regarding this (old) mail, could you please give details of the current plans (if any) for 2.0 support in Xalan-C ? thanx, -udi-
----- Original Message ----- From: "Henry Zongaro" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, August 28, 2003 4:54 AM Subject: XSLT and XPath 2.0 development > Hello, > > Last year, several Xalan-J developers worked on a prototype > implementation of the XSLT/XPath 2.0 draft recommendations based on the > Xalan-Java Interpretive processor. The work was carried out on the xslt20 > branch of the xml-xalan module. Some preliminary work also began on 2.0 > support for XSLTC. As the developers who worked on the xslt20 branch > began to focus on other projects, nobody was available to carry on that > work, so it has languished for some time. The work was based on older > draft revisions of the recommendations; that, coupled with bug fixes and > performance enhancements on the main branch, has caused the code on the > xslt20 branch to become badly out of date. > > Over the past year, Xalan-J developers have placed a lot of emphasis on > improving XSLTC's level of conformance with the XSLT/XPath 1.0 > recommendations. More recently, there's been a number of significant > performance improvements to XSLTC. The way things currently stand, it > looks like it would be better for future development of XSLT/XPath 2.0 to > resume on the XSLTC code-base. XSLTC has much better performance > characteristics than Xalan-J Interpretive, and it would be much easier to > add missing functionality to XSLTC than it would be either to continue > supporting and developing two very different processors in parallel, > thereby dividing scarce resources, or to develop only Xalan-J Interpretive > and try to catch up to XSLTC in terms of performance. > > If there's significant continued interest in Xalan-J Interpretive, or if > there are things that could be done with the interpretive processor that > just can't be done with the compiling processor, we could look at reviving > XSLT/XPath 2.0 support in Xalan-J Interpretive. But in the short-term and > medium-term, I think that we're more likely to see this work succeed by > focusing on XSLTC. > > Some groundwork for XSLT/XPath 2.0 support in XSLTC has already > begun. In particular: > > . Morris Kwan has been adapting XSLTC to use the JJTree-generated XPath > 2.0 parser, using the AST code contributed by Lionel Villard, that was used on the xslt20 branch - the grammar from which that parser > is derived is generated from the same source as the grammar that appears > in the XPath 2.0 draft recommendation. Scott Boag is bringing the grammar > up to date with the current version in the latest XPath 2.0 draft. > > . Christine Li has begun prototyping support for XPath 2.0 Functions and > Operators. > > . Brian Minchau has begun to look at requirements for serialization in > XSLT 2.0. > > . Joseph Kesselman and Myriam Midy have been working to adapt the Extended > Data Model (XDM) support from the xslt20 branch to XSLTC. That's not > really something that enables XSLT/XPath 2.0 support, but rather opens up > Xalan-J to accepting input from a wide array of sources. > > Very shortly, we'd like to contribute those first pieces of code to > Apache, and publish a prelimary development plan to get us on the path to > XSLT/XPath 2.0 support. There should be plenty of work for all interested > parties! > > In the meanwhile, I'd like to propose that we rename the existing > xslt20 branch to xslt20-interp, and that we create a new xslt20-compiled > branch on which we can develop XSLTC. It will probably take a fair amount > of time before the new development can replace the existing processors, so > I'd propose that we continue to maintain and develop the existing > XSLT/XPath 1.0 processors on the MAIN branch of xml-xalan. At some point > in the future, the community can decide whether to move the new XSLT 2.0 > processor to the MAIN branch. > > Questions, comments, endorsements and objections would be welcomed! > > Thanks, > > Henry > ------------------------------------------------------------------ > Henry Zongaro Xalan development > IBM SWS Toronto Lab T/L 969-6044; Phone +1 905 413-6044 > mailto:[EMAIL PROTECTED]
