A view from the hill

Gary King discusses some issues of XSLT. He concludes:

I still feel as if there is less here than meets the eye; that it ought to be possible to express these graph-transformations more elegantly and with less fuss and bother.

To me, the only interesting part of XSLT isn't XSLT itself, it's the embedded XPath where XSLT's power comes from. XPath is a pair of scissors for cutting out the nodes of an XML document instance you're interested in and is about as powerful (and hence horrible to get right) as regular expressions (although it's something completely different, of course). XSLT is just the framework which provides a relatively boring set of instructions and control-flow operations. And it's "clean functional" design only gets in the way every so often. Sure, coming from a Prolog and Lisp background, I know all the tricks to work around the hassle, but quite often it would be way easier to just set that damned variable *again*. If I want to do clean functional programming, I know where I can find a language without that XML syntax, thanks. Give me the unclean intermix of programming styles offered by Common Lisp anyday, please.

Being a Lisp guy just like Gary, I would be happy to use a language with parenthesis, as I have to do XML transformations quite often and the intermix of elements from different namespaces (XSLT namespace and target namespace) is mostly a pain to read and write. Using xslide, an Emacs mode for XSLT, eases the pain a considerable bit, but it still isn't really fun. And sometimes I need to hack XSLT in a proprietary system which only provides editor capabilities that know nothing about XML (think notepad-style editing capabilities) and then XSLT suddenly has the next most horrible syntax imaginable. However, the corporate world has its own rules and to be fair, the major benefit of XSLT is that you have one standard syntax for XML transformations rather than having xyz numbers of incompatible library APIs.

Update: Also in response to Gary, David Lichteblau pointed out his approach to (macro-)pre-processing XSLT stylesheets to overcome some of Gary's problems.

So ärgerlich das ist, dass man in letzter Zeit immer mehr schwachsinnige Politikerideen per Gerichtsurteil kippen muss, muss man doch dankbar dafür sein, dass es diese Möglichkeit a) überhaupt gibt und es b) auch noch genügend Bürger gibt, die nicht jeden Unfug mitmachen. Aktuelles Beispiel: Verwaltungsgericht Mannheim stoppt Französisch-Zwangsunterricht an Gymnasien. Geklagt hatten wohl ein Vater und Sohn aus der Elterninitiative in Karlsruhe. Herzlichen Glückwunsch!

Was hat uns die vergangene Woche gebracht? Einen Vorschlag, im Bio-Unterricht die biblische Schöpfungsgeschichte zu lehren, etwa.

Die Gesetzesverabschiedung zur Illegalisierung von normalen Tätigkeiten von Systemadministratoren müsste eigentlich den Fachkräftemangel in der IT-Branche demnächst kräftig erhöhen.

Und dann mal wieder eine Diskussion über die Vorratsdatenspeicherung, mit Ausnahmen für, nein, nicht für Ärzte oder Rechtsanwälte, sondern für Geistliche und Abgeordnete. Man glaubt es nicht, und das ist wohl der größte Fehler.

Der Oberhammer kam aber mal wieder von unser aller Möchte-Gern-Stasi-Chef: Gezielte Erschießungen und Internierungen sind das nächste Ziel. Da hat Fefe völlig recht: Dachau wäre doch gut geeignet. Aber das geht dann wohl sogar Beckstein zu weit, wenn man dieser Reaktionszusammenfassung auf tagesschau.de glauben darf (ausgerechnet Beckstein!).

Tolle Woche, das, muss man schon sagen. Das Nichtstun wird momentan zur größten Gefährdung, denn dann haben solche Schießbudenfiguren in Amt und Würden freie Fahrt 50 Jahre Grundgesetz zu ruinieren.

Well, I'm sure Isaac Brock wasn't too happy about his injury. Yesterday I heard that because of his injury the Modest Mouse concert in Frankfurt in June had to be cancelled, which would have taken place during my holiday. Instead, the concert now took place yesterday at the Batschkapp, and I was even able to get a card via eBay. Yes! The concert went quite well, although the Batschkapp was completely sold out. The warm-up band was pretty bad, but Modest Mouse hit the roof, although they were aiming for ... you know. What I learned during the show was that I like the songs from "Good news ..." more than the ones from "We were dead ...". This is of course an over-generalization, e.g. "Dashboard" is certainly among the best songs of MM, but overall the songs from "Good news ..." have more variation and also more life in them. But, hey, I felt almost like the protagnoist from How soon is never?, seeing Johnny Marr. Now I only have to find out from which LP that song is that they played after "Float on". Update: Some good soul from the forum on plattentests.de said it was "Tiny cities made of ashes" from "The Moon& Antarctica" and indeed, I recognized it was. However, played live, it sounded quite differently, much more powerful. And something else I forgot to mention: after the Trail of Dead in 2005, this was the second concert which featured two drummers and just as with ToD, this had a terrific effect on the sound.

Recently, there was a discussion about "the rise of functional languages" over on Linux weekly news, in which one of the participant claimed that one of the major reasons why nobody uses functional languages in industrial settings would be the lack of explicit resource handling (where a resource is some supposedly "alien" object in the system, say a database handle or something like that). What he was referring to was the inability to run code on allocating/deallocating a piece of resource. Of course, some people pointed him to various solutions, in particular I recurred to the usual WITH-* style-macros in which one would nest the access to the data while at the same time hiding all what one would do on allocation/de-allocation. His reply went something along the lines that such objects may need to be long-lived (thus a WITH-macro is inappropriate) and that the only resort would be the garbage collector and that there simply is no way of running code at a guaranteed (de-allocation) time. I have to admit that I have no idea how I could code around that problem in Common Lisp (garbage collection even isn't a defined term in the ANSI specification of CL, and I'm very sure I haven't seen any mention of allocation/deallocation in it).

Now, some months later, there is a discussion in comp.lang.lisp on the topic of "portable finalizers" and Rainer Joswig pointed to this chapter in the Lisp machine manual which talks about explicit resource handling the lisp machine. From the excerpt, I can't judge whether resources are first-class CLOS objects and hence the functions to handle them are generic functions, but if so that would actually allow running code on deallocating a resource, of course with the price of having to handle allocation/deallocation manually. I really wonder if any of todays CL implementations offers the same or at least similar functionality?