Re: [xml-dev] DTD vs XSD: No Duplicate Types in (Mixed) Content Models

[=?UTF-8?B?TWFpayBTdMO8aHJlbmJlcmc=?= <maik.stuehrenberg@uni-bielefeld.de>]

Hello Ghislain,

thank you very much for the hint, that helped indeed. Interesting to see 
that the XSD spec is somewhat more accurate (or at least more detailed) 
on duplicate types that the corresponding part of the XML spec.

Kind regards,

Maik

Am 31.01.11 16:04, schrieb Fourny Ghislain:
> Hello Maik,
>
> I think XSD processors make a difference because of the Unique Particle Attribution Constraint, mentioned in the XML Schema specification:
> http://www.w3.org/TR/xmlschema-1/#cos-nonambig
> "A content model must be formed such that [...] the particle component contained [...] therein with which to attempt to validate each item in the sequence in turn can be uniquely determined [...] without any information about the items in the remainder of the sequence."
>
> Your example corresponds to what is said in the non-normative part H:
> http://www.w3.org/TR/xmlschema-1/#non-ambig
> "A content model will violate the unique attribution constraint if it contains two particles which overlap and which [...] may validate adjacent information items and the first has {min occurs} less than {max occurs}."
>
> The last two xs:element particles in your first example (below) seem to fulfill this criterion.
>
> I hope this helps?
>
> Kind regards,
> Ghislain
>
>
> On Jan 31, 2011, at 3:27 PM, Maik Stührenberg wrote:
>
>> It would be interesting to know why XSD processors do make a difference
>> between
>>
>> <xs:element name="a">
>>      <xs:complexType>
>>        <xs:sequence>
>>          <xs:element ref="b"/>
>>          <xs:element ref="b"/>
>>          <xs:element ref="b"/>
>>          <xs:element ref="b" minOccurs="0" maxOccurs="1"/>
>>          <xs:element ref="b" minOccurs="0" maxOccurs="1"/>
>>        </xs:sequence>
>>      </xs:complexType>
>>    </xs:element>
>>
>> and
>>
>> <xs:element name="a">
>>      <xs:complexType>
>>        <xs:sequence>
>>          <xs:element ref="b" minOccurs="3" maxOccurs="5"/>
>>        </xs:sequence>
>>      </xs:complexType>
>>    </xs:element>
>
>

-- 

Maik Stührenberg, M.A.

Universität Bielefeld
Fakultät für Linguistik und Literaturwissenschaft
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