[Bug 2062] R-073: Question about unions of attribute uses

http://www.w3.org/Bugs/Public/show_bug.cgi?id=2062

           Summary: R-073: Question about unions of attribute uses
           Product: XML Schema
           Version: 1.0
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: XSD Part 1: Structures
        AssignedTo: ht@w3.org
        ReportedBy: sandygao@ca.ibm.com
         QAContact: www-xml-schema-comments@w3.org


The {attribute uses} property for an Attribute Group Definition schema 
component is defined as:

"The union of the set of attribute uses corresponding to the <attribute> 
[children], if any, with the {attribute uses} of the attribute groups resolved 
to by the actual values of the ref [attribute] of the <attributeGroup> 
[children], if any."

When performing the union operation, are duplicate attribute uses included in 
the final set? For example, consider the following:

 <xsd:attributeGroup name="fred" >
      <xsd:attributeGroup ref="bas:bill"/>
      <xsd:attributeGroup ref="bas:bill"/>
 </xsd:attributeGroup>

 <xsd:attributeGroup name="bill">
      <xsd:attribute name="bob" type="xsd:string"/>
 </xsd:attributeGroup>
When we compose the "set" of {attribute uses} for fred, should we only include 
the attribute use for "bob" once? Or does the final set of {attribute uses} 
contain 2 duplicate attribute uses for "bob" and result in an error according 
to constraint 2, section 3.6.6?

See:
http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001OctDec/0003.html

Received on Friday, 9 September 2005 02:43:59 UTC