- From: Michael Sperberg-McQueen <U35395@UICVM.UIC.EDU>
- Date: Tue, 10 Jun 97 18:25:48 CDT
- To: W3C SGML Working Group <w3c-sgml-wg@w3.org>
On Mon, 9 Jun 1997 09:56:15 -0400 (EDT) Bernhard Weichel said:
>Some weeks ago, I raise the question if any well formed XML document can
>be "upgraded" to a valid XML document. Occasionally I was misunderstood
>to raise the question on good or bad DTDs.
My apologies for misconstruing your note.
>So I want to raise the question again with a simple example:
>
>
>
><wellformed>
> <empty, x="foo"/>
> <empty, x="bar">now empty is not empty</empty>
></wellformed>
>
>
>Is this fragment part of a well formed document?
I believe so.
If we preface it with a DTD, it can also be a valid document instance:
<!DOCTYPE wellformed [
<!ELEMENT wellformed (empty+)>
<!ELEMENT empty (#PCDATA)>
<!ATTLIST empty
x CDATA #IMPLIED >
]>
<wellformed>
<empty, x="foo"/>
<empty, x="bar">now empty is not empty</empty>
</wellformed>
The form <e/> is required for all elements declared EMPTY. It is not
necessarily required for all elements which happen to be empty -- but is
certainly well-formed XML and will be valid SGML after the TC allows the
'sole-tag' (<e/>) form to indicate an element with no content.
-C. M. Sperberg-McQueen
Received on Tuesday, 10 June 1997 19:31:28 UTC