Confirmation welcome: whiteSpace facet to derive simplec ontents

Hi,

Just wondering... is there any reason why this should be forbiden (as 
Xerces-J tells me)?

<xs:complexType name="token">
  <xs:simpleContent>
   <xs:restriction base="string">
    <xs:whiteSpace value="collapse"/>
   </xs:restriction>
  </xs:simpleContent>
</xs:complexType>

("string" is a simple content complex type derived by extension of 
xs:string).

Thanks

Eric
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Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
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