Because of multiple requests, the deadline for contributions to the 2010 European Lisp Symposium has been extended by one week, to 5th February 2010. Submissions will of course be accepted in advance of this new deadline; don't feel you have to wait until the last minute...

The deadline for submissions to the 2010 European Lisp Symposium is now less than one week away. In the meantime, I'm pleased to be able to announce the invited speakers for the symposium:

• Matthias Felleisen, of Northeastern University and the TeachScheme! project will speak on the topic of PLT Scheme;

• Nick Levine, independent consultant at Ravenbrook, has twenty years of Lisp experience after a serendipitous encounter, and over that time has taken on roles from system implementor to contractor; from educator to conference organiser; and most currently, author of a new book on Lisp;

• Kent Pitman, with his background of over three decades of involvement in the design, implementation and use of Lisp-family languages, will offer historical perspectives and thoughts for the future.

I hope that this lineup provides additional motivation for people to complete their submissions!

I feel I don't get to do very much hacking any more.

I shouldn’t complain, really: I have a decent and stable job, which is mostly fun; I have a certain amount of freedom in what I do, as long as everything that has to get done gets done; I work with all sorts of interesting people, both formally and informally. But things that I want to do have to live a long way down the priority queue; preparing lecture materials, paper drafts, committee agendas, bursary agreements, course proposals, courseworks, exams, student feedback, paper redrafts, reports, meeting notes, grant proposal drafts, paper reviews, examiners’ reports, reading lists, grant proposal redrafts, and the like all seem to take priority over even the research on a funded project that I am part of, let alone the discretionary research that I might actually want to do.

So sometimes I have to be sneaky, and combine my hacking with teaching-related work instead. One of the more fun things I’ve learnt over the last couple of years is enough colour theory to be dangerous; it started off because I was casting around for ideas on what to teach students on our Creative Computing programme – and I do teach them about colour, among other things – but it’s sufficiently interesting as a technical area in itself that I can see writing code to illustrate aspects of it. So, here’s a (not very good) colour picker “application” for McCLIM, whose only redeeming feature is that it uses knowledge of the colour attributes of consumer-grade display hardware to present colours of the same intensity together. That’s a bit hard to visualize, so here’s a screenshot, where all the colours in the triangle should seem to have about the same brightness (viewers might need to adjust their viewing angle):

Source code is here; I’m not particularly proud of it, and it needs work in all sorts of directions (optimizing, generalizing, cleaning up). One of the reasons I had put off blogging about this is that I was hoping for a lovely literate-programming system to optimized for single-file Lisp programs to appear, generating HTML and PDF output from minimally-marked-up Lisp code. Sadly, that hasn't happened, and my best attempt can only be described as, well, deranged... so no impeccably formatted and indexed code snippets in this blog, not this time anyway.

I hosted SBCL10 this week; I'll be putting links to materials from the workshop as they come in. Things mostly seemed to work; minor failures along the way (for my reference if, heaven forfend, I organize another similar event) included the approximeeting arrangements with Martin Cracauer and James Y. Knight on Sunday at the Imperial War Museum; the hilarious failure to remember the coffee maker on Monday morning until halfway to the stations; and of course relying on college catering to provide a light lunch at the time booked (rather than failing to do so and needing to be chased). One thing that I think did work well was the format: motivational talks to kick off, then hacking sessions interspersed with lighting talks – there was a good variety of stuff going on and stuff being talked about; even the open session at the end was focussed and productive. Particular thanks go to my local support team: Jamie Forth, Karen Hodgson, Richard Lewis and Wendy McDonald (and thanks to James Knight for the use of his AirPort Express; thanks also to my department for giving me the green light to organize this, along with an initial push.

Did I say “heaven forfend”? Now my attention must properly turn to the 2010 European Lisp Symposium; there is now a website, and the Call for Papers was sent to a wide variety of Lisp-related venues, so hopefully everyone knows about it now. Cunningly, the Call for Papers failed to include any guidance on a page count for submitted papers; 15 pages in the J.UCS style is the limit – but please submit through EasyChair, not to J.UCS!

Some more emacs lisp for interacting with launchpad by email (specifically, with Gnus). Previously, I wrote some code which allowed for easy transfer of a bug report by e-mail to launchpad; I've since adapted that to add a Cc to the original reporter, so that they know the bug has been filed (sadly too late for any of the reports that I have actually filed; maybe this blog can serve as a heads-up...)

However, this doesn't solve the entire issue, which is painless and seamless interaction. Comments to bugs are delivered by mail, and filtered using the X-Launchpad-Bug header to an appropriate mail directory, but replies to those comments need to be cryptographically signed for those replies to be accepted by launchpad. How to do that? Initially, I hoped that there would be some group parameter or posting style which would automatically insert the mml code for signing; suspicion alighted on `gnus-message-replysign', but unfortunately the messages that launchpad sends aren't signed, even if the ones that are sent to it must be.

It would also seem that there isn't an appropriate hook for this; all the hooks I could find seem to be run too early, and attempts to call `mml-secure-message-sign-pgpmime' gave me errors about a corrupt mail buffer (because the body separator hadn't been set up yet). So, instead, I ended up piggy-backing on the code handling gnus-message-replysign anyway, by advising the relevant function as follows:

(defadvice gnus-summary-handle-replysign
  (after handle-launchpad-replysign activate)
  (when (string-match "list.*-launchpad" gnus-newsgroup-name)
    (mml-unsecure-message)
    (mml-secure-message-sign-pgpmime)))

The alert will note that this automatically signs not replies to messages from my sbcl-launchpad buffer, but from any of my list groups matching -launchpad. Is this just speculative generality, I hear you ask? No, because Alastair Bridgewater has kindly volunteered to participate in CLX development and release engineering, and his first and second acts were to set up a mailing list (hopefully permanent, this time, after clozure and metacircles abandonment) and a launchpad bugtracker. So if you've been building up scads of patches and annoyances with my clx branch (or even worse, the ancient 0.7.3 release), now might be a good time to attempt to report the annoyances and integrate the patches; particularly from those still-active projects with heavy CLX use (e.g. StumpWM, Eclipse (no not that one) and McCLIM).