DEF1

New access

Thu, 05 Mar 2009 07:38:45 GMT

So now I can also blog from my iTouch, let's see if that will help me blog more.

Dynamic programming languages.

Fri, 03 Oct 2008 09:19:09 GMT

The jaoo.dk conference is taking place in Århus these days and following this there was an interview with Lars Bak, one of the drivers behind the V8 Javscript engine, in a danish newsletter. Here he talks about the joys and wonders of dynamic typing over static ditto. He makes manay good points on how dynamic typing helps to increase programmer productivity.

At least two of these points was something I had no thought so much about before.

One was that the tools surrounding statically typed languages tends to be very phase oriented. You make a chance, compile, do a test run to see if it worked and then you get back to editing. Dynamic languages such as Lisp, Smalltalk or (I guess) Javascript allows you to work much more directly with the (running) program, interleaving thinking, editing and testing almost seemlessly.

The other thought provoking point, one I also absolutely believes in, is that programmers working in dynamic languages tends to focus on the program logic whereas programmers working with static languages tends to focus on all of the much less important trimmings surrounding the logic.

The bottom line,as he puts it, is that the bottleneck today is not those last 20-30 % of performance but rather programmer productivity and everything we can do to facilitate that should be pursued. And even if one does get concerned over performance, one should rather seek to solve the problems rather than giving up without trying. Lisp was not born as efficient as it is today (neither was C) but can not fix a problem if one does not try to fix it.

Just a big a problem, I think, in many languages is the apperent view from the language designers that the biggest threat to the purity of the program is the programmer. This is most dominant in static languages where the type diciplines provides the language architect with a multitude of ways to fence those rascal programmers in but even in dynamic languages such as Erlang one can find traces of this.

The logic seems to be that we want to prevent the programmers from making mistakes, and that logic is not as such flawed, there are mistakes you just do not make in a statically typed programming language. Unfortunately, the statement that a program is typecorrect is an incredible weak statement about its usefulness!

Happy Birthday Professor McCarthy.

Thu, 04 Sep 2008 11:59:38 GMT

I have done entirely too little blogging for far too long but that is no excuse for not wishing the father of Lisp, Professor Emeritus John McCarthy, a happy birthday. I wish you all the best for the years to come.

Fun with FFI

Fri, 25 Jan 2008 21:43:47 GMT

Leslie Polzer has posted an excellent little example on Getting started with CFFI.

However, I think it deserves mentioning that playing around with FFI definitions is a grand way of getting to know a C library. Unlike C, Lisp is an interactive programming environment which means that you can slowly build up the necessary chunks of code, trying out stuff in order to properly understand what the various bits and pieces does.

For this, 'getloadavg' (the example used in the aforementioned article) is actually too simple to properly relate to the power this gives you. Consider instead wanting to get to know something more involved such as OpenOBEX (for talking to your mobile phone) or SAF (for building highly available systems), then having an interactive environment is a tremendous benefit. Anybody who has tried to understand a complex C library by writing small snippets of C programs with printf's to demonstrate proper working should be able to appreciate the advantage of this.

In fact, I think that the interactivity of Lisp is one of the top five secrets of why Lisp programmers are so darn productive. Rather than building up large suites of tests, we just try out constructs as we write the code and the code is correct from the outset (well, sort of) rather than having to go through a couple of iterations to weed out the silly mistakes. If I didn't have the REPL nearby, I know I would never ever use something as complicated as reduce, my head starts boiling everytime I have to construct even just a slightly complex 'reduce' expression, but being to able to iteratively build up and verify such expressions gives me the necessary confidence to stick it into my code anyway.

In case you think that writing the initial boilerplate for a C library interface, you should check out something like the Verrazano/Fetter project. This is able to generate CFFI bindings by parsing C header files. The result is not necessarily perfect but certainly a good start.

Verrazano is an old Google summer of Code of project and endured a slowdown but has again picked up steam and some of the problems in the initial implementation has been fixed in the curren instantiation; and I have found the developers to be very responsive on the mailing list when I reported some concerns. Highly Recommended (with a small salute to the Jerry Pournelle columns in Byte Magazine).

Happy Birthday Professor McCarthy.

Tue, 04 Sep 2007 18:59:34 GMT

The father of Lisp, Professor Emeritus John McCarthy turns 80 today!

I had the honour to see the legend at the 2002 International Lisp Conference. The sensation of being among so many Lisp people, including such giants as McCarthy, was a tremendous experience to me.

ICFP Programming Contest

Fri, 20 Jul 2007 06:12:35 GMT

Gentle men and women, on your marks, the ICFP Programming Contest will start in less than 4 hours! Will Lisp make it to the top this year?

Quote of the day
A comment made by Dan barlow made on comp.lang.lisp (I think) back in june 2005:

> all developers would HAVE TO work TOGETHER (in harmony)
The beatings will continue until morale improves

ILC07 pictures.

Mon, 14 May 2007 19:04:19 GMT

I have pulled myself together and posted the pictures I took at the ILC07 on my web site.

Some of the minatures on page 2 and 3 looks strange in my Safari but ok in Firefox. They should load ok however.

In case you have been wondering about the site, whether it has become a study in how unstable a server can get, I should say that I hope it is better now. The server is set up here at home on my old Linux box running SBCL and AllegroServe. It is also using wireless LAN and it took me quite some time to realise that I am working at the very edge of the range of my el-cheapo netgear wlan router.

Quote of the day:
A quote from Ray Dillinger back in the spring of 2005, in relation to an announcement of the Boston Lisp Announcement Email List:

Christopher C. Stacy: Weren't the bothons the fish people in Star Wars?

Ray Dillinger: You know, I've had a similar thought; except if I were to do it it would be the "Than Franthithco Lithp Utherth Thothiety."

Impromptu

Sat, 12 May 2007 09:28:49 GMT

Via the swedish lisp mailinglist I have just discovered Impromptu, a scheme based environment for composers and sound artists. There are some movies in their gallery demonstrating how it works. Impromptu is free but Mac only and seems quite cool.

Quote of the day:

From Michael Westergaard on an internal DAIMI newsgroup back in 2005 (translated from danish):

If one has a strange definition of strange, is that necessarily a recursive definition?

Dynamic Languages are coming.

Wed, 18 Apr 2007 20:25:02 GMT

On the latest ACM TechNews newsletter, there was a reference to an InfoWorld story on the virtues of Dynamic Languages. The case is being made that the industry to a still greater extent turn to dynamic languages to tap into improved productivity.

I am a great beliver in the promise of dynamic languages and I am here not just thinking of Lisp but dynamic languages in general including Ruby and Python that are among the ones mentioned in the article. In fact I am convinced that the next big thing in programming languages (whenever that will materialise itself) will be a dynamic language.

Continuing through various links in the article I arrived at two other interesting sites: Tiobe which keeps score on language popularity based on web search engine statistics and the Language Shootout which maintains an impressive list of benchmarks implemented in various langauges.

Obviously such things should not be overrated in importance (as the saying goes: there are lies, damn lies and benchmarks/statistics) but it is quite funny to look for Lisp there and compare to something like Erlang which seems to create quite a buzz, also i Lisp circles. Erlang actually fares a lot worse (according to the aforementioned websites) than I had imagined. In the Tiobe popularity index, the Lisp and scheme group is currently ranked 17 while Erlang is in the group of rank 51-100. Even if the entry named "CL" relates to a breakout of Common Lisp from the Lisp/Scheme grouping (which I do not think judging from the explanations), it is still at position 37 and thus before Erlang. In the all languages shootout SBCL is at ratio 1.9 compared to C where Erlangs best ratio is 4.2.

Quote of the day

American author Kurt Vonnegut died recently. From the danish blog (in danish) Harddisken I have scooped up the following quote:

"If you really want to disappoint your parents, and don't have the nerve to be gay, go into the arts."

In Memoriam rydis

Sat, 14 Apr 2007 18:09:33 GMT

Martin "rydis" Rydström, who went missing the 24. of February, has been found but sadly not alive. More information can be found here.

ILC07: specifics

Tue, 10 Apr 2007 18:19:41 GMT

I found most of the talks interesting and some of the speakers were directly outstanding. I am not in violent disagreement with the other reports, but I will try to list some items I found noteworthy. In this, I will most undeservingly skip a lot of interesting and fun stuff, for which I apologise in advance.

Sunday was dedicated to tutorials. Like many others, I would have wished I could have gone to all of them. I ended up with the webapp tutorial Edi Weitz gave on Hunchentoot and Duane Rettigs tutorial on optimization in Allegro CL. I found Hunchentoot interesting and my impression is that it is a pretty well engineered piece of software which is little surprising given Edis trackrecord. The Allegro tutorial ended up being more ACL specific than I had hoped but it did offer a good insight into the mechanics of ACL and Duane is a good presenter. Some good stuff is on its way in ACL 8.1, that's for sure.

The conference started for real Monday. One thing that struck me was the creativity with respect to presentation layouts. As I normally move around in the corporate world and Microsoft PowerPoint presentations, it was and inspiring to see how much could be done, also with freeware tools. PowerPoint was represented, but mostly in the Mac instantiation. I saw very few people running windows. Some presenters used quite some time moving back and forth between their talk and their demos. More people should probably have done like Chris Connolly who did a talk on the FREEDIUS imaging system in using a virtual desktop to streamline the changing back and forth. Chris used Virtue on his Mac. I have since downloaded it to my own Mac and it works really well.

Robert Strandh gave a talk on ESA (a part of McCLIM) and the future of Emacs like applications in Common Lisp and CLIM. While I like the prospects of having a stronger programming language behind the editor, I am also somewhat worried that his idea that one should pack things into separate applications will move ESA and Climacs in a direction away from Emacs that will make porting from Emacs to Climacs (and similar tools) difficult. He did demo a mail client and while it was neat that such a thing exists, it probably has a long way to go before it is as powerful as GNUS. He did say at one point that he uses Climacs and the mail client every day. We will see how ESA will affect the world.

Antonio Leitao spoke on translating Java libraries into Common Lisp. It was based on the analysis that Java and Perl has many more libraries than CL and that many of the existing CL libraries suffered from the 80% problem in that they would develop to the point where the cover the authors needs rather than going all the way. The first part is obviously correct, the latter I am less sure of, certainly numerous exceptions exists, but with a much smaller number, semidead projects are of course much more noticeable. His approach was interesting but obviously also one that demanded significant manual intervention. A thing one might wonder was how well the difference in number of libraries reflect actually deficiencies in the Lisp world; perhaps the effect lies less in the numbers as such and more in the size of the particular markets leading to some high-quality options.

Christian Queinnec talked about Computer Science education. He is a very good speaker, funny and interesting, and they are clearly doing a lot of good stuff at the Université Pierre et Marie Curie. They have automated a big part of the grading in the undergraduate education which among other things means that they can go back in time and study the growing corpus of examination and exercise answers and for instance retry the grading part. In the questions part, he gave a simple recipe for comparing texts for similarity. Gzip each text separately and the gzip the concatenation of them. If the latter is much smaller in size than the sum of the individuals, a big overlap must exist!

Michael Sperber gave an enticing report from the Scheme R6RS process. He confirmed that standardisation is a very hard and painful process (he claimed it to be the most painful thing he has done since the breakup with his first girlfriend), a quite apropos comment to the ongoing debate on comp.lang.lisp. He also said that the R6RS process has abandoned the old consensus principle the other revisions employed in favour of being able to move forward at all. There will also be a community process once the committee has finalised the report which incidently will consist of two parts, one for the language and one for a standard library. My favourite item in the whats new part has to be the addition of Serious IO :-)

Tuesday started with a talk on CL-HTTP. I really liked the talk, unlike others who found it weird to various degrees. One thing that struck me was that CL-HTTP seems less dead than I thought it was. There are some issues with the license, and I understand that the attitude of "nobody has been sued yet" is not good enough for a commercial user, but I cannot really see CL-HTTP as being in a whole different situation than so many other open source projects. The authors concentrate on some things and leave other things behind. Apparently the license it not so easy to change but remains good enough for John Mallory so I think it to be a bit unfair to blame him for not prioritising the issue. I have definitely decided to check it out.

From the talk on SC, a set of SEXP languages that compiles to C, I noted the comment that C is useful as an intermediate language but it lacks access to the execution stack, something that the SC system solved as I understand it.

The talk on social network analysis (CL-SNA) clearly demonstrated that there is a lot of theory on the subject. It is not quite my field, but I did wonder if some of the analysis apparatus would not be useful to telecom operators trying to understand the traffic in their networks. The speakers also revealed that the next European Lisp Users Group meeting would be in Istanbul. The idea is good, I would very much like to see Istanbul and Turkey being the tourist it is means that travelling there should not be completely out of reach. We shall see; if anybody said (or has posted elsewhere) when it is, I have missed it.

Cyrus Harmon has elsewhere been applauded for a good talk. I read in one of the other reports that it was done using LaTeX which surprises me, given the high quality of the layout. Most of the software he has developed for his PhD is available; I am going to check out his gcc-xml-ffi in my long and dusty search for a good FFI tool.

From the talk/demonstration of LispWorks, I picked up a very neat idea: step-to-cursor. Perhaps nothing new, but it was to me. LispWorks incidently offered all conference attendees a 30 days evaluation copy of LispWorks. I picked one up and look forward to trying it out.

Richard Jones gave a good talk on Dynamic Memory Management and the challenges in garbage collection. I noted the mentioning of Azul Systems that makes custom hardware that somehow supports garbage collection in a way I have now forgotten. One of the thing Richard said was that the Lisp community, having invented and forefronted GC, should make sure hard earned lessons from the Lisp machines and other places are not forgotten and left to reinvention in modern systems design.

Wednesday started with a rather impressive talk on and demonstration of HOP, a web programming framework built on top of a homegrown Scheme implementation. Manuel Serranos presentation was all coded directly in HOP and it seemed really neat. I spotted Erick Gallesios name on the frontpage. I really liked his STk scheme implementation that used many years ago; I believe these guys know what they are doing even if the 200-300 KLOC code base sounds a bit scary.

I found the talk on the OWL reasoner interesting. A few good points I noted down: description logics are about possible worlds - OO is about one particular world and RDF triples is the cons cell of the semantic web. Incidently, their product (Racer Pro) uses CL-HTTP. Mentioned was also Wilbur.

The talk on XMLisp was interesting. The idea is to modify the reader to be able to use real XML with angle brackets and all directly inside the lisp code. To me it seemed to improve readability but at the cost of typing where the conventional SEXP based form should be easier to deal with (and better supported by editors such as emacs). XMLisp would translate XML trees into objects which some sitting close by found a very unnatural representation but perhaps not if one is into the DOM/SAX way of looking at things. Certainly it showed of just how powerful the Common Lisp reader is! Alexander Repenning also seems to be doing very interesting work with respect to teaching children about programming, a most important issue.

I had looked forward to Jans Aasmans talk on scalable Lisp and was no disappointed. It might have been better of as a half tutorial rather than a 50 minutes talk but a lot of good stuff on dealing with very big data sets was presented. It appears that Franz has been deeply immersed in the ACM library searching for techniques for their AllegroCache and AllegroGraph products. Their was some talks during the question session on the value of cons-free functions which went somewhat over my head.

ILC07: generics

Mon, 09 Apr 2007 13:11:37 GMT

A few days has past and reports from the ILC are pouring in (Zach is keeping track). My own report will be divided in two, one for the talks and this one for the rest.

Overall, the conference was a magnificent success, I think. A very well done goes out to the organising commitee in general and Nick Levine in particular. Lots and lots of work went into allowing the rest of us to just show up and enjoy the ride.

The venue in Cambridge was incredible nice and quiet. For some reason I kept waking at around 06:00 and the only thing heard was the occassional owl somewhere in the distance and a few early birds in the court yard.

It was a very special feeling to be staying at an institution that will celebrate its 800'th birthday in 2009. With the colleges, and the banquet in the great hall of Clare College (the third oldest of the colleges), I was not the only person to feel like being in the midst of a Harry Potter story.

The conference website has put up the group photo that was taken (a very nice idea by the way) and promises to deliver links to various goodies such as photos, blogs, recordings and pdfs. There will also be a list of those participants that opted in to have it listed.

Food (breakfast and lunch) was provided, partly because the organizers realised that if people had to scatter for lunch, half would no come back for the afternoon sessions which I think was very well seen. Food was overall very good. In the evenings, we generally teamed up in larger groups to a much bigger extent than I remember doing when I was at the ILC 2002 in San Francisco. Perhaps the combination of a smaller crowd and a smaller city, or the fact that most lived in the college accomodations was a part of the reason for that.

The conference location was a bit more scattered than I had imagined, but fortunately the weather was mostly very good with only a single cloudy day with a few drips so this was not a problem. It was a bit chilly though most of the time.

I flew directly from Århus to Stansted with Ryan Air. It was very nice to have a direct and cheap connection but I must admit that I am glad I do not normally travel like this. The plane was packed both out and home and the weight limit of 15 Kg for checked baggage is ridiculously low. Obviously, it was not Ryan Airs fault that I came back to Stansted later than I should have (I should have calculated at least two hours) but the home trip ended up being rather stressfull; I even managed to forget my laptop at the security check point, but for some reason I decided to check whether it was there or not shortly after, so I was able to get hold of it without problems.

I decided to pay a visit to the big Cambridge University Press bookstore, but I had some problems fitting it in to the schedule. I ended up dashing off in the Wednesday afternoon break (and subsequenty missed most of the Liskell talk) but I was glad I did. It had a rather interesting Computer Science part and I ended up buying three books, one on the great pyramids of Egypt, one on Abductive Inference and one on Planning Algorithms which apparently is also available for download.

I arrived Saturday but unfortunately too late for the punting and city walk. After registration I was given several option for where to go for dinner. I ended up at the Free Press which was indeed cosy with good beer and a nice curry. English draught beer, of which Greene King was prominently featured in the pubs I went to, is somewhat different from the continental style with noticeably less carbondioxide. I kind of prefer the continental style but the beer I got was good none the less.

Walking back to Clare College, I discovered that there was a festival going in Cambridge. I didn't have the energy to try to catch anything that evening but I decided to go to the Wednesday concert with Bachs St. Johns Passion at the Kings College Chapel with the King College Choir and Academy of Ancient Music. The concert was really good although I did need a little while to tune in to the music. Among the soloist, especially the Evangelist (William Kendall) stood out but the choir was magnificent as well.

Happy Birthday RMS.

Fri, 16 Mar 2007 09:05:30 GMT

Today is Richard Stallmans 54. birthday.

RMS, and his Free Software movement, is a controversial person. Personally, I have always been kind of attracted to the somewhat hippie and positive attitude towards the world that RMS is such an exponent for. I do not in any way has his rigour and stamina in the pursuit of the idea, but I can certainly respect him for being so dedicated to what he believes in.

RMS is of course also a big lisp hacker and has worked at the MIT AI lab and thus knows lisp machines intimately. He gave an interesting talk about some of his experiences at ILC 2002.

I sometimes wonder how the world would have looked today, if he had decided to start the GNU project, not by with developing a high quality C toolchain, but rather a Lisp environment.

Having a free and gratis toolchain is not enough to ensure the popularity of a language, but I strongly believe that a language can not become very popular without having also gratis alternatives, which is why I think the existence of free Lisp implementations is a good thing for the Lisp language.

Incidently, today is also the 5. birthday of the release of GNU Emacs 21.2.

Quote of the day
Via Edi Weitz on comp.lang.lisp back in 2004, a quote from Larry Wall:

Lispers are among the best grads of the Sweep-It-Under-Someone-Else's-Carpet School of Simulated Simplicity.

Lisp sighting

Sun, 11 Mar 2007 10:24:54 GMT

In the glossy magazine ACM Queue, they have a column entitled What's on your harddrive where they interview various industry people asking what they love and loathe in terms of tools.

Much to my pleasant surprise, I saw Lisp (specifically emacs+slime+SBCL) mentioned in the "Tools I love" category in the February issue.

I kind of like ACM Queue, as it has a reasonably hitrate of interesing articles. However, some notable people dislikes the ACM.

Quote of the day
Comment from David Kastrup, once again in alt.religion.emacs, back in February 2005:

The sunlight does not get brighter elsewhere if you place a parasol over every mudhole.

Quote of the day

Mon, 05 Mar 2007 18:17:29 GMT

Darn, I forgot the quote. I have collected a rather substantial amount of messages over the years containing stuff or sentences I find (or at least found at the time) to be funny and I have decided to try to include one with very post.

The quote for today is unfortunately one I have lost attribution of, but I find it funny none the less (it is probably from a signature seen on comp.lang.lisp):

Curiosity didn't kill the cat.
Stupidity killed it.

The joys and wonders of scripting

Mon, 05 Mar 2007 18:03:41 GMT

I have a strong resentment towards repetitive and repeated tasks and often go to considerable lengths to semi-automate such things. Fortunately, this is one area where UNIX makes things rather easy through scripting. I mostly use bourne shell scripts since I haven't really taken the time to learn perl or tcl or python and often sh will suffice, well sort of.

One script I use a lot is update-all that will iterate across all directories in the current directory and perform an update. This is really handy when tracking a number of projects on places like cl-net or sf. The idea is that one checks out a particular project and then later runs update-all in the directory above and it will update all sandboxes (provided it knows about the different kind of sandboxes).

But even more interesting than downloading stuff is building stuff, so I have made myself a build-core script that is based on a kind of configuration file for each package (such as McCLIM) such that I easily can build a new core file with the latest and greatest version. Two examples of such configuration files are clx.lisp and clim.lisp that will build a core containing CLX and one for McCLIM (which is based on the CLX core). The build-core script also uses a common setup file, named in lisp pun style common.lisp such that one can make common set ups across different kinds of lisps.

The nice thing about bulding cores is that start up is a lot faster, which is quite relevant for large package such as McCLIM but the downside is that combining things becomes more difficult since one cannot just build a core containing package A and another core containing library B and start a lisp instance combining the two cores.

Obviously, these scripts have been tailored for my ideosyncratic tastes but they are posted above in the hope that they may serve as inspiration. I know that this post also is rather scarce on how to use the scripts, but feel free to contact me for more info in the case where the code does not suffice.

Going... going... gone!

Mon, 26 Feb 2007 19:47:02 GMT

I have installed a countdown widget on my dashboard. And why would I do such a silly thing? Because I am going to the International Lisp Conference in Cambridge in the beginning of april!

This is going to be so incredible cool. I was also at the ILC in San Francisco in 2002 and I have high hopes that this years conference will be every bit as exciting. Not only will it be like heaven to spend a full 4 days talking and hearing nothing but Lisp, but I am also looking forward to visit Cambridge and breathe a bit of Ye Olde University atmosphere.

Quote of the day

A signature used by Alexey Dejneka on the CMUCL mailing list in 2004:

"Alas, the spheres of truth are less transparent than those of illusion." -- L.E.J. Brouwer

First Entry

Sun, 25 Feb 2007 18:57:45 GMT

Ok, it's decided. I will continue blogging here at LiveJournal, rather than maintaining my old blog back at DEF1. Thanks to Zach for helping me out with the numerous problems with the old blog and for pointing me in this direction.

It is cool that LJ sports an emacs client, being the religious emacs fanatic that I am, unfortunately it did not seem to work out of the box with Aquamacs on my powermac. It is probably something relatively stupid.. It is not that it directly failed, but ultimately nothing happened so some investigation is needed.