enumeration and defaults

[Tim Bray]

At 10:06 AM 9/14/99 -0400, John Cowan wrote:
>And so I do.  I must say that I can see no possible reason for
>distinguishing, in an enumeration context, among not-present and
>null-string.  In a CDATA context, yes, because the zero-length
>string is a perfectly legitimate string distinct from logical null.

Well, except for detecting the not-present condition requires that your
software carry around the knowledge that this element foo could have had
a bar attribute but didn't, and treating that as equivalent to null-string.
Which is significant extra work.  Which leads me to think that legalizing
declarations like

<!ATTLIST foo bar (important|irrelevant|)>

would make a real difference.  Mind you, I don't hear mobs with pitchforks
in the streets crying for this... -Tim

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)