- From: Arjun Ray <aray@q2.net>
- Date: Sat, 30 Jun 2001 00:38:58 -0400 (EDT)
- To: www-talk@w3.org
On Fri, 29 Jun 2001, Ian Hickson wrote:
> On Thu, 28 Jun 2001, Arjun Ray wrote:
>> (Personally, I think Dr. Goldfarb was right when he proposed "External
>> Subset Considered Harmful" for XML. This message is not publicly
>> available because the W3C continues to keep the XML-SIG archive under
>> wraps in the Members Area of lists.w3.org.)
>
> And presumably because Dr. Goldfarb hasn't thought it important
> enough to republish it in a public context (?).
Well, even though it was a considered opinion, the issue is moot now.
IIRC, the subject at the time was whether element declarations ought
to be allowed in XML internal subsets, the difficulty being that
parsing content models would mean significant overhead for lightweight
non-validating parsers, and thus the implication being that some kinds
of declarations would have to be only in external entities. Well,
that was a long and involved discussion, but whichever side one took
it still didn't follow that XML needed the syntactic sugar of an
external identifier in the document type declaration itself. Given
that the canonical form of a document type declaration involves only
an internal subset (with references to external entities, of course),
eliminating the external subset special syntax would
1. Simplify parsing by eliminating an unnecessary variant form.
2. Allow a single set of rules for declaration processing, based on
declaration type and provenance in an external entity, without
any need for special casing (including the lexically non-obvious
one that the "special" external subset is processed last.)
I don't recall any objections other than those based on the status of
element declarations (which was in doubt at the time), but in the
event, the external subset syntax remained in the XML spec.
Oh well, no one said the XML spec was perfect;)
Arjun
Received on Saturday, 30 June 2001 00:23:58 UTC