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Re: XML-* [was: ... XML subsetting...]

From: Tim Bray <tbray@textuality.com>
Date: Wed, 04 Dec 2002 15:57:24 -0800
Message-ID: <3DEE9664.1020001@textuality.com>
To: Paul Grosso <pgrosso@arbortext.com>
Cc: www-tag@w3.org

Paul Grosso wrote:
> I am not sure what I think (though I'm generally skeptical
> about the need to do anything here).  But let me raise
> some of the arguments already raised the last time the
> XML Core WG discussed this.

Good stuff, thanks Paul.

> 1.  Arguments about making XML easier to implement are
> not effective.  

This seems correct, and would not in itself be a reason to do this. 
Although being able to reduce the size/complexity of XML processors is 
unambiguously a good thing.

> 2.  As far as user requirements, it is hard to see how removing
> capabilities from XML can benefit users.  Users use what they
> use, and they might be negatively impacted if you remove some
> feature, but how can they be positively impacted by removal
> of features?

Users of SOAP would benefit because as XML 1.0 is specified they are 
open to a severe and hard-to-resist denial-of-service attack via the old 
billion-laughs scam.  In fact this benefit extends to anyone who wants 
to provide a high-performance wire protocol using XML.

> 3.  As far as adding features, the (only somewhat facetious)
>     argument goes like this:
>   a.  Any attempt to develop an XML 2.0 will realistically
>       take at least two years from start to Rec, and that
>       only if you select only the most crucially needed
>       features to add (and that doesn't include getting
>       wide and interoperable implementor support).
>   b.  Any feature that can wait two+ years can't be needed so 
>       badly as to be crucial enough to consider it as a possible
>       addition to XML 2.0.

I think those are excellent arguments and not facetious at all.  So my 
personal proposal (*not* speaking for the TAG) is that this project be 
strictly forbidden from adding any new features whatsoever - one is too 
many - beyond those that are in XML 1.1, namespaces 1.1, the infoset, 
and (maybe) xml:base, and strongly encouraged to remove some, in 
particular DTDs.

In response to the problem observed by the XMLP people, there are really 
only three possible responses:

1. You can't legally subset XML so what you're doing isn't XML and we're 
not going to help you
2. We're going to give you a mechanism for subsetting XML
3. We're going to do a new rev of XML that you won't need to subset.

> The last time the WG discussed this, we were very far from
> consensus on what to do or even if we should do anything.  

Up until very recently I would have been one of those counselling inaction.

> Therefore, before spending major time and effort to develop XML 2.0,
> it would be important to get a firm statement from the AC that
> we should invest this effort and what the desired scope/direction
> should be.

s/major/any/, and no kidding. -Tim
Received on Wednesday, 4 December 2002 18:57:27 UTC

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