Re: Check out the DCD submission

Peter Murray-Rust (peter@ursus.demon.co.uk)
Tue, 11 Aug 1998 09:21:50


At 16:20 10/08/98 -0700, Tim Bray wrote:
>There's a new IBM/Microsoft submission at
>
> http://www.w3.org/Submission

I assume this is the same document as at:

http://www.w3.org/TR/NOTE-dcd

My comments are directed to the latter.

> fashion as traditional XML DTDs. DCD also provides additional properties,
> such as basic datatypes.

I am primarily concerned with the basic datatypes section 4. I want to use
these (or something like them) in CML, healthcare and so on. I shall
extract this subset of the document and re-use the concepts in JUMBO2.
(Having spent many years weaning myself off FORTRAN, I'm not very excited
by section 4.3 (COBOL pictures) and shan't implement them, but I assume
they meet mainstream database longings. They look awfully like bolting
presentation/formatting into XML which we are told is a Bad Thing.
Shouldn't this be a stylesheet issue?)

I note that max and min have changed from being content to attributes. I
just re-tooled to be XML-data-compatible (<min> and <max> as children of
the element. I used to write my variables like:
<Item min="1.2" max="2.3" title="density" units="Mg m-3">1.8</Item>
but found that things like units were too rich to be a simple attribute. So
I moved, XML-data-like, to having them all as children. I am not convinced
they should be attributes.
Pro:
they are defaulted in the schema
they don't appear in the tree
Con:
they can't (easily) be tailored for each instance because they don't
occur in the document (unless I have the schema mechanism wrong)
they can't be qualified (e.g.
<min helpRef="some-ISO-doc.xml">1.2</min>

>
>I have lots of opinions about it, which can wait for Montreal now. -Tim

We'd be delighted if you feel inspired to answer any queries before then...

P.

Peter Murray-Rust, Director Virtual School of Molecular Sciences, domestic
net connection
VSMS http://www.nottingham.ac.uk/vsms, Virtual Hyperglossary
http://www.venus.co.uk/vhg