Re: [Bug 7198] can inheritable attributes appear, on elements with simple types

Thanks, a lot for the clarification.

The information would be very helpful to me.

On Sat, Aug 8, 2009 at 1:58 AM, C. M.
Sperberg-McQueen<cmsmcq@blackmesatech.com> wrote:
> In connection with bug 7242, reported today, I have just reviewed
> the text of the relevant portions of the spec; I apologize for not
> doing this earlier.  I should have corrected the misimpression
> reported in the second paragraph quoted above:  in reality, as
> currently specified, inherited attributes are visible in the XDM
> instances used to test conditional type assignment, but not in
> the XDM instances used to test assertions.  It's a natural thing
> to think the two cases will be, or should be, treated the same way,
> but for technical reasons the attributes used in tests for
> conditional type assignment are untyped, while the WG elected to
> make the attributes and descendants used in testing assertions
> carry their full PSVI information, including their type assignments
> and validity.  In that context, including inherited attributes
> would introduce some serious complications:  either we would need
> a story about why the type assignments are not consistent from
> one instance to another, or we would need some way to ensure that
> type assignments are consistent.  We were able to resolve bug 5003
> successfully largely because the technique of using untyped
> attributes allowed us to avoid those complications.  (The treatment
> of assertions would have been much simpler, too, if we had used an
> untyped XDM, but the WG chose otherwise.)
>
> So my earlier response to your second question was misleading:
> instead of saying that inherited attributes were designed to
> be useful only for assertions or conditional type assignment, I
> should have said:  really, only for CTA.  (The definition of a
> term for them in the PSVI does not actually make much difference
> in practice, since the information in question has always been
> present in any case:  any attribute among the [inherited attributes]
> of an element is necessarily present among the [attributes] of
> an ancestor element.)
>
> Sorry for not noticing this point earlier.
>
> --
> ****************************************************************
> * C. M. Sperberg-McQueen, Black Mesa Technologies LLC
> * http://www.blackmesatech.com
> * http://cmsmcq.com/mib
> * http://balisage.net
> ****************************************************************



-- 
Regards,
Mukul Gandhi

Received on Saturday, 8 August 2009 10:14:50 UTC