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Michael Kay writes:

> I think it's not so much a question of whether tools implement redefine or
> not, it's a question of whether they handle the corner cases, and how they
> handle the cases that are not well-described in the specification. Exampl=
es
> are whether two schema documents B and C can both redefine A, and under w=
hat
> circumstances those redefinitions can coexist. Or what happens if you loa=
d a
> schema incrementally (for example because of xsi:schemaLocation) and you'=
ve
> already started validating before you encounter a redefinition. Or what
> happens if you are doing something other than straight validation.
>
> I think it would be wise for anyone using xs:redefine to check that their
> usage of it is supported by the tools they consider important in their
> market.

Another way of going forward wrt Eliot's concerns is to observe that
for _non_-corner cases, redefine implementations are in my experience
pretty good and consistent.  If the DITA schema's usage of redefine
doesn't explore the darker corners such as those Mike mentions above
(and it's not hard to stay out of those corners), you should be in
pretty good shape.

ht
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 Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
                     Half-time member of W3C Team
    2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
            Fax: (44) 131 650-4587, e-mail: ht@i...
                   URL: http://www.ltg.ed.ac.uk/~ht/
[mail really from me _always_ has this .sig -- mail without it is forged sp=
am]
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From ekimber@r... Wed Jan 09 13:17:45 2008
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