Re: [xml-dev] Create a special purpose programming language, in XML, usi

[Michael Kay <mike@saxonica.com>]

> 
> By the time I could figure out WTF was going on, and where some text was output or not and why I had the whole fricken
> monster delicately balanced in my brain ready to explode with the loony bin on speed dial.

I do know the problem. The stylesheets that we use for processing the W3C specs are an awful mess too. They've evolved over 15 years, lots of people have added bits, there have never been any tests apart from the documents we are actually publishing, and XSLT does encourage this style of development where if you don't like what the stylesheet does, you just add an override rule somewhere. It makes it easy for people to make changes even when they don't understand the full picture, which is nice except that no-one ever knows the full picture, and in the end, when things don't work, it can be very hard to find out what's going on. The lesson is that languages that make it easy to change and modify code (loosely, scripting languages) can also encourage a lack of software engineering discipline. I think a lot of it is to do with the fact that no-one is developing this code as their day job; it's just a tool to help you get things done.

That's probably also why I have never invested the effort to fully explore what IDEs like oXygen are capable of in terms of debugging support. I know there are a lot of features there, such as the ability to analyze which bits of the stylesheet generated which parts of the output, but I so rarely do any tough XSLT debugging that learning new techniques is a lower priority than solving the problem.

Michael Kay
Saxonica