- From: T.V Raman <raman@google.com>
- Date: Tue, 19 May 2009 10:50:27 -0700
- To: noah_mendelsohn@us.ibm.com
- Cc: ashok.malhotra@oracle.com, timbl@w3.org, raman@google.com, www-tag@w3.org, David_E3@VERIFONE.com, cmsmcq@w3.org, holstege@mathling.com, mike@saxonica.com, sandygao@ca.ibm.com, ian@w3.org, shh@us.ibm.com
Noah, The sentiments you express in this case --- "There's no way I'm going to spend years working in the W3C if ..." are shared by those who invested many years of their lives working on XHTML "because --- in 1998, at the `future of html workshop', W3C declared that as the *future direction*". Glad to see that in this case you appreciate a point of view that is shared with you by a large portion of the XHTML/clean-markup community. Incidentally, the questions Rick asks about XSD if answered would be a far less revolutionary change than abandoning clean,well-formed markup in favor of TAAG-soup. noah_mendelsohn@us.ibm.com writes: > (I'm writing here as a TAG member, not as chair) > > Ashok Malhotra wrote: > > > I have some trepidation about this line of reasoning which would > > seem to be: XML Schema is widely used, therefore it is good and > > should continue! > > I have some trepidation about what's going on here, but for somewhat > different reasons. After XSD 1.0 went to Recommendation, the XML Schema > Working group was rechartered (more than once, FWIW). Here are some > quotes from the latest charter [1], under which the Candidate > Recommendation [2,3] has been published: > > "The XML Schema working group will maintain and revise the XML Schema > specification developed beginning in 1998 and published as a W3C > Recommendation on 2 May 2001. " > > [...] > > "Goals: to finish publication of version 1.1 of the XML Schema > Recommendation, which corrects known errors and makes modest improvements > to the language, and do preparatory work for a possible version 1.2. > Changes in function or syntax incompatible with XML Schema 1.0 have been / > will be made only if the resulting improvements compellingly justify the > loss of interoperability with existing systems and documentation. Some > substantive changes have been made in the interests of aligning version > 1.1 with the needs of the XML Query 1.0, XPath 2.0, and XSLT 2.0 family of > specifications and with XML 1.1. Requests for substantive changes may also > come from other groups. [plus other goals not quoted]" > > Now, spurred by Rick Jelliffe's request [4], we're asking a question that > boils down to: "shouldn't the W3C cancel this effort to provide > incremental improvements to Schema 1.0, and instead start on a new, > cleaner language?" > > I strongly believe that this is a question that should have been settled, > and indeed was settled, when the working group was chartered with the > above goals. The charter very clearly says: build on the XSD 1.0 base, > and to the extent possible, retain syntactic compatibility. (There is a > later goal that allows for experimentation with new syntax too, but that's > in addition to not instead of enhancing the existing syntax; nowhere is a > brand new language core discussed.) The W3C membership has every > opportunity to provide guidance on the content of such charters, and the > time to consider proposals for a new language would have been when the > charters were written. > > To change the goals of an effort like this now is not only counter to the > letter of the W3C process, it's hugely disruptive both in this particular > case and as a precedent. There's no way that people like me are going to > devote years to working in the W3C, toward agreed goals, if at the end we > say: never mind, those weren't the goals. > > Rick raises some interesting and important technical points about XSD. No > doubt it has shortcomings, though I don't necessarily agree with all that > he lists. I also think XSD has some strengths, which he tends to > de-emphasias, and FWIW the other languages have their own shortcomings, > but my point here is not to claim that XSD is better, or that if I were > starting from scratch I might not look very hard at just the technical > direction that Rick proposes. The fact is that most of these concerns > have been understood in general for a long time and Rick among others has > raised them for a long time. Most of them were understood when the > decision was made to create a charter that would focus on improving the > experience of the many users who have adopted the W3C XML Schema > Recommendation. We, the W3C, decided to invest in maintaining and > enhancing a Recommendation that was being widely adopted. > > Indeed, evidence is clear that there is very widespread use of XSD, > arguably extraordinarily widespread use of XSD, and so lack of adoption is > in no way a reason to revisit the charter goals now. That is, IMO, the > only reason we are in this thread considering relative rates of adoption > of these languages at all. The fact is that XSD 1.0 is very widely used, > and XSD 1.1 is designed to make the language more valuable for the many > users who have invested in it. XSD 1.0 is also a W3C Recommendation, and > while I have no problem with the W3C considering alternative languages on > the merits from time to time, the presumption should be that we support > and maintain our Recommendations, and that we honor our agreed charters. > > Noah > > P.S. The question of which schema languages are how widely used remains an > interesting one, and if I turn up any useful facts based on my inquiries > in IBM [5] I will pass them on. So far, all the evidence I've seen > suggests that XSD is more widely used than the other languages by many > measures, and by quite a significant margin, though there are interesting > communities that strongly prefer RelaxNG and/or Schematron. There appear > to be more .xsd documents accessible on the Web; I believe XSD is used by > more widely-deployed tooling; and preliminary investigations suggest that > XSD is used normatively by more "vertical" XML standards (some using XSD > alone, and some using XSD+Schematron) than the alternatives. Of course, > XSD also forms the type system for W3C XML Query, XSLT 2.0, and XPath 2.0. > As I say, I'm still trying to check the facts on those adoption claims, > and I'll pass on what I can. > > [1] http://www.w3.org/2006/06/XML/schema-wg.html > [2] http://www.w3.org/TR/2009/CR-xmlschema11-1-20090430/ > [3] http://www.w3.org/TR/2009/CR-xmlschema11-2-20090430/ > [4] http://lists.w3.org/Archives/Public/www-tag/2009May/0021.html > [5] http://lists.w3.org/Archives/Public/www-tag/2009May/0046.html > > -------------------------------------- > Noah Mendelsohn > IBM Corporation > One Rogers Street > Cambridge, MA 02142 > 1-617-693-4036 > -------------------------------------- > > > > > > > > > ashok malhotra <ashok.malhotra@oracle.com> > Sent by: www-tag-request@w3.org > 05/18/2009 07:05 PM > Please respond to ashok.malhotra > > To: "T.V Raman" <raman@google.com> > cc: www-tag@w3.org, (bcc: Noah Mendelsohn/Cambridge/IBM) > Subject: Re: XML Schema usage statistics (WAS: Draft > minutes of 2009-05-12 TAG weekly) > > > I have some trepidation about this line of reasoning which would seem to > be: > XML Schema is widely used, therefore it is good and should continue! > > I think we need to ask some more nuanced questions. For example > 1. Clearly all the statistics are based on Schema 1.0. Are the > additions in 1.1 beneficial, necessary or excess baggage? > Should the Schema WG be rechartered to add yet more features. > 2. Is there a core subset of features in XML Schema that is heavily used > and can be isolated? If so, should we consider a profile? > > I'm sure you smart folks can think of other good questions! > All the best, Ashok > > > T.V Raman wrote: > > It would also be enlightening to find out how many of those XSD > > files were generated from rng/ files. I know for a fact that many > > groups inside W3C routinely produce their obligatory xsd schema > > for their specs by first creating rng files. > > > > Julian Reschke writes: > > > Paul Cotton wrote: > > > > From the draft May 12 TAG minutes: > > > > > > > >> raman: XML Schema hasn't worked out very well. I'm skeptical that > it > > > > really dominates > > > > ... > > > >> timbl: Skeptical about preponderance of XSD usage, would like to > see some > > > > figures > > > >> noah: Any volunteers? > > > >> (silence) > > > > > > > > Searching Google code for .xsd files ( > http://www.google.ca/codesearch?hl=en&lr=&q=file%3A.*%5C.xsd%24) finds > 44,800 files. > > > > > > > > Searching Google code for .rng files ( > http://www.google.ca/codesearch?hl=en&lr=&q=file%3A.*%5C.rng%24) finds > only 3,000 files. > > > > > > > > Not necessarily a reliable survey but it certainly indicates that > in publicly visible code stores indexed by "Google code" .xsd file > occurrence is significantly greater than that of Relax NG files. > > > > > > > > Personal opinion: I expect that the ratio in enterprise systems > whose code stores are not visible to a tool like "Google code" that this > ratio would be even more slanted towards XML Schema. > > > > > > > > /paulc > > > > ... > > > > > > Plus ~1000 in RNC (Compact) format. > > > > > > It would be interesting to have a comparison of the # of > specifications > > > that use XSD, RNC, or RNG as part of the spec text. > > > > > > BR, Julian > > > > > > -- Best Regards, --raman Title: Research Scientist Email: raman@google.com WWW: http://emacspeak.sf.net/raman/ Google: tv+raman GTalk: raman@google.com, tv.raman.tv@gmail.com PGP: http://emacspeak.sf.net/raman/raman-almaden.asc
Received on Tuesday, 19 May 2009 17:52:16 UTC