Jeni's Musings

The Free Our Bills campaign was launched recently in the UK. Some of the comments I’ve seen about the campaign makes me think that it might be helpful if people understood more about how Bills and legislation get published in the UK. I thought I’d offer a bit of background based on my experience (though there are many people with more intimate knowledge of the processes involved; perhaps they’ll correct me when I get it wrong).

Another question to answer:

I’ve been reading about RDF, and I’m not sure in what situations it is more appropriate to use RDF over straight XML. I usually see RDF expressed as XML, but sometimes I see it written as language-independent functions (or methods).

Part of me is wondering if RDF is more appropriate for this project. What might the benefits be? And if it is, how difficult it would be to refactor it.

We just had photos taken of the children, and it’s put me in a reflective mood. Norm posted the other day about his experience with information/task management products:

Then it hit me.

None of them, with the notable exception of Tinderbox, seem to store the data in any open format. I was seriously considering one of these commercial black boxes for an important chunk of the data that drives my day-to-day life. The little voice in my head reacted viscerally when the observation was made: “What the hell you thinking, man! Stop that!”

A Ruby on Rails specialist friend and I are building a Web 2.0 application. I would say it’s “social networking for the dead” except that I doubt that description would be attractive to most people (my ex-Goth defacto being a rare exception), and it can be for the living too. It’s a bit like all those genalogy websites, except that our focus is on people’s social relationships as well as their familial ones.

(I should say that this is all very casual. We’re both fitting it in around our other responsibilities, and are mainly interested in working together, learning new things, and trying out all the best practices that everyone keeps talking about. So don’t think I’m becoming a dotcom entrepreneur or anything. Its got a very Web 2.0 name, and I’m only not telling you in case you start hitting our servers. We’re nowhere near ready for visitors.)

A lot of people run into problems with namespaces, and most of those arise from using default namespaces (ie not giving namespaces prefixes). The transformation technology you use can have a big effect on how confusing and irritating it gets.

Default namespaces make XML documents easier to read because they allow you to just give the local name of an element rather than using prefixes all over the place. For example, using:

<house status="For Sale" xmlns="http://www.example.com/ns/house">
  <askingPrice>...</askingPrice>
  <address>...</address>
  <layout>...</layout>
</house>

I’ve finally finished my “Progress in Processing” talk for this year’s XML Summer School. It’s been really interesting looking at the different APIs developed for different programming languages in the last few years, all so much easier to use than the DOM. One of the themes is the use of path-based syntax to query XML.

Whatever algorithm you use to calculate Levenshtein distance, one of its great features is that you can tweak the cost of letter substitutions. For example, you can do a case-insensitive comparison of two strings, or perhaps more interestingly a semi-case-sensitive comparison of two strings, where the cost of replacing a character for its upper or lower case equivalent is less than the cost of replacing a character with an unrelated character, but more than zero. But that requires knowledge of whether and how two characters are related.

Of course all that information is stored in the Unicode Database, which are a bunch of text files in a structured format. I looked for an XML version but couldn’t find one (well, Googling “Unicode database XML” isn’t much help). So I downloaded UnicodeData.txt and NamesList.txt and put together an XSLT 2.0 stylesheet to create an XML version of the Unicode database.