use Perl

Went to see Tim speak at the UK UNIX User group last night. Tim entertained a capacity crowd here to what I suspect is the usual blend of thought provoking stuff and humour.

I wonder if his slides will be published?

I recognised acme and davorg in the crowd (from their Identikit pictures on Crimewatch!)

Why do references always trip me up? I tend not to use them greatly and always struggle when I do. Context: I was trying to make a subroutine return a reference to a slice of an array. I wrote
 
  \@array[0..3]
 
which just returned a reference to a scalar before finding what I needed was
 
  [@array[0..3]]

This week I've been doing the routine data munging thing. Turning a file with : separated fields into something else, in this case DocBook tables. All fairly straightforward, but it makes you long for the DocBook equivalent of CGI.pm. DocBook::Table goes someway to doing what I want so maybe I'll start to look at building something on top of it.
 
I suppose that the set of Perl users AND DocBook users AND CPAN module writers is fairly small, which explains why there are only 4 modules found in searching...

A work colleague has started getting interested in Perl, he's reading Learning Perl (which can't be bad) - his background is in simple shell scripts. We've planned some short, informal, around the keyboard sessions - so far we've done opening, reading, and writing files. Today we do arrays, lists, and hashes.
 
I've been doing a very very simple "Cookbook" approach and so far it has seemed to work. It's great to get back to basics, but sometimes hard when you have to explain something that you have been doing for years without really thinking about it.
 
Future topics include pattern matching, regexes, and subroutines - but I haven't thought beyond that (suggestions welcome!).

After about 5 years of living 10 minutes walk from work I'm working about 2 hours single journey from home. I'd forgotten how much I hated driving up and down the motorways - and how tiring it is. Still, it's only supposed to be for 3 weeks.

Wychwood Brewery (in Oxfordshire, England) have released their Halloween beer and called it Pumpking. "... imparts a flavour reminiscent of dried fruits. The Northdown hops provide a balance with a heady, hoppy, bitterness. A delighful mysterious blend of pleasures"

I've been looking for Perl scripts/modules that will help with developing a taxonomy/classification system. Basically I want to be able to ask n questions and then based on the answer select a further m questions to ask etc. etc. until the end of the tree is reached.

The application I have in mind is identification of typefaces - but I don't think that is particularly relevant.

For UK readers with long memories there was a program for the BBC Model B that "understood" animals and would do a reasonable job of "guessing" what animal you were thinking of based on simple questions about number of legs/wings/horns etc. It also could be configured to add new animals - provided that you could give a distinguishing question. At the moment this is the sort of complexity I need.

Searching CPAN (keywords: taxonomy, classification) hasn't yielded anything that looks relevant - for the first time ever in my experience! - is this a wheel that hasn't been invented yet?

Can anybody point me in the right direction?

Update: The answer is probably Clips with a Perl front end to make the question/answer part easy.

I've been playing with GraphViz to try to make it produce family trees. It seems to be one of those things that look easy until you try it when it suddenly becomes non-trivial.

Basic problem: how do you make it put the husband and wife in the same rank with their childen in the next lower rank.

I note than some of the GraphViz::X authors report that reordering of the nodes is a problem - for family trees you almost always want the children to be in order of birth and not to be reordered by the layout algorithm.

The ability to produce a pretty diagram from a simple .dot file is very impressive however.