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Re: Inheritance of restriction facets?

From: Eddie Robertsson <erobertsson@allette.com.au>
Date: Mon, 05 Aug 2002 11:19:29 +1000
Message-ID: <3D4DD2A1.60701@allette.com.au>
To: zze-MARCHEGAY Michael stagiaire FTRD/DTL/LAN <michael.marchegay@rd.francetelecom.com>
CC: xmlschema-dev@w3.org

Hi Michael,

>I'm sorry to have submitted an invalid schema. But would it have been 
>invalid if I had written the following schema instead?
>
I'm not sure. My intuition says that this should be invalid but like you 
I couldn't find this in the spec either.

Cheers,
/Eddie

>
><xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
>  <xsd:simpleType name="foo">
>      <xsd:restriction base="xsd:string">
>        <xsd:enumeration value="A"/>
>        <xsd:enumeration value="AA"/>
>        <xsd:enumeration value="AAA"/>
>      </xsd:restriction>
>  </xsd:simpleType>
>
>  <xsd:element name="bar">
>    <xsd:simpleType>
>      <xsd:restriction base="foo">
>        <xsd:minLength value="2"/>
>      </xsd:restriction>
>    </xsd:simpleType>
>  </xsd:element>
></xsd:schema>
>
>XML Spy 4.3 validates this schema but sqc doesn't. It complains that 
><xsd:minLength value="2"/> is not compatible with the enumeration facets
>
>defined by the ancestors foo, however I can't find out the clause that 
>justifies that in the Recommandation.
>
>  
>
>>Hi Michael,
>>
>>    
>>
>>>I have a question concerning restriction facets. 
>>>When a derivation by restriction of a simpleType is performed, are 
>>>the facets of the base type inherited by the deriving type?
>>>
>>>      
>>>
>>Yes, the facets on the base type are still enforced for the derived 
>>types which makes your example below invalid.
>>
>>    
>>
>>>For example, which content do the following schema allow for 
>>>      
>>>
>>bar element?
>>    
>>
>>> - A, AA and AAA?
>>> - AA and AAA?
>>> - ...?
>>>
>>>      
>>>
>>It will never come to this since the schema below is invalid 
>>and hence 
>>can't be used to validate a document.
>>
>>    
>>
>>><schema>
>>> <simpleType name="foo">
>>>   <restriction base="string">
>>>     <minLength value="2"/>
>>>   </restriction>
>>> </simpleType>
>>>
>>> <element name="bar">
>>>   <simpleType>
>>>     <restriction base="foo">
>>>       <enumeration value="A"/>
>>>
>>>      
>>>
>>This is the enumeration value that is invalid. If you remove "A" your 
>>schema is fine.
>>
>>    
>>
>>>       <enumeration value="AA"/>
>>>       <enumeration value="AAA"/>
>>>     </restriction>
>>>   </simpleType>
>>> </element>
>>></schema>
>>>
>>>Thanks.
>>>
>>>      
>>>
>>Cheers,
>>/Eddie
>>
>>
>>
>>    
>>
>
>  
>
Received on Sunday, 4 August 2002 21:04:22 GMT

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