Re: [xml-dev] A flexible way to represent trees in XML

[Thomas Passin <list1@tompassin.net>]

On 1/20/2017 11:02 AM, Costello, Roger L. wrote:
> Hi Folks,
>
> As you know, a tree data structure can be represented in XML using
> parent-child relationships.
...
> Lesson Learned: The binary relation representation is a flexible way to
> represent trees.
>
> Caveat: Of course, it is not wise to use binary relations exclusively.
> That would defeat the purpose of XML. Parent-child relationships are
> very useful. So, you might have a part of your XML document where great
> flexibility is needed. That would be a good use of binary relations –
> embedded within a larger XML document. The binary relation contains
> volatile stuff; the other part contains the non-volatile stuff. This way
> you minimize the need for schema changes.
>
> Comments?
Or you could give every node an ID attribute.  Then you can add 
attributes presenting parent and child, which point to other IDs.  By 
adding the right parent/child attributes, you can get the same nodes to 
represent any number of trees, even simultaneously.  The only schema 
changes needed would be the new parent/child attributes.

Roger seems to like to avoid attributes.  But sometimes they make things 
simpler.

TomP