Re: Re PEs

On Jun 10,  8:33pm, Terry Allen wrote:
> Subject: Re: Re PEs
> Michael responds:
> | >for SGML DTDs increases without bound.  If I need to maintain
> | >my DTD in SGML even when I'm going to output XML, why do I
> | >need an XML DTD?  Would it not be simpler to eliminate DTDs
> |
> | I don't know about you; I need it because I would like to maintain my
> | documents in XML, rather than maintaining them in Full SGML and
> | down-translating at publication time.  That means I need an XML DTD for
> | validation, etc., all the things Len mentioned.
>
> It might be easier to build a reliable SGML>XML translation tool,
> use only SGML DTDs, produce SGML instances, and filter to XML.
>
Or might it not be better to constrain your DTDs so all conforming documents
are also Well Formed XML?  Then you don't need to filter, and you're always in
XML land unless you really need to validate.  We've always had the assumption
that validation will be required far less than WF.

If we take this approach we can split the DTD issue into 2 pieces:

1) DTDs for generating and validating documents
2) The DTD subset needed for WF checking and other processing (but also still
sufficient for small, simple DTDs - with training wheels)

There should be a deterministic means to translate 1->2.

The first kind of DTD is mostly server-side for generating documents.  It would
only be transmitted to the client on request.  It is not required to conform to
the MGSW (maybe we should say WF in a week, Valid in a fortnight) and can
include all the bells and whistles a DTD designer needs while remaining in the
WF category (i.e, no SHORTREFs).  Since we're keeping the XML lexing model
simple, this would still be a lot easier than a full SGML DTD parser.

> | >The question "why not eliminate DTDs from XML entirely" is a
> | >serious one, as are all my questions, and I expect a response
> | >to it from the SGML ERB.
> |
> | This is not to be taken as an official response from the ERB.
>
> Understood, but it is a response from an ERB member, and that's all
> I ask for.  Thanks and good luck.

Obviously document producers have different requirements than consumers.
Does making this distinction help?

Matthew Fuchs
matt@wdi.disney.com

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Received on Wednesday, 11 June 1997 12:38:22 UTC