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NOTE: the primary server is going down for immediate maintenance.

Haskell on Reddit - Tue, 11/18/2014 - 1:35pm

Hello *,

The primary domain,, is hosted on a system which seems to have lost one of its RAID disks completely.

We were planning on moving this machine in the next few weeks to new infrastructure, but we are now expediting this plan and will be doing it ASAP.

As we move this server, both the webserver and the mailing system will be going down. Please don't be alarmed if your emails aren't delivered or things go quiet. Many services will continue to work, but we do realize this will be upsetting for many.

You can follow the progress on #haskell-infrastructure on Freenode, and see updates on

If you need to download something like a GHC binary or Haskell Platform package, you can use in the mean time, which is a new service we were hoping to announce more officially soon, but is already working today.

Unfortunately we cannot give an expected time of completion for the move, but we'll try to keep people well informed through IRC or something like Reddit.


submitted by aseipp
[link] [3 comments]
Categories: Incoming News

Facebook releases "Flow", a statically typed JavaScript variant

Lambda the Ultimate - Tue, 11/18/2014 - 1:19pm

The goal of Flow is to find errors in JavaScript code with little programmer effort. Flow relies heavily on type inference to find type errors even when the program has not been annotated - it precisely tracks the types of variables as they flow through the program.

At the same time, Flow is a gradual type system. Any parts of your program that are dynamic in nature can easily bypass the type checker, so you can mix statically typed code with dynamic code.

Flow also supports a highly expressive type language. Flow types can express much more fine-grained distinctions than traditional type systems. For example, Flow helps you catch errors involving null, unlike most type systems.

Read more here.
Here's the announcement from Facebook.

Categories: Offsite Discussion

ghc weekly news 2014/11/18

Haskell on Reddit - Tue, 11/18/2014 - 12:22pm
Categories: Incoming News

The GHC Team: GHC Weekly News 2014/11/18

Planet Haskell - Tue, 11/18/2014 - 11:35am

Hello *,

Once more we have the GHC Weekly news! This one is a bit late due to Austin being in limbo unexpectedly for a few days last week. (The next one will of course come again on Friday to keep things straight.)

With that out of the way, let's see what exactly is going on:

  • The STABLE freeze is happening at the end of this week! That means if you have something you want to get in, try to get people aware of it! Austin (yours truly) has a backed up review queue it would seem, but hopes to clear a bunch of it out before then.
  • Herbert Valerio Riedel has finally landed integer-gmp2, AKA ​Phab:D86, which implements a complete overhaul of the integer-gmp library. This library will be switched on by default in GHC 7.10.1, which means the integer-gmp library version will have a super-major bump (version This is the beginning of a longer-term vision for more flexible Integer support in GHC, as described by Herbert on the design page: ​ This implementation also fixes a long standing pain point where GHC would hook GMP allocations to exist on the GHC heap. Now GMP is just called to like any FFI library.
  • Jan Stolarek made a heads up to help out GHC newcomers: if you see a ticket that should be easy, please tag it with the newcomer keyword! This will let us have a live search of bugs that new developers can take over. (Incidentally, Joachim mentions this is the same thing Debian is doing in their bug tracker): ​
  • Adam Gundry, Eric Seidel, and Iavor Diatchki have grouped together to get a new, unexpected feature into 7.10: type checking plugins. Now, GHC will be able to load a regular Haskell package as a plugin during the compilation process. Iavor has a work-in-progress plugin that solves constraints for type-level natural numbers using a SMT solver. The code review from everyone was published in ​Phab:D489.

Closed tickets this week include: #9785, #9053, #9513, #9073, #9077, #9683, #9662, #9646, #9787, #8672, #9791, #9781, #9621, #9594, #9066, #9527, #8100, #9064, #9204, #9788, #9794, #9608, #9442, #9428, #9763, #9664, #8750, #9796, #9341, #9330, #9323, #9322, #9749, #7381, #8701, #9286, #9802, #9800, #9302, #9174, #9171, #9141, #9100, #9134, #8798, #8756, #8716, #8688, #8680, #8664, #8647, #9804, #8620, #9801, #8559, #8559, #8545, #8528, #8544, #8558

Categories: Offsite Blogs

Silk is looking for a Haskell engineer

Haskell on Reddit - Tue, 11/18/2014 - 11:32am

Hi! We are Silk and we are working on an awesome product (we think) and could really use some help developing our software. Our product is written as a pretty conventional client/server web architecture of which the backend is entirely written in Haskell. and a tiny bit of node.js, but please don't tell anyone

We are looking for an experienced Haskell developer with a great engineering mindset and a good feeling for high level software design. Besides helping to improve our current backend we might put you to work on some interesting new challenges. Mostly in the area of graph databases and query language design, machine learning for our suggestion engines, and distributed process management. Of course many new projects may come up in the future.

We are a small startup company with a motivated team and love the Haskell community. We use tons of open source software from Hackage and try to contribute ourself where we can.

This is a full time position in our Amsterdam office and we're currently not looking for remote workers. Ideally we are looking for someone from within the EU, because that simplifies the hiring process significantly. We might be willing to make exceptions on this rule in exceptional cases.

Please let us know if you're interested!

submitted by sfvisser
[link] [21 comments]
Categories: Incoming News

The next 7000... abstractions to learn!

haskell-cafe - Tue, 11/18/2014 - 1:48am
Hi all, I'm using Haskell since nearly three years now and I think I have well understood that types are the most important part of our programs. I have looked all around to learn as many datatypes/typeclasses as possible. But I suffer for a lack of direction to pursue my learning. I have well understood Prelude's one and some random ones (include someones for Category Theory), but I can't handle Kmett's code. Are there some intermediates abstractions I can learn? (For example in some librairies). Thanks by advance for your help. Regards. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
Categories: Offsite Discussion

Darcs: Darcs News #107

Planet Haskell - Mon, 11/17/2014 - 9:45pm
News and discussions
  1. Darcs has received two grants from the Google Summer of Code program, as part of the umbrella organization Alejandro Gadea will work on history reordering:
  2. Marcio Diaz will work on the cache system:
  3. Repository cloning to remote ssh hosts has been present for years as darcs put. This feature has now a more efficient implementation:
Issues resolved (11)
issue851 Dan Frumin
issue1066 Guillaume Hoffmann
issue1268 Guillaume Hoffmann
issue1416 Ale Gadea
issue1987 Marcio Diaz
issue2263 Ale Gadea
issue2345 Dan Frumin
issue2357 Dan Frumin
issue2365 Guillaume Hoffmann
issue2367 Guillaume Hoffmann
issue2379 Guillaume Hoffmann
Patches applied (41)
See darcs wiki entry for details.
Categories: Offsite Blogs

Darcs: Darcs News #109

Planet Haskell - Mon, 11/17/2014 - 9:45pm
News and discussions
  1. We are in the feature freeze period of darcs 2.10:
  1. Our two Summer of Code projects ended up two months ago. Marcio and Ale's code will be part of the upcoming new stable version of darcs. In case you missed them, here are the latest posts of Marcio for his project:
  1. Ale's posts:
Issues resolved (7)
issue1514 Guillaume Hoffmann
issue1624 Marcio Diaz
issue2153 Andreas Brandt
issue2249 Mateusz Lenik
issue2380 Owen Stephens
issue2403 Ganesh Sittampalam
issue2409 Ganesh Sittampalam
Patches applied (118)
See darcs wiki entry for details.
Categories: Offsite Blogs

Any good linux haskell tutorials?

Haskell on Reddit - Mon, 11/17/2014 - 6:10pm

I have been meaning to get into haskell on my machine for a while but cannot find a good tutorial that explains the structure and syntax of the language that appeals to complete novices like myself. please post.

submitted by EndGameLoot
[link] [6 comments]
Categories: Incoming News

Up to 15 fully-funded doctoral studentships in CS atOxford

General haskell list - Mon, 11/17/2014 - 4:06pm
Dear all, My department has just received a big award from Google, which will mostly be spent on DPhil student scholarships. The topic is open to anything the dept works in, but I would particularly welcome strong students in functional programming. Please pass this around to anyone you think might be interested, or ask me if you'd like to know more. Thanks! * Following a generous donation by Google, the Department of Computer Science at the University of Oxford is delighted to invite applications for up to 15 fully-funded DPhil (Oxford'ss PhD) studentships tenable from 1st October 2015. The University of Oxford is consistently ranked amongst the very best Computer Science departments in the world, for both teaching and research. We are committed to attracting the world's most talented students and working with them to continue the success of the department. The topics for the studentships are open, but should relate to the interests of one of t
Categories: Incoming News

How I Start: Haskell

Haskell on Reddit - Mon, 11/17/2014 - 9:15am
Categories: Incoming News

[ANN] elevator: getting to a top of a monadtransformer stack

haskell-cafe - Mon, 11/17/2014 - 8:37am
Hello everybody, I created an elevator to navigate a monad transformer stack, liberating us from creating a Monad* class and instances. The key function, elevate, can be whatever you need: elevate :: IO a -> IO a elevate :: IO a -> StateT s IO a elevate :: State s a -> StateT s IO a elevate :: IO a -> MaybeT (StateT s IO) a If you want to elevate actions above your monad, just write instance Tower YourMonad to declare that YourMonad is one-storied. Hackage: Cheers Fumiaki Kinoshita _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
Categories: Offsite Discussion