Re: PIs and RE handling

At 11:45 96/09/12 +0000, (James Clark) wrote:
>> From: Charles@SGMLsource.com (Charles F. Goldfarb)
>> Cc: w3c-sgml-wg@w3.org
>> Date: Thu, 12 Sep 1996 10:14:43 GMT
>I certainly wouldn't advocate using comments to do what PIs do.  But I
>might advocate using elements to do what PIs do, and introducing some
>DTD feature to allow convenient specification of elements that can
>occur anywhere (without the special RE treatment that 8879 gives to
That new kind of element is not now in 8879. Backward compatibility means
that new use can't break the old, but possibly just invoking a warning.
>> If the
>> objective is DTDless parsing, the real problem isn't PIs but included
>> subelements. Without the DTD, there is no way to distinguish them from proper
>> subelements.
>I would hope XML wouldn't have inclusions (at least not as they are in

Agreed. I would retain exclusion exceptions.

>> The net is that this is really a problem with RE handling, not with PIs
per se. 
>So one might argue that the problem is really mixed content, and that
>the solution is to restrict it, by, for example, saying that elements
>- have element content, in which PI, comments and so on would also be
>allowed or
>- have PCDATA content in which elements, PIs, comments are not
>but they can't mix PCDATA with elements, PIs or comments in a single
I like that recommendation.
Without inclusions and mixed content, doesn't PCDATA become a "fixed" RCDATA, 
where the proper matching endtag closes it, not just any ETAGO?