James Clark wrote: "RE: - they ought to have be able to structured
values, just like elements (i.e. one could view the content of an
element as a special unnamed attribute), .."
Agreed. Attributes are highly useful as a means to attach metadata or
annotations to elements. Metadata itself may have structure and may
have metadata, hence the utility of structured attributes and attributes
of attributes.
The obvious syntactic device (in a future version of XML) for a
structured attribute is something that looks much like an element, e.g.
<Poem>
<@title>Paradise Lost</@title>
<@author>
<@birth>1608</@birth>
<@death>1674</@death>
John Milton
</@author>
Of Man's First Disobedience and the Fruit
Of that Forbidden Tree, whose mortal tast
Brought Death into the World, and all our woe,
With loss of Eden, till one greater Man
Restore us, and regain the blissful Seat,
Sing Heav'nly Muse ...
</Poem>
