December 2013 - Haskell-Cafe

Troubleshooting-type questions
by Lucas Paul 20 Dec '13

20 Dec '13

I wouldn't want to clutter the list with off-topic stuff, so I'll ask first. Once in a while I'll have trouble trying to use some piece of software, like Shpider or Yesod. Is it on-topic to ask specific "how-do-I-use/do"-type questions for particular packages like that on this list? -- Lucas Paul

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Haskell Job Opportunity
by Jeff Polakow 20 Dec '13

20 Dec '13

AlephCloud is an early stage Silicon Valley startup creating a secure cloud content management system. Haskell is our main server side language and we are looking to hire a few more Haskell programmers. Some topics of interest to us are: cloud services, cryptography/security, cross compilation (javascript, iOS, ARM). We are somewhat flexible about location, though we¹d prefer people on the west coast of the US. If interested feel free to contact me (jeff(a)alephcloud.com) for more information, or send a message (and/or a resume) to resume(a)alephcloud.com. thanks, Jeff

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Fwd: Package Maintenance: dtd-types, dtd-text
by Montez Fitzpatrick 20 Dec '13

20 Dec '13

I would like to take over maintenance of the following two packages: "dtd-types" & "dtd-text". I have attempted to e-mail the original package author with no response. I realize this can be a busy time of the year; personally, I would have no problems what-so-ever when/if the original author returns to relinquish stewardship of the aforementioned packages. Montez

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Haskell Weekly News: Issue 288
by Daniel Santa Cruz 20 Dec '13

20 Dec '13

Welcome to issue 288 of the HWN, an issue covering crowd-sourced bits of information about Haskell from around the web. This issue covers the week from December 08 to 14, 2013. Quotes of the Week * nlogax: With FRP.Sodium and Graphics.UI.GLUT you could put together a MonadSodium GLUTamate Top Reddit Stories * The reason why `cabal update` takes so long Domain: github.com, Score: 175, Comments: 89 On Reddit: [1] http://goo.gl/NCsf34 Original: [2] http://goo.gl/BLp5LB * structured-haskell-mode — Structured editing minor mode for Haskell in Emacs Domain: github.com, Score: 103, Comments: 37 On Reddit: [3] http://goo.gl/t8dyd9 Original: [4] http://goo.gl/v6W7js * Amazing LVars talk by Linsey Kuper Domain: youtu.be, Score: 86, Comments: 20 On Reddit: [5] http://goo.gl/JcbNQn Original: [6] http://goo.gl/JPyVnG * 24 Days of Hackage: acid-state Domain: ocharles.org.uk, Score: 84, Comments: 15 On Reddit: [7] http://goo.gl/CBU18T Original: [8] http://goo.gl/W4u7GG * 24 Days of Hackage: pandoc Domain: ocharles.org.uk, Score: 66, Comments: 14 On Reddit: [9] http://goo.gl/rUO2yc Original: [10] http://goo.gl/PhTTFC * text 1.0.0.0 Domain: hackage.haskell.org, Score: 64, Comments: 25 On Reddit: [11] http://goo.gl/9k7ksP Original: [12] http://goo.gl/ISESbc * 24 Days of Hackage: async Domain: ocharles.org.uk, Score: 59, Comments: 11 On Reddit: [13] http://goo.gl/rhrdgM Original: [14] http://goo.gl/C4sQeh * 24 Days of Hackage: sbv (guest post by Tikhon Jelvis) Domain: ocharles.org.uk, Score: 57, Comments: 21 On Reddit: [15] http://goo.gl/YkLqo9 Original: [16] http://goo.gl/frHdyn * 24 Days of Hackage: data-memocombinators Domain: ocharles.org.uk, Score: 56, Comments: 18 On Reddit: [17] http://goo.gl/0FgDo6 Original: [18] http://goo.gl/4GcFKd * Bryan O'Sullivan - Package dependency management: more debate is needed Domain: plus.google.com, Score: 51, Comments: 45 On Reddit: [19] http://goo.gl/Xr7NkU Original: [20] http://goo.gl/f1VPxt * 24 Days of Hackage: gloss Domain: ocharles.org.uk, Score: 49, Comments: 10 On Reddit: [21] http://goo.gl/yBAlXk Original: [22] http://goo.gl/mplvhP * The future of array-oriented computing in Haskell — a survey Domain: justtesting.org, Score: 45, Comments: 11 On Reddit: [23] http://goo.gl/doVpgz Original: [24] http://goo.gl/ezkftd * Progress Reporting in Shake Domain: neilmitchell.blogspot.it, Score: 42, Comments: 3 On Reddit: [25] http://goo.gl/1hvu6c Original: [26] http://goo.gl/4izrhK * [ANN] SFML and SFML-control Domain: self.haskell, Score: 40, Comments: 20 On Reddit: [27] http://goo.gl/NhMJbR Original: [28] http://goo.gl/NhMJbR * 24 Days of Hackage: heist Domain: ocharles.org.uk, Score: 40, Comments: 28 On Reddit: [29] http://goo.gl/FtvnLs Original: [30] http://goo.gl/nEU9Hw Top StackOverflow Questions * How are J/K/APL classified in terms of common paradigms? votes: 10, answers: 1 Read on SO: [31] http://goo.gl/ImISrG * Is it possible to extend free monad interpreters? votes: 9, answers: 5 Read on SO: [32] http://goo.gl/CiJupH * How to detect a Monad? votes: 8, answers: 4 Read on SO: [33] http://goo.gl/WiUhba * Why do Haskell type signature declarations have multiple arrows? votes: 7, answers: 3 Read on SO: [34] http://goo.gl/0LWfMb * “Inheriting” instance of wrapped type votes: 7, answers: 1 Read on SO: [35] http://goo.gl/qBhrqD * Equality function for pair components votes: 7, answers: 1 Read on SO: [36] http://goo.gl/mLk49N * Motivation of having Functional Dependencies votes: 7, answers: 1 Read on SO: [37] http://goo.gl/E31zjJ * Haskell - Lenses, use of 'to' function votes: 7, answers: 1 Read on SO: [38] http://goo.gl/5A028y * What does PINNED mean in -hc profile of Haskell program? votes: 6, answers: 1 Read on SO: [39] http://goo.gl/Qx9eJB Until next time, [40]+Daniel Santa Cruz References 1. https://github.com/nominolo/HTTP/commit/b9bd0a08fa09c6403f91422e3b23f08d339… 2. http://www.reddit.com/r/haskell/comments/1sh67u/the_reason_why_cabal_update… 3. https://github.com/chrisdone/structured-haskell-mode 4. http://www.reddit.com/r/haskell/comments/1sd3aj/structuredhaskellmode_struc… 5. http://youtu.be/8dFO5Ir0xqY 6. http://www.reddit.com/r/haskell/comments/1skf3x/amazing_lvars_talk_by_linse… 7. http://ocharles.org.uk/blog/posts/2013-12-14-24-days-of-hackage-acid-state.… 8. http://www.reddit.com/r/haskell/comments/1svlm2/24_days_of_hackage_acidstat… 9. http://ocharles.org.uk/blog/guest-posts/2013-12-12-24-days-of-hackage-pando… 10. http://www.reddit.com/r/haskell/comments/1srcz6/24_days_of_hackage_pandoc/ 11. http://hackage.haskell.org/package/text-1.0.0.0 12. http://www.reddit.com/r/haskell/comments/1st4jl/text_1000/ 13. http://ocharles.org.uk/blog/posts/2013-12-13-24-days-of-hackage-async.html 14. http://www.reddit.com/r/haskell/comments/1stf7l/24_days_of_hackage_async/ 15. http://ocharles.org.uk/blog/guest-posts/2013-12-09-24-days-of-hackage-sbv.h… 16. http://www.reddit.com/r/haskell/comments/1shnr7/24_days_of_hackage_sbv_gues… 17. http://ocharles.org.uk/blog/posts/2013-12-08-24-days-of-hackage-data-memoco… 18. http://www.reddit.com/r/haskell/comments/1settx/24_days_of_hackage_datamemo… 19. https://plus.google.com/103469090998089605155/posts/HdC6oCy8RWW 20. http://www.reddit.com/r/haskell/comments/1sdwot/bryan_osullivan_package_dep… 21. http://ocharles.org.uk/blog/posts/2013-12-10-24-days-of-hackage-gloss.html 22. http://www.reddit.com/r/haskell/comments/1sl0y5/24_days_of_hackage_gloss/ 23. http://justtesting.org/post/69439080517/the-future-of-array-oriented-comput… 24. http://www.reddit.com/r/haskell/comments/1sfg7l/the_future_of_arrayoriented… 25. http://neilmitchell.blogspot.it/2013/12/progress-reporting-in-shake.html 26. http://www.reddit.com/r/haskell/comments/1sqsyi/progress_reporting_in_shake/ 27. http://www.reddit.com/r/haskell/comments/1sjemq/ann_sfml_and_sfmlcontrol/ 28. http://www.reddit.com/r/haskell/comments/1sjemq/ann_sfml_and_sfmlcontrol/ 29. http://ocharles.org.uk/blog/posts/2013-12-11-24-days-of-hackage-heist.html 30. http://www.reddit.com/r/haskell/comments/1sob71/24_days_of_hackage_heist/ 31. http://stackoverflow.com/questions/20558170/how-are-j-k-apl-classified-in-t… 32. http://stackoverflow.com/questions/20564633/is-it-possible-to-extend-free-m… 33. http://stackoverflow.com/questions/20495627/how-to-detect-a-monad 34. http://stackoverflow.com/questions/20459981/why-do-haskell-type-signature-d… 35. http://stackoverflow.com/questions/20481718/inheriting-instance-of-wrapped-… 36. http://stackoverflow.com/questions/20515404/equality-function-for-pair-comp… 37. http://stackoverflow.com/questions/20526828/motivation-of-having-functional… 38. http://stackoverflow.com/questions/20528718/haskell-lenses-use-of-to-functi… 39. http://stackoverflow.com/questions/20478805/what-does-pinned-mean-in-hc-pro… 40. https://plus.google.com/105107667630152149014/about

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Job opportunities at Galois Inc.
by Iavor Diatchki 19 Dec '13

19 Dec '13

Hello, Galois is still hiring! We are located in beautiful Portland, Oregon and are currently looking for researchers, principal investigators, and software engineers, including those with expertise in functional programming, formal methods, computer security, control systems, informatics, or networking. For more information, take a look at http://corp.galois.com/careers and please feel free to drop me an e-mail if you have questions. Happy Holidays, -Iavor

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Haskell and Big Data
by jean-christophe mincke 19 Dec '13

19 Dec '13

Hello Cafe, Big Data is a bit trendy these days. Does anybody know about plans to develop an Haskell eco-system in that domain? I.e tools such as Storm or Spark (possibly on top of Cloud Haskell) or, at least, bindings to tools which exist in other languages. Thank you Regards J-C

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Persisting a Map
by Andrew Cowie 19 Dec '13

19 Dec '13

I have a Map. It's a lovely Map, with keys and values and everything. It's not _that_ large. Few 10s of MB at most. Unfortunately, I need to persist it somewhat reliably. I'd somewhat like to avoid having to use an external database (obviously a key/value store like Riak would work, but that's a major dependency to impose on the system) so I'm wondering if there is a low tech way to do this. I can control concurrent access to the file (or whatever), and the file system is robust. So that part is fine. I just need to externalize the map. I'm wondering if just using cereal or so would be sufficient (there is a Serialize instance, of course), or whether I should be using some acid-state thing, or a Haskell binding to gdbm, or sqlite, or... Any suggestions? AfC Sydney

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ANNOUNCE: Ajhc Haskell Compiler 0.8.0.10 Release
by Kiwamu Okabe 18 Dec '13

18 Dec '13

We are happy to announce Ajhc 0.8.0.10 as Christmas release! You can get Ajhc using "cabal install drift && cabal install ajhc" command. The usage is found at Ajhc's project web site http://ajhc.metasepi.org/. The source code at https://github.com/ajhc/ajhc. Welcome sending any bugs or your ideas to https://github.com/ajhc/ajhc/issues. ## News ### Android demo Android demo application using Haskell is available at Google Play. https://play.google.com/store/apps/details?id=org.metasepi.ajhc.android.cube ### Clear license notification * Runtime: [MIT License](https://github.com/ajhc/ajhc/blob/master/rts/LICENSE) * Haskell libraries: [MIT License](https://github.com/ajhc/ajhc/blob/master/lib/LICENSE) * The others: [GPLv2 or Later](https://github.com/ajhc/ajhc/blob/arafura/COPYING) ## Other changes * Depend on DrIFT again / Do not need derive * Fix GC root BUG * Use findExecutable instead of the raw `which` * Come back bytestring * And fix other BUGs Enjoy! :) - - - Metasepi team

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SYB supports genuine gmap. [Was: Polymorphic updating with TC/TFs?]
by oleg＠okmij.org 18 Dec '13

18 Dec '13

adam vogt wrote > Changing type parameters isn't supported by the ones I know (syb), but > you can still fake it: <http://www.haskell.org/haskellwiki/SYB#fmap>. SYB supports the type-changing generic map, of the signature > gmap2 :: forall a b c . (Data a, Data b, > Data (c a), Data (c b), Data (c X)) => > (a -> b) -> c a -> c b It was discovered back in 2008. Please see the following thread starting http://www.haskell.org/pipermail/generics/2008-July/000349.html The fake described in haskellwiki/SYB#fmap with unsafeCoerce is not needed at all. There is a genuine gmap.

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Monad.Reader #23 call for copy
by Edward Z. Yang 18 Dec '13

18 Dec '13

Call for Copy: The Monad.Reader - Issue 23 -------------------------------------------- Whether you're an established academic or have only just started learning Haskell, if you have something to say, please consider writing an article for The Monad.Reader! The submission deadline for Issue 23 will be: **Friday, January 17, 2014** The Monad.Reader ~~~~~~~~~~~~~~~~ The Monad.Reader is a electronic magazine about all things Haskell. It is less formal than journal, but somehow more enduring than a wiki- page. There have been a wide variety of articles: exciting code fragments, intriguing puzzles, book reviews, tutorials, and even half-baked research ideas. Submission Details ~~~~~~~~~~~~~~~~~~ Get in touch with me if you intend to submit something -- the sooner you let me know what you're up to, the better. Please submit articles for the next issue to me by e-mail (ezyang(a)mit.edu) Articles should be written according to the guidelines available from http://themonadreader.wordpress.com/contributing/ Please submit your article in PDF, together with any source files you used. The sources will be released together with the magazine under a BSD license. If you would like to submit an article, but have trouble with LaTeX please let me know and we'll work something out.

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