July 2021 - Haskell-Cafe

FMCAD Student Forum CFP (Deadline Sat July 10)
by Mark Santolucito 09 Jul '21

09 Jul '21

# Student Forum Continuing the tradition of the previous years, FMCAD 2021 is hosting a Student Forum that provides a platform for students at any career stage (undergraduate or graduate) to introduce their research to the wider Formal Methods community, and solicit feedback. The Student Forum will be held in a hybrid format, online via video conferencing. ## Submissions Submissions must be short reports describing research ideas or ongoing work that the student is currently pursuing. Joint submissions from two students are allowed, provided the students contributed equally to the work - however, joint submissions must be presented by a single student. The topic of the reports must be within the scope of the FMCAD conference. These reports will NOT be published, thus we welcome reports based on already submitted/published papers. However, the novel aspects to be addressed in future work must be clearly described. Submissions should follow the same formatting guidelines as those for regular FMCAD conference submissions, except that the length is limited to 2 pages IEEE format, including all figures and references. ## Important Dates - Student forum submission: July 10, 2021 - Student forum notification: Aug 6, 2021 These deadlines are 11:59 pm AoE (Anywhere on Earth) More info here: https://fmcad.org/FMCAD21/student_forum/ ## Main Activities ### Student Forum Talks. Each student will give a lightning talk. In the case that a student is attending FMCAD physically, the talk will be given in-person at the conference. In the case that a student is attending FMCAD remotely, the talk will be given over Zoom. ### Discussion Groups. Students will have the opportunity to explain and discuss their work in small groups. More details to come on the logistics of discussion for remote participants. Submissions for the event must be short reports describing research ideas or ongoing work that the student is currently pursuing, and must be within the scope of FMCAD. Work, part of which has been previously published, will be considered; the novel aspect to be addressed in future work must be clearly described in such cases. All submissions will be reviewed by a subgroup of FMCAD committee members. ## Format The event will consist of short presentations by the student authors of each accepted submission, and of a virtual poster session. All participants of the conference are encouraged to attend the talks, ask questions and discuss with their fellow students in the virtual post sessions. Instructions for the preparation of the talks and poster sessions will be announced on notification of acceptance. ## Visibility Accepted submissions will be listed, with title and author name, in the event description in the conference proceedings. The authors will also have the option to upload their slide deck/poster/presentation to the FMCAD website. The report itself will not appear in the FMCAD proceedings; thus, the presentation at FMCAD should not interfere with potential future submissions of this research (to FMCAD or elsewhere). The best contributions (determined by public vote by attendees) will be given public recognition and a certificate at the event. ***Forum Chair*** Mark Santolucito (msantolu(a)barnard.edu) chairs the Student Forum. Feel free to send an email if you have questions about the event.

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Hyrum's law (Was: [RFC] Support Unicode characters in instance Show String)
by Henning Thielemann 09 Jul '21

09 Jul '21

moving to Haskell Cafe On Thu, 8 Jul 2021, Bardur Arantsson wrote: > On 08/07/2021 17.53, Oleg Grenrus wrote: > > [--snip--] > >> >> 78 out of 2819 tests failed (35.88s) >> > > The use of Show in 'golden' test suites is interesting because Show > doesn't really guarantee any real form of stability in its output. > > I guess Hyrum's Law applies here too. > > Anyway... just an idle observation. Obviously, breaking loads of test > suites is going to be hard to swallow. I found this explanation: https://www.hyrumslaw.com/ Nice to have a name for this observation. I think the problem can be relaxed if there are multiple implementations for the same interface. But then you often find, that the implementations do not even adhere to the interface, thus people start guessing what the interface actually means. I hope that in the future we can describe interfaces more formally, such that a user knows what he can rely on.

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Where have the discussions moved to?
by Carette, Jacques 09 Jul '21

09 Jul '21

Haskell Café used to be quite active. But in the last 2 years, at least, there have been much less traffic. In the same time frame, Haskell's popularity and community has expanded greatly. The logical conclusion is that discussions have moved elsewhere. I know that, for example, there are at times a large amount of discussion happening via github on the proposals [1] (in fact, so much so that I unsubscribed). I am aware that the community page [2] does mention quite a few places - too many. Is there one of those places where the kinds of discussions that used to happen here have moved to? Jacques [1] https://github.com/ghc-proposals/ghc-proposals [2] https://www.haskell.org/community/

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[ANN] Copilot 3.4 - hard realtime C runtime verification
by Frank Dedden 09 Jul '21

09 Jul '21

Dear all, We are pleased to announce the release of Copilot 3.4, a stream-based DSL for writing and monitoring embedded C programs, with an emphasis on correctness and hard realtime requirements. Copilot is typically used as a high-level runtime verification framework, and supports temporal logic (LTL, PTLTL and MTL), clocks and voting algorithms. Among others, Copilot has been used at the Safety Critical Avionics Systems Branch of NASA Langley Research Center for monitoring test flights of drones. This release introduces a number of bug fixes and deprecates functions that have been superseded. The newest release is available on hackage [1]. For more information, including documentation, examples and links to the source code, please visit the webpage [2]. Current emphasis is on facilitating the use with other systems, and improving the codebase in terms of stability and test coverage. Users are encouraged to participate by opening issues and asking questions via our github repo [3]. Kind regards, The Copilot developers: - Frank Dedden - Alwyn Goodloe - Ivan Perez [1] https://hackage.haskell.org/package/copilot [2] https://copilot-language.github.io [3] https://github.com/Copilot-Language/copilot

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How to debug SQL disconnect error
by Olaf Klinke 08 Jul '21

08 Jul '21

Dear Café, How can I go about examining an SQL error [1] when using persistent- odbc to access an MS SQL database? Set up a pristine MS SQL server 2012. Installed the driver on Debian using apt-get install msodbcsql17. Upon running either of persitent's printMigration or runMigration, the disconnect produces an error: *** Exception: SqlError {seState = "["25000"]", seNativeError = -1, seErrorMsg = "freeDbcIfNotAlready/SQLDisconnect: ["0: [Microsoft][ODBC Driver 17 for SQL Server]Invalid transaction state"]"} Running the printed SQL statements with isql executes allright, so it is not the particular migration at fault here. Presently I don't even know whether persistent or persistent-odbc or any false assumptions about the connection configuration is the cause. Thanks in advance Olaf [1] https://github.com/gbwey/persistent-odbc/issues/26

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FMBC 2021 - Call for Participation
by Bruno Bernardo 06 Jul '21

06 Jul '21

[ Please distribute, apologies for multiple postings. ] ======================================================================== 3rd International Workshop on Formal Methods for Blockchains (FMBC) 2021 - Call for Participation https://fmbc.gitlab.io/2021 July 18 and 19, 2021, Online, 8AM-10AM PDT Co-located with the 33rd International Conference on Computer-Aided Verification (CAV 2021) http://i-cav.org/2021/ --------------------------------------------------------- The FMBC workshop is a forum to identify theoretical and practical approaches of formal methods for Blockchain technology. Topics include, but are not limited to: * Formal models of Blockchain applications or concepts * Formal methods for consensus protocols * Formal methods for Blockchain-specific cryptographic primitives or protocols * Design and implementation of Smart Contract languages * Verification of Smart Contracts The list of lightning talks and conditionally accepted papers is available on the FMBC 2021 website: https://fmbc.gitlab.io/2021/program.html There will be one keynote by David Dill, Lead Researcher on Blockchain at Novi/Facebook and professor emeritus at Stanford University, USA. Registration Registration to FMBC 2021 is done through the CAV 2021 registration form: http://i-cav.org/2021/attending/ (*Early bird deadline is July 9.*)

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ANN: hledger-1.22
by Simon Michael 04 Jul '21

04 Jul '21

I'm pleased to announce hledger 1.22 ! https://hledger.org/release-notes.html#hledger-1-22 describes the user-visible changes. Highlights include: - Optimisations: about 20% faster overall, with register about 2x faster and 4x more memory-efficient - Bugfixes, including fixes for several regressions. Thank you to the following release contributors this time around: Felix Yan, crocket, Eric Mertens, Damien Cassou, charukiewicz, Garret McGraw, and especially Stephen Morgan. hledger (https://hledger.org) is a dependable, cross-platform "plain text accounting" tool, with command-line, terminal and web interfaces. It is an actively maintained, largely compatible reimplementation of Ledger CLI with many improvements. You can use it to track money, time, investments, cryptocurrencies, inventory and more. See also the Plain Text Accounting site (https://plaintextaccounting.org) https://hledger.org/download shows all the ways to install hledger on mac, windows or unix (stack, cabal, brew, nix, CI binaries, your package manager..). Or, run this bash script to install or upgrade to the latest release: $ curl -sO https://raw.githubusercontent.com/simonmichael/hledger/master/hledger-insta… $ less hledger-install.sh # security review $ bash hledger-install.sh New users, check out https://hledger.org/quickstart or the tutorials (with pictures!) at hledger.org -> FIRST STEPS or the https://hledger.org/videos.html. To get help, see https://hledger.org#help, and join one of our chat rooms: - #hledger:matrix.org (http://matrix.hledger.org) - #hledger:libera.chat (http://irc.hledger.org) Beginners and experts, contributors, sponsors, and all feedback are most welcome! Wishing you health and prosperity, -Simon

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