[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Re: XSLT2 - which parts solve real 1.0 problems,which make
On Fri, 2004-12-31 at 15:27 +1100, Dimitre Novatchev wrote: > One has to realize that error raising/handling in a functional language is > essentially nondeterministic and much more challenging as such. XPath 1.0 > compatibility would also be very problematic, as there's almost no such > thing as raising an error in XPath 1.0. I don't understand. There are some errors defined for XPath 1.0, e.g. using a namespace prefix that is not declared in the context. Side note: the example in Mike Kay's saxon:try extension seems to intimate that 1 div 0 is an error, which it isn't: it's just Inf. The spec does not say how implementations should deal with such errors (correctly so), but there are errors defined. > More on implementing exceptions in a functional language can be found in the > classic work of Simon-Peyton Jones "Tackling the awkward squad: monadic > input/output, concurrency, exceptions, and foreign-language calls in > Haskell", at > http://research.microsoft.com/Users/simonpj/papers/marktoberdorf/ > > While I actually made some successful experiments 1 1/2 years ago, it seems > too early to expect these in XSLT. My predictions (which are typically > optimistic) are for HOF support in XPath/XSLT 3.0 and try/catch-type error > handling in XPath/XSLT 4.0. I appreciate this caution, but I think that providing error handling declarations, dynamic evaluate and higher-order-functions in XSLT 2.0 would have been much more useful than any of the things that did make it in. I find Mike Kay's recounting of the history of the try/catch idea very interesting as an illustration of how close integration with XQuery proved detrimental in the development of XSLT and XPath 2.0. -- Uche Ogbuji Fourthought, Inc. http://uche.ogbuji.net http://4Suite.org http://fourthought.com Use CSS to display XML - http://www.ibm.com/developerworks/edu/x-dw-x-xmlcss-i.html Full XML Indexes with Gnosis - http://www.xml.com/pub/a/2004/12/08/py-xml.html Be humble, not imperial (in design) - http://www.adtmag.com/article.asp?id=10286 UBL 1.0 - http://www-106.ibm.com/developerworks/xml/library/x-think28.html Use Universal Feed Parser to tame RSS - http://www.ibm.com/developerworks/xml/library/x-tipufp.html Default and error handling in XSLT lookup tables - http://www.ibm.com/developerworks/xml/library/x-tiplook.html A survey of XML standards - http://www-106.ibm.com/developerworks/xml/library/x-stand4/ The State of Python-XML in 2004 - http://www.xml.com/pub/a/2004/10/13/py-xml.html
|
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|