[Haskell-cafe] Haskell Weekly News: Issue 236

Welcome to issue 236 of the HWN, an issue covering crowd-sourced bits of information about Haskell from around the web. This issue covers the week of July 8 to 14, 2012. Quotes of the Week * RichardBuckminsterFuller: When I am working on a problem, I never think about beauty. But when I h

[Haskell-cafe] How to add constraint to .cabal?

Hi, Say I have a package that only appends --constraint="template-haskell==2.7.0.0" --constraint="warp-tls==1.2.1" could I install it. Now I want to release the package, then how could I have these constraint into the .cabal so the user would not get troubled? -- 竹密岂妨流水过 山高哪阻野云飞 And for G+, ple

[Haskell-cafe] HDBC nested withTransaction

Hi, are there any plans of implementing nested transactions using withTransaction in HDBC? In mysql exists checkpoints and in postgres explicit subtransactions, Andras Gyomrey ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org

Re: [Haskell-cafe] strange hangs with -threaded runtime (now with test case)

Just following up to my problem, I was seeing lots of hangs in various places in my program when it was built with the threaded runtime. I eventually tracked every single hang back to calls to MissingH's System.Cmd.Utils, including pipeFrom, pipeTo, pipeBoth, and pOpen. I was at this point runnin

[Haskell-cafe] Haskell Symposium 2012 - Call for Participation (early registration closes 9th August)

CALL FOR PARTICIPATION ACM SIGPLAN Haskell Symposium 2012 Copenhagen, Denmark 13th September, 2012 (directly after I

Re: [Haskell-cafe] Interest in typed relational algebra library?

On Wed, 18 Jul 2012, Jay Sulzberger wrote: On Tue, 10 Jul 2012, o...@okmij.org wrote: And yes to first order predicate calculus too! Just two weeks ago Chung-chieh Shan and I were explaining at NASSLLI the embedding in Haskell of the higher-order predicate logic with two base types (so

Re: [Haskell-cafe] How do I marshall a pointer over SendMessage LPARAM or WPARAM?

On Wed, 2012-07-18 at 18:22 +0200, Simon Peter Nicholls wrote: > Some "sending" code: > > Foreign.C.String.withCWString "frustrator" $ \s -> do > let wParam = System.Win32.Types.castPtrToUINT s :: > System.Win32.Types.WPARAM > Graphics.Win32.sendMessage

Re: [Haskell-cafe] Cabal install fails due to recent HUnit

On Wed, Jul 18, 2012 at 05:16:19PM +0100, Simon Hengel wrote: > CCing: Ross Paterson and Richard G. > > On Wed, Jul 18, 2012 at 05:54:44PM +0200, Martijn Schrage wrote: > > On 18-07-12 17:37, Erik Hesselink wrote: > > >Hi Martijn, > > > > > >Yes, upgrading will obviously fix things (we do use 0.14

[Haskell-cafe] How do I marshall a pointer over SendMessage LPARAM or WPARAM?

Cross-posted from Haskell-beginners. Apologies for not posting in the right place (though I am a beginner and have probably made a simpleton error). I'm new to Haskell, and have had some good success with FFI so far, but using Win32's sendMessage to send a pointer in LPARAM or WPARAM is resulting

Re: [Haskell-cafe] Cabal install fails due to recent HUnit

CCing: Ross Paterson and Richard G. On Wed, Jul 18, 2012 at 05:54:44PM +0200, Martijn Schrage wrote: > On 18-07-12 17:37, Erik Hesselink wrote: > >Hi Martijn, > > > >Yes, upgrading will obviously fix things (we do use 0.14 on our > >development machines) > Well, to me it wasn't entirely obvious th

Re: [Haskell-cafe] lambdabot-4.2.3.3

I should probably be more clear - it supports all the same resource limiting mechanisms as Mueval because it uses Mueval (modified to support Safe Haskell). On Jul 18, 2012, at 11:37 AM, James Cook wrote: > The irc server it runs on has about 10 users, all of whom I know and trust, > so I have

Re: [Haskell-cafe] Cabal install fails due to recent HUnit

On 18-07-12 17:37, Erik Hesselink wrote: Hi Martijn, Yes, upgrading will obviously fix things (we do use 0.14 on our development machines) Well, to me it wasn't entirely obvious that upgrading to Cabal-1.10.2.0 fixes the problem for cabal-install-0.12, and I still think this is a good solution

Re: [Haskell-cafe] Cabal install fails due to recent HUnit

Hi Martijn, Yes, upgrading will obviously fix things (we do use 0.14 on our development machines), but we have not set up any infrastructure for building a custom cabal on production servers. We just use the one from the Ubuntu repositories, which uses Cabal 1.10.1.0 on oneiric. So until we upgrad

Re: [Haskell-cafe] lambdabot-4.2.3.3

The irc server it runs on has about 10 users, all of whom I know and trust, so I have not tested it extensively but it should be as safe as anything else running Safe Haskell. Mueval uses the ghc API and with a minor modification can do so in "safe" mode. As long as you don't trust any packages

Re: [Haskell-cafe] lambdabot-4.2.3.3

At Wed, 18 Jul 2012 11:04:17 -0400, Cale Gibbard wrote: > Lambdabot doesn't have a maintainer. So is it just orphaned and anyone can upload? That does not sound right, also considering that lambdabot is used on the IRC channel, it'd be nice to have a more structured way to push fixes and improveme

Re: [Haskell-cafe] Cabal install fails due to recent HUnit

Hi Erik, A similar thing happened to me with the GraphViz package. As Duncan explained to me, the problem is that Cabal-1.10.0.0 (and I believe also 1.10.1.0) incorrectly reports an error when conditionals are used in test suites. Upgrading to Cabal-1.10.2.0 (or cabal-install-0.14.0 with Cab

Re: [Haskell-cafe] lambdabot-4.2.3.3

On Wed, Jul 18, 2012 at 11:12 AM, James Cook wrote: > It diverged from the official version quite a while ago, but it builds on > the latest GHC and uses Safe Haskell for the @eval module. That doesn't sound very safe. How does it handle all the DoS attacks etc in the mueval test suite? -- gw

Re: [Haskell-cafe] lambdabot-4.2.3.3

For what it's worth, I've been maintaining a fork for personal use for quite a while[1]. It diverged from the official version quite a while ago, but it builds on the latest GHC and uses Safe Haskell for the @eval module. If someone happens to want to use it they are free to do so, and I'll ev

Re: [Haskell-cafe] lambdabot-4.2.3.3

Lambdabot doesn't have a maintainer. On 18 July 2012 08:33, Francesco Mazzoli wrote: > At Wed, 18 Jul 2012 15:14:47 +0400, > Dmitry Malikov wrote: >> A few days ago I tried to install lambdabot package from hackage >> (4.2.3.2). Cabal install failed. >> >> Then I found DanBurton's github repo wit

Re: [Haskell-cafe] lambdabot-4.2.3.3

On 07/18/2012 04:33 PM, Francesco Mazzoli wrote: At Wed, 18 Jul 2012 15:14:47 +0400, Dmitry Malikov wrote: A few days ago I tried to install lambdabot package from hackage (4.2.3.2). Cabal install failed. Then I found DanBurton's github repo with some approaches to make lambdabot install fixed.

Re: [Haskell-cafe] Monads with "The" contexts?

Done with some exercises on Gaussian distribution as a monad! http://en.pk.paraiso-lang.org/Haskell/Monad-Gaussian What do you think? Will this be a good approach or bad? Also this is the first page in my attempt to create runnable, and even testable wiki pages. To run the tests, please use hacka

[Haskell-cafe] Cabal install fails due to recent HUnit

Hi all, All cabal installs using cabal-install-0.10.2 are currently failing for us. This is due to the cabal file for HUnit-1.2.5.0, which was recently uploaded to hackage. The ouput I'm getting from cabal is just: Reading available packages... Resolving dependencies... cabal: Couldn't read cabal

Re: [Haskell-cafe] Fwd: hackage compile failure with QuickCheck 2.5

On Wed, Jul 18, 2012 at 11:29 AM, Ross Paterson wrote: > On Wed, Jul 18, 2012 at 09:35:52AM +0100, Erik Hesselink wrote: >> I don't think you can install this package on 7.4. As Andres said, it >> requires containers 0.5, but ghc 7.4's base libraries (in this case, >> template-haskell) use contain

Re: [Haskell-cafe] lambdabot-4.2.3.3

At Wed, 18 Jul 2012 15:14:47 +0400, Dmitry Malikov wrote: > A few days ago I tried to install lambdabot package from hackage > (4.2.3.2). Cabal install failed. > > Then I found DanBurton's github repo with some approaches to make lambdabot > install fixed. > > All dependency packages (IOSpec, num

[Haskell-cafe] lambdabot-4.2.3.3

Hi. A few days ago I tried to install lambdabot package from hackage (4.2.3.2). Cabal install failed . Then I found DanBurton's github repo with some approach

[Haskell-cafe] A useful function for forking a thread, but letting the parent do setup first

Here's a useful little function: -- | Fork a thread, but wait for the main thread to perform a setup action -- using the child's 'ThreadID' before beginning work in the child thread. forkSetup :: (ThreadId -> IO (Maybe a, r)) -- ^ Setup action to be called before the t

Re: [Haskell-cafe] Fwd: hackage compile failure with QuickCheck 2.5

On Wed, Jul 18, 2012 at 10:37:31AM +0100, Gregory Collins wrote: > Is there any reason QuickCheck specifically requires containers >= 0.5? > Perhaps its lower bound could be relaxed. It is sbv-2.2 that has that constraint. > On Wed, Jul 18, 2012 at 11:29 AM, Ross Paterson wrote: > Actually -

Re: [Haskell-cafe] Fwd: hackage compile failure with QuickCheck 2.5

> I'm talking about unattended automated builds, so tweaking isn't an > option. On the other hand breaking the package environment isn't so bad, > because I'm throwing it away after each build. I'm not convinced that we should try to build packages at any price. If they're likely to cause problem

Re: [Haskell-cafe] Fwd: hackage compile failure with QuickCheck 2.5

Is there any reason QuickCheck specifically requires containers >= 0.5? Perhaps its lower bound could be relaxed. On Wed, Jul 18, 2012 at 11:29 AM, Ross Paterson wrote: > On Wed, Jul 18, 2012 at 09:35:52AM +0100, Erik Hesselink wrote: > > I don't think you can install this package on 7.4. As And

Re: [Haskell-cafe] Fwd: hackage compile failure with QuickCheck 2.5

On Wed, Jul 18, 2012 at 09:35:52AM +0100, Erik Hesselink wrote: > I don't think you can install this package on 7.4. As Andres said, it > requires containers 0.5, but ghc 7.4's base libraries (in this case, > template-haskell) use containers 0.4, and can't be reinstalled. I > guess your best bet is

Re: [Haskell-cafe] Fwd: hackage compile failure with QuickCheck 2.5

On Wed, Jul 18, 2012 at 10:19 AM, Ross Paterson wrote: > On Wed, Jul 18, 2012 at 06:50:31AM +0100, Andres Löh wrote: >> Using --avoid-reinstalls blindly or as a default flag is also >> unfortunately not a good idea in general. There are simply too many >> cases where installing older versions of p

Re: [Haskell-cafe] Fwd: hackage compile failure with QuickCheck 2.5

On Wed, Jul 18, 2012 at 06:50:31AM +0100, Andres Löh wrote: > Using --avoid-reinstalls blindly or as a default flag is also > unfortunately not a good idea in general. There are simply too many > cases where installing older versions of packages (which is often the > only thing that helps) is not r

Re: [Haskell-cafe] stripSuffix

>> I can think of two cases where I'd want something like this. >> One is manipulating file extensions, where I'd want to use >> System.FilePath.splitExtension or something like that anyway. >> The other is suffix stripping for text processing, where I'd >> want to use a trie to match a whole lot o

Re: [Haskell-cafe] Interest in typed relational algebra library?

On Tue, 10 Jul 2012, o...@okmij.org wrote: And yes to first order predicate calculus too! Just two weeks ago Chung-chieh Shan and I were explaining at NASSLLI the embedding in Haskell of the higher-order predicate logic with two base types (so-called Ty2). The embedding supports type-safe