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SCSS 2014: Deadline extension

General haskell list - Tue, 06/24/2014 - 6:07pm
[Please post - apologies for multiple copies.] Deadline Extension ================================================ SCSS 2014 Symbolic Computation in Software Science 6th International Symposium Gammarth, La Marsa, Tunisia, December 7-11, 2014 ================================================ Important Dates --------------- July 7, 2014: Abstract submission deadline (extended) July 14, 2014: Paper submission deadline (extended) August 25, 2014: Notification September 22, 2014: Camera-ready copy deadline December 7-11, 2014: SCSS 2014 in Gammarth Scope -------- The purpose of SCSS 2014 is to promote research on theoretical and practical aspects of symbolic computation in software science. The symposium provides a forum for active dialog between researchers from several fields of computer algebra, algebraic geometry, algorithmic combinatorics, computational logic, and software analysis and verification. SCSS 2014 solicits both regular and tool papers on
Categories: Incoming News

Need help - my haskell code is over 50 times slower than equivalent perl implementation

haskell-cafe - Tue, 06/24/2014 - 5:08pm
Dear cafe, I have created a reproducible app here - Essentially I am trying to open a number of files and printing out their sized by reading them in and computing it's length. I have the equivalent perl program also there. I'd appreciate it very much if someone could take a look at my Haskell implementation and point out what I am doing wrong. Since it's over 50 times slower than the perl code, I assume I am doing something obviously incorrect. Regards, Kashyap _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
Categories: Offsite Discussion

What's your favorite response to the "show me the magic" question when it comes to Haskell?

Haskell on Reddit - Tue, 06/24/2014 - 2:34pm

Most everyone I talk to about haskell is already a programmer with their own favorite languages. What are some small, interesting/amazing things I can show people on a whiteboard to explain the power of haskell?

I'm looking (vaguely) for examples somewhat like 2.3 and 3.3 from here, or maybe like these examples I found. But, I'm hoping to find examples that can be given more on the fly, and at a somewhat high-language level to "evangelize" with, for lack of a better term.

Ideally the examples would be plain word examples that could be scratched out on a whiteboard impromptu. So for the above I might describe it something along the lines of "you could write out the sheep linage as "sheep, dad, dad's mom" ... etc. But if one of the sheep didn't have a parent, the entire chain would return "nothing". However in haskell you can write out monads to simplify the entire thing down to "grandma = sheep's mom's mom" and it takes care of all the possible lack of parents because of the monad class ... etc."

I realize haskell's true power comes from the paradigm shift you experience when programming, and from other things that are not as easy to explain, especially briefly or high-level, but rather have to be somewhat experienced on your own. That being said, can you guys think of any examples, even so?

submitted by thang1thang2
[link] [69 comments]
Categories: Incoming News

Decided to play with TChan last night, made a little worker pool + queue example. How would you improve it?

Haskell on Reddit - Tue, 06/24/2014 - 2:31pm

Primary concerns are on practicality, production readiness, etc. without making example too verbose.

Things I already know could be done:

  • Use TQueue (more efficient)
  • Use TBQueue (bounded and more efficient - back-pressure is difficult to do right)
  • Instead of sinking into side effects, send results as Async promises downstream or back to worker supervisor
  • Rate limiting (I mean above and beyond limiting worker pool size)
  • Dynamic adjustment of worker pool size in response to workload
  • Worker status updates, monitoring - I was thinking of maybe checking queue/chan size and submission of "time to complete last task" rolling metrics to get an idea of "how backed up are we?"
  • Use Pipes, pipes-concurrency, MVC, Conduit, Iteratees, io-streams, or simple-conduit - using any of these wouldn't change my operational/visibility concerns.

It's fine if you want to elaborate on any of the above, but they don't need mentioned now that I have.

Any ideas? This was inspired by a friend diving into Pipes recently to see if he could be happier with some Haskell code he was using at work. I was partly trying to see if the CSP'ish patterns I'm accustomed to "translate" to Haskell nicely.

I'm quite satisfied so far, but I know it's very naïve still.

submitted by Mob_Of_One
[link] [8 comments]
Categories: Incoming News

ANN: Graphics.OpenSCAD

haskell-cafe - Tue, 06/24/2014 - 1:14pm
Graphics.OpenSCAD provides an algebraic data type for creating OpenSCAD 3d models, as well a a function to generate an OpenSCAD program from a data structure. OpenSCAD is a "programmers" CAD tool. It provides a declarative language for 3d models with a primitive functional language for doing computation. The Graphics.OpenSCAD module tries to preserve the declarative parts by providing tools for building data structures that match the OpenSCAD declarative models, then embedding that in a powerful, modern functional language. The critical problem with OpenSCAD is the error handling. At it's best, it will say "syntax error" and provide sufficient location information to easily find the error. At times, the location information points outside the file. Errors in dealing with variables may have no error messages, or messages that are easy to overlook, resulting in models that are radically different from what was expected with no way to determine the problem except searching the complete program text. Graphics
Categories: Offsite Discussion

fsync(2), fdatasync(2), posix_fadvise(2) and posix_fallocate(2)

libraries list - Tue, 06/24/2014 - 12:55pm
I can't find a reason might have stalled but it seems like it has from my perspective. Can someone tell me I'm wrong or what to do to unstall it? This is very useful functionality that is actually part of IEEE Std 1003.1. -davean _______________________________________________ Libraries mailing list Libraries< at >
Categories: Offsite Discussion

Question about Cabal dependency resolution (vs Rust)

Haskell on Reddit - Tue, 06/24/2014 - 9:22am

Rust introduced it's package manager Cargo [1], and has the following feature:

If I have three packages: - uno depends on json 1.3.6 - dos depends on json 1.4.12 - tres depends on json 2.1.0 Cargo will use json 1.4.12 for uno and dos, and json 2.1.0 for tres.

I don't believe Cabal works like this (encouraging the use of SemVer [2] to version and aid dependency resolution of packages)

I know the way Cabal works is well-thought out. Would we want to do the same for Cabal, or is it trying to solve a harder problem (and what do we gain)?

(I looked at briefly)



submitted by Platz
[link] [13 comments]
Categories: Incoming News

FARM Workshop programme announced

Haskell on Reddit - Tue, 06/24/2014 - 5:38am
Categories: Incoming News

wren gayle romano: Reading Notes: Whipping Girl, chs.4–5

Planet Haskell - Tue, 06/24/2014 - 12:06am

Chapters 4 and 5 capture much of the experience of transitioning and of being trans, respectively. These are the chapters which so many trans memoirs convey in their narration, though often they avoid stating it quite so directly. Both chapters do a good job of conveying the lived experience of trans women, and are well worth reading by cis audiences for that reason.

Read more... )

Chapter 5 especially was nice to read as it cuts to the core of the fact that there are both conscious and subconscious components to our experiences of (our own) gender. Read more... )

Categories: Offsite Blogs

how to upgrade to a new version of Haskell?

haskell-cafe - Mon, 06/23/2014 - 10:48pm
I am currently running an old installation of the Haskell environment from 2012, and I would like to upgrade. Can I just grab the installer from and run it? This is on Windows.
Categories: Offsite Discussion

determine hoolge database directory

haskell-cafe - Mon, 06/23/2014 - 9:36pm
Hi haskellers, i'm new to haskell and am currently working on some tool that is supposed to fiddle with hoogle database files. Now I'm looking for a sane way to determine the directory where hoogle stores its database directories (when you perform `hoogle data`). In my case this is: .cabal/share/x86_64-linux-ghc-7.8.2/hoogle-4.2.33/databases So this is [home directory]/.cabal/[ghc-version]/[hoogle-version]/databases Could someone suggest me a sane way how I can determine this path at runtime ? Maybe there is a way to extract this from somewhere ? I'm out of ideas on this. I could of course take the easy way out and let users declare the path as config parameter but it would be nice if there was a way ... thanks in advance. regards, Tobi
Categories: Offsite Discussion

wren gayle romano: Reading Notes: Whipping Girl (2007), chs.0–2

Planet Haskell - Mon, 06/23/2014 - 9:30pm

I'm finally getting around to reading Julia Serano's Whipping Girl (2007), and I thought I'd make a few comments as I go along.

The first couple chapters are, by and large, an introduction to the terminology standard in gender studies and transgender circles. For those already familiar, it's light reading; though there are a few important notes of positioning. The first, and one I agree with wholeheartedly, is explicitly stating that "sex" is a socially constructed concept— exactly as "gender" is. Read more... )

The second positioning Serano makes is one I take issue with. Serano names herself a feminist and considers her work in exposing and discussing trans issues to be part of the feminist enterprise. Read more... )

The most interesting point so far is her distinguishing between anti-female ideologies and anti-feminine ideologies. The distinction between femaleness and femininity should make sense to anyone. Serano goes a bit further in trying to systematically distinguish them and to identify when particular acts serve to subjugate women vs subjugating femmes. Feminism, for example, is very pro-female and has successfully built a world where it is natural to say "men and women are equal"; however, it has done so largely at the cost of sacrificing femininity— a woman can do anything a man can do, just so long as she's not too girly about it. I very much hope Serano delves into this topic more.

Categories: Offsite Blogs