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Re: xsd:group and minOccurs

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 30 Aug 2002 08:48:43 +0100
To: Jeni Tennison <jeni@jenitennison.com>
Cc: xmlschema-dev@w3.org, Eddie Robertsson <erobertsson@allette.com.au>, "Gregory M. Messner" <gmessner@breezefactor.com>
Message-ID: <f5br8ggrdlw.fsf@cogsci.ed.ac.uk>

Jeni Tennison <jeni@jenitennison.com> writes:

> In fact, it's impossible to create an instance that is valid against
> that schema, which is why the note under the validation rule says:
>   no sequence can be ·valid· with respect to [a group whose
>   {particles} is empty] whose {compositor} is choice
> For some reason this isn't a constraint that's checked at the schema
> level -- you only work out that your schema isn't ever going to work
> when you try to validate instances against it.

Because the _schema_ is prefectly OK -- we thought it was worse to
actually rule this out, when it might arise e.g. through the
definition of a group changing, in a branch of a larger content model
that didn't get taken anyway in validating some documents.

  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2002, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
 [mail really from me _always_ has this .sig -- mail without it is forged spam]
Received on Friday, 30 August 2002 03:48:51 UTC

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