All the Perl that's Practical to Extract and Report

Shot heard round the 'net

ziggy on 2002-06-05T13:22:39

James Clark has been rather quite of late. There's a good reason for that -- he's been working on RELAX NG, a better schema language for XML than the W3C's XML Schema.

James also makes it clear that XML technologies are a community development effort, not something owned by the W3C.

Here are very significant reasons to avoid XML Schema, regardless of it's parentage, blessing or corporate support:

The definition of validity is so flexible in W3C XML Schema as to seriously impact interoperability. [...] With RELAX NG, this sort of bogosity does not arise: there is a clear, unambiguous notion of validity. If you have a RELAX NG schema, there is no doubt about what instances are valid.

The role of a schema in a specification is to serve as a formalism. How good is a formalism if that formalism itself lacks a proper formal basis?

I often hear people say: "It doesn't really matter that the spec W3C XML Schema Rec is so hard to understand; only W3C XML Schema implementors need to do this". I think this is misguided.

(To be fair, James is asking equal billing for RELAX NG, even though he cites compelling reasons for abandoning XML Schema.)

A brilliant piece

mir on 2002-06-05T15:08:47

James Clark's email is really a brilliant piece. You can tell he is thouroughly po'ed at the W3C and how they push the monstruosity known as W3C Schemas!
I sure hope his weight will help to make people understand that the fact that a W3C blessed committee argued^H^H^H^H^H^Hworked for years on a standard does not automagically mean that the result should be accepted by the marketplace/community without restrictions.

Re:A brilliant piece

ziggy on 2002-06-05T15:16:19

Only time will tell. But my money is on the schema language with a well-defined formal foundation, clear rules, and multiple interoperable implementations (whichever schema language that may happen to be :-).

In other news, I just got called back to revise some courseware I did about XML Schema. Ugh. One final foray into the belly of the beast, I hope.