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https://hackage.haskell.org/package/hoq build problems
by Vasili I. Galchin 14 Oct '15

14 Oct '15

Hello, I stumbled across hoq and it sounds very interesting to me. However, it has build problems now enumerated in the official build reports. I was thinking to investigate and possibly fix these build problems. However, when I run "cabal configure", I already ran into a problem: "unrecognized option `--extra-prog-path=/home/vasili/.cabal/bin'" I have been trying to track this down. Not sure how to fix this. Any help?? Regards, Vasily

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[Announce] haskintex-0.6.0.0
by Daniel Díaz Casanueva 13 Oct '15

13 Oct '15

Dear Haskell users, I just released a new version of haskintex, the program that runs Haskell code inside LaTeX documents. http://hackage.haskell.org/package/haskintex # More about haskintex For those who don't know the program yet, _haskintex_ is a tool that executes Haskell code inside LaTeX documents, creating a new LaTeX document where each Haskell expression has been replaced by its result. Furthermore, since haskintex has a special command for using the HaTeX library, you will be able to write Haskell code that generates LaTeX code. Find more details in the haskintex documentation page: http://daniel-diaz.github.io/projects/haskintex # What's new? One of the main issues when evaluating Haskell code with haskintex was that haskintex was not aware of sandbox environments, so it had to rely on user or global package databases. From version 0.6.0.0, haskintex can now detect and use sandbox package databases, with no additional effort required from you. The -nosandbox flag has been added in case you still want the old behavior. Another addition is the -autotexy flag. Without the flag, every expression contained in a \hatex command is required to have type LaTeX. When the flag is enabled, this restriction is relaxed to any type that is an instance of the Texy typeclass. This typeclass contains instances for types that can be rendered to LaTeX syntax. Could be some text, numbers, or even matrices. You can create your own instances too. Suggestions, bugs, questions? Head to the haskintex issue tracker: https://github.com/Daniel-Diaz/haskintex/issues Happy texing, Daniel Díaz.

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CFP: Workshop on Real World Domain Specific Languages, March 2016
by Simon Thompson 12 Oct '15

12 Oct '15

CALL FOR PAPERS ================================= Workshop on Real World Domain Specific Languages https://sites.google.com/site/realworlddsl In conjunction with The International Symposium on Code Generation and Optimisation 2016. http://cgo.org/cgo2016 Barcelona, 12-13 March, 2016 ================================= As the use of computers proliferates, the complexity and variety of systems continues to grow. As a result, it is becoming increasingly inflexible to "hard wire” behaviours into software. Software developers can enable more control over their software configurations by exploiting Domain Specific Languages (DSLs). Such DSLs provide a systematic way to structure the underlying computational components: to coin a phrase, a DSL is a library with syntax. There is an enormous variety of DSLs for a very wide range of domains. Most DSLs are highly idiosyncratic, reflecting both the specific natures of their application domains and their designers’ own preferences. This workshop will bring together constructors of DSLs for “real world” domains; that is, DSLs intended primarily to aid in building software to solve real world problems rather than to explore the more theoretical aspects of language design and implementation. We are looking for submissions that present the motivation, design, implementation, use and evaluation of such DSLs. ================================= Key Dates: ---------------- Paper submission deadline: 10 January 2016. Author notification: 2 February 2016. Final manuscript due: 21 February 2016. Workshop: 12-13 March 2016. ---------------- Submission Instructions: The EasyChair submission page for this workshop is https://easychair.org/conferences/?conf=rwdsl16 Accepted submissions will be published in the ACM Digital Library within its International Conference Proceedings Series. Submissions should be 8-10 in ACM double-column format. Authors should follow the information for formatting ACM SIGPLAN conference papers, which can be found at http://www.sigplan.org/Resources/Author. We will provide more details of the submissions format and process at the beginning of November. ================================= Program Chairs Rob Stewart, Heriot-Watt University Greg Michaelson, Heriot-Watt University PC Members Jost Berthold, Commonwealth Bank of Australia Andy Gill, University of Kansas Kevin Hammond, University of St Andrews Rita Loogen, Philipps Universitat Marburg Patrick Maier, University of Glasgow Josef Svenningsson, Chalmers University Simon Thompson, University of Kent Phil Trinder, University of Glasgow Contact Please email inquiries concerning the workshop to: R.Stewart(a)hw.ac.uk Simon Thompson | Professor of Logic and Computation School of Computing | University of Kent | Canterbury, CT2 7NF, UK s.j.thompson(a)kent.ac.uk | M +44 7986 085754 | W www.cs.kent.ac.uk/~sjt

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GHC 7.10.2 Stage 1 compiler
by Alexey Raga 12 Oct '15

12 Oct '15

Hello, On the "Download" page (https://www.haskell.org/ghc/download_ghc_7_10_2) I see the archive with the binaries for ARM. Unfortunately this archive doesn't seem to include stage 1 compiler (which would be a cross-compiler from x86 or x64 to ARM as far as I understand). I am trying to build one myself, but unfortunately no luck so far. Is it possible to know the detailed instructions on how the existing ARM package has been built? A script or a dockerfile would be ideal. I could tune that build and make a docker container that could cross-compile x64 -> ARM... Regards, Alexey.

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ANNOUNCE: mezzolens 0.0.0 & a puzzle
by roconnor＠theorem.ca 11 Oct '15

11 Oct '15

This is a pre-release of mezzolens, a library of first-order functional references based purely on profunctors. I wrote it because https://www.reddit.com/user/Faucelme asked for one. You can find it at https://hackage.haskell.org/package/mezzolens The main purpose of this pre-release is to provide background for framing the following question: In a pure profunctor lens libray, how do you write choosing and beside in such a way that it supports all the following types? choosing :: Lens ta tb a b -> Lens sa sb a b -> Lens (Either ta sa) (Either sa sb) a b choosing :: Traversal ta tb a b -> Travesal sa sb a b -> Traversal (Either ta sa) (Either sa sb) a b choosing :: SEC ta tb a b -> SEC sa sb a b -> SEC (Either ta sa) (Either sa sb) a b beside :: Traversal ta tb a b -> Travesal sa sb a b -> Traversal (Either ta sa) (Either sa sb) a b beside :: SEC ta tb a b -> SEC sa sb a b -> SEC (Either ta sa) (Either sa sb) a b One sufficent solution for choosing would be to write a single function that combines lensVL :: (forall f. Functor f => (a -> f b) -> ta -> f tb) -> Lens ta tb a b traversal :: (forall f. Applicative f => (a -> f b) -> ta -> f tb) -> Traversal ta tb a b into one. The obvious approach is to write an suitable adaptor that transforms any (strong) profunctor into a functor, and if the profunctor is wandering, it produces an applicative functor. But I haven't been able to devise such a suitable adaptor. -- Russell O'Connor <http://r6.ca/> ``All talk about `theft,''' the general counsel of the American Graphophone Company wrote, ``is the merest claptrap, for there exists no property in ideas musical, literary or artistic, except as defined by statute.''

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Final Call for Haskell Prime language committee Nominations!
by Herbert Valerio Riedel 11 Oct '15

11 Oct '15

The submission deadline (Wed, Oct 14 23:59:59 UTC 2015) for Haskell Prime self-nominations (see also original CfN at [1]) is near! If you have already submitted a self-nomination, please make sure (if it was sent to the haskell-prime list) that it shows up in the mailing list archives at - https://mail.haskell.org/pipermail/haskell-prime/2015-September/ or - https://mail.haskell.org/pipermail/haskell-prime/2015-October/ or (if you have only sent it to me directly) that I acknowledged receiving your submission by an email reply. Regards, Herbert Valerio Riedel [1]: https://mail.haskell.org/pipermail/haskell-prime/2015-September/003936.html

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Monads for Drummers! Yet another monad tutorial with pictures!
by Anton Kholomiov 10 Oct '15

10 Oct '15

Yes! It's another monad tutorial. I've tried hard not to do it but finally it came out. I wrote a book on Haskell in Russian. It's a translation of the chapter that is dedicated to monads. I was convinced by friends to publish it. The monads are explained with pictures and Kleisli categories. Hope this can help to someone to grasp the monad concept. ------------------------------------- ps: pictures were made with diagrams Thank you for being kind with my awkward English!

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ANNOUNCE: unordered-graphs
by Ivan Lazar Miljenovic 10 Oct '15

10 Oct '15

I have a relatively hacked-together graph library that uses unordered-containers as a backend available if anyone finds it interesting/useful: http://hackage.haskell.org/package/unordered-graphs It's primarily developed just for my own needs and thus I'm not sure how much future work I'll be doing on it, but I'm willing to accept pull requests. This library was semi-experimental in that I also tried a few things out with it: * Polymorphic node type * Fixed auto-generated edge type: this is because (node,node, label) triples (ala fgl) do not provide sufficient information to be able to distinguish between multiple edges, etc. * Type parameter to determine whether the graph is directed or undirected. * Typeclass to allow you to determine the type/output of a a match (I didn't end up actually using this, as the one time I needed to do a match I found the extra polymorphism caused problems; it also isn't comprehensive as I didn't write all that many instances.) -- Ivan Lazar Miljenovic Ivan.Miljenovic(a)gmail.com http://IvanMiljenovic.wordpress.com

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Interfacing with the GHC runtime from a library
by Nicola Gigante 10 Oct '15

10 Oct '15

Hi everybody, suppose to have an Haskell library which is in part implemented in C for whatever reason. Can the C part talk with the runtime, in particular the scheduler? In other words, does the runtime expose the functionality needed to implement, for example, the STM library from outside the GHC runtime itself? Thank you, Nicola

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Vote/comment on usability survey feedback
by Rick Dzekman 09 Oct '15

09 Oct '15

*Responses* Over 100 people responded to the Hackage usability survey. For a qualitative survey this was far more than expected so thank you all for contributing. I'm still going through the responses and will post a csv of the combined web, email and reddit responses soon. *Vote and comment* In the meantime I went through and collated all of the gripes and suggestions people made into two Trello boards: Suggestions board: https://trello.com/b/WJRNDtkD/hackage-usability-suggestions Issues & bugs board: https://trello.com/b/8YSJ5XYV/hackage-usability-issues If you have a Trello account (it's free to register) you can comment and vote on issues. *Please vote on the issues/suggestions you think are the best or most important*. Feel free to make any relevant comments on the cards as well. To vote simply open the card, look in the "Actions" section and select vote. That's it. If reading through the suggestions/issues makes you think of something new simply comment on the very top card and I can add your new suggestion to the list. *What happens next?* There are two things that I want to achieve: 1. Come up with a list of simple, easy to implement changes that can be done on Hackage/Haddocks 2. Come up with wireframes for a potential future state of Hackage that the community can comment on / contribute to, which encompasses everything learned from the survey Not every suggestion is going to be feasible regardless of how popular it is. Additionally, any suggestions which are feasible have to be implemented by someone. The more enthusiasm there is behind an idea (or issue) the more likely we are to see progress.

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