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Re: What is the difference between a "struct" and an "array" in the e dge case?

From: Marc Hadley <marc.hadley@sun.com>
Date: Tue, 02 Jul 2002 14:57:29 +0100
Message-ID: <3D21B149.9070909@sun.com>
To: Jacek Kopecky <jacek@systinet.com>
CC: Kevin Johnsrude <kevinj@roguewave.com>, xml-dist-app@w3.org

Jacek Kopecky wrote:
>  Marc,
>  the way I was reading that text was that "if, when accessing the
> compound type, the edges are accessed by their label only, the
> element qname is the label. If they are accessed by position, the
> label is ignored and so is the element qname then." Basically,
> "distinguishing between accessors" I understand as "what I use to 
> get one of them", not "how are they different".
>
Hmmm, I think we may have stumbled on an issue here - do you agree ?

Regards,
Marc.

> 
> 
> 
> On Tue, 2 Jul 2002, Marc Hadley wrote:
> 
>  > Jacek Kopecky wrote:
>  > >  Marc, Kevin, 
>  > >  I believe that since in array the names are irrelevant, we must 
>  > > not assume that they are the same. The name may be used for type 
>  > > matching (if using some schema validation as suggested in 
>  > > http://www.w3.org/TR/soap12-part2/#encschema ) or it may be 
>  > > generated or (usually) it can be the same (like 'item' or 
>  > > something) but the latter is just one of the options.
>  >  >
>  > Hmmm, thats not my reading of it. The rules in [1] are:
>  >  > "1. For a graph edge which is distinguished by label ("struct" or 
>  > "generic"), the namespace name and local name properties of the element 
>  > information item together determine the value of the edge label.
>  >   2. For a graph edge which is distinguished by position ("array" or 
>  > "generic"):
>  >      * The ordinal position of the graph edge corresponds to the 
>  > position of the element information item relative to its siblings
>  >      * If outbound edges are distinguished only by position ("array") 
>  > then the local name and namespace name properties of the element 
>  > information item are not significant."
>  >  > If the names of the child elements are not the same then the outbound 
>  > edges are NOT distinguished only by position (see 2, bullet 2 above) and 
>  > hence you have a generic rather than an array.
>  >  > I agree that the actual names of the array elements are not significant 
>  > (although, as Jacek notes, they can be used for type matching) but they 
>  > should all be the same.
>  >  > Marc.
>  >  > [1] http://www.w3.org/TR/2002/WD-soap12-part2-20020626/#complexenc
>  >  >  > >  > >  > >  > > On Tue, 2 Jul 2002, Marc Hadley wrote:
>  > >  > >  >  > Kevin Johnsrude wrote:
>  > >  > > In SOAP 1.2, 3.1.2 "Encoding compound values" [1], is there any way to
>  > >  > > distinguish between a "struct" and an "array" that has neither an "itemType"
>  > >  > > nor an "arraySize" attribute?  Note that this appears to be permitted per
>  > >  > > item 3.
>  > >  > >  > IIRC, an array's child elements all have the same name. A struct's child 
>  > >  > elements all have different names. A generics child elements can be a 
>  > >  > mixture of the two.
>  > >  >  > So, for a struct or array with only one child element then its difficult 
>  > >  > to tell the difference without the attributes.
>  > >  >  > Regards,
>  > >  > Marc.
>  > >  >  > > [1] http://www.w3.org/TR/2002/WD-soap12-part2-20020626/#complexenc
>  > >  > >  >  >  >  >  >  >  >  > 



-- 
Marc Hadley <marc.hadley@sun.com>
XML Technology Centre, Sun Microsystems.
Received on Tuesday, 2 July 2002 09:58:06 GMT

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