>subset (except when some are ruled out by block/final, which I prefer not to
>think about unless I have to).
>
>Example:
>
><element name="bird" abstract="true"/>
>
><element name="flighted-bird" substitutionGroup="bird" abstract="true"/>
><element name="robin" substitutionGroup="flighted-bird"/>
>
><element name="flightless-bird" substitutionGroup="bird" abstract="true"/>
><element name="penguin" substitutionGroup="flightless-bird"/>
>
>_Element decl_   _SG actual members_
>bird             {robin, penguin}
>flighted-bird    {robin}
>robin            {robin}
>flightless-bird  {penguin}
>penguin          {penguin}
>
>xan
>
>-----Original Message-----
>From: Dan Vint [mailto:dvint@mindspring.com]
>Sent: Friday, April 18, 2003 11:23 AM
>To: xmlschema-dev@w3.org
>Subject: Re: Substitution group chains - which can be abstract?
>
>What would be the purpose in saying that this group X based upon this
>abstract head Y, has all these things that can substitute for it and then
>have one of those substitution items also have abstract applied to it?
>
>Now the head and an internal member both cannot be used in the data stream.
>Maybe you might get the use of the second element for use in the schema but
>the end result would be the same wouldn't? You sort of have 2 head
>elements, but only one common set of substitution elements.
>
>..dan
Received on Friday, 18 April 2003 12:16:50 GMT

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