XML and SML

[Rick Jelliffe]

From: Don Park <donpark at docuverse.com>

>I don't think the SML discussion is taking attention away
>from XML Schema discussions.  Why all the hostility, Rick?

I apologize to Don Park: there was no intention to be discourteous.

SML is a well-trodden path.

I first put out a grammar on comp.text.sgml for a simplified SGML
sometime about 1994 which I recall (I don't want to embarrass myself by
reading it) was pretty similar to what Don is suggesting, probably
SMLwith simple DTDs.  And there were several other, better efforts
around at a similar time.

At the time, Charles Goldfarb contacted me over it, and he gently
pointed out that however much SGML needed simplificiation or revision,
it had to come from credible grassroots demand and work, respecting the
generic markup principles behind SGML. In the fullness of time, that
came about through Jon Bosak and W3C, and everyone knows that the ISO
working group welcomed it (indeed, XML is incorporated into ISO 8879
through Annex L).

And, as for whether SML is a distraction from XML schemas, how many
postings have there been on XML-DEV about the structure drafts?  There
have been a couple of good ones about the datatypes, but not on the
structures, that I recall.  I predict that the moment that the XML
Schema becomes a recommendation, this mailing list will bustle with
well-reasoned calls for  simplified XML Schema--alas too late.

> Is And Borenstein's markup language XML?
> SML is and I believe it makes a difference.

The spec for text/enriched can be found at
        ftp://ftp.isi.edu/in-notes/rfc1563.txt
It has well-formed tags, a handful of pre-defined elements, the notional
top-level element must be omitted, and the notional paragraphs start tag
is (if we treat it as SGML) shortreffed to a blank line. If Don wants to
persue SML to standards-level, then one strategy could be to integrate
it with text/enriched: you could upgrade that so that if the
text/enriched document starts with a start-tag or comment, then it uses
the SGML rules other wise it uses the current text/enriched rules.

Another approach you could take for SML is to integrate it with a
short-tag system.
I have two small C utilities at http://www.sinica.edu.tw/~ricko/src/
that may be of interest.  The first short-tag-compress.c    compresses
an XML file using shorttag ommission.  The file short-tag-uncompress.c
uncompresses the file. (I wrote them to claims about verify XML's
behaviour w.r.t. deflate compression.) There is the  kernel of a very
simple XML in them it. (B.t.w., my results were that probably it would
be useful to use shorttag ommission on an XML document because even
though there was only a small effect when combined with compression, the
result was that more information would make it into the vital first
packet-group; the first group is important because it may contain link
in headers: the earlier these resources can be requested, the better the
perceived performance to the user. And, in any case, the code is so
trivial that even a 1% decrease in filesize might be enough to justify
it.)


Rick Jelliffe



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