Zach Beane's Blog

Boston Lisp meetings are a lot of fun. Here's Alex Plotnick's announcement for the next meeting:

I'm pleased to announce that François-René Rideau will speak at the next Boston Lisp meeting on his recent work on ASDF 3. The meeting will take place on Thursday, 23 May at 6:30 PM, in the Star Conference room at MIT's Stata Center (MIT 32-D463; <http://whereis.mit.edu/?go=32>).

I'm sorry about the short notice on this one; communications problems of all kinds have been gumming up the works. Please feel free to spread the word about the meeting via whatever mechanisms are available to you.

Talk details (courtesy of Faré) follow. I hope to see you all there!

Title: "ASDF 3, or lessons in building portable Common Lisp programs"

Summary:
"ASDF (Another System Definition Facility) has been the de facto standard Common Lisp build system for over ten years. I recently rewrote it completely, several times, all the time (mostly) preserving backwards compatibility. The latest incarnation, ASDF 3, in addition to fixing deep design bugs older than ASDF itself, also includes extensive portability library, UIOP, not to be confused with an existing parallelizing extension, POIU. I will show how to use ASDF, explain the recent improvements, and discuss the challenges of writing portable Common Lisp programs and what that means for the past and future of Lisp."

About the speaker:
"François-René Rideau is a Lisp plumber. On good days, he designs great piping for persistent data, to be used in airline reservation system of ITA (now part of Google). On bad days, he dons his rubber gloves and scrubs the pipes. He also has a blog, Cybernethics, where he writes on liberty, music, programming, and dynamic systems in general."

I can't make it, but if you're in the Boston area, you should go!

Important news:

Subject: ECLM 2013 - two days left to register
Date: Mon, 13 May 2013 19:17:26 +0200
From: Edi Weitz

Ladies and Gentlemen,

This is our last call - there are two days left to register for this year's ECLM in case you haven't done so already:

   http://weitz.de/eclm2013/

We have more than 50 registrations so far, but we wouldn't mind seeing another dozen or two...

Best regards,
Arthur & Edi.

I greatly enjoyed my last visit to ECLM and I can't recommend it highly enough if you want to meet people with interesting Common Lisp projects and ideas.

I'm very excited to be attending both ECLM and ELS in Madrid this year. This is the last week to register for ECLM, so if you want to go, you should register ASAP.

Today I was running some analysis on about 9,000 files, basically mapping a function over each to warm up a cache. Something like this:

* (map nil 'analyze-file *9000-files*)
time passes

I had no idea how well it was progressing, and whether I'd need to take a snack break or let it run overnight. So I interrupted it and wrote a quick and dirty REPL utility function:

(defun :dot-every (count fun)
  (let ((i 0))
    (lambda (&rest args)
      (when (< count (incf i))
        (setf i 0)
        (write-char #\. *trace-output*)
        (force-output *trace-output*))
      (apply fun args))))

It prints out one dot per COUNT invocations of the function it returns, giving some indication of progress. Sensible values for COUNT depend on the volume of function calls.

For this problem, I called it with a COUNT of 100:

* (map nil (:dot-every 100 'analyze-file) *9000-files*)
............etc

The cached analyses printed out a ton of dots quickly, and the uncached analyses started printing dots at a slow but steady pace, and I could tell that it would be done in a few minutes instead of a few hours.

So now I'm going to use this to wrap up any function I have to call a ton of times and I want to get a sense of how it's progressing.

• The crucial role of the readtable
• Emacs is NOT required to hack Lisp
• The historical context of Baker's META
• Designing an OS for the PDP-8 (and part 2)

Well, it has been more than 20 years with Lisp in earnest... I'm sitting on a gold mine of great code that I have
used over the entire period, and still use daily in my work. But it seems the Lisp community is a bit short on
libraries of code. No point sitting on all this stuff till I die...

One of the (many) great things I have found with Lisp is that Code Rot (I always called this Bit-Rot, but I
realize that I'm wrongly attributing when I do that) is almost a non-problem, compared to just about every
other language system that I have used in my 40+ year career. I'm still using a large body of code that I wrote
nearly 15-20 years ago and has never needed any maintenance.

My code generally grows organically to supply solutions to problems I am facing in my own work. I generally
don't write libraries for others to use. And that will show through in a lot of what I share with the world.
C'est la vie...

The upshot in terms of Lisp evangelism has been quite good, BTW. Most
of the students have only been exposed to Java and scripting languages
so far and there are always some who express an immediate interest in
learning more about CL.