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Galois is hiring!
by Jason Dagit 01 Mar '13

01 Mar '13

Galois is hiring! We're looking for functional programmers, formal methods practitioners, and project leads, with a variety of positions open at all professional experience levels. For more information on the job openings and Galois in general, see: http://corp.galois.com/careers I've written before about what makes Galois a great organization to be a part of: http://blog.codersbase.com/2012/03/life-at-galois.html Thanks, Jason

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cabal install ghc-mod installs 3 years old version
by Niklas Hambüchen 01 Mar '13

01 Mar '13

Hi, I just did cabal update and cabal install ghc-mod, and for some reason it tries to install version 0.3.0 from 3 years ago: " cabal install ghc-mod -v Reading available packages... Choosing modular solver. Resolving dependencies... Ready to install ghc-mod-0.3.0 Downloading ghc-mod-0.3.0... " cabal --version cabal-install version 1.16.0.2 using version 1.16.0.3 of the Cabal library Does anyone have an idea why that could be? Thanks

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The state of binary (de)serialization
by Nicolas Trangez 01 Mar '13

01 Mar '13

All, In order to implement some network protocol clients recently, I needed binary serialization of commands and deserialization of responses ('Command -> ByteString' and 'ByteString -> Response' functions, preferably for both strict as well as lazy ByteStrings). My go-to packages have always been 'binary' and 'cereal', but I was wondering about the current (and future) state/goals: - cereal supports chunk-based 'partial' parsing (runGetPartial). It looks like support for this is introduced in recent versions of 'binary' as well (runGetIncremental) - cereal can output a strict bytestring (runPut) or a lazy one (runPutLazy), whilst binary only outputs lazy ones (runPut) - Next to binary and cereal, there's bytestring's Builder interface for serialization, and Simon Meier's "blaze-binary" prototype There are some blog posts and comments out there about merging cereal and binary, is this what's the goal/going on (cfr runGetIncremental)? In my use-case I think using Builder instead of binary/cereal's PutM monad shouldn't be a major problem. Is this advisable performance-wise? Overall: what's the advised future-proof strategy of handling binary (de)serialization? Thanks, Nicolas

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Haskell Weekly News: Issue 260
by Daniel Santa Cruz 01 Mar '13

01 Mar '13

Welcome to issue 260 of the HWN, an issue covering crowd-sourced bits of information about Haskell from around the web. This issue covers the week of February 17 to 23, 2013. Quotes of the Week * danharaj: zygohistobfuscatory maintainomorphism * merijn: after a week you can delete 80% of your code and replace it with whatever edwardk wrote that day ;-) * merijn: If Oleg is the unit of type hackery I propose Edward as the unit of haskell productivity. * edwardk: the merijn is the unit for the number of distinct units you've named * elliott: If you encounter an edwardk in the wild: nod reassuringly when he talks about something you understand. Under NO circumstances EVER give your GitHub account name Top Reddit Stories * An awesome Haskell Valentines card, from my non-programmer girlfriend. Domain: i.imgur.com, Score: 127, Comments: 32 On Reddit: [1] http://goo.gl/5Cxwr Original: [2] http://goo.gl/BeksW * Announcing SmallCheck 1.0 Domain: ro-che.info, Score: 61, Comments: 16 On Reddit: [3] http://goo.gl/R0gvO Original: [4] http://goo.gl/7b5Dq * Intro to FRP and purely functional games: live-coding the basics of Mario in ~30 lines in Elm [video] Domain: ustream.tv, Score: 50, Comments: 12 On Reddit: [5] http://goo.gl/E22PW Original: [6] http://goo.gl/q7r8e * Reflections After a Hard Day in Haskell GUI Land Domain: fluffynukeit.com, Score: 49, Comments: 53 On Reddit: [7] http://goo.gl/xQv8i Original: [8] http://goo.gl/0hvT6 * Duncan Coutts on Parallelism and Concurrency with Haskell, Distributed Programming with Cloud Haskell Domain: infoq.com, Score: 44, Comments: 5 On Reddit: [9] http://goo.gl/jU9EH Original: [10] http://goo.gl/UkRDk * A Game of Type-Safe Tic-Tac-Toe Domain: github.com, Score: 42, Comments: 20 On Reddit: [11] http://goo.gl/SrIEx Original: [12] http://goo.gl/dFIyd * The Algebra of Algebraic Data Types, Part 3 Domain: chris-taylor.github.com, Score: 36, Comments: 7 On Reddit: [13] http://goo.gl/NQI8S Original: [14] http://goo.gl/CPkiV * Write Yourself a Haskell... in Lisp Domain: gergo.erdi.hu, Score: 36, Comments: 3 On Reddit: [15] http://goo.gl/YqdSl Original: [16] http://goo.gl/E3yzO * Overloading record fields with Lens Domain: statusfailed.com, Score: 31, Comments: 19 On Reddit: [17] http://goo.gl/oF7zN Original: [18] http://goo.gl/SOEz4 * On partial functions in Idris Domain: edwinb.wordpress.com, Score: 29, Comments: 3 On Reddit: [19] http://goo.gl/0HquS Original: [20] http://goo.gl/OaO2r * Who's using Haskell commercially? New collection of real-world case studies from FP Complete. Domain: fpcomplete.com, Score: 26, Comments: 12 On Reddit: [21] http://goo.gl/IM2rb Original: [22] http://goo.gl/zsf4c * Making 'Super Nario Bros.' in Haskell Domain: youtube.com, Score: 26, Comments: 11 On Reddit: [23] http://goo.gl/2Hg7o Original: [24] http://goo.gl/9Bb5t Top StackOverflow Questions * Why is there no implicit parallelism in Haskell? votes: 29, answers: 4 Read on SO: [25] http://goo.gl/n6VkF * Why is (a,b,c,d) not sugar for (a,(b,(c,(d,()))))? votes: 26, answers: 2 Read on SO: [26] http://goo.gl/aW6K2 * How can I understand “(.) . (.)”? votes: 21, answers: 5 Read on SO: [27] http://goo.gl/kqbcO * Are there any advantages of using Rank2Types in favor of RankNTypes? votes: 18, answers: 2 Read on SO: [28] http://goo.gl/V5naQ * What's the closest thing to Haskell's typeclasses in OCaml? votes: 16, answers: 4 Read on SO: [29] http://goo.gl/AWvgl * Why does ghci give me a type for “1 ++ 2” instead of ragequitting? votes: 16, answers: 2 Read on SO: [30] http://goo.gl/66Pti * Is (>>) supposed to discard all left-side output? votes: 11, answers: 2 Read on SO: [31] http://goo.gl/wvnLJ * Find inferred type for local function votes: 11, answers: 3 Read on SO: [32] http://goo.gl/WFCz1 * STUArray s i e - space leak only when i == Int? votes: 11, answers: 2 Read on SO: [33] http://goo.gl/fbyPE * Connecting to the System GHC votes: 10, answers: 1 Read on SO: [34] http://goo.gl/FGVN5 * Correctness of implicit lifting votes: 10, answers: 2 Read on SO: [35] http://goo.gl/5s8pR Until next time, +Daniel Santa Cruz References 1. http://i.imgur.com/P0d7v7z.jpg 2. http://www.reddit.com/r/haskell/comments/18q510/an_awesome_haskell_valentin… 3. http://ro-che.info/articles/2013-02-19-smallcheck.html 4. http://www.reddit.com/r/haskell/comments/18uhfy/announcing_smallcheck_10/ 5. http://www.ustream.tv/recorded/29330499 6. http://www.reddit.com/r/haskell/comments/190n1t/intro_to_frp_and_purely_fun… 7. http://fluffynukeit.com/2013/02/reflections-after-a-hard-day-in-haskell-gui… 8. http://www.reddit.com/r/haskell/comments/18p0nu/reflections_after_a_hard_da… 9. http://www.infoq.com/interviews/coutts-haskell 10. http://www.reddit.com/r/haskell/comments/18zvk2/duncan_coutts_on_parallelis… 11. https://github.com/leonidas/codeblog/blob/master/2013/2013-02-19-typesafe-t… 12. http://www.reddit.com/r/haskell/comments/18tys6/a_game_of_typesafe_tictacto… 13. http://chris-taylor.github.com/blog/2013/02/13/the-algebra-of-algebraic-dat… 14. http://www.reddit.com/r/haskell/comments/18p3p5/the_algebra_of_algebraic_da… 15. http://gergo.erdi.hu/blog/2013-02-17-write_yourself_a_haskell..._in_lisp/ 16. http://www.reddit.com/r/haskell/comments/18pm7r/write_yourself_a_haskell_in… 17. http://statusfailed.com/blog/2013/02/19/overloading-record-fields-with-lens… 18. http://www.reddit.com/r/haskell/comments/18t2n7/overloading_record_fields_w… 19. http://edwinb.wordpress.com/2013/02/19/on-partial-functions-in-idris/ 20. http://www.reddit.com/r/haskell/comments/18tbkj/on_partial_functions_in_idr… 21. http://fpcomplete.com/announcing-case-studies/ 22. http://www.reddit.com/r/haskell/comments/18p5n4/whos_using_haskell_commerci… 23. http://www.youtube.com/watch?v=gVLFGQGRsDw 24. http://www.reddit.com/r/haskell/comments/18v4ep/making_super_nario_bros_in_… 25. http://stackoverflow.com/questions/15005670/why-is-there-no-implicit-parall… 26. http://stackoverflow.com/questions/14973459/why-is-a-b-c-d-not-sugar-for-a-… 27. http://stackoverflow.com/questions/15029843/how-can-i-understand 28. http://stackoverflow.com/questions/15020428/are-there-any-advantages-of-usi… 29. http://stackoverflow.com/questions/14934242/whats-the-closest-thing-to-hask… 30. http://stackoverflow.com/questions/15041581/why-does-ghci-give-me-a-type-fo… 31. http://stackoverflow.com/questions/14953032/is-supposed-to-discard-all-left… 32. http://stackoverflow.com/questions/15034392/find-inferred-type-for-local-fu… 33. http://stackoverflow.com/questions/15038386/stuarray-s-i-e-space-leak-only-… 34. http://stackoverflow.com/questions/14918453/connecting-to-the-system-ghc 35. http://stackoverflow.com/questions/14928302/correctness-of-implicit-lifting 36. https://plus.google.com/105107667630152149014/about

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Split and substitution using regex-pcre
by Simon Marechal 28 Feb '13

28 Feb '13

I could not find the perl-equivalents of these functions on Hackage, so I quickly wrote mine. Code is there: https://github.com/bartavelle/pcre-utils It should behave like perl (not really tested actually), and do strange things like : > splitCompile "a" "aaaab" Right ["","","","","b"] > splitCompile "a" "aaaabaaa" Right ["","","","","b"] This will go on Hackage as I need it for the language-puppet package, but I am interested in comments, especially concerning the namespaces: * is the name of this package OK ? * is the name of the package OK ? * should I work with the regex-pcre maintainer to try to merge it ?

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How to return a network connection to C
by C K Kashyap 28 Feb '13

28 Feb '13

Hi, I am using Network.Connection to connect to gmail in my Haskell module - that's compiled to DLL and invoked from C. I need a mechanism to return the connection handle to C so that it can pass it in the subsequent calls. How can I achieve this? Regards, Kashyap

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Question about forkIO
by C K Kashyap 28 Feb '13

28 Feb '13

Hi All, Say I have a haskell function 'f' that does a forkIO and starts an action "a". I create a DLL of this haskell code and inovke "f" from C. Can I expect the "a" to continue to run once "f" has returned to C? Regards, Kashyap

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How does one create an input handle bound to a string instead of a file?
by John D. Ramsdell 28 Feb '13

28 Feb '13

How does one create a value of type System.IO.Handle for reading that takes its input from a string instead of a file? I'm looking for the equivalent of java.io.StringReader in Java. Thanks in advance. John

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Implementing name-mangling in GHC?
by Ismael Figueroa Palet 28 Feb '13

28 Feb '13

Hi café, I'm working on a small project, and I need to rename all ocurrences of a data type in a module. For instance, if the program is module Foo where data Bar fun :: Bar -> Bar fun = ... I'd like that during compilation the module looks as if it was written like: module Foo where data _BarXZY fun :: _BarXZY -> _BarXZY fun ... I think the simplest way to do this is using TH to define a special $data splice, which directly mangles the name. But then I'd need another splice every time I want to use the type. I've read other options like implementing a GHC compiler plugin ( http://www.haskell.org/ghc/docs/7.2.1/html/users_guide/compiler-plugins.html ) is it possible to perform the renaming by modifying the ModGuts structure in a compiler pass? Can you please give more pointers on how to perform this task? Thanks -- Ismael

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Problem accessing Hackage
by Roman Cheplyaka 28 Feb '13

28 Feb '13

I have this weird problem accessing hackage, when the first response gets delayed by 30 seconds: http://superuser.com/q/557271/53951 Does anyone else experience it? (No need to reply with "works for me" — I know that it works for most people.) Any clues about what can be the problem? Roman

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