Février 2021 - Gambit-list - mailman.iro.umontreal.ca

Gambit versus Python+GMP: Timing for Chudnovskys' algorithm for pi
by Bradley Lucier 08 Avr '22

08 Avr '22

Bakul Shah wrote a particularly elegant Scheme program for Chudnovskys' algorithm for pi based on the Common Lisp program here: https://bitbucket.org/tarballs_are_good/numericl/src/5fe8fe7089f48ab1c8a388… Nick Craig-Wood wrote a Python program using the GMP multiprecision library that appears to use exactly the same algorithm here: http://www.craig-wood.com/nick/articles/pi-chudnovsky/ I modified both programs a bit and include them here. They time the calculation of $10^n$ digits of pi for $n=1,2,3,4,5,6,7$. The results are heine:~/programs/gambiteer/gambit> !py python pi_chudnovsky_bs_gmpy.py 31415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679 ('chudnovsky_gmpy_mpz_bs: digits', 10, 'time', 1.0967254638671875e-05) ('chudnovsky_gmpy_mpz_bs: digits', 100, 'time', 3.0040740966796875e-05) Last 5 digits 70679 OK ('chudnovsky_gmpy_mpz_bs: digits', 1000, 'time', 0.00025582313537597656) Last 5 digits 01989 OK ('chudnovsky_gmpy_mpz_bs: digits', 10000, 'time', 0.00386810302734375) Last 5 digits 75678 OK ('chudnovsky_gmpy_mpz_bs: digits', 100000, 'time', 0.0834801197052002) Last 5 digits 24646 OK ('chudnovsky_gmpy_mpz_bs: digits', 1000000, 'time', 1.655979871749878) Last 5 digits 58151 OK ('chudnovsky_gmpy_mpz_bs: digits', 10000000, 'time', 30.67442488670349) Last 5 digits 55897 OK heine:~/programs/gambiteer/gambit> gsi chud1.scm Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10, CPU time: 0.. Last 5 digits 26535. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100, CPU time: 0.. Last 5 digits 70679. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000, CPU time: .004. Last 5 digits 1989. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000, CPU time: .028. Last 5 digits 75678. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100000, CPU time: .472. Last 5 digits 24646. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000000, CPU time: 6.448. Last 5 digits 58151. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000000, CPU time: 98.612. Last 5 digits 55897. So it appears that for this algorithm applied to large integers, GMP's bignum routines are about 3-4 times as fast as Gambit's bignum routines. Not so bad. For smaller bignums, GMP has a bigger advantage. The C program gmp-chudnovsky.c includes certain optimizations to this basic algorithm: http://gmplib.org/pi-with-gmp.html ftp://ftp.gmplib.org/pub/misc/gmp-chudnovsky.c On my machine, compiled with gcc -O3 -march=native -o gmp-chudnovsky gmp-chudnovsky.c -lgmp -lm the CPU times for 1,000,000 and 10,000,000 digits are 1.064 and 18.200 seconds, respectively. This is with a somewhat older machine model name : Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz running Ubuntu 13.04 with heine:~/programs/gambiteer/gambit> gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.7.3-1ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --with-system-zlib --enable-objc-gc --with-cloog --enable-cloog-backend=ppl --disable-cloog-version-check --disable-ppl-version-check --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) heine:~/programs/gambiteer/gambit> gsi -v v4.6.9 20130607151908 x86_64-unknown-linux-gnu "./configure '--enable-single-host' '--enable-multiple-versions' '--enable-shared'" and the Ubuntu-provided GMP 5.0.5. (I'm sure the GMP folks have a better way to build GMP on my machine than the "generic" 64-bit version provided by Ubuntu.) Brad

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georgjz/functional-geometry-gambit-scheme: A simple implementation based in Peter Henderson's paper "Functional Geometry"
by Bradley Lucier 10 Mai '21

10 Mai '21

https://github.com/georgjz/functional-geometry-gambit-scheme This appeared on Scheme Reddit, but I thought it may be of interest to some people on this list. Brad

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Re: [gambit-list] R: Contributing to Gambit
by Amirouche Boubekki 30 Avr '21

30 Avr '21

Le ven. 29 janv. 2021 à 16:58, luca regini <luca.regini(a)gmail.com> a écrit : > > I would also be willing to contribute more to Gambit but the hard fact is that this requires a big investment of time upfront. > > Getting into the internals without specific documentation probably requires to invest at least 2 weeks full-time upfront. > > Which is not impossible if one is fully dedicated to this project ( as a student can be ) but for people with a job and a family this is impossible. I can dedicate time in bursts of 1 hours maybe 2 hours max. > > An idea that I could suggest is to write a commercial book describing the implementation so to sponsor some additional work on Gambit. I would be willing to buy such a book but have no idea how many other would be willing to spend money on that. I agree I would buy a book about gambit compiler, and other internal aspects (like how macro works). FWIW, my plan WAS to build my own scheme that targets javascript with Chez as host. Among other things because it is difficult, but also because gambit is great, and I want to take part in something bigger than myself. I do my best to document what I am doing with gambit (https://github.com/pre-srfi/webui/) and try to workaround some behaviors that are not perfect or at least could be improved upon. I can work around those. But more important than all of the above. I agree that the compiler or compilers must be documented. It might be the first and most important priority to help gambit grow as a community. nanopass is overrated. It seems to me based on a few couple hours of hacking that it is possible to build something simpler and easier to use. Again, I am not a compiler specialist. Maybe a nanopass is a dead end for gambit, or maybe gambit approach is better. Who knows? Marc, you are in the best position to describe the compiler.

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[Reminder CfP] ELS 2021, 14th European Lisp Symposium, May 3-4
by Didier Verna 26 Fév '21

26 Fév '21

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 14th European Lisp Symposium Call for Papers May 3 - May 4, 2021 Online / Everywhere http://www.european-lisp-symposium.org/2021 Sponsored by EPITA and RavenPack ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Invited Speakers ~~~~~~~~~~~~~~~~ Nada Amin - Harvard SEAS others tba Important Dates ~~~~~~~~~~~~~~~ - Submission deadline: March 7, 2021 - Author notification: April 6, 2021 - Final papers due: April 19, 2021 - Symposium: May 3 - May 4, 2021 Scope ~~~~~ The European Lisp Symposium is a premier forum for the discussion and dissemination of all aspects of design, implementation and application of any of the Lisp dialects, including Common Lisp, Scheme, Emacs Lisp, Clojure, Racket, ACL2, AutoLisp, ISLISP, Dylan, SKILL, Hy, Shen, Carp, Janet, uLisp, Picolisp, Gamelisp, TXR, and so on. We encourage everyone interested in Lisp to participate. The European Lisp Symposium 2021 invites high quality papers about novel research results, insights and lessons learned from practical applications, and educational perspectives. We also encourage submissions about known ideas as long as they are presented in a new setting and/or in a highly elegant way. Topics include but are not limited to: - Context-, aspect-, domain-oriented and generative programming - Macro-, reflective-, meta- and/or rule-based development approaches - Language design and implementation - Language integration, inter-operation and deployment - Development methodologies, support and environments - Educational approaches and perspectives - Experience reports and case studies Technical Program ~~~~~~~~~~~~~~~~~ We invite submissions in the following forms: * Papers: Technical papers of up to 8 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. All submissions should be formatted following the ACM SIGS guidelines and include ACM Computing Classification System 2012 concepts and terms. Submissions should be uploaded to Easy Chair, at the following http://www.easychair.org/conferences/?conf=els2021 Note: to help us with the review process please indicate the type of submission by entering either "paper", "demo", or "tutorial" in the Keywords field. Programme Chair ~~~~~~~~~~~~~~~ Marco Heisig - FAU Erlangen-Nürnberg, Germany Local Chairs ~~~~~~~~~~~~ Michał Herda Mark Evenson - RavenPack Programme Committee ~~~~~~~~~~~~~~~~~~~ Ioanna Dimitriou - Igalia Irène Durand - LaBRI University of Bordeaux R. Matthew Emerson - thoughtstuff LLC Matthew Flatt - University of Utah Jonathan Godbout - Google Paulo Matos - Linki Tools David McClain - SpectroDynamics, LLC Stefan Monnier - University of Montreal Jim Newton - EPITA Research Lab Kent Pitman - HyperMeta Inc. Christophe Rhodes - Google Kai Selgrad - OTH Regensburg Olin Shivers - Northeastern University Robert Smith - Rigetti Quantum Computing Michael Sperber - DeinProgramm Evrim Ulu - Middle East Technical University Breanndán Ó Nualláin - Machine Learning Programs -- Didier Verna <didier(a)elsaa.org> ELS Steering Committee

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Off Topic: How I First Heard About Calculus
by Bradley Lucier 23 Fév '21

23 Fév '21

I wrote a short piece about how I first heard about calculus (spoiler: it was in a comic strip) that was published in the Journal of Humanistic Mathematics: https://scholarship.claremont.edu/jhm/vol11/iss1/18/ It's a good story, you may enjoy it. Like I said, it's "off topic" for this mail list, but I don't have Twitter or Facebook accounts ;-). Brad

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Question about |##still-copy| and a |##still?| typechecker
by Phillip Suero 19 Fév '21

19 Fév '21

Dear Marc, I am sending over an u8vector from the Scheme world to the C world. Of course the u8vector must be still, so that its heap allocated object's memory address is not moved by Gambit's memory system. To get clear on this topic, I have three quick questions for you: (1) I see there's the function |##still-copy| in Gambit's runtime. Browsing its code I don't see the keyword ___STILL mentioned anywhere in it. How does it get the ___STILL property, is that an implicit argument to ___alloc_scmobj ? (2) Is |##still-copy| a "universal copier" of any heap allocated object, into an equivalent of itself that is ___STILL, so I can use it for, say, u32vector, floating point number, complex number, string, Scheme struct? (3) Is there any checker in Gambit's runtime, e.g. a |##still?|, whereby I can check if a heap allocated object is ___STILL already? Your clarification is much appreciated, thanks! Phil

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Creating a list of C structs and returning it to Scheme
by clc_xce＠tutanota.com 09 Fév '21

09 Fév '21

Hi everyone, Long time reader, first time writer. I want to create a list of C structs and return them to Scheme with the following code: (c-declare #<<c-list-of-structs typedef struct my_struct my_struct; struct my_struct { int* data; }; ___SCMOBJ my_struct_free( void* p ) { my_struct* s = (my_struct*)p; if( !s ) { printf( "list_struct_free: %i\n", *s->data ); free( s->data ); return ___FIX( ___NO_ERR ); } return ___FIX( ___UNKNOWN_ERR ); } // create a list of n my_structs ___SCMOBJ create_list( int n ) { ___SCMOBJ ___err = ___FIX( ___NO_ERR ); ___SCMOBJ list = ___NUL; ___SCMOBJ new_list; my_struct* ls; while( n > 0 ) { ls = malloc( sizeof( my_struct ) ); ls->data = malloc( sizeof ( int ) ); *ls->data = n; ___SCMOBJ element = ___NUL; ___err = ___STRUCT_to_SCMOBJ( ___PSTATE, ls, ___FAL, my_struct_free, &element, 0 ); new_list = ___EXT( ___make_pair ) ( ___PSTATE, element, list ); ___EXT( ___release_scmobj ) ( list ); ___EXT( ___release_scmobj ) ( element ); list = new_list; --n; } return list; } c-list-of-structs ) ;(c-define-type my-struct (struct "my_struct")) (c-define-type my-struct (struct "my_struct" 'my-struct "my_struct_free")) (c-define-type my-struct* (pointer my-struct)) (define create-list (c-lambda (int) scheme-object "create_list")) (define square-my-struct! (c-lambda (my-struct) void "*___arg1.data *= *___arg1.data;")) (define print-my-struct (c-lambda (my-struct) void #<<c-print-my-struct printf( "my_struct: %i\n", *___arg1.data ); c-print-my-struct )) (define test-list (create-list 10)) (map print-my-struct test-list) (map square-my-struct! test-list) (map print-my-struct test-list) While this kind of works, there's two problems here: One, how do I fix the tags for my foreign objects in the list so that they're displayed as my-struct, not foreign? Two, how do I make the GC call my release-function correctly for my_struct? Any help is much appreciated. Background: I have a STM32 Nucleo board, I'd like the C code on it to be able to communicate with a Scheme program on my laptop. Kind regards, Georg

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Call for Papers: PACMPL issue ICFP 2021
by Sam Tobin-Hochstadt 02 Fév '21

02 Fév '21

PACMPL Volume 5, Issue ICFP 2021 Call for Papers Accepted papers to be invited for presentation at The 26th ACM SIGPLAN International Conference on Functional Programming To Be Held Virtualy http://icfp21.sigplan.org/ ### Important dates Submissions due: 2 March 2021 (Tuesday) Anywhere on Earth https://icfp21.hotcrp.com Author response: 20 April (Tuesday) - 23 April (Friday) 17:00 UTC Notification: 7 May (Friday) Final copy due: 30 June (Wednesday) Conference: 22 August (Sunday) - 27 August (Friday) ### About PACMPL Proceedings of the ACM on Programming Languages (PACMPL <https://pacmpl.acm.org/>) is a Gold Open Access journal publishing research on all aspects of programming languages, from design to implementation and from mathematical formalisms to empirical studies. Each issue of the journal is devoted to a particular subject area within programming languages and will be announced through publicized Calls for Papers, like this one. ### Scope [PACMPL](https://pacmpl.acm.org/) issue ICFP 2021 seeks original papers on the art and science of functional programming. Submissions are invited on all topics from principles to practice, from foundations to features, and from abstraction to application. The scope includes all languages that encourage functional programming, including both purely applicative and imperative languages, as well as languages with objects, concurrency, or parallelism. Topics of interest include (but are not limited to): * Language Design: concurrency, parallelism, and distribution; modules; components and composition; metaprogramming; macros; pattern matching; type systems; type inference; dependent types; session types; gradual typing; refinement types; interoperability; domain-specific languages; imperative programming; object-oriented programming; logic programming; probabilistic programming; reactive programming; generic programming; bidirectional programming. * Implementation: abstract machines; virtual machines; interpretation; compilation; compile-time and run-time optimization; garbage collection and memory management; runtime systems; multi-threading; exploiting parallel hardware; interfaces to foreign functions, services, components, or low-level machine resources. * Software-Development Techniques: algorithms and data structures; design patterns; specification; verification; validation; proof assistants; debugging; testing; tracing; profiling; build systems; program synthesis. * Foundations: formal semantics; lambda calculus; program equivalence; rewriting; type theory; logic; category theory; monads; continuations; control; state; effects; names and binding; program verification. * Analysis and Transformation: control flow; data flow; abstract interpretation; partial evaluation; program calculation. * Applications: symbolic computing; formal-methods tools; artificial intelligence; systems programming; distributed systems and web programming; hardware design; databases; XML processing; scientific and numerical computing; graphical user interfaces; graphics and multimedia; GPU programming; scripting; system administration; security. * Education: teaching introductory programming; parallel programming; mathematical proof; algebra. Submissions will be evaluated according to their relevance, correctness, significance, originality, and clarity. Each submission should explain its contributions in both general and technical terms, clearly identifying what has been accomplished, explaining why it is significant, and comparing it with previous work. The technical content should be accessible to a broad audience. PACMPL issue ICFP 2021 also welcomes submissions in two separate categories — Functional Pearls and Experience Reports — that must be marked as such when submitted and that need not report original research results. Detailed guidelines on both categories are given at the end of this call. Please contact the associate editor if you have questions or are concerned about the appropriateness of a topic. ### Preparation of submissions **Deadline**: The deadline for submissions is **Tuesday, March 2, 2021**, Anywhere on Earth (<https://www.timeanddate.com/time/zones/aoe>). This deadline will be strictly enforced. **Formatting**: Submissions must be in PDF format, printable in black and white on US Letter sized paper, and interpretable by common PDF tools. All submissions must adhere to the "ACM Small" template that is available (in both LaTeX and Word formats) from <https://www.acm.org/publications/authors/submissions>. There is a limit of **25 pages for a full paper or Functional Pearl** and **12 pages for an Experience Report**; in either case, the bibliography will not be counted against these limits. Submissions that exceed the page limits or, for other reasons, do not meet the requirements for formatting, will be summarily rejected. Supplementary material can and should be **separately** submitted (see below). See also PACMPL's Information and Guidelines for Authors at <https://pacmpl.acm.org/authors.cfm>. **Submission**: Submissions will be accepted at <https://icfp21.hotcrp.com/> Improved versions of a paper may be submitted at any point before the submission deadline using the same web interface. **Author Response Period**: Authors will have a 72-hour period, starting at 17:00 UTC on **Tuesday, April 20, 2021**, to read reviews and respond to them. **Supplementary Material**: Authors have the option to attach supplementary material to a submission, on the understanding that reviewers may choose not to look at it. This supplementary material should **not** be submitted as part of the main document; instead, it should be uploaded as a **separate** PDF document or tarball. Supplementary material should be uploaded **at submission time**, not by providing a URL in the paper that points to an external repository. Authors are free to upload both anonymized and non-anonymized supplementary material. Anonymized supplementary material will be visible to reviewers immediately; non-anonymized supplementary material will be revealed to reviewers only after they have submitted their review of the paper and learned the identity of the author(s). **Authorship Policies**: All submissions are expected to comply with the ACM Policies for Authorship that are detailed at <https://www.acm.org/publications/authors/information-for-authors>. **Republication Policies**: Each submission must adhere to SIGPLAN's republication policy, as explained on the web at <http://www.sigplan.org/Resources/Policies/Republication>. ### Review Process This section outlines the two-stage process with lightweight double-blind reviewing that will be used to select papers for PACMPL issue ICFP 2021. We anticipate that there will be a need to clarify and expand on this process, and we will maintain a list of frequently asked questions and answers on the PACMPL issue website to address common concerns. **PACMPL issue ICFP 2021 will employ a two-stage review process.** The first stage in the review process will assess submitted papers using the criteria stated above and will allow for feedback and input on initial reviews through the author response period mentioned previously. As a result of the review process, a set of papers will be conditionally accepted and all other papers will be rejected. Authors will be notified of these decisions on **May 7, 2021**. Authors of conditionally accepted papers will be provided with committee reviews along with a set of mandatory revisions. After four weeks (June 4, 2021), the authors will provide a second submission. The second and final reviewing phase assesses whether the mandatory revisions have been adequately addressed by the authors and thereby determines the final accept/reject status of the paper. The intent and expectation is that the mandatory revisions can be addressed within four weeks and hence that conditionally accepted papers will in general be accepted in the second phase. The second submission should clearly identify how the mandatory revisions were addressed. To that end, the second submission must be accompanied by a cover letter mapping each mandatory revision request to specific parts of the paper. The cover letter will facilitate a quick second review, allowing for confirmation of final acceptance within two weeks. Conversely, the absence of a cover letter will be grounds for the paper’s rejection. **PACMPL issue ICFP 2021 will employ a lightweight double-blind reviewing process.** To facilitate this, submitted papers must adhere to two rules: 1. **author names and institutions must be omitted**, and 2. **references to authors' own related work should be in the third person** (e.g., not "We build on our previous work ..." but rather "We build on the work of ..."). The purpose of this process is to help the reviewers come to an initial judgement about the paper without bias, not to make it impossible for them to discover the authors if they were to try. Nothing should be done in the name of anonymity that weakens the submission or makes the job of reviewing the paper more difficult (e.g., important background references should not be omitted or anonymized). In addition, authors should feel free to disseminate their ideas or draft versions of their paper as they normally would. For instance, authors may post drafts of their papers on the web or give talks on their research ideas. ### Information for Authors of Accepted Papers * As a condition of acceptance, final versions of all papers must adhere to the new ACM Small format. The page limit for the final versions of papers will be increased by two pages to help authors respond to reviewer comments and mandatory revisions: **27 pages plus bibliography for a regular paper or Functional Pearl, 14 pages plus bibliography for an Experience Report**. * Authors of accepted submissions will be required to agree to one of the three ACM licensing options: open access on payment of a fee (**recommended**, and SIGPLAN can cover the cost as described next); copyright transfer to ACM; or retaining copyright but granting ACM exclusive publication rights. Further information about ACM author rights is available from <http://authors.acm.org>. * PACMPL is a Gold Open Access journal, and authors are encouraged to publish their work under a CC-BY license. Gold Open Access guarantees permanent free online access to the definitive version in the ACM Digital Library, and the recommended CC-BY option also allows anyone to copy and distribute the work with attribution. Gold Open Access has been made possible by generous funding through ACM SIGPLAN, which will cover all open access costs in the event authors cannot. Authors who can cover the costs may do so by paying an Article Processing Charge (APC). PACMPL, SIGPLAN, and ACM Headquarters are committed to exploring routes to making Gold Open Access publication both affordable and sustainable. * ACM offers authors a range of copyright options, one of which is Creative Commons CC-BY publication; this is the option recommended by the PACMPL editorial board. A reasoned argument in favour of this option can be found in the article [Why CC-BY?](https://oaspa.org/why-cc-by/) published by OASPA, the Open Access Scholarly Publishers Association. * ACM Author-Izer is a unique service that enables ACM authors to generate and post links on either their home page or institutional repository for visitors to download the definitive version of their articles from the ACM Digital Library at no charge. Downloads through Author-Izer links are captured in official ACM statistics, improving the accuracy of usage and impact measurements. Consistently linking to the definitive version of an ACM article should reduce user confusion over article versioning. After an article has been published and assigned to the appropriate ACM Author Profile pages, authors should visit <http://www.acm.org/publications/acm-author-izer-service> to learn how to create links for free downloads from the ACM DL. * The official publication date is the date the papers are made available in the ACM Digital Library. This date may be up to *two weeks prior* to the first day of the conference. The official publication date affects the deadline for any patent filings related to published work. * Authors of each accepted submission are invited to attend and be available for the presentation of that paper at the conference. The schedule for presentations will be determined and shared with authors after the full program has been selected. ### Artifact Evaluation Authors of papers that are conditionally accepted in the first phase of the review process will be encouraged (but not required) to submit supporting materials for Artifact Evaluation. These items will then be reviewed by an Artifact Evaluation Committee, separate from the paper Review Committee, whose task is to assess how the artifacts support the work described in the associated paper. Papers that go through the Artifact Evaluation process successfully will receive a seal of approval printed on the papers themselves. Authors of accepted papers will be encouraged to make the supporting materials publicly available upon publication of the papers, for example, by including them as "source materials" in the ACM Digital Library. An additional seal will mark papers whose artifacts are made available, as outlined in the ACM guidelines for artifact badging. Participation in Artifact Evaluation is voluntary and will not influence the final decision regarding paper acceptance. ### Special categories of papers In addition to research papers, PACMPL issue ICFP solicits two kinds of papers that do not require original research contributions: Functional Pearls, which are full papers, and Experience Reports, which are limited to half the length of a full paper. Authors submitting such papers should consider the following guidelines. #### Functional Pearls A Functional Pearl is an elegant essay about something related to functional programming. Examples include, but are not limited to: * a new and thought-provoking way of looking at an old idea * an instructive example of program calculation or proof * a nifty presentation of an old or new data structure * an interesting application of functional programming techniques * a novel use or exposition of functional programming in the classroom While pearls often demonstrate an idea through the development of a short program, there is no requirement or expectation that they do so. Thus, they encompass the notions of theoretical and educational pearls. Functional Pearls are valued as highly and judged as rigorously as ordinary papers, but using somewhat different criteria. In particular, a pearl is not required to report original research, but, it should be concise, instructive, and entertaining. A pearl is likely to be rejected if its readers get bored, if the material gets too complicated, if too much specialized knowledge is needed, or if the writing is inelegant. The key to writing a good pearl is polishing. A submission that is intended to be treated as a pearl must be marked as such on the submission web page, and should contain the words "Functional Pearl" somewhere in its title or subtitle. These steps will alert reviewers to use the appropriate evaluation criteria. Pearls will be combined with ordinary papers, however, for the purpose of computing the conference's acceptance rate. #### Experience Reports The purpose of an Experience Report is to help create a body of published, refereed, citable evidence that functional programming really works -- or to describe what obstacles prevent it from working. Possible topics for an Experience Report include, but are not limited to: * insights gained from real-world projects using functional programming * comparison of functional programming with conventional programming in the context of an industrial project or a university curriculum * project-management, business, or legal issues encountered when using functional programming in a real-world project * curricular issues encountered when using functional programming in education * real-world constraints that created special challenges for an implementation of a functional language or for functional programming in general An Experience Report is distinguished from a normal PACMPL issue ICFP paper by its title, by its length, and by the criteria used to evaluate it. * Both in the papers and in any citations, the title of each accepted Experience Report must end with the words "(Experience Report)" in parentheses. The acceptance rate for Experience Reports will be computed and reported separately from the rate for ordinary papers. * Experience Report submissions can be at most 12 pages long, excluding bibliography. * Each Experience Report accepted to the PACMPL issue will be presented at the conference, but depending on the number of Experience Reports and regular papers accepted, authors of Experience reports may be asked to give shorter talks. * Because the purpose of Experience Reports is to enable our community to accumulate a body of evidence about the efficacy of functional programming, an acceptable Experience Report need not add to the body of knowledge of the functional-programming community by presenting novel results or conclusions. It is sufficient if the Report states a clear thesis and provides supporting evidence. The thesis must be relevant to the PACMPL issue, but it need not be novel. The review committee will accept or reject Experience Reports based on whether they judge the evidence to be convincing. Anecdotal evidence will be acceptable provided it is well argued and the author explains what efforts were made to gather as much evidence as possible. Typically, more convincing evidence is obtained from papers which show how functional programming was used than from papers which only say that functional programming was used. The most convincing evidence often includes comparisons of situations before and after the introduction or discontinuation of functional programming. Evidence drawn from a single person's experience may be sufficient, but more weight will be given to evidence drawn from the experience of groups of people. An Experience Report should be short and to the point: it should make a claim about how well functional programming worked on a particular project and why, and produce evidence to substantiate this claim. If functional programming worked in this case in the same ways it has worked for others, the paper need only summarize the results; the main part of the paper should discuss how well it worked and in what context. Most readers will not want to know all the details of the project and its implementation, but the paper should characterize the project and its context well enough so that readers can judge to what degree this experience is relevant to their own projects. The paper should take care to highlight any unusual aspects of the project. Specifics about the project are more valuable than generalities about functional programming; for example, it is more valuable to say that the team delivered its software a month ahead of schedule than it is to say that functional programming made the team more productive. If the paper not only describes experience but also presents new technical results, or if the experience refutes cherished beliefs of the functional-programming community, it may be better to submit it as a full paper, which will be judged by the usual criteria of novelty, originality, and relevance. The associate editor will be happy to advise on any concerns about which category to submit to. ### ICFP Organizers General Chair: Sukyoung Ryu (KAIST, South Korea) Accessibility Co-Chairs: Lindsey Kuper (UC Santa Cruz, USA), Kathrin Stark (Princeton University, USA) Artifact Evaluation Co-Chairs: Gabriel Scherer (INRIA Saclay, France), Brent Yorgey (Hendrix College, USA) Industrial Relations Co-Chairs: Alan Jeffrey (Roblox, USA), Simon Marlow (Facebook, England) Programming Contest Co-Organisers: Alex Lang, Jasper Van der Jeugt (Fugue, Switzerland) Publicity and Web Chair: Sam Tobin-Hochstadt (Indiana University, USA) Student Research Competition Chair: Anders Miltner (University of Texas, USA) Student Volunteer Co-Chairs: Lily Bryant (University of British Columbia, Canada), Jaemin Hong (KAIST, South Korea), Hanneli Tavante (McGill University, Canada) Video Co-Chairs: Leif Andersen (Northeastern University, USA), Benjamin Chung (Northeastern University, USA) Workshops Co-Chairs: Leonidas Lampropoulos (University of Maryland, USA), Zoe Paraskevopoulou (Princeton University, USA) ### PACMPL Volume 5, Issue ICFP 2021 Associate Editor: Ronald Garcia, (University of British Columbia, Canada) Review Committee: Zena Ariola (University of Oregon, USA) Stephanie Balzer (Carnegie Mellon University, USA) Matteo Cimini (UMass Lowell, USA) Youyou Cong (Tokyo Institute of Technology, Japan) Harley Eades (University of Augusta, USA) Andrew Gordon (Microsoft Research & University of Edinburgh, United Kingdom) Benjamin Greenman (Brown University, USA) Arjun Guha (Northeastern University, USA) Jurriaan Hage (Utrecht, The Netherlands) Favonia (University of Minnesota, USA) Suresh Jagannathan (Purdue University, USA) Patricia Johann (Appalachian State University, USA) Ralf Jung (Max Planck Institute, Germany) Ekaterina Komendantskaya (Heriot-Watt, Scotland) Leonidas Lampropoulos (University of Maryland, USA) Kazutaka Matsuda (Tohoku University, Japan) Akimasa Morihata (Univeristy of Tokyo, Japan) Stefan Muller (Illinois Institute of Technology, USA) Max New (Wesleyan University, USA) Rishiyur Nikhil (Bluespec , USA) Cyrus Omar (University of Michigan, USA) Brigitte Pientka (McGill University, Canada) Norman Ramsey (Tufts University, USA) Christine Rizkallah (University of New South Wales, Australia) Taro Sekiyama (National Institute for Informatics, Japan) Eijiro Sumii (Tohoku University, Japan) Amin Timany (Aarhus University, Denmark) Mitchell Wand (Northeastern University, USA) Steve Zdancewic (University of Pennsylvania, USA)

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