[DPF] Is the order of children important

Hi Jeremy and Mark,

This message contains a response to comments on

http://www.w3.org/TR/2004/WD-DPF-20041122/

Is the order of children important

Our RDF graph differs from Figure 2 in that no ordering is given  
between the sibling IBM:GPS and NOKIA:GPS elements. This seems to us  
to be a better design. Most of the time ordering is artifactual. e.g.  
an x,y coordinate pair <x>4</x> <y>5</y> describes the same point as  
<y>5</y> <x>4</x> since the ordinates are labeled. Application code  
that relied on the x coordinate coming before the y coordinate, by  
for example, getting the first and the second children, rather than  
the x child and the y child, would, in our view, be broken. (e.g. it  
would not work if there was a new child labelling the point with a  
string given as the first sibling).  In the (relatively few) cases  
where ordering is important then making the tree deeper to express  
this seems appropriate. e.g. an rdf:Seq construct can be used, with  
properties rdf:_1 rdf:_2 rdf:_3 ... for the first, second, third values


Ordering is not important. Text has been added to Section 2 Point 6  
as follows:

The DPF component does not guarantee the order of properties.

In addition, order of DPFPropertyList is not guaranteed either.

-Keith Waters

Received on Monday, 6 June 2005 21:57:49 UTC