Parser compliance

Simon St.Laurent simonstl at
Thu Nov 18 13:34:04 GMT 1999

At 10:59 PM 11/17/99 -0800, Eric Bohlman wrote:
>On Wed, 17 Nov 1999, Richard Lanyon wrote:
>> Not from me, that's for sure. But if people want validation from their XML
>> processors (and people do, it would seem, possibly because so many XML
>> books spend so much time talking about validity and DTDs), then we'd
>> better give it to them or someone else will...
>It seems to me that the reason why books and articles talk about
>validation so much is the journalists and authors have gotten the idea
>that it's important; if you believe the articles, the primary purpose of a
>parser is to determine whether or not a document is valid (that idea may
>be the result of a surface exposure to parsing theory, since an abstract
>parser is in fact a language recognizer).

I think that a large part of the reason book and article writers have
focused on DTDs is their large (and relatively difficult) place in the XML
1.0 specification and the need to explain to people some kind of
technical-sounding 'how' of creating new vocabularies.

In my latest book (not yet published), I spent a lot of time talking about
things like notations, parameter entities, unparsed entities, and all the
'black art' stuff involved in DTDs and validation.  I covered the material
in that kind of depth not because it's in massive demand (as far as I can
tell) but because it's typically under-covered in other XML books,
including several of my own.

On the other hand, I spent a lot of time explaining the need to create
human-readable documentation for XML, whether or not it uses validation,
and about the kinds of things XML developers need to make clear to all
programmers implementing their work - like whether or not external
entities, external DTDs, and namespaces will be used.  I also closed with a
description of a markup universe where DTDs and schemas are ignored
completely, and information is passed on a role-to-role basis without any
master plan or concern for validation.  Both approaches are equally
plausible (to me) as ways around the pros and cons of DTDs and the
varieties of parsers available.

Simon St.Laurent
XML: A Primer, 2nd Ed.
Building XML Applications
Inside XML DTDs: Scientific and Technical
Sharing Bandwidth / Cookies

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at
Archived as: and on CD-ROM/ISBN 981-02-3594-1
To unsubscribe, mailto:majordomo at the following message;
unsubscribe xml-dev
To subscribe to the digests, mailto:majordomo at the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at

More information about the Xml-dev mailing list