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Bed & Breakfast maintainer?

libraries list - Tue, 04/14/2015 - 6:05pm
Anyone out there maintaining (or willing to take over) the bed-and-breakfast package? 0.4.3 (the latest release) doesn't compile with 7.8 because of the changes to Typeable. The git repo has fixes for this in it, along with some other stuff, but that's nearly a year old, and hasn't been released yet. My requests to the author & maintainer (Julian Fleischer < julian.fleischer< at >>) have gone unanswered. _______________________________________________ Libraries mailing list Libraries< at >
Categories: Offsite Discussion

[ANN] bower-json: read bower.json from Haskell

Haskell on Reddit - Tue, 04/14/2015 - 5:12pm

I just made a little library for parsing bower.json files in Haskell. I'd appreciate any feedback:

submitted by hdgarrood
[link] [5 comments]
Categories: Incoming News

Final CFP - SBLP 2015: 19th Brazilian Symposium onProgramming Languages

General haskell list - Tue, 04/14/2015 - 3:47pm
FINAL CALL FOR PAPERS - SBLP 2015 19th Brazilian Symposium on Programming Languages 21-26 September 2015 Belo Horizonte, Brazil *** DEADLINE APPROACHING *** +++++++++++++++++++++++++++++++++++++++++++++++++++ IMPORTANT DATES Abstract submission: 20 April, 2015 Paper submission: 27 April, 2015 Author notification: 18 June, 2015 Camera ready deadline: 2 July 2015 INTRODUCTION The Brazilian Symposium on Programming Languages is a well-established symposium which provides a venue for researchers and practitioners interested in the fundamental principles and innovations in the design and implementation of programming languages and systems. SBLP 2015 is part of 6th Brazilian Conference on Software: Theory and Practice, CBSoft 2015, that will be held in Belo Horizonte, Minas Gerais, Brazil, from September 21st to September 26th, 2015. Authors are invited to submit original research on any relevant topic which can be either in the form of regular or short papers. TOPICS Topic
Categories: Incoming News

Submitting a conflicting package to Hackage

Haskell on Reddit - Tue, 04/14/2015 - 3:10pm

Basically, I've written a small library mimicking the functionality of [Control.Concurrent.Async][], with a few notable differences.

I'm currently calling this library Control.Concurrent.FutureIO and this is currently how I plan to submit the package to Hackage. Currently, there are only two functions that exist as a part of the API, async :: IO a -> FutureIO a and await :: FutureIO a -> IO a, instead of Async' s functions async :: IO a -> IO (Async a) and wait :: IO (Async a) -> IO a.

The benefit of my implementation (in my eyes) is that FutureIO is an instance of the Functor/Applicative/Monad classes and it composes neatly. For instance, the following code will only take ~1s instead of 3s to complete.

wait1s = threadDelay 1000000 slowMulti = async $ wait1s >> return (*) slowProd1 = async $ wait1s >> return 42 slowProd2 = async $ wait1s >> return 24 await $ slowMulti <*> slowProd1 <*> slowProd2

Ignoring this incredibly trivial example, in my eyes this has a pretty strong benefit over the Control.Concurrent.Async package. My question is "Is there a better way for me to submit this than just under the FutureIO moniker?"

*(note: As a Haskell newbie, I'm fully aware that this could be dumb, redundant, etc. and I would love it if you told me so I could learn)

submitted by cghio
[link] [10 comments]
Categories: Incoming News

The GHC Team: GHC Weekly News - 2015/04/14

Planet Haskell - Tue, 04/14/2015 - 11:44am

Hi *,

It's been a few weeks since the last news bulletin - your editor apologizes about that. It's actually been a relatively slow few weeks here too, and busy-ness outside of GHC has attracted some of my attention. Despite that, GHC 7.10.1 was released, a new HP alpha is out, and things are moving along smoothly. Now that the release is done, things are quitely moving along in HEAD - with people committing code with reckless abandon, of course.

This week, GHC HQ met up, but it's been very light since the 7.10.1 release. Currently there isn't anything pushing us to do a 7.10.2 release at least for a few more weeks it looks like - but see below.

  • We puzzled a bit about the release status of 7.10.2, and thought: it's only holding up people who are depending on it. So, who's depending on it, and what do they need fixed? See below for more.
  • We also talked a bit about performance - it seems the compiler has been getting much slower over time since the 7.8.x release series, and it's time to reign it in. Austin will be spending his week investigating a bit of this, and the causes.
7.10.2 Status

So, you may be wondering when the 7.10.2 release is. The trick is it happens when you tell us it should happen!

So far, taking a look at milestone:7.10.2, we've fixed about half the bugs we currently have marked down to fix. But we're probably going to punt some of those - and we're not sure all the ones that are there should be.

So this is a call: If you need something to be fixed during 7.10.2, please file a ticket, set the milestone, and alert us. The sooner the better, because it'll inform us as to when we should release. Emailing is also a sure-fire way to get our attention.

And remember: you can always find out the latest about the next release at the Status page (in this case, for 7.10.2) - ​

Call for help: DocBook to AsciiDoc

The GHC team needs some help. A few months ago, we put out a poll to convert our DocBook-based manual to AsciiDoc.

The poll had a mostly lukewarm reception, with the idea that it will A) make life easier for people who frequently modify the users guide, and B) make life easier for people who add things irregularly, as a lower barrier to entry.

It looks like we still want to do this - but alas, many of us don't have time!

So, we're asking the public: Is anyone willing to step up and help here? For example, it may be possible to get a long ways with just pandoc, but we need someone to finish it - and in return, we'll help along the way!

List chatter
  • A GHC user, Dave, asked the list about some questions with Cross Compilation, as he's attempting to get GHC to work natively inside the Open Embedded build environment. Unfortunately, things haven't been going well so far, and any input from enterprising hackers is appreciated: ​
  • Dan Aloni has started a discussion about improving GHC's error messages, spurred by a popular blog post he wrote and posted on Reddit about some Happy/GHC improvements he's made. This is a difficult area (error messages in general are hard) to work on, so thanks to Dan for helping! ​
  • Tamar Christina started a thread about replacing ghc-split, an old Perl script inside GHC, but he wanted to know: what do we do about a regex replacement? Mikhail Glushenkov spoke up about a similar decision the LLVM developers used: to use the OpenBSD regex implementation. ​
Noteworthy commits Closed tickets

#10222, #10219, #8057, #10226, #10220, #9723, #10230, #10208, #10236, #10213, #10231, #10240, #10243, #10237, #10224, #8811, #10197, #10252, #9958, #10253, #8248, #10207, #10214, #9964, #10194, #10251, #10188, #10257, #10247, #10247, #9160, #10259, #9965, #10265, #10264, #10286, #10282, #10290, #10291, #10300, #9929, #8276, #10218, #10148, #10232, #10274, #10275, #10195, and #10233.

Categories: Offsite Blogs

Swap type class

Haskell on Reddit - Tue, 04/14/2015 - 10:57am
Categories: Incoming News

Generalized swap

Haskell on Reddit - Tue, 04/14/2015 - 10:51am
Categories: Incoming News

Dimitri Sabadie: Generalized swap

Planet Haskell - Tue, 04/14/2015 - 8:31am
Generalized swap

I pushed a pull request to Edward Kmett’s either package to implement two functions some guys was complaining not to find: flipEither :: Either e a -> Either a e and flipEitherT :: EitherT e m a -> EitherT a m e.

When implementing the functions, I wondered: “Hey, flipping stuff is a pretty common operation. Don’t we have an abstraction for that yet?”. I haven’t found any.

Meet Swap

I decided to make a little typeclass to see what it’d be.

class Swap s where
swap :: s a b -> s b a

instance Swap (,) where
swap (a,b) = (b,a)

instance Swap Either where
swap = flipEither

-- let’s go wild and fooled
instance Swap Map where
swap = fromList . fmap swap . toList

If you think that’s handy, I’ll write a little package with default instances to make it live.

Happy hacking folks!

Categories: Offsite Blogs

Philip Wadler: Codes that changed the world

Planet Haskell - Tue, 04/14/2015 - 7:04am
Aleks Krotoski tackles programming languages in BBC Radio 4's Codes that Changed the World. The five episodes comprise: Fortran, Cobol, Basic, Java, and The Tower of Babel. Functional programming and Haskell are singled out for special attention in the final programme, which includes a interview with Haskell developer Elise Huard; online is a clip of interview with Simon Peyton Jones that did not make it on air.

Categories: Offsite Blogs

FP Complete: Announcing: stackage-view

Planet Haskell - Tue, 04/14/2015 - 5:20am

As part of our announcement of open sourcing ide-backend, there was a video demonstrating a tool called “fpview” (that was our internal name for this tool).

<iframe allowfullscreen="allowfullscreen" frameborder="0" height="315" src="" width="420"></iframe>

Like many of our tools, after some internal development, we're now releasing it open source here at: stackage-view.

It looks like this:

The README documents the features, but here's a quick rundown:

  • Go to definition: You can double-click any identifier to jump straight to the definition.
  • Type information of any expression or pattern binding. Just click any identifier to see its type. Alternatively, you can select an expression to see the type of that. Hitting the <-> expansion button will expand the selection to a parent node.

The first purpose behind the tool was to target general teams of people who may not all be using the same tooling (Haskellers are like cats, they prefer to do their own thing!), some users may be on Emacs, Vim, or Sublime, FP Eclipse, Leksah, etc. whereas this read-only tool serves as a way to inspect a codebase with handy information and jumping available.

The second purpose was to serve as a demonstration and acid test for our combination GHCJS and React library ghcjs-react. It makes for a nice simple-but-non-trivial demonstration of the library. There is real-world state handling going on, interacting with third-party APIs (aside from React itself, the Ace editor).

It also serves as a demonstration of using ide-backend programmatically. If you look in the source of stackage-view you'll see it's quite straight-forward to use. To build it, you will need the Git version of ide-backend found here. Currently it cannot be uploaded to Hackage due to an issue with the -dynamic flag.

Categories: Offsite Blogs

LOLA 2015: Second Call for Talk Proposals

General haskell list - Mon, 04/13/2015 - 5:29pm
SECOND CALL FOR TALK PROPOSALS ______________________________________________________________________ LOLA 2015: Syntax and Semantics of Low Level Languages Sunday, 5 July 2015, Kyoto, Japan A satellite workshop of ICALP/LICS ______________________________________________________________________ /Important Dates/ Abstract submission: Monday, 20 April 2015 Author notification: Friday, 1 May 2015 LOLA 2015 workshop: Sunday, 5 July 2015 /Invited Speakers/ Katsuhiro Ueno, Tohoku University, Japan Other invited speakers to be announced. /Workshop Description/ It has been understood since the late 1960s that tools and structures arising in mathematical logic and proof theory can usefully be applied to the design of high level programming languages, and to the development of reasoning principles for such languages. Yet low level languages, such as machine code, and the compilation of high level languages into a low level ones have traditionally been seen as having little
Categories: Incoming News


glasgow-user - Sat, 04/11/2015 - 5:44pm
What’s the story with this? I tried to follow the instructions here: <> but I get Dominic Steinitz dominic< at > _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users< at >
Categories: Offsite Discussion

New gtk2hs 0.12.4 release

gtk2hs - Wed, 11/21/2012 - 12:56pm

Thanks to John Lato and Duncan Coutts for the latest bugfix release! The latest packages should be buildable on GHC 7.6, and the cairo package should behave a bit nicer in ghci on Windows. Thanks to all!


Categories: Incoming News