- 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>
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.
ht
--
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