Again wit da AND and Repetitions

[Terje Norderhaug]

At 5:11 PM 5/14/99, roddey at us.ibm.com wrote:
>>>Does anyone believe that these can be done in less than brute force tree
>search
>>>times?
>>
>>XML requires deterministic content models. This allows validators to do
>>their job without having to look more than one element ahead or do brute
>>force tree searches.
>
>Actually it does not require deterministic models, it just allows you to check
>for them. And, I guess its not really what XML does or does not do that's in
>question here, its what the new upcoming schema spec proposes to do that's at
>issue.

The XML 1.0 specification, 3.2.1 states that:

"For compatability, it is an error if an element in the document can match
more than one occurance of an element type in the content model".

See also Appendix E to the specification, which describes in further detail
what is meant by a deterministic and ambigous content model.

It follows from the definition that a validating XML parser doesn't have to
look ahead. This is important as it simplifies implementing validation.

-- Terje <Terje at in-progress.com> | Media Design in*Progress

   Software for Mac Web Professionals at <http://www.in-progress.com>
   Take advantage of XML with Emile, the first XML editor for Mac.



xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1
To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)