pro

pro@common-lisp.net

344 discussions

[pro] [Q] naming convention
by Didier Verna 05 Apr '12

05 Apr '12

Hello, I have a FROB functionality that I would like to make available both at run-time via a function and at compile-time via a macro (which in turn will call the function). Are there any general conventions (apart from DEFINE- / MAKE-) for this kind of thing ? I'm having a hard time finding nice names for FROB the function and FROB the macro... Thanks. -- Resistance is futile. You will be jazzimilated. Scientific site: http://www.lrde.epita.fr/~didier Music (Jazz) site: http://www.didierverna.com

8 10

[pro] GPU/CUDA & common lisp
by Tamas Papp 05 Apr '12

05 Apr '12

Hi everyone, I am about to buy a new server for number crunching, and I would like to keep my options open about GPU/CUDA based computations. The most intensively parallelizable thing that I am doing is particle filtering, and currently that works fine (and is really fast) in a multi-core CPU with SBCL, but I keep hearing wonderful things about GPUs from people, and I was wondering if I could make use of them but still program in CL. I basically have two questions: - What is the current status of using CPUs for computation in CL (in particular SBCL)? All I found was CL-GPU but I haven't tried it yet (my current server does not have a GPU). - What hardware is supported (if I want to use CL)? Can I use something like Nvidia's TESCLA C line? Any help/pointers/accounts would be appreciated, I am just exploring this so I don't know much about it yet, apologies if I am not asking the right questions. Best, Tamas

4 5

[pro] how to validate an XML file agains an DTD?
by Alexandre Rademaker 04 Apr '12

04 Apr '12

Hello, I know that probably this is not the best place to ask this question but my message to cxml-devel had no answer!! ;-( http://lists.common-lisp.net/pipermail/cxml-devel/2012-March/000554.html I need to validate a XML file that doesn't have the doctype declaration. Actually, I don't have control over the creation of the XML files so I am not able to change the fact that those files don't have doctype declarations. My problem is how to validate does files against a DTD. I found at http://common-lisp.net/project/cxml/sax.html#parser that the correctly way should be: > (let ((d (cxml:parse-file "0675365413696898.xml" (cxml-dom:make-dom-builder))) (x (cxml:parse-dtd-file "LMPLCurriculo.DTD"))) (dom:map-document (cxml:make-validator x #"CURRICULO-VITAE") d)) But that gives me two warnings and returns NIL Warning: deprecated SAX default method used by a handler that is not a subclass of SAX:ABSTRACT-HANDLER or HAX:ABSTRACT-HANDLER Warning: deprecated SAX default method used by a handler that is not a subclass of SAX:ABSTRACT-HANDLER or HAX:ABSTRACT-HANDLER NIL That is, it is working. I also tried with an invalid XML and the code fired an error as expected! What about these warnings? Does anything changed in the library and was not documented? How to solve them? Best, Alexandre Rademaker http://arademaker.github.com/

1 0

[pro] Sub-function free variable binding differences between Scheme and CL
by Burton Samograd 05 Mar '12

05 Mar '12

Hello, I am curently translating the logic circuit simulator code from SICP into Common Lisp and have run into a snag that I would like to ask about. The Scheme code is as follows from section 3.3.4 (page 223 of my hardcover edition): (define (and-gate a1 a2 output) (define (and-action-procedure) (let ((new-value (locical-and (get-signal a1) (get-signal a2)))) (after-delay and-gat-delay (lambda () (set-signal! output new-value))))) (add-action! a1 and-action-procedure) (add-action! a2 and-action-procedure)) The code basically binds the local function and-action-procedure into a list of functions in a1 and a2 which are then called by another routine later to perform the action when a value is set on the wire. My translated Common Lisp code is: (defun make-and-gate (a1 a2 output) (flet ((logical-and (a b) (if (= a 1) b a)) (and-action-proc () (let ((new-value (logical-and (get-signal a1) (get-signal a2)))) (set-signal output new-value)))) (add-action a1 #'and-action-proc) (add-action a2 #'and-action-proc))) The problem is that the bindings of a1 and a2 in and-action-proc are not being bound to the values of the calling function in the Common Lisp version. This causes the calling of and-action-proc to fail because a1 and a2 are not bound and I am assuming being treated as dynamic (special) variables. I have also tried to define and-action-proc using labels with no difference in results. Is this a total schemantic difference between CL and Scheme? Is every function in Scheme a closure where free variables of sub-functions bound to the calling functions environment? If so, is there a way to emulate this in Common Lisp? I would also like to note that I am currently trying out writing this code using LispWorks Personal Edition, rather than my usual SBCL environment, if that would make any difference. -- Burton Samograd

2 3

[pro] ELS 2012, Zadar, Croatia
by Marco Antoniotti 01 Feb '12

01 Feb '12

Apologies for the multiple postings. PAPER SUBMISSION DEADLINE EXTENDED European Lisp Symposium 2012, Zadar, Croatia, April 30th - May 1st, 2012 http://european-lisp-symposium.org 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, and so on. We encourage everyone interested in Lisp to participate. The main theme of the 2012 European Lisp Conference is "Interoperability: Systems, Libraries, Workflows". Lisp based and functional-languages based systems have grown a variety of solutions to become more and more integrated with the wider world of Information and Communication Technologies in current use. There are several dimensions to the scope of the solutions proposed, ranging from "embedding" of interpreters in C-based systems, to the development of abstractions levels that facilitate the expression of complex context dependent tasks, to the construction of exchange formats handling libraries, to the construction of theorem-provers for the "Semantic Web". The European Lisp Symposium 2012 solicits the submission of papers with this specific theme in mind, alongside the more traditional tracks which have appeared in the past editions. We invite submissions in the following forms: Papers: Technical papers of up to 15 pages that describe original results or explain known ideas in new and elegant ways. Demonstrations: Abstracts of up to 4 pages for demonstrations of tools, libraries, and applications. Tutorials: Abstracts of up to 4 pages for in-depth presentations about topics of special interest for at least 90 minutes and up to 180 minutes. Lightning talks: Abstracts of up to one page for talks to last for no more than 5 minutes. All submissions should be formatted following the ACM SIGS guidelines and include ACM classification categories and terms. For more information on the submission guidelines and the ACM keywords, see: http://www.acm.org/sigs/publications/proceedings-templates and http://www.acm.org/about/class/1998. Important dates: February 15th 2012: submission deadline (extended deadline) March 7th 2012: acceptance results April 30th 2012: Conference opens Program Commitee. Chair: Marco Antoniotti, Università degli Studi di Milano Bicocca, Milan, ITALY Local organizers: Damir Cavar, Eastern Michigan University Franjo Pehar, University of Zadar Damir Kero, University of Zadar Members: Giuseppe Attardi, Università degli Studi di Pisa, Pisa, ITALY Pascal Costanza, Intel, Bruxelles, BELGIUM Marc Feeley, Université de Montreal, Montreal, CANADA Scott McKay, Google, U.S.A. Kent Pitman, U.S.A. Christophe Rhodes, Department of Computing, Goldsmiths, University of London, London, UNITED KINGDOM Robert Strandh, LABRI, Université de Bordeaux, Bordaux, FRANCE Didier Verna, EPITA / LRDE, FRANCE Taiichi Yuasa, Kyoto University, JAPAN -- Marco Antoniotti -- Marco Antoniotti, Associate Professor tel. +39 - 02 64 48 79 01 DISCo, Università Milano Bicocca U14 2043 http://bimib.disco.unimib.it Viale Sarca 336 I-20126 Milan (MI) ITALY Please note that I am not checking my Spam-box anymore. Please do not forward this email without asking me first.

1 0

[pro] Defined but no used variable warning during setf expansion
by Burton Samograd 24 Jan '12

24 Jan '12

Hello, I am wondering if anyone can explain the reason for the defined but not used variable in setf that this code is experiencing: CL-USER> (set-macro-character #\$ (lambda (stream char) (declare (ignore char)) (let ((v (read stream))) (list (get v 'setf-handler-name) v)))) (defmacro defactive (var value &key write-handler read-handler) (let ((setf-handler-name (gensym))) `(progn (defparameter ,var ,value) (defmacro ,setf-handler-name (,var) (let ((read-handler (gensym))) `(let ((,read-handler (get ',',var :read-handler))) (if ,read-handler (funcall ,read-handler (eval ,',var)) ,',var)))) (defsetf ,setf-handler-name (,var) (new-val) (let ((write-handler (gensym))) `(let ((,write-handler (get ',',var :write-handler))) (when ,write-handler (funcall ,write-handler (eval ,',var) ,new-val)) (setf ,',var ,new-val)))) (setf (get ',var 'setf-handler-name) ',setf-handler-name) (setf (get ',var :write-handler) ,write-handler) (setf (get ',var :read-handler) ,read-handler) ,value))) (defmacro setactive (var &key read-handler write-handler) `(progn (when ,read-handler (setf (get ',var :read-handler) ,read-handler)) (when ,write-handler (setf (get ',var :write-handler) ,write-handler)))) (defactive x 0 :write-handler (lambda (old-val new-val) (format t "old: ~A new: ~A" old-val new-val)) :read-handler (lambda (val) (format t "value: ~A" val) val)) ;(setactive x :read-handler (lambda (val) (format t "~A !!! ~A" val))) ;(setactive x :write-handler (lambda (old-val new-val) (format t "~A !!! ~A" old-val new-val))) (defactive d6 (random 6) :read-handler (lambda (val) (let ((old val)) (setf d6 (random 6)) old))) STYLE-WARNING: redefining COMMON-LISP-USER::DEFACTIVE in DEFMACRO STYLE-WARNING: redefining COMMON-LISP-USER::SETACTIVE in DEFMACRO 1 CL-USER> (setf $x 10) ; in: SETF (#:G1129 X) ; (LET* ((#:G1175 X)) ; (MULTIPLE-VALUE-BIND (#:G1176) ; 10 ; (LET ((#:G1177 #)) ; (WHEN #:G1177 (FUNCALL #:G1177 # #:G1176)) ; (SETF X #:G1176)))) ; ; caught STYLE-WARNING: ; The variable #:G1175 is defined but never used. ; ; compilation unit finished ; caught 1 STYLE-WARNING condition old: 0 new: 10 10 -- Burton Samograd http://kruhft.dyndns.org

5 5

[pro] Declarations in compilers (feedback welcome)
by Juan Jose Garcia-Ripoll 30 Dec '11

30 Dec '11

After struggling mentally with this for a few weeks, I would like to have some consultation before I introduce some changes in ECL -- not that I expect many users here, but at least some implementor-fellows and power users of other implementations. My concerns right now relate to how declarations should be used by a compiler, and in particular how declarations interact with SAFETY levels. Please correct me if I am wrong, but I have seen more or less the following approaches [a]- Most implementations blindly believe declarations below a certain safety level. Above it, they seem more or less useless. [b]- SBCL takes declarations (and THE) as type assertions. For instance, in (LET ((Y (FOO X))) (DECLARE (FIXNUM Y))) ...) the assignment to Y would be checked to be a FIXNUM. This means the type declaration is actually enforced and believed and only at SAFETY 0 the checks are dropped (*) In both cases one ends up with a model in which in order to truly believe a declaration and have no extra burden (assertions), one has to drop to SAFETY 0 in all code that is involved with it, which is a mess, because it might inadvertently affect other parts of the code. It is for this reason that I am considering an alternative model for ECL which would grade safety as follows - Type declarations are always believed - SAFETY >= 1 adds type checks to enforce them. - SAFETY = 0, no checks. - SAFETY = 1, the special form THE or additional proclamations on the functions can be used to deactivate the check. As in (LET ((Y (THE FIXNUM (FOO X))) ...) This would allow one to keep most code safe, while deactivating some checks when they are really known to be true (**). Do you think this is useful/useless? The problem I see with this approach is that all code around is written for model [a] or [b], but I could not come up with something more sensible so far. Juanjo (*) Actually the checks are also deactivated when SBCL can infer the type of the value that is assigned to Y. This is somewhat contradictory, because (SETF Y (THE FIXNUM (FOO X))) would still generate a check, but proclaiming FOO to return a FIXNUM would completely bypass the check. (**) Yes, indeed I know that LOCALLY exists for a reason, but it does more than THE. For instance, if I (LOCALLY (DECLARE (SAFETY 0)) (THE FIXNUM (FOO (SLOT-ACCESSOR X)))... this influences the safety of the code that accesses a structure, which is not good. P.S.: Thanks to Paul Khuong for pointing out that SBCL behaves differently w.r.t. declarations. -- Instituto de Física Fundamental, CSIC c/ Serrano, 113b, Madrid 28006 (Spain) http://juanjose.garciaripoll.googlepages.com

4 6

[pro] what lisp command line arg parser is good?
by Mark H. David 21 Dec '11

21 Dec '11

Anyone with some thoughts on which command line parser is good to use? There seem to be n of them out there. None really stands out, that I can tell. Must be quicklisp readable, other than that, I don't have any kind of fancy requirements. Just something simple, and reliable. Widely used would be good, and/or well maintained. Any pro tips? Thanks, Mark

8 10

[pro] Keyword arguments and compiler macros
by Juan Jose Garcia-Ripoll 05 Dec '11

05 Dec '11

[Sorry for possible duplicates] I just realized that compiler macros might be too restrictive in some implementations. Take for instance (define-compiler-macro foo (a &key key-arg) ...) This is assuming that FOO is only going to be invoked with _constant_ keyword arguments. I know, I know, most uses will have always one argument or :KEY-ARG, but suppose you want to call (FOO some-value a-non-constant-expression some-other-value)... What is the compiler to do? I _now_ think that the compiler macro processor should simply recognize the failure to parse the form and return the original form, unprocessed, but the implementations I have at hand do not do that. ECL to begin with, but also CCL and SBCL. Any opinions on this? Juanjo -- Instituto de Física Fundamental, CSIC c/ Serrano, 113b, Madrid 28006 (Spain) http://juanjose.garciaripoll.googlepages.com

5 8

[pro] Bignum Arithmetic
by David McClain 04 Dec '11

04 Dec '11

I'm getting more deeply involved in Bignum prime-field and Elliptic Curve computations. Wonder if anyone knows the degree to which the Bignum support in Lisp is enhanced, in the sense that multiple algorithms can be used for, e.g., multiplication, depending on bignum operand sizes. FFT's over integer fields for large numbers, Montgomery multiplication elsewhere, etc.?? I just reviewed GnuMP docs and saw a fairly sophisticated collection of internal optimizations. Would it pay to migrate to GnuMP for specialized applications? Dr. David McClain dbm(a)refined-audiometrics.com

6 5

← Newer
1
...
20
21
22
23
24
25
26
...
35
Older →

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

pro