[Prev][Next][Index][Thread]

Re: D.1 Distinguish partial and full DTDs?



At 5:23 PM 10/29/96, Michael Sperberg-McQueen wrote:
>On Fri, 25 Oct 1996 12:05:01 -0400 Tim Bray said:

>>More concisely, I do *not* favor partial DTD's in the context of
>>validation.
>
>It seems to me this means we need to know whether something is in
>fact a partial DTD, or is (intended to be) a full DTD.

>snip snip...

>In the one case, having an element with an unknown GI is an error
>and should be flagged as such by any validating parser.  In the
>other case, such an element is the normal state of affairs and it is
>senseless to try to validate the document:  an ideally helpful
>system would say "Er, it's pointless trying to validate this, it
>only has a partial DTD" rather than issuing a few hundred error
>messages.  But no system can know which to do unless it can
>distinguish a full DTD from a partial DTD, i.e.  unless there is
>something in the document to say "This set of markup declarations is
>complete" or "This set of markup declarations is not complete".
>
>So, I think the answer to the original question is, Yes, there
>should be an XML parameter entity to indicate whether the DTD
>given is a full DTD (as for SGML) or a partial DTD not intended
>to make the document valid (probably, in practice, intended only
>to make it well-formed).

Or, we can avoid any feature that would make this distiction necessary. So
we have _no declarations_ or a _full DTD_. This is why I favor some
distinctive syntax for empty elements (any of the possibilities will do). I
can't remember what other sticking points there are to eliminating the
notion of partial DTDs.

Oh, yes, entities. If we allow transclusion semantics, browsers can treat
an undefined entity as a broken link, in the same way they treat a broken
grapic now... This is another reason I think that unresolved entities are
natural.
Or undefined entities can be an error in a DTD- and subset-less document.
BTW what is happening with the subset?

   If we need "partial DTDs" couldn't we implement them more nicely as
subsets to empty doctypes (which in this case would add value for the user,
by letting them declare entities). A subset without a DTD would be
well-formed, whatever declarations it contained.

   -- David

RE delenda est.
I am not a number. I am an undefined character.
_________________________________________
David Durand              dgd@cs.bu.edu  \  david@dynamicDiagrams.com
Boston University Computer Science        \  Sr. Analyst
http://www.cs.bu.edu/students/grads/dgd/   \  Dynamic Diagrams
--------------------------------------------\  http://dynamicDiagrams.com/
MAPA: mapping for the WWW                    \__________________________
http://www.dynamicdiagrams.com/services_map_main.html