LC-209 Open Enumerations (XForms comment on XML Schema Last-Call Working Draft)

Dear XForms Working Group

The W3C XML Schema Working Group has spent the last several months
working through the comments received from the public on the last-call
draft of the XML Schema specification.  We thank you for the comments
you made on our specification during our last-call comment period, and
want to make sure you know that all comments received during the
last-call comment period have been recorded in our last-call issues
list (http://www.w3.org/2000/05/12-xmlschema-lcissues).

Among other issues, you raised the point registered as issue LC-209, Open
Enumerations

The Schema Working Group believes that the support for union types in the
simpleType construct addresses this issue allowing for example the following
type definitions;

<!-- Enumeration of all US state abbreviations -->
<xsd:simpleType name="US-State" base="xsd:string">
  <xsd:enumeration value="AK"/>
  <xsd:enumeration value="AL"/>
  <xsd:enumeration value="AR"/>
  <!-- and so on ... -->
</xsd:simpleType>

<!-- string of exactly 2 characters -->
<xsd:simpleType name='stringwithtwochars'>
  <xsd:length value='2'/>
</xsd:simpleType>

<!-- union of the above two type -->
<xsd:simpleType name='WeMightNeedMoreUSStates'>
  <xsd:union memberTypes='US-State stringwithtwochars' />
</xsd:simpleType>

which would allow instances to contain any one of the existing US State
abbeviations ( as defined in the type US-State ) or any other string values
of exactly two characters. For example the following would all be valid
instances of the type 'WeMightNeedMoreUSStates'

<state>AK</state>
<state>AR</state>
<state>XX</state>
<state>ZZ</state>


It would be helpful to us to know whether you are satisfied with the
decision taken by the WG on this issue, or wish your dissent from the
WG's decision to be recorded for consideration by the Director of
the W3C.

Regards

Martin Gudgin
XML Schema Working Group

Received on Thursday, 21 September 2000 11:49:50 UTC