Re: XML Core WG requests comment: control characters in XML 1.1

[ I got three copies of this message, all apparently addressed to the xml-plenary.
  I'm CC'ing this one to the core WG because it seems appropriate ]

/ John Cowan <jcowan@reutershealth.com> was heard to say:
| This is a request for comment from this mailing list (or anyone else)
| on a proposal by Shigemichi Yazawa for a standard representation for
| the Unicode control characters that are not legal in XML 1.0.  See
| http://lists.w3.org/Archives/Public/www-xml-blueberry-comments/2002May/0000.ht
| ml
|
| In essence, this provides an element "<xml:orphanedChar value="#x0001">"
| which can be used *by convention* in place of an actual (and illegal) #x1
| character.  The Infoset would view this as an element, not a character; it
| would not be usable in attribute values; it is not fully general-purpose.
| It would also require explicit declaration in schema languages, unless
| they were modified to ignore it; even then, an element with an XSD
| datatype would not be able to use this feature.

I think this proposal overlaps significantly with similar proposals
for supporting what are colloquially called "character entities" in
environments where entity declarations are unavailable or tedious to
provide.

One possibility would be to extend this proposal so that it covers the
"character entity" cases. For example, by allowing <xml:orphanedChar
name="UNICODE CHARACTER NAME"/>. The really adventurous might also
suggest allowing entityname='eacute' (adopting the "standard" ISO
character entity names).

This adds significant complexity and I expect such a proposal would
have determined opponents. On the other hand, I'm afraid that
accepting the xml:orphanedChar proposal as is would make it even
harder to justify a subsequent "named character" variant. On that
ground, I'd be inclined to oppose it.

| An alternative proposal is to use a processing instruction such as
| "<?xmlchar #x1?>", which would be invisible to schemas.  A little *too*

No! :-)

                                        Be seeing you,
                                          norm

-- 
Norman.Walsh@Sun.COM   | A great deal may be done by severity, more by
XML Standards Engineer | love, but most by clear discernment and
XML Technology Center  | impartial justice.--Goethe
Sun Microsystems, Inc. |

Received on Saturday, 11 May 2002 07:36:43 UTC