- From: <noah_mendelsohn@us.ibm.com>
- Date: Tue, 6 Feb 2007 19:45:37 -0500
- To: "Michael Kay" <mike@saxonica.com>
- Cc: "'Boris Kolpackov'" <boris@codesynthesis.com>, ccodere@ieee.org, "'Pete Cordell'" <petexmldev@tech-know-ware.com>, xmlschema-dev@w3.org
Michael Kay writes: > On the other hand, it might be that everyone ends up > implementing the whole > of XPath 2.0 because it's too much of a pain to implement a > subset. That's > certainly what I intend to do. Everytime something like this comes up our community winds up rediscovering or rediscussing the same tradeoffs. I think it's worth pointing out that the above point, while very important in some contexts, is less pertinent in others. In particular, if you're in an environment where you have or can conveniently integrate an existing full function XPath implementation, then you're right. Providing the full XPath not only gives users a richer capability, it may be easier for the implementer. Conversely, if you're in an environment in which the existing XPath implemenations aren't appropriate for one of the many reasons existing implementations sometimes can't be used (e.g. performance, packaging, licensing, implementation programming lanuage, error handling or reporting model, if evaluation is to be type aware, whether type information can be conveniently conveyed from your validation framework to the XPath implementation, etc., etc.) then requiring the full XPath language is indeed a significant implementation task. It's also more function to test, and whether one can just "trust" the testing done against an existing XPath implementation is a maybe. So, I don't think there's one answer that's clearly the right one for everyone: you can make good cases both for and against full XPath 2.0, limited subset, or some sort of variability. A related debate has to do with whether evaluation should be type-aware. -------------------------------------- Noah Mendelsohn IBM Corporation One Rogers Street Cambridge, MA 02142 1-617-693-4036 --------------------------------------
Received on Wednesday, 7 February 2007 00:43:51 UTC