- From: <noah_mendelsohn@us.ibm.com>
- Date: Mon, 25 Mar 2002 12:47:20 -0500
- To: "Kriegesmann, Peter" <Peter.Kriegesmann@softwareag.com>
- Cc: xmlschema-dev@w3.org
In your example, the fragment:
<xs:element name = "child">
<xs:complexType>
<xs:sequence>
<xs:element ref = "x" minOccurs = "0"></xs:element>
<xs:element ref = "x" minOccurs = "0"></xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
violates the unique article attribution constraint. Reason: when
validating the instance
<child>
<x/>
</child>
you don't know whether the <x/> matches the first for the second reference
to x. If you look at the specification at [1] you will see that the
declaration of the sequence turns into a list of two particles. The fact
that both particles reference the same declaration as their {term} [2]
does not result in the two particles being combined. There are two
particles and thus an ambiguity.
[1] http://www.w3.org/TR/xmlschema-1/#Model_Group_details
[2] http://www.w3.org/TR/xmlschema-1/#cParticles
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Received on Monday, 25 March 2002 13:02:37 UTC