April 2015 - Haskell-Cafe

cabal install glade
by Jean Lopes 22 Apr '15

22 Apr '15

Hello, I am trying to install the Glade package from hackage, and I keep getting exit failure... Hope someone can help me solve it! What I did: $ mkdir ~/haskell/project $ cd ~/haskell/project $ cabal sandbox init $ cabal update $ cabal install alex $ cabal install happy $ cabal install gtk2hs-buildtools $ cabal install gtk #successful until here $ cabal install glade The last statement gave me the following error: $ [1 of 2] Compiling SetupWrapper ( /tmp/cairo-0.12.5.3-5133/cairo-0.12.5.3/SetupWrapper.hs, /tmp/cairo-0.12.5.3-5133/cairo-0.12.5.3/dist/dist-sandbox-acbd4b7/setup/SetupWrapper.o ) $ $ /tmp/cairo-0.12.5.3-5133/cairo-0.12.5.3/SetupWrapper.hs:91:17: $ Ambiguous occurrence ‘die’ $ It could refer to either ‘Distribution.Simple.Utils.die’, $ imported from ‘Distribution.Simple.Utils’ at /tmp/cairo-0.12.5.3-5133/cairo-0.12.5.3/SetupWrapper.hs:8:1-32 $ or ‘System.Exit.die’, $ imported from ‘System.Exit’ at /tmp/cairo-0.12.5.3-5133/cairo-0.12.5.3/SetupWrapper.hs:21:1-18 $ Failed to install cairo-0.12.5.3 $ [1 of 2] Compiling SetupWrapper ( /tmp/glib-0.12.5.4-5133/glib-0.12.5.4/SetupWrapper.hs, /tmp/glib-0.12.5.4-5133/glib-0.12.5.4/dist/dist-sandbox-acbd4b7/setup/SetupWrapper.o ) $ $ /tmp/glib-0.12.5.4-5133/glib-0.12.5.4/SetupWrapper.hs:91:17: $ Ambiguous occurrence ‘die’ $ It could refer to either ‘Distribution.Simple.Utils.die’, $ imported from ‘Distribution.Simple.Utils’ at /tmp/glib-0.12.5.4-5133/glib-0.12.5.4/SetupWrapper.hs:8:1-32 $ or ‘System.Exit.die’, $ imported from ‘System.Exit’ at /tmp/glib-0.12.5.4-5133/glib-0.12.5.4/SetupWrapper.hs:21:1-18 $ Failed to install glib-0.12.5.4 $ cabal: Error: some packages failed to install: $ cairo-0.12.5.3 failed during the configure step. The exception was: $ ExitFailure 1 $ gio-0.12.5.3 depends on glib-0.12.5.4 which failed to install. $ glade-0.12.5.0 depends on glib-0.12.5.4 which failed to install. $ glib-0.12.5.4 failed during the configure step. The exception was: $ ExitFailure 1 $ gtk-0.12.5.7 depends on glib-0.12.5.4 which failed to install. $ pango-0.12.5.3 depends on glib-0.12.5.4 which failed to install. Important: You can assume I don't know much. I'm rather new to Haskell/cabal

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Help wanted with Wiki.Haskell.Org
by Gershom B 21 Apr '15

21 Apr '15

One of the central repositories of knowledge in the Haskell world is the HaskellWiki (https://wiki.haskell.org) This wiki has been with the Haskell community for years, and contains a wealth of knowledge. Like other services on the haskell.org domain and with haskell.org equipment, ultimate responsibility for maintaining it falls on the Haskell Committee. However, it is a community wiki, and requires care and maintenance and contributions from all of us. The wiki has been, and continues to be, a vital component in the Haskell world. Like any wiki, it is fueled by contributions from many people, and in this sense it is thriving. However, it could use a certain amount of attention and work in three key areas. We are looking for volunteers to step up in these regards, 1) Account Creation Management: Account creation is manual only because spambots otherwise destroy us. It would be worth investigating if a full upgrade and new plugins could help this issue. In the meantime, the responsibility for creating new accounts has fallen on only one person for years. This is not a good situation. We would like to set up a mail alias for wiki admins and extend account creation rights to a range of people. If you would be willing to be one of a team of responders to account creation requests, please write and let us know. 2) Technical and design oversight: Now that we have a new haskell.org homepage, the current wiki frontpage could use a redesign. For that matter, the whole wiki could use a bit of a redesign to bring it into a more modern style. Along with that, it may be the case that additional plugins — such as for typesetting code or equations better — could be quite helpful. It would be good to have a mediawiki admin who wants to help improve the technical capacities of the site, as well as to overhaul its look. Again, if you are interested in taking charge of this, please let us know. 3) Content curation: One issue with a large collection of documents written by different people is the lack of curation. Some pages fall out of date, information is spread across multiple pages instead of collected together, and quality varies greatly. Without a central authority, no one is responsible (or empowered) to fix the situation. There is a balance between keeping things up-to-date and preserving the historic content of the wiki, and without people feeling empowered to make big changes, the tendency will always fall towards the latter. We're looking for people in the community to volunteer to help improve this status quo. The task, generally speaking, is to be responsible for curating and improving the content of the wiki, but that's clearly a vague description with lots of room for individual embellishment. This doesn't need to be a single person either: a team working in a coordinated fashion could be incredibly effective. Once more, depending on response, we’d be happy to designate and empower people to make broader changes on the wiki or to organize a team to do so. If you are interested in this as well, please let us know. Gershom, for the Haskell.org Committee

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haskell.org
by Ertugrul Söylemez 21 Apr '15

21 Apr '15

Hi everybody, I'd like to note that the prime "sieve" example that is sitting at the top of the homepage is not a real sieve and will more likely make people with number theory experience (like me) feel highly irritated rather than fascinated. A real sieve does not only run a million times (!) faster and consumes far less memory, but is also much longer, even in Haskell. Here is a real one: <http://lpaste.net/101980> I don't want to make a mountain out of a molehill, but please note: If I'd be new to Haskell, that example would have turned me off, because it would have hurt my ability to take Haskell programmers seriously. You can easily promote your tools when you claim that they can build a car easily, except in reality it's just a toy bicycle. It's the same feeling to cryptographers when people call a regular stream cipher a "one-time pad" and promote it as such. It rings the "this is snake oil!" alarm bell. So I propose to either rename the 'sieve' function to something more appropriate (like `trialDiv`) or replace the example altogether. I would suggest an example that truly shows Haskell's strengths. Trial division search is really just a bad substitute for the more common and equally inappropriate list quicksort example. Greets, Ertugrul

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Looking for Senior Software Engineers
by Jonathan Fischoff 21 Apr '15

21 Apr '15

Dear Haskellers, There are two senior software engineer openings at skedge.me, a Haskell and NixOS based company located in Manhattan NY. Here are the job postings. http://www.indeed.com/cmp/skedge.me/jobs/Senior-Software-Engineer-18d7f042d… http://www.indeed.com/cmp/skedge.me/jobs/Senior-Software-Engineer-b62e69029… Professional Haskell experience is not required. Provided you have experience maintaining and developing web services, this is your chance to become a professional Haskeller (if you're not one already). Relocation will be provided, but remote is not an option. Please send your resumes to jobs(a)skedge.me if you are interested. Sincerely, Jonathan Fischoff VP of Engineering at skege.me

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ANN: Upload agentx, Library for write extensible SNMP agents.
by Алексей Смирнов 21 Apr '15

21 Apr '15

Can be useful for create monitoring tools. Usage example in docs. get, set, walk, context is work. Bulk work as simple get. Tables don't work, Indexes don't work. https://hackage.haskell.org/package/agentx https://github.com/chemist/agentx -- Alexey Smirnov.

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[ANN] Haskell Music - Two tracks in the Jungle style
by Anton Kholomiov 21 Apr '15

21 Apr '15

Dear list. I'd like to share two new tracks made in haskell (with csound-expression lib). They are two etudes in the style of the Jungle. One track is just a joke. I hope that Simon doesn't mind me sampling him. The track is made in Haskell :) So it's a musical thank-you for the wonderful language! https://soundcloud.com/anton-kho/jungle-etude-1 https://soundcloud.com/anton-kho/jungle-etude-2-feat-simon-peyton-jones Anton

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ANN: ssh, darcsden vulnerability
by Simon Michael 20 Apr '15

20 Apr '15

We recently learned of a serious undocumented vulnerability in the ssh <http://hackage.haskell.org/package/ssh> package. This is a minimal ssh server implementation used by darcsden <http://hackage.haskell.org/package/darcsden> to support darcs push/pull. If you use the ssh package, or you have darcsden’s darcsden-ssh server running, you should upgrade to/rebuild with the imminent ssh-0.3 release right away. Or if you know of someone like that, please let them know. Also, if you're interested in cryptography/security, additional help and patches for the ssh and darcsden packages would be very welcome. I've blogged more details at http://joyful.com/blog/2015-04-20-ssh-darcs-hub-vulnerability.html <http://joyful.com/blog/2015-04-20-ssh-darcs-hub-vulnerability.html> (if you're a Darcs Hub user, hopefully you've already seen it). Best - Simon

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Attempt to emulate subclasses in Haskell, am I reinventing the wheel?
by Clinton Mead 20 Apr '15

20 Apr '15

I've linked to an ugly attempt to emulate subclasses in Haskell, and I'm wondering if anyone has done what I have perhaps in a cleaner way. Firstly, the code is here: http://ideone.com/znHfSG To explain what I've done, I first thought that a "method" basically takes some "input" (which I've called "i"), an object (which I've called "c" for class) and returns some output "o" and a potentially modified object "c". I've captured this behaviour in the badly named class "C". I've then made a class "User", with methods "getFirstName" and "putFirstName" and defined them appropriately. Furthermore, I've then made a data type "Age", and then "ExtendedUser" which combines "User" with "Age". At this point, I can still call "getFirstName" and "putFirstName" on "ExtendedUser", as would be hoped. I also defined "getAge", which naturally works on ExtendedUser. Furthermore, I can override "getFirstName" on "ExtendedUser", which I have done to instead return a capitalised version. Is what I've done of any practical use? And has someone done it better than me?

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Fall Internship Opportunities at Galois
by Ryan Wright 20 Apr '15

20 Apr '15

Galois has some exciting opportunities for interns in software engineering/research for the Fall of 2015. Most of our projects use Haskell to some extent, so this is a great chance to get experience applying functional programming to important real-world problems. Please pass along this posting to anyone you think might be interested--even if they don't yet know Haskell! Thank you, Ryan Wright — # Galois Software Engineering/Research Intern # Galois is currently seeking software engineering and research interns for Fall 2015 at all educational levels. We are committed to matching interns with exciting and engaging engineering work that fits their particular interests, creating lasting value for interns, Galois, and our community. A Galois internship is a chance to tackle cutting-edge, meaningful problems in a uniquely collaborative environment with world-leading researchers. Roles may include technology research and development, requirements gathering, implementation, testing, formal verification, and infrastructure development. Past interns have integrated formal methods tools into larger projects, built comprehensive validation suites, synthesized high-performance cryptographic algorithms, written autopilots for quad-copters, designed the syntax and semantics of scripting languages, and researched type system extensions for academic publication. We deeply believe in providing comprehensive support and mentorship to all of our employees, particularly interns. We provide our employees with a steward who regularly checks in to ensure that they feel welcome and safe in the Galois community while gaining real value from their experiences. ## Important Dates ## Applications due: June 1st, 2015 Internship period (flexible): September through December, 2015 ## About Galois ## Our mission is to create trustworthiness in critical systems. We’re in the business of taking blue-sky ideas and turning them into real-world technology solutions. We’ve been developing real-world systems for over ten years using functional programming, language design, and formal methods. Galois values diversity. We believe that differing viewpoints and experiences are essential to the process of innovation. We look broadly, including outside of established communities, to deliver innovation. ## How to Prepare ## An internship is an opportunity for learning and growth as an engineer. To make the most of the opportunity, we ask that candidates have experience reading, writing, and maintaining code in a realistic project. Many university courses involve multi-week collaborative projects that provide this type of experience. Most of our projects use the Haskell programming language and the git version control system. These tools aren’t often taught in computer science classes, but there are many free resources available that we recommend for learning: - [Learn You a Haskell] for Great Good! [1] by Miran Lipovača - [Real World Haskell] [2] by Bryan O’Sullivan, Don Stewart, and John Goerzen - [tryGit] [3] by Code School - [Pro Git] [4] by Scott Chacon [1]: http://learnyouahaskell.com/ [2]: http://book.realworldhaskell.org/ [3]: http://try.github.io [4]: http://git-scm.com/book ## Qualifications ## The ability to be geographically located in Portland during the internship Experience reading, writing, and maintaining code in a project as described above Proficiency in software development practices such as design, documentation, testing, and the use of version control Well-developed verbal and written communication skills; comfort in a collaborative team environment The following skills are not required, but may be relevant to a particular project. - Proficiency in Haskell or other programming languages with rich type systems (eg., Scala, OCaml, Standard ML) - Experience using C and assembly languages for low-level systems programming - Development experience in high assurance systems or security software - Specific experience in an area of Galois’ expertise, such as: - Assured information sharing - Software modeling and formal verification - Cyber-physical systems and control systems - Operating systems, virtualization and secure platforms - Networking and mobile technology - Cyber defense systems - Scientific computing - Program analysis and software evaluation - Web security ## Logistics ## The length and start date of the internship are negotiable: starting any time from the new year through next spring is acceptable, but an intern must be at Galois for at least three continuous months. The internship is paid competitively, and interns are responsible for living arrangements (although we can certainly help you find arrangements). Galois is located in the heart of downtown Portland with multiple public transportation options available and world-class bicycle infrastructure. ## Application Details ## We’re looking for people who can invent, learn, think, and inspire. We reward creativity and thrive on collaboration. If you are interested, please send your cover letter and resume to us via http://galois-inc.hiringthing.com.

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New Functional Programming Job Opportunities
by Functional Jobs 20 Apr '15

20 Apr '15

Here are some functional programming job opportunities that were posted recently: Mid/Senior Software Development Engineer at Lookingglass Cyber Solutions http://functionaljobs.com/jobs/8810-mid-senior-software-development-enginee… Senior/Principal Software Development Engineer at Lookingglass Cyber Solutions http://functionaljobs.com/jobs/8809-senior-principal-software-development-e… Cheers, Sean Murphy FunctionalJobs.com

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