- Haskell-Cafe - Haskell.org

Network deprecation
by Evan Laforge 06 Nov '18

06 Nov '18

I'm starting to get deprecation warnings about Network in the network package. I know this has been in the works for a long time, but now that I search I can't find any info about the rationale and suggested replacement (the deprecation message suggests Network.Socket, but this is a completely different lower level api). Does anyone out there have links to discussions, articles, or whatnot? Thanks in advance!

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reading file content with conduit
by Fabien R 05 Nov '18

05 Nov '18

Hello, I have a strange behaviour with my code when reading data from a file saved by sinkFile. I only see the first record of the file, although the file seems to contain several records. Any hints ? -- built in a sandbox with GHC 8.2.2, base 4.10.1.0, binary 0.8.5.1, bytestring 0.8.10.2, conduit 1.3.1 {-# LANGUAGE DeriveGeneric #-} import qualified Data.ByteString as DB import qualified Data.ByteString.Lazy as DBL import qualified Data.Binary as DBI import GHC.Generics (Generic) import Conduit import Data.Int (Int64) data MySubRec = MySubRec { sr1 :: Float, sr2 :: Float } deriving (Generic, Show) data MyRec = MyRec { r1 :: Int64, r2 :: String, r3 :: [MySubRec], r4 :: [MySubRec] } deriving (Generic, Show) instance DBI.Binary MySubRec instance DBI.Binary MyRec es = MySubRec { sr1 =1.0, sr2 =1000.5 } myList = repeat es e1 = MyRec{ r1=1, r2="e1", r3=take 2 myList, r4=take 1 myList} e2 = MyRec{ r1=2, r2="e2", r3=take 2 myList, r4=take 1 myList} myData = concat $ repeat [e1,e2] dataToBs :: Monad m => ConduitT MyRec DB.ByteString m () dataToBs = do d <- await case d of Just bs -> do yield $ DBL.toStrict $ DBI.encode bs dataToBs _ -> return () bsToData :: Monad m => ConduitT DB.ByteString MyRec m () bsToData = do d <- await case d of Just bs -> do yield $ DBI.decode $ DBL.fromStrict bs bsToData _ -> return () main = do runConduitRes $ yieldMany (take 10 myData) .| dataToBs .| sinkFile "/tmp/res.bin" runConduitRes $ sourceFile "/tmp/res.bin" .| bsToData .| mapM_C (liftIO . putStrLn . show)

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Journal of Functional Programming - Call for PhD Abstracts
by Graham Hutton 05 Nov '18

05 Nov '18

Dear all, If you or one of your students recently completed a PhD in the area of functional programming, please submit the dissertation abstract for publication in JFP: simple process, no refereeing, open access, deadline 30th November 2018. Please share! Best wishes, Graham Hutton ============================================================ CALL FOR PHD ABSTRACTS Journal of Functional Programming Deadline: 30th November 2018 http://tinyurl.com/jfp-phd-abstracts ============================================================ PREAMBLE: Many students complete PhDs in functional programming each year. As a service to the community, the Journal of Functional Programming publishes the abstracts from PhD dissertations completed during the previous year. The abstracts are made freely available on the JFP website, i.e. not behind any paywall. They do not require any transfer of copyright, merely a license from the author. A dissertation is eligible for inclusion if parts of it have or could have appeared in JFP, that is, if it is in the general area of functional programming. The abstracts are not reviewed. Please submit dissertation abstracts according to the instructions below. We welcome submissions from both the PhD student and PhD advisor/supervisor although we encourage them to coordinate. ============================================================ SUBMISSION: Please submit the following information to Graham Hutton <graham.hutton(a)nottingham.ac.uk> by 30th November 2018. o Dissertation title: (including any subtitle) o Student: (full name) o Awarding institution: (full name and country) o Date of PhD award: (month and year; depending on the institution, this may be the date of the viva, corrections being approved, graduation ceremony, or otherwise) o Advisor/supervisor: (full names) o Dissertation URL: (please provide a permanently accessible link to the dissertation if you have one, such as to an institutional repository or other public archive; links to personal web pages should be considered a last resort) o Dissertation abstract: (plain text, maximum 350 words; you may use \emph{...} for emphasis, but we prefer no other markup or formatting; if your original abstract exceeds the word limit, please submit an abridged version within the limit) Please do not submit a copy of the dissertation itself, as this is not required. JFP reserves the right to decline to publish abstracts that are not deemed appropriate. ============================================================ PHD ABSTRACT EDITOR: Graham Hutton School of Computer Science University of Nottingham Nottingham NG8 1BB United Kingdom ============================================================ This message and any attachment are intended solely for the addressee and may contain confidential information. If you have received this message in error, please contact the sender and delete the email and attachment. Any views or opinions expressed by the author of this email do not necessarily reflect the views of the University of Nottingham. Email communications with the University of Nottingham may be monitored where permitted by law.

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Re: [Haskell-cafe] Looking for feedback on my beginner's Haskell resource
by Olaf Klinke 03 Nov '18

03 Nov '18

This guide would be a perfect fit for literate Haskell [1]. It is a file format where you mix markup (e.g. LaTeX) and Haskell, so the file can be interpreted either way. In a nutshell, your html content becomes Haskell comments or the Haskell becomes <code> blocks in html. In that way, your readers could just load your document into ghci and play with it. Not sure whether html is supported out of the box, though. You might need to pass the .lhs file through pandoc [2] or another tool. Can anyone clarify/help on this? Cheers, Olaf [1] https://wiki.haskell.org/Literate_programming [2] https://groups.google.com/forum/#!topic/hakyll/lFfHAk2nxbs

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Get number of fields for non-record ADTs using Data type class?
by Markus Läll 03 Nov '18

03 Nov '18

Dear list, Is it possible te get the number of fields for data constructors for a plain ADT, i.e something with no record fields? E.g for data T = A Int Double | B String (Maybe String) it would give 2 for both `A` and `B`. For a record it's possible using the `constrFields` function from Data.Data. I was trying to follow this tutorial by Christopher Done https://chrisdone.com/posts/data-typeable, and I feel that it must be possible somehow to get these numbers with the gmap*/gfold* functions, but the use of them is over my head at the moment. Best, -- Markus Läll

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Re: [Haskell-cafe] 2018 State of Haskell Survey
by Doug McIlroy 03 Nov '18

03 Nov '18

The survey didn't work for me in either Internet Explorer or Microsoft Edge: In IE an attempt to scroll a pull-down "Add an option" menu would dismiss the menu. In ME the same menus needed a scroll bar, but the bar was missing. Doug McIlroy

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2018 State of Haskell Survey
by Jasper Van der Jeugt 02 Nov '18

02 Nov '18

Hi all, (apologies if you receive multiple copies of this email) We are running a 2018 State of Haskell Survey here: https://airtable.com/shr8G4RBPD9T6tnDf If you have some time to spare, please submit a response. This goes a long way in helping the community. The survey closes on the 15th of November. This survey is co-sponsored by Haskell.org and Haskell Weekly, but I'd like to give credit where credit is due, so I'll add that Taylor Fausak did almost all of the hard work -- thanks a lot! Kind regards Jasper Van der Jeugt on behalf of the Haskell.org committee

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Intention to Take Over adblock2privoxy Hackage Package
by Steven Smith 30 Oct '18

30 Oct '18

Dear Haskell Cafe, I’m writing to publicly state my intention to take over the adblock2privoxy Hackage package: http://hackage.haskell.org/package/adblock2privoxy <http://hackage.haskell.org/package/adblock2privoxy> using the forked github repo at: https://github.com/essandess/adblock2privoxy <https://github.com/essandess/adblock2privoxy> I have been unable to contact the package’s creator/maintainer at the email provided, and the original repo <https://projects.zubr.me/wiki/adblock2privoxy> has not been updated for several years. I forked this project about a year and a half ago, and since then have addressed <https://github.com/essandess/adblock2privoxy/commits/master> many issues and incorporated feedback and fixed from the github community, including compilation with the most recent GHC compiler. I am following up on a suggestion made here to publish the latest version in Hackage, following the procedure to take over a package: https://github.com/essandess/adblock2privoxy/pull/29#issue-215776931 <https://github.com/essandess/adblock2privoxy/pull/29#issue-215776931> https://wiki.haskell.org/Taking_over_a_package <https://wiki.haskell.org/Taking_over_a_package> My Hackage username is essandess. Sincerely, Steve

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Call For Workshop Proposals
by Sam Tobin-Hochstadt 30 Oct '18

30 Oct '18

CALL FOR WORKSHOP AND CO-LOCATED EVENT PROPOSALS ICFP 2019 24th ACM SIGPLAN International Conference on Functional Programming August 18 - 23, 2019 Berlin, Germany https://icfp19.sigplan.org/ The 24th ACM SIGPLAN International Conference on Functional Programming will be held in Berlin, Germany on August 18-23, 2019. ICFP provides a forum for researchers and developers to hear about the latest work on the design, implementations, principles, and uses of functional programming. Proposals are invited for workshops (and other co-located events, such as symposiums) to be affiliated with ICFP 2019 and sponsored by SIGPLAN. These events should be less formal and more focused than ICFP itself, include sessions that enable interaction among the attendees, and foster the exchange of new ideas. The preference is for one-day events, but other schedules can also be considered. The workshops are scheduled to occur on August 18th (the day before ICFP) and 22-23th of August (the two days after ICFP). ---------------------------------------------------------------------- Submission details Deadline for submission: November 25, 2018 Notification of acceptance: December 23, 2018 Prospective organizers of workshops or other co-located events are invited to submit a completed workshop proposal form in plain text format to the ICFP 2019 workshop co-chairs (Jennifer Hackett and Christophe Scholliers), via email to icfp-workshops-2019(a)googlegroups.com by November 25, 2018. (For proposals of co-located events other than workshops, please fill in the workshop proposal form and just leave blank any sections that do not apply.) Please note that this is a firm deadline. Organizers will be notified if their event proposal is accepted by December 23, 2018, and if successful, depending on the event, they will be asked to produce a final report after the event has taken place that is suitable for publication in SIGPLAN Notices. The proposal form is available at: http://www.icfpconference.org/icfp2019-files/icfp19-workshops-form.txt Further information about SIGPLAN sponsorship is available at: http://www.sigplan.org/Resources/Proposals/Sponsored/ ---------------------------------------------------------------------- Selection committee The proposals will be evaluated by a committee comprising the following members of the ICFP 2019 organizing committee, together with the members of the SIGPLAN executive committee. Workshop Co-Chair: Jennifer Hackett (University of Nottingham) Workshop Co-Chair: Christophe Scholliers (University of Ghent) General Chair: Derek Dreyer (MPI-SWS) Program Chair: François Potier (Inria) ---------------------------------------------------------------------- Further information Any queries should be addressed to the workshop co-chairs (Jennifer Hackett and Christophe Scholliers), via email to icfp-workshops-2019(a)googlegroups.com

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ANN: Major releases of 'fltkhs-themes' and 'fltkhs' for nice looking, portable native GUIs
by aditya siram 28 Oct '18

28 Oct '18

I'm happy to announce two major releases: fltkhs-themes [1] : a drop-in replacement to FLTKHS [2] with a vastly better looking UX [3] . The small but growing showcase app should hopefully give a better feel for it. And to help you get started with your own project there is a starter app [7] and a lot more documentation [8]. fltkhs[2]: the underlying GUI binding to FLTK which after nearly 6 months of continuous work has been overhauled with a ton of bug fixes and shoring up of the API (fixing leaks, making types more precise via newtypes etc.) and new features have been added including new widgets and out-of-the-box HiDPI and SVG support (which fltkhs-themes relies on heavily for nicer widgets). All the starter kits and demo packages have been updated to this version. If you need help migrating an existing app to the new API feel free to send email to the address on Hackage page or hit me up on Twitter. There a lot more documentation on installation and getting started in the Hackage docs [4]. As always if you have any problems please open an issue on fltkhs [5], fltkhs-themes or any of my other repos. Hopefully these releases help you make Haskell native GUI apps that are fast, portable, easy to install/deploy, and nice looking! [1] http://hackage.haskell.org/package/fltkhs-themes [2] http://hackage.haskell.org/package/fltkhs [3] https://github.com/deech/fltkhs-themes-demo#screenshots [4] http://hackage.haskell.org/package/fltkhs/docs/Graphics-UI-FLTK-LowLevel-FL… [5] https://github.com/deech/fltkhs/issues [6] https://github.com/deech/fltkhs-themes/issues [7] https://github.com/deech/fltkhs-light-theme-skeleton [8] http://hackage.haskell.org/package/fltkhs-themes/docs/Graphics-UI-FLTK-Them…

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