Re: VOTable session @ Interop.Moscow

From: Mark Taylor <m.b.taylor-at-bristol.ac.uk>
Date: Wed, 20 Sep 2006 18:51:21 +0100 (BST)


Alberto,

I agree with most of your comments,

On Wed, 20 Sep 2006, Alberto Micol wrote:

> But I think we should think of the usage of such a VOTable;
> the main aspect is not philosophical or aesthetic satisfaction,
> but a more pragmatic "how the heck will my parser understand what
> is written there"? :-)

especially that one!

About two-way references for linking STC descriptions with FIELDs:

> Why the double reference was not proposed?
> That is, to have both FIELDrefs in the group, and the refs in the
> FIELDs?

It is a possible option, but I would argue against it. If you are saying that references may go either one way or the other, then the parser has to deal with both possibilities, which is harder than just dealing with one. If you are saying that they must go both ways, then you have to decide what to do if/when you come across a document in which the references in the different directions are inconsistent with each other - check for consistency, signal an error, make an assumption about which direction reference to believe, ...? Errors in the document would become harder to track down (some parsers would process a broken document the way the author expected, others would not). We should not make it easy for document authors to write broken documents (they'll find a way even if we make it hard).

> I think that would be useful, and leave more freedom to the parser
> implementors.

Freedom is not always a good thing! As a parser implementor I'd generally rather have a well-defined job that there is only one sensible way of doing than a number of choices about how to go about it.

Mark

-- 
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor@bris.ac.uk +44-117-928-8776 http://www.star.bris.ac.uk/~mbt/
Received on 2006-09-20Z19:51:58