- Haskell-Cafe - Haskell.org

ghci on ARM m3?
by Mike Meyer 06 Feb '15

06 Feb '15

Lately, I've not been doing much Haskell because I've buried in embedded systems work. The code is all C, with only a smidgen of C++ (for which I am grateful). One of the things I've been toying with is turning part of the on-chip configuration information a haskel functions. They'd even be pure code, and would be a lot more expressive than what's there now. The target platforms are running Cortex M3 CPUs. I know that jhc/ajhc will generate code for those CPUs, but I really need at least a subset of the compiler running on the target processor with no pre-installed RTOS. Has that been done? Is it likely to even be possible? As part of the project, I'll need to install both a cross-compiler on my Unix box, and the the compiler (or parts of it) on the M3. Can someone provide pointers to tutorials on that? My google-foo wasn't powerful enough to find any. I'm thinking about using either an Aruino Due (as it has the M3 CPU on it) as a testbed platform. So tutorials targeted for that platform would be particularly appreciated. Since I hopefully have the eyes of people experienced with these things, should I be considering a raspberry pi or something similar instead of the Due? Basically, will I be able to run code built for the M3 CPU on the pi CPUs? thanks, Mike

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ANNOUNCE: bash script for haskell
by James Crayne 06 Feb '15

06 Feb '15

I'm sure variations of this exist, but for some reason I didn't find any while searching, so I made my own. The idea is for using haskell on the command line instead of perl or awk etc. https://github.com/jimcrayne/hk

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ANNOUNCE: UISF Release
by Daniel Winograd-Cort 05 Feb '15

05 Feb '15

I'm happy to announce the release of UISF on Hackage! http://hackage.haskell.org/package/UISF UISF provides an arrowized FRP library for graphical user interfaces. It stems from work done on Euterpea (http://haskell.cs.yale.edu/euterpea/) and is built atop GLFW. One of the neat things about UISF is how it behaves with ArrowChoice. Specifically, one can create dynamic arrows so long as they are *predictably* dynamic. This means that it is possible to have widgets activate, deactivate, and even replicate without resorting to switch. If you're interested in playing around with it, feel free to take a look at the example files, some of which are pretty well documented (note that there are more than just the two displayed on the hackage page). Do let us know about comments you have and bugs you find. -Daniel

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Re: [Haskell-cafe] stuck at the first part of chapter 1 of the CIS course
by Roelof Wobben 05 Feb '15

05 Feb '15

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ghc --make Vs runhaskell
by Madhu Babu 05 Feb '15

05 Feb '15

Hi !, I have the following program from “Learn You a Haskell” ( http://learnyouahaskell.com/input-and-output#randomness ). When i run this using runhaskell, code works perfectly fine. However, when i compile and run the binary file, code behaves differently. Basically, in the following code, we print a line first and the read the line from stdin. This behavior works perfectly fine when using “runhaskell guess.hs”. But when i say “./guess”, i had to type in a number directly ( i.e. first prompt is skipped ). btw.. i am using mac yosomite command terminal. Any help greatly appreciated.. Thanks a lot in advance.. import System.Random import Control.Monad(when) main = do ranGen <- getStdGen let (rand,_) = randomR (1,10) ranGen :: (Int,StdGen) putStr "Guess a number between 1 and 10 : " numStr <- getLine when(not $ null numStr) $ do let num = read numStr if rand == num then putStrLn "Yuhaa!! you are right baby!" else putStrLn $ "Sorry dude!! it was " ++ show rand newStdGen main

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Re: [Haskell-cafe] learn you a good haskell exercises
by Roelof Wobben 04 Feb '15

04 Feb '15

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learn you a good haskell exercises
by Roelof Wobben 04 Feb '15

04 Feb '15

Hello, If I want to look if I understand the contents of the book , are these good exercises : https://github.com/noelmarkham/learn-you-a-haskell-exercises Roelof

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Haskell opportunities at Facebook
by Bryan O'Sullivan 04 Feb '15

04 Feb '15

Hi, friends – I have a number of very interesting openings at Facebook HQ in Menlo Park, California. There are two different teams hiring. The first set of positions are for an entirely new team. This project involves distributed systems, data mining, and machine learning. There may be roles on this team for less experienced candidates in a few months, but right now we are looking for people who have written a reasonable amount of Haskell, have built real production systems in some language or other (and have the scars to prove it), and can contribute in major ways to the design and construction of a demanding new system that we're building from scratch. The second set of positions are for a cousin team, which is building on the success of our Haxl project to extend our capability to fight spam and malware. For these roles, we're open to a broader range of experience levels. If you're interested, please drop me an email with a current CV. Cheers, Bryan.

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hiring fp engineers for information security systems
by Khushil Dep 04 Feb '15

04 Feb '15

About Guardtime We are team of US and Estonian scientists, network architects, software developers and security specialists who have decades of experience building cyber security solutions in our nations' military, supporting national objectives for mission and information assurance. In 2007 we invented Keyless Signature Infrastructure (KSI), a block-chain security technology designed for real-time detection and mitigation of cyber attack. About The Role We're looking for experienced functional software engineers to work on real-time backend systems dealing with high volume events. We need people who want to build systems to apply the power of workflow processing to security events to build deep intelligence platforms. We want people who understand the benefits of converged understanding over imperative understanding. About You - You should have an appetite for tackling complex and interesting software challenges. - Want to build systems that handle data on a global scale in a timely manner. - Have a strong understanding of Linux/UNIX kernel operations - Understand the value of documentation. - Be able to disseminate complex ideas to a wider audience. - Prepared to work in an agile but structured manner. - Prepared to travel in the E.U. - Prepared to travel to the U.S.A. on a quarterly basis. Minimum Qualifications - BS in Computer Science, Mathematics or Physics or equivalent work and life experience. - Clojure, Scala, Java, C/C++ Programming experience. - Large systems software design and development experience, with knowledge of Unix/Linux. Preferred Qualifications - MS or PhD in Computer Science, Mathematics or Physics. - Strong FP skills. - Strong competencies in data structures, algorithms, and software design. - Haskell, Clojure, Scala, Java, C/C++, NodeJS, Python programming experience, database design, knowledge of TCP/IP and network programming. Application Process In the first instance please send your C.V. and GitHub username (if you have one) to khushil.dep(a)guardtime.com. We have a two stage interview process and we hire quickly.

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GHC API - list all exports of a module
by Jochen Keil 02 Feb '15

02 Feb '15

Dear Cafe, currently I'm working on a small program for which I need a list of all *exported* function and data types. In order to achieve this I've been toying around with the GHC API. My observations so far: * Using the pure `parser` function yields a `HsModule` object, which gives me a list of all exports and all declarations (internal & exported). I cannot or don't know how to use the list of exports (just `RdrName`s) to filter the declarations. * Using `parseModule` (which is essentially the same as the `parser` function) and `typecheckModule` on a `ModuleGraph` yields a `TypecheckedModule` object which contains a list of exported `Name`s which in turn can be used to get additional information about them. So, the second approach seems more promising, but I'm not too happy with it. The reason is that calling `typecheckModule` results in a compilation of the module and all of its dependencies, which I think is not necessary for what I want to achieve. This is especially cumbersome for large modules like `GHC.hs` where I'm struggling to figure out all of the dependencies without the build system. My main goal would be to have a program which takes two modules of different versions, compare them and highlight the differences between them. I think that'd be helpful for upgrading dependant packages or for writing compatibility layers. Thank you and all the best, Jochen

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