role vs. arcrole

The July 3 XLink candidate recommendation introduces a new arcrole
attribute for arc type elements only, and it forbids the normal role
attribute on arc elements.

However, there really isn't that much difference between role and
arcrole, in fact absolutely nothing as far as an XLink processor is
concerned, so I'm wondering why the two separate attributes?  Both role
and arcrole must contain URIs (though parsers aren;t required to enforce
this). In both cases, the details of how or whether or when an XLink
processor will follow the URI in a role or an arcrole is application
dependent, as is the interpretation of what it does with the document it
finds at that URI.

The only difference I can find between role and arcrole is that the
document at the role URI describes the element whose role it is in some
general sense, whereas the document at the arcrole URI should
(unenforceably) describe the relationship between the two sides of the
arc (e.g. parent-child, employer-employee, etc.).  No details are
provided for what the syntax of these documents should be or how
applications should handle them. 

Given everything that's unspecified I don't see the importance of
distinguishing these two attributes. I propose making XLink simpler by
deleting arcrole and allowing role attributes on arc elements. A
suggestion as to what the role of an arc element should be can still be
provided, but I see no justification for two separate attributes here.

-- 
+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo@metalab.unc.edu | Writer/Programmer |
+-----------------------+------------------------+-------------------+ 
|               Java I/O (O'Reilly & Associates, 1999)               |
|            http://metalab.unc.edu/javafaq/books/javaio/            |
|   http://www.amazon.com/exec/obidos/ISBN=1565924851/cafeaulaitA/   |
+----------------------------------+---------------------------------+
|  Read Cafe au Lait for Java News:  http://metalab.unc.edu/javafaq/ | 
|  Read Cafe con Leche for XML News: http://metalab.unc.edu/xml/     |
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Received on Monday, 10 July 2000 19:07:54 UTC