XSchema Spec, Section 1.0 (Draft 2)

[Rick Jelliffe]

> From: Simon St.Laurent in his draft

> DTDs have many well-documented flaws and it is necessary to
> experiment with
> new ideas in schema design.

I strongly object to this sentence.

The "design flaws" of DTDs are not well-documented. In the absense of any
HCI studies in DTDs which might give a scientific veneer, there is the
anecdotes of

1) a lot of people who use them
2) some people who dont use them but use something else (e.g. EDD)
3) a lot of people who have never used anything
4) some people who have never used anything but think they would prefer to
use something else, for cosmetic or intellectual reasons

The use of a specialized syntax in DTDs is certainly not a design flaw. The
use of regular expression syntax in content models is not a design flaw. The
modest functionality of DTDs is not a design flaw. Parameter entities are
not a design flaw.

That sentence is polemical and wrong. Why not say

> DTDs have a limited expressiveness and it is necessary to
> experiment with
> new ideas in schema design.

since that can be agreed on by everyone. The danger is that the mythologies
arise fast, especially in difficult areas like text, which people expect to
be easy but is not.


Rick Jelliffe


xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/
To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)