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Re: SD5 - Namespaces

From: Peter Murray-Rust <Peter@ursus.demon.co.uk>
Date: Thu, 22 May 1997 09:12:58 GMT
Message-Id: <7064@ursus.demon.co.uk>
To: cbullard@hiwaay.net
Cc: w3c-sgml-wg@w3.org
In message <33838EA3.241D@hiwaay.net> len bullard writes:
> Peter Murray-Rust wrote:
> > 
> > In message <libSDtMail.9705201713.542.altheim@mehitabel> altheim writes:
> > > > > It isn't essential to have the ':', but it's much less elegant without it.
> > > >
> > > > You can have it.  You have to declare it. XML as with SGML doesn't
> >     ^^^^^^^^^^^^^^^   ^^^^^^^???^^^^^^^^^^^^
> > I don't think I *can* have it unless the ERB says so (productions [3]-[6]).
> > How would I declare it?
> 
> Unless I missed the point, you are saying you want to divide a GI by a
> colon 
> to provide and application with a morphology for a namespace.  My

Yes.  I want to write things like <CML:VAR> and <MathML:VAR> in the same
document.  My reading of the spec was that these are Names [5] and that the
only currently allowed chars in names are Letters, Digits, '.', '_' and '-'.
So I would like ':' added to the list of MiscName.  I need the ERB's 
blessing for that, because parsers are written to the current spec.  I can't
use an SGML declaration (and wouldn't even if I could, because my community
would rebel!).

Whether it goes further and there is a formal definition of name as
Name ::= (Namespace ':')? ShortName 
or something similar I leave to the ERB.

Whilst on this topic, I read MartinB's post about namespace.  Obviously if
a WG8 solution is going to emerge it will be thought out to apply beyond the
confines of XML.  If possible, XML should then try to adopt it.  Not being 
familiar with WG8 processes and timescale I have no idea how long Martin's
mechanism would take.  I believe that Martin's approach would require
amendments to SGML (?) so isn't adoptable tomorrow.  It would also require
very significant amendments to current XML and parsers.

The colonic approach is implementable today with no changes other than [3],
and minor tweaks to the parsers.  I am not prescribing any semantics for the
use of colon, and semantics don't concern the parsers, but editors
and applications.  If we don't get the colon, then we shall probably use 
some other characters like:
	<CML--VAR>
which is currently legal XML.

As Len and others have pointed out, we have to address the namespace or
DOCTYPE becomes as useful as it is in HTML :-(.  We are not addressing the 
people who produce tag soup like

<Q> What did Queen Victoria say?</Q>
<A> <Q>We are not amused</Q>, see <A HREF="home.html"> my Home Page</A></A>

but those who already have DTDs and where both the syntax and the semantics
have to be precisely identified.

	P.

-- 
Peter Murray-Rust, domestic net connection
Virtual School of Molecular Sciences
http://www.vsms.nottingham.ac.uk/
Received on Thursday, 22 May 1997 06:10:16 UTC

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