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Re: Multiple enumeration

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 22 Dec 2000 10:46:49 +0000
To: Elena Litani <hlitani@jtcsv.com>
Cc: xmlschema-dev@w3.org
Message-ID: <f5bitocvili.fsf@cogsci.ed.ac.uk>
Elena Litani <hlitani@jtcsv.com> writes:

> I am not sure I understand specs correctly. See section (Schema
> Representation Constraint: Simple Type Restriction (Facets)):
> "A simple type definition (call it R) restricts another simple type
> definition (call it B) with a set of facets (call this S) if: 
> 1.1  ... 
> 1.2  The {facets} of R are the union of S and the {facets} of B, without
> duplicates. To avoid duplicates, when a facet of the same kind occurs in
> both S and the {facets} of B, the one in the {facets} of B is not
> included, with the exception of enumeration and pattern facets, for
> which multiple occurrences with distinct values are allowed." 
> Is the following example valid?
> <simpleType name ="B">
>      <restriction base ="float">
>          <enumeration value="1"/>
>          <enumeration value="2"/>
>      </restriction>
> </simpleType>
> <simpleType name ="R">
>      <restriction base ="myFloat">
>      <enumeration value="3"/>
>      </restriction>
> </simpleType>

They are by the above prose, but you're right, this is a bug, and R
should not be allowed.

> B can have values {1,2}.


> ** Is R allowed to have values {1,2,3}
> OR 
> ** Is R does not allow to have any values (intersection of B enumeration
> and R enumeration)?

Yes, or rather, R is not valid at all.

> If for type R enumeration would be:
> <enumeration value="1"/>  (instead of value="3")
> Does it mean that R can have value {1}?


  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, 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/
Received on Friday, 22 December 2000 05:46:53 GMT

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