- pro - mailman3.common-lisp.net

ML Maintainer wanted
by Hans Hübner 30 Nov '17

30 Nov '17

Hi, I would like to step down from being the pro@ mailing list maintainer. It is not a lot of regular work (maybe one or two visits to the Mailman page per month to forward or reject a message from a non-subscriber), but it might be that the list needs to be moved or something and I would like to avoid getting into a situation where maintenance is required and I don't have time to do it. Also, I'm not a professional Common Lisp user anymore, so I don't qualify for the list at this point anyway :D Any takers? Thanks, Hans

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Optimizing a function over multiple types for its arguments
by Chaitanya Gupta 28 Nov '17

28 Nov '17

While I was working on qbase64[1], I stumbled over a peculiar problem: I wanted it to work as fast as possible when optimized array types (SIMPLE-ARRAY, SIMLPE-BASE-STRING, etc.) were passed to the encoding/decoding routines, but I also wanted to support the more general types. If I defined my core encoding routine like this: (defun %encode (bytes string) (declare (type (simple-array (unsigned-byte 8)) bytes)) (declare (type simple-base-string string)) (declare (optimize speed)) ...) SBCL would produce very fast code, but the function would no longer work for other ARRAY or STRING types: And if I was to redefine the routine with more general types: (defun %encode (bytes string) (declare (type array bytes)) (declare (type string string)) (declare (optimize speed)) ...) The code produced would be significantly slower. My solution to this conundrum was to create a macro that would take all the different type combinations I wanted to optimize and support upfront: (defun/td %encode (bytes string) (((bytes (simple-array (unsigned-byte 8))) (string simple-base-string)) ((bytes (simple-array (unsigned-byte 8))) (string simple-string)) ((bytes array) (string string))) (declare (optimize speed)) ...) and generate code which would dispatch over the type combinations, then use LOCALLY to actually declare the types and splice the body in: (defun %encode (bytes string) (cond ((and (typep bytes '(simple-array (unsigned-byte 8))) (typep string 'simple-base-string)) (locally (declare (type bytes (simple-array (unsigned-byte 8)))) (declare (type string simple-base-string)) (declare (optimize speed)) ...)) ((and (typep bytes '(simple-array (unsigned-byte 8))) (typep string 'simple-string)) (locally (declare (type bytes (simple-array (unsigned-byte 8)))) (declare (type string simple-string)) (declare (optimize speed)) ...)) ((and (typep bytes 'array) (typep string 'string)) (locally (declare (type bytes array)) (declare (type string string)) (declare (optimize speed)) ...)) (t (error "Unsupported type combination")))) If the run-time dispatch incurs a slight penalty, it is more than offset by gains made by using optimized array types, esp. since these routines have to typically visit every element of the given arrays. I was wondering if there was a better way to do this. Have I missed a trick or two? I was reading about the Lisp Interface Library[2] which supports parametric polymorphism, but not sure if it would result in optimized code like the one my macro generates. Chaitanya 1. https://github.com/chaitanyagupta/qbase64 2. https://common-lisp.net/%7Efrideau/lil-ilc2012/lil-ilc2012.html

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lisp.org
by Nick Levine 20 Nov '17

20 Nov '17

Now that we've established why lisp.org and its friends are long-term off air... The website at lisp.org contained a photo of John McCarthy (and nothing else) since the week he died six years ago. What's the message? In contrast take a quick look at (say) python.org, a site devoted to really assisting people to use that language. Do we care, and if we do how do we go about effecting change? - nick

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Can compiler macros make use of type declarations?
by Chaitanya Gupta 09 Nov '17

09 Nov '17

Let's say I have created a function called `FOO`: (defun foo (x) ...) To optimize this function, I write a compiler macro. Can I make use of type declarations that users of `FOO` might have made for the argument `X` that is passed in to it? That is, let's say `FOO` is used like this: (let ((a (something-that-returns-an-integer))) (declare (integer a)) (foo a)) The compiler macro for `FOO` cannot make any optimizations on the value of `A`, but can it take advantage of the fact that `A` is declared as in `INTEGER` here? Chaitanya

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ALU websites
by Nick Levine 12 Oct '17

12 Oct '17

I am concerned that alu.org (Association of Lisp Users), lisp.org and international-lisp-conference.org are all offline, and have been for at least several weeks. The first two of these didn't really serve anything of use but the ILC site contained proceedings of several past conferences and shouldn't be lost. Does anyone know what's going on? I can't write directly to the ALU because its site is down and so there's no contact list (and I imagine emailing @alu.org is like talking to a black hole). - nick

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In search of Road to Lisp Survey archive
by Ken Tilton 29 May '17

29 May '17

Did anyone happen to snag a backup of the ALU/Cliki Road to Lisp survey responses? I am thinking about resurrecting/hosting that. -- Kenneth Tilton http://tiltontec.com/

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before and after methods
by Didier Verna 20 May '17

20 May '17

Hi! Does anyone know why the non-standard built-in method combinations do not support before and after methods? Thanks. -- Resistance is futile. You will be jazzimilated. Lisp, Jazz, Aïkido: http://www.didierverna.info

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defsystem history
by Faré 23 Mar '17

23 Mar '17

Is there any old timer alive who can tell me about the early history of defsystem? I *suppose* it was inspired by Unix Make — but was it? When did defsystem appear? It's already quite elaborate in the 1981 edition of the chine nual. But when was it first written? What did lispers use before? Ad hoc load scripts? What do older Lisp Machine tapes contain? Where can I find those tapes? Does any old MIT tech report tell us anything about defsystem? Which versions of defsystem did or did not have problems with propagating timestamps? —♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org It has been my observation that most people get ahead during the time that others waste. — Henry Ford

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Best practices analogous to "debug" and "release" builds?
by John Morrison 16 Mar '17

16 Mar '17

Hi; I want to prune all the developer-centric stuff (e.g., clouseau:inspector, which in turn, brings in McCLIM, maybe some formatted I/O) from my CL software when I package it as a dumped SBCL image (vs delivering source). Would also like to change the optimize directives (debug, speed, etc.). What are the best practices? My Googling didn't turn up much. Or am I thinking about this in entirely the wrong way? Thanks in advance, -jm

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[CfPart] 10th European Lisp Symposium, Apr 3-4 2017, Brussels
by Didier Verna 03 Mar '17

03 Mar '17

ELS'17 - 10th European Lisp Symposium VUB - Vrije Universiteit Brussel Belgium April 3-4, 2017 In co-location with <Programming> 2017 Sponsors: Brunner Software GmbH, Franz Inc., LispWorks Ltd. and EPITA http://www.european-lisp-symposium.org/ Recent news: - Invited speakers announced (see below) - Registration open. Don't miss the March 13 deadline for the full <Programming> conference early bird discount! The purpose of the European Lisp Symposium is to provide a forum for the discussion and dissemination of all aspects of design, implementation and application of any of the Lisp and Lisp-inspired dialects, including Common Lisp, Scheme, Emacs Lisp, AutoLisp, ISLISP, Dylan, Clojure, ACL2, ECMAScript, Racket, SKILL, Hop and so on. We encourage everyone interested in Lisp to participate. Keynote speakers: - Hans Hübner -- Identity in a World of Values - Bohdan B. Khomtchouk -- How the Strengths of Lisp Facilitate Building Complex and Flexible Bioinformatics Applications Important dates: - 13 Mar 2017 Early registration deadline - 03-04 Apr 2017 Symposium - 05-06 Apr 2017 <Programming> main tack Programme chair: Alberto Riva, University of Florida, USA Programme committee: Marco Antoniotti, Università Milano Bicocca, Italy Marc Battyani, FractalConcept Theo D'Hondt, Vrije Universiteit Brussel, Belgium Marc Feeley, Université de Montreal, Canada Erick Gallesio, Université de Nice Sophia-Antipolis, France Stelian Ionescu, Google Rainer Joswig, Independent Consultant, Germany António Menezes Leitão, Technical University of Lisbon, Portugal Nick Levine, RavenPack Henry Lieberman, MIT, USA Mark Tarver, Shen Programming Group Jay McCarthy, University of Massachusetts Lowell, USA Christian Queinnec, Université Pierre et Marie Curie, France François-René Rideau, Bridgewater Associates, USA Nikodemus Siivola, ZenRobotics Ltd Alessio Stalla, Università degli Studi di Genova, Italy Chris Stacy, CS Consulting Search Keywords: #els2017, ELS 2017, ELS '17, European Lisp Symposium 2017, European Lisp Symposium '17, 10th ELS, 10th European Lisp Symposium, European Lisp Conference 2017, European Lisp Conference '17 -- Resistance is futile. You will be jazzimilated. Lisp, Jazz, Aïkido: http://www.didierverna.info

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