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Problem installing svgcairo
by Roly Perera 23 Oct '11

23 Oct '11

Hi, I'm having a problem installing svgcairo with Cabal, which I need for something else. I don't know what's going on, but something (maybe a C preprocessor, judging by Google search results) barfs with the complaint: ./Graphics/Rendering/Cairo/SVG.chs:209:28: error: missing binary operator before token "(" I can't find the file SVG.chs on my system to inspect this line, but perhaps I'm looking in the wrong place. Has anyone encountered this? Am I perhaps using the wrong version of Cairo or Gtk? Any suggestions welcome. thanks Roly ====== $ cabal install svgcairo Resolving dependencies... [1 of 2] Compiling SetupWrapper ( /tmp/svgcairo-0.12.125554/svgcairo-0.12.1/SetupWrapper.hs, /tmp/svgcairo-0.12.125554/svgcairo-0.12.1/dist/setup/SetupWrapper.o ) [2 of 2] Compiling Main ( /tmp/svgcairo-0.12.125554/svgcairo-0.12.1/Setup.hs, /tmp/svgcairo-0.12.125554/svgcairo-0.12.1/dist/setup/Main.o ) Linking /tmp/svgcairo-0.12.125554/svgcairo-0.12.1/dist/setup/setup ... [1 of 2] Compiling Gtk2HsSetup ( Gtk2HsSetup.hs, dist/setup-wrapper/Gtk2HsSetup.o ) [2 of 2] Compiling Main ( SetupMain.hs, dist/setup-wrapper/Main.o ) Linking dist/setup-wrapper/setup ... Configuring svgcairo-0.12.1... Preprocessing library svgcairo-0.12.1... ./Graphics/Rendering/Cairo/SVG.chs:209:28: error: missing binary operator before token "(" gtk2hsC2hs: Error during preprocessing chs file cabal: Error: some packages failed to install: svgcairo-0.12.1 failed during the building phase. The exception was: ExitFailure 1

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Web API attempt: Thrift + Evernote API -- apparent brick wall: HTTPS support
by Ryan Newton 23 Oct '11

23 Oct '11

Hi all, An old fogey here -- new to this world of web APIs / rpc over HTTP. I was thinking that since Thrift supports Haskell that it wouldn't be to hard to plug my Haskell program into the Thrift-based Evernote API to upload notes to the cloud. The first step to do that would be to authenticate: http://www.evernote.com/about/developer/api/evernote-api.htm#_Toc297053064 Uh, oh! Trouble already. You must use THttpClient to connect using HTTPS! It looks like the Thrift library for Haskell doesn't offer that option (plain HttpClient only). Presumably because the package HTTP doesn't support https? http://stackoverflow.com/questions/3988115/haskell-network-browser-https-co… Is there a way that libcurl could be used to provide THttpClient? I don't know enough to say... More generally, my problem is that it hard to figure out how to use Thrift from Haskell. Simple examples like this are helpful: http://mortenib.wordpress.com/2009/10/29/thrift-and-haskell/ But the Thrift library itself lacks full Haddock documentation: http://hackage.haskell.org/package/Thrift-0.6.0 And the generated Thrift code doesn't restrict its export lists to give you a hint as to what the "entry points" are. This is not to blame the thrift authors. They have N languages to support! But for someone with some extra time from the Haskell community, it seems like there would be some good return-on-investment for effort spent cleaning up the Haskell Thrift support. Maybe this is what Christian Lavoie is already doing? (http://hackage.haskell.org/package/thrift) Cheers, -Ryan P.S. One final note in the language-interop department. Since OCaml is supported by SWIG, Haskell should be too! Manuel's caveats notwithstanding: http://www.haskell.org/pipermail/c2hs/2003-May/000016.html

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Data.Vector.Mutable.mapM
by Joachim Breitner 23 Oct '11

23 Oct '11

Hi, I’m consdering to change some performance critical code from Vector to MVector, hopefully avoiding a lot of copying and garbage collecting. But it seems that the Data.Vector.Mutable interface at http://hackage.haskell.org/packages/archive/vector/0.9/doc/html/Data-Vector… is quite limited; e.g. I am missing simple functions having type modifyM :: PrimMonad m => (a -> m a) -> MVector (PrimState m) a -> m () that would do something with each element in the vector. Is this an indication that such use is actually not desired, or is it just the case that nobody has developed that yet? Thanks, Joachim -- Joachim "nomeata" Breitner mail(a)joachim-breitner.de | nomeata(a)debian.org | GPG: 0x4743206C xmpp: nomeata(a)joachim-breitner.de | http://www.joachim-breitner.de/

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hackage and cabal test support: why does it claim I have no type field when I do?
by Doug Burke 23 Oct '11

23 Oct '11

I've just been updating my code to take advantage of the test support in Cabal. I have it so that cabal configure --enable-tests cabal build cabal test works. However, when I try to upload to hackage, I get cabal upload -c dist/swish-0.6.2.0.tar.gz Checking dist/swish-0.6.2.0.tar.gz... Error: dist/swish-0.6.2.0.tar.gz: 400 Error in upload 400 Error in upload line 271: The 'type' field is required for test suites. The available test types are: exitcode-stdio-1.0 and here are the relevant lines from the cabal file: 267 if flag(developer) 268 ghc-options: -Werror 269 ghc-prof-options: -auto-all 270 271 Test-Suite test-builtinmap 272 type: exitcode-stdio-1.0 273 Hs-Source-Dirs: tests/ src/ 274 Main-Is: BuiltInMapTest.hs 275 Other-Modules: TestHelpers 276 As you can see, there's a type field for the Test-Suite and I don't see any obvious discrepancy with the information from the user's guide (http://www.haskell.org/cabal/users-guide/#test-suites) I also have Cabal-Version: >= 1.9.2 in the file; the full version can be found at https://bitbucket.org/doug_burke/swish/src/4545220d88e2/swish.cabal#cl-271 What am I doing wrong? Thanks in advance, Doug

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runStateT execution times measurement baffling
by thomas burt 22 Oct '11

22 Oct '11

Hello - I've been trying to measure execution time for some code I'm running with the StateT monad transformer. I have a function f :: StateT MyState IO a Now, I measure the time it takes to run an invocation of this function from beginning to end, i.e. f = do t0 <- getCurrentTime stuffToDo t1 <- getCurrentTime liftIO $ putStrLn (show $ diffUTCTime t1 t0) And also measure like this: g :: IO g = do t0 <- getCurrentTime (val,newState) <- runStateT f initialState t1 <- getCurrentTime putStrLn $ "outside: " ++ (show $ diffUTCTime t1 t0) Curiously, the times reported for "outside" are about 5-8 times as long. I should probably note that stuffToDo calls itself a few hundred times (and uses liftIO once per loop). Anyone with ideas on why runStateT apparently has so much overhead? By the way I'm using ghc-6.10.4 and Control.Monad.Trans.State.Strict. Thanks for any suggestions or advice. Thomas

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Haddock fails on ConfigFile, but why?
by Magnus Therning 22 Oct '11

22 Oct '11

Would love to get some help on making Haddock accept ConfigFile[1]. The error message is about as far from helpful as you can get ;) dist/build/tmp-15743/src/Data/ConfigFile/Monadic.hs:34:1: parse error on input `import' The author is informed but is as confused as me, it seems[2]. /M [1] http://hackage.haskell.org/package/ConfigFile [2] https://github.com/jgoerzen/configfile/issues/4 -- Magnus Therning OpenPGP: 0xAB4DFBA4 email: magnus(a)therning.org jabber: magnus(a)therning.org twitter: magthe http://therning.org/magnus Most software today is very much like an Egyptian pyramid with millions of bricks piled on top of each other, with no structural integrity, but just done by brute force and thousands of slaves. -- Alan Kay

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What is the etiquette for posting to multiple forums?
by Michael Litchard 21 Oct '11

21 Oct '11

I know it's bad form to post the same question to multiple mailing lists. But what about say, the beginner's mailing list and stackoverflow.com?

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ANN: OpenCL 1.0.1.3 package
by Luis Cabellos 21 Oct '11

21 Oct '11

Hello, all. I want to show you the OpenCL package. I have done this using Jeff Heard OpenCLRaw package, but I create a new one due the lack of updates of the former. # Where to get it * Hackage page (http://hackage.haskell.org/package/OpenCL) * Repository (https://github.com/zhensydow/opencl) * Bugs (https://github.com/zhensydow/opencl/issues) * Examples (https://github.com/zhensydow/opencl/tree/master/examples) # Things: * I write it's high-level binding to OpenCL libraries, but only because I added more types to hide most of the alloc/free of the API, and hide the enums using c2hs enums. * The worst problem of the OpenCLRaw is the bad types it use, I learn to fix 32/64 bits issues with c2hs, and test it on linux machines. * Tested on Linux + NVidia only. * Jason Dagit is helping with Windows, OSX testing in own fork, also the call-conv fork in github has changes to work on Windows Please, Consider it's on experimental status but it works, I need lots of feedbacks for detect posible errors, Thanks,

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Trying to install hpodder on OS X Lion
by seanh 21 Oct '11

21 Oct '11

I'd really like to get hpodder installed on OS X Lion, I can't find it packaged anywhere (macports, homebrew...) Has anyone got it working? I have the haskell platform installed from the pkg file from haskell.org: http://hackage.haskell.org/platform/mac.html So I tried `cabal install hpodder` but it failed. First I get a lot of warnings like: ld: warning: text reloc in _cZh_str to _stg_ap_pppppp_fast ld: warning: text reloc in _cZh_str to _stg_ap_ppppp_fast ld: warning: text reloc in _cZh_str to _stg_ap_pppp_fast ld: warning: text reloc in _cZh_str to _stg_ap_pppv_fast ld: warning: text reloc in _cZh_str to _stg_ap_ppp_fast ld: warning: text reloc in _cZh_str to _stg_ap_ppv_fast ld: warning: text reloc in _cZh_str to _stg_ap_pp_fast ld: warning: text reloc in _cZh_str to _stg_ap_pv_fast ld: warning: text reloc in _cZh_str to _stg_ap_p_fast ld: warning: text reloc in _cZh_str to _stg_ap_n_fast ld: warning: text reloc in _cZh_str to _stg_ap_l_fast ld: warning: text reloc in _cZh_str to _stg_ap_d_fast ld: warning: text reloc in _cZh_str to _stg_ap_f_fast ld: warning: text reloc in _cZh_str to _stg_ap_v_fast ld: warning: text reloc in _cZh_str to _stg_ap_pppppp_info I get each of those warnings many times in a row. There are some other warning when compiling things as well. Then I eventually get: cabal: Error: some packages failed to install: hpodder-1.1.5 failed during the building phase. The exception was: ExitFailure 1 Here's the error from the compiler before that: Commands/SetStatus.hs:59:33: Ambiguous type variable `e0' in the constraint: (E.Exception e0) arising from a use of `E.catch' Probable fix: add a type signature that fixes these type variable(s) In the expression: E.catch (E.evaluate (read x)) (\ _ -> fail $ "Invalid status supplied; use one of: " ++ possibleStatuses) In a case alternative: Just x -> E.catch (E.evaluate (read x)) (\ _ -> fail $ "Invalid status supplied; use one of: " ++ possibleStatuses) In a stmt of a 'do' expression: newstatus <- case lookup "status" args of { Just x -> E.catch (E.evaluate (read x)) (\ _ -> fail $ "Invalid status supplied; use one of: " ++ possibleStatuses) Nothing -> fail "setstatus: --status required; see hpodder setstatus --help" }

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Functional Programmer required for a Greenfield project in a software house in London.
by Oliver Horncastle 21 Oct '11

21 Oct '11

Ideally from a high performance computing, real-time systems background (OO experience, either java or c++). Get in touch for more details. Oliver Horncastle Madison Maclean Email: Oliver.horncastle(a)madisonmaclean.com<mailto:Oliver.horncastle@madisonmaclean.com> Direct Line: 020 30 30 50 53

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