Re: it is impossible to compare QNames

I'd like to deal with this at the next conf call (Tuesday if possible).
We ought to be able to fix this or provide an sensible answer to 
Matthew.

Cheers

Steve T

On 27 May 2006, at 22:45, Matthew Rawlings wrote:

>
> This is feedback on the WS-CDL Choreography CR of 2005-11-09. I have 
> been
> implementing CDL at a bank and have some questions and feedback on the 
> CR.
>
> The problem I have with the CR is the XML Schema for WS-CDL requires 
> you to
> compare a QName type with an NCName type. This comparison is impossible
> because the QName type does not have equality or ordering defined for 
> it.
>
> Section 4.2 of the CDL specification states that field
> /package/relationshipType/roleType/@typeRef (a QName), must reference 
> the
> field /package/roleType/@name (a NCName). I took this from the text: 'A
> relationshipType element MUST have exactly two roleTypes defined. Each
> roleType is specified by the typeRef attribute within the roleType 
> element.
> The "QName" value of the typeRef attribute of the roleType element MUST
> reference the name of a roleType.'
>
> Please tell me why the datatype QName was used. I have been unable to 
> work
> out why QName was used. QName is normally used to reference elements 
> rather
> than the contents of elements.
>
> I have been assuming the word "reference" is as an equality test as 
> defined
> by XPath 1.0. This should be explicit in the specification.
>
> Looking through the mail-list examples (e.g.
> http://lists.w3.org/Archives/Public/public-ws-chor/2005Sep/0001) it 
> seems
> that QName and NCName are being used in the style of xs:ID and 
> xs:IDREF. Why
> not just use xs:ID and xs:IDREF? This would also have the benefit of 
> making
> the constraint that a typeRef must reference a roleType name explicit. 
> Both
> xs:ID and xs:IDREF are subtypes of xs:NCName.
>
> At the very least typeRef and roleType should be some type of string 
> that is
> comparable, otherwise references cannot be tested.
>
> Matthew Rawlings
> +44 791 539 7824
>
>
>
>
>
>

Received on Monday, 29 May 2006 19:25:56 UTC