[Haskell-cafe] haskell; json-rpc
Apologize in advance for the English language.
I'm working with json-rpc interface (http://json-rpc.org/) via http.
Requests and responses look like this:
- {jsonrpc : 2.0, id : 1, method : user.authenticate,
params : { user : myUser, password : myPassword }}
-
{jsonrpc:2.0,result:97d4b59d2f2fbf703bb7aa257aae5254,id:1}
- {jsonrpc : 2.0, id : 2, method : user.getObjects,
auth : 97d4b59d2f2fbf703bb7aa257aae5254,
params : { alias : myUser }}
-
{jsonrpc:2.0,result:[{userid:3,alias:myUser,name:lala,
surname:lala,passwd:c5aba41f671a02a3c8a6f10a2a7d8a19,
url:myUrl,autologin:1,autologout:0,lang:ru_ru,
refresh:30,type:1,theme:css_bb.css,attempt_failed:0,
attempt_ip:0.0.0.0,attempt_clock:1282502966,
rows_per_page:50}],id:2}
How can i describe in Haskell my task?
P.S. The first request is required for authentication (field auth in
the following queries). Using the second query, I want to know
userid).
P.P.S. My first approach is to describe rpc query as following:
data RpcQuery = RpcQuery {
rpcVersion :: String,
rpcId :: String,
rpcMethod :: String,
rpcAuth :: String,
rpcParams :: AuthUser
} deriving (Show)
data AuthUser = AuthUser {
authUser :: String,
authPassword :: String
} deriving (Show)
instance JSON AuthUser where
showJSON au = makeObj
[ (user, showJSON $ authUser au)
, (password, showJSON $ authPassword au)
]
readJSON (JSObject obj) = let
jsonObjAssoc = fromJSObject obj
in do
user - mLookup user jsonObjAssoc = readJSON
password - mLookup password jsonObjAssoc =
readJSON
return $ AuthUser
{ authUser = user
, authPassword = password
}
readJSON _ = fail
But this scheme is not extended.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] video for linux two (v4l2) bindings
On 3 July 2011 21:46, Daniel Fischer daniel.is.fisc...@googlemail.com wrote: On Sunday 03 July 2011, 21:34:17, Christopher Done wrote: I just had a quick try with cabal-install and got the below. I'm not sure where linux/posix_types is supposed to come from. Is this error obvious to you? glibc-devel or the equivalent package for your distro, I think. It turned out that I needed the linux development files from linux-libc-dev. FWIW to anyone, I'm on Ubuntu. The packages I installed were: sudo apt-get install linux-libc-dev sudo apt-get install libv4l-dev Then I got this problem: /home/chris/Programs/bin/ghc --make -o dist/build/v4l2-capture/v4l2-capture -hide-all-packages -fbuilding-cabal-package -package-conf dist/package.conf.inplace -i -idist/build/v4l2-capture/v4l2-capture-tmp -i. -idist/build/autogen -Idist/build/autogen -Idist/build/v4l2-capture/v4l2-capture-tmp -optP-include -optPdist/build/autogen/cabal_macros.h -odir dist/build/v4l2-capture/v4l2-capture-tmp -hidir dist/build/v4l2-capture/v4l2-capture-tmp -stubdir dist/build/v4l2-capture/v4l2-capture-tmp -package-id base-4.2.0.2-5fc3ebcb886ceae9a06b0bab7e8d4680 -package-id bindings-libv4l2-0.1-8dde216a9ec82cb90bbe93e20783ff8c -package-id bindings-linux-videodev2-0.1-7a032e0014085bf53e381d004d794b50 -package-id bindings-mmap-0.1-3144f93204d922458a3be21650b85f1f -package-id bindings-posix-1.2.2-00b879b119996c2d3acc7989dde2ba63 -package-id c-io-0.1.0-dcc629f98d0e4b2e0d55acbaaa6262b6 -package-id ioctl-0.0.1-60f1d8091a07bb23f1736fec7d2b4dd8 -O -Wall ./src/v4l2-capture.hs [1 of 1] Compiling Main ( src/v4l2-capture.hs, dist/build/v4l2-capture/v4l2-capture-tmp/Main.o ) Linking dist/build/v4l2-capture/v4l2-capture ... /usr/bin/ld: /home/chris/.cabal/lib/bindings-posix-1.2.2/ghc-6.12.3/libHSbindings-posix-1.2.2.a(Signal.o):(.text+0x5dfb): error: undefined reference to 'pthread_kill' /usr/bin/ld: /home/chris/.cabal/lib/bindings-posix-1.2.2/ghc-6.12.3/libHSbindings-posix-1.2.2.a(Signal.o):(.text+0x5ee2): error: undefined reference to 'pthread_kill' /usr/bin/ld: /home/chris/.cabal/lib/bindings-posix-1.2.2/ghc-6.12.3/libHSbindings-posix-1.2.2.a(Signal.o):(.text+0x5f87): error: undefined reference to 'pthread_sigmask' /usr/bin/ld: /home/chris/.cabal/lib/bindings-posix-1.2.2/ghc-6.12.3/libHSbindings-posix-1.2.2.a(Signal.o):(.text+0x6092): error: undefined reference to 'pthread_sigmask' collect2: ld returned 1 exit status cabal: Error: some packages failed to install: v4l2-examples-0.1 failed during the building phase. The exception was: ExitFailure 1 chris@cn-done:~/v4l2-examples-0.1$ But I solved it by adding -lpthread: chris@cn-done:~/v4l2-examples-0.1$ /home/chris/Programs/bin/ghc --make -o dist/build/v4l2-capture/v4l2-capture -hide-all-packages -fbuilding-cabal-package -package-conf dist/package.conf.inplace -i -idist/build/v4l2-capture/v4l2-capture-tmp -i. -idist/build/autogen -Idist/build/autogen -Idist/build/v4l2-capture/v4l2-capture-tmp -optP-include -optPdist/build/autogen/cabal_macros.h -odir dist/build/v4l2-capture/v4l2-capture-tmp -hidir dist/build/v4l2-capture/v4l2-capture-tmp -stubdir dist/build/v4l2-capture/v4l2-capture-tmp -package-id base-4.2.0.2-5fc3ebcb886ceae9a06b0bab7e8d4680 -package-id bindings-libv4l2-0.1-8dde216a9ec82cb90bbe93e20783ff8c -package-id bindings-linux-videodev2-0.1-7a032e0014085bf53e381d004d794b50 -package-id bindings-mmap-0.1-3144f93204d922458a3be21650b85f1f -package-id bindings-posix-1.2.2-00b879b119996c2d3acc7989dde2ba63 -package-id c-io-0.1.0-dcc629f98d0e4b2e0d55acbaaa6262b6 -package-id ioctl-0.0.1-60f1d8091a07bb23f1736fec7d2b4dd8 -O -Wall ./src/v4l2-capture.hs -lpthread Linking dist/build/v4l2-capture/v4l2-capture ... chris@cn-done:~/v4l2-examples-0.1$ I guess on Claude's system it's linked to by default. So for guys trying the examples with that error I'd recommend the following commandline: cabal install v4l2-examples --ghc-option=-lpthread Can't really play about with the webcam right now but I'd had a small but cool project I've had in mind for a while that v4l is perfectly suited for, so I'll get back to you with my experiences. Thanks for releasing it, Claude. :-) Ciao! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell and Databases
On Fri, Jul 1, 2011 at 8:45 PM, Tobias Schoofs tobias.scho...@gmx.net wrote: Database programs, usually, do not just issue isolated SQL statements, but implement a processing logic with nested queries and DML statements. Frequently using cursors or issuing queries from a loop often means you've missed out on the declarative and set based nature of SQL and databases. http://www.sqlservercentral.com/articles/T-SQL/66097/ http://stackoverflow.com/questions/287445/why-do-people-hate-sql-cursors-so-much Granted, you could still argue that it should be supported, for the few cases where it actually makes sense. Isak ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Splitting Hackage Packages and re-exporting entire modules (with same module name)
If you give the module a new name in the new package then the old module can re-export all of the symbols in the new module. In GHC I don't think there is a way for two packages to export the same module and have them be recognized as the same thing, as far as I know. Antoine On Tue, Jul 5, 2011 at 12:36 AM, Thomas DuBuisson thomas.dubuis...@gmail.com wrote: All, I have decided it would be beneficial to split System.Crypto.Random and the rest of crypto-api into different packages. Is there I way I can create a package, entropy, with System.Crypto.Random but continue to expose that module from crypto-api (allowing people who use that module some time to move)? If so, how? If not, does anyone else see value in this and how it can be added to the infrastructure? Cheers, Thomas ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] NVIDIA's CUDA and Haskell
I should mention that the version of 'accelerate' on hackage is a little old and unloved at the moment, but the source repo should work: https://github.com/mchakravarty/accelerate Also, the CUDA bindings package hasn't yet been tested/updated for the recent 4.0 toolkit release. -T On 05/07/2011, at 10:13 AM, Don Stewart wrote: There's a lot of active work: Direct access to CUDA: http://hackage.haskell.org/package/cuda CUDA in Haskell: http://hackage.haskell.org/package/language-c-quote Direct access to OpenCL: http://hackage.haskell.org/package/OpenCLRaw High-level pure data parallelism targetting your GPU: http://hackage.haskell.org/package/accelerate On Mon, Jul 4, 2011 at 8:09 PM, Vasili I. Galchin vigalc...@gmail.com wrote: Hi, NVIDIA's CUDA library seems to be really hot in the massively parallel world: http://www.nvidia.com/object/cuda_home_new.html. I realize that given CUDA seems to be implemented in an extension of ANSI C that it is pervaded by statefulness. However, is there any effort to build a bridge between Haskell and CUDA, foreign language bindings or maybe better yet a monad to encapsulate state?? Kind regards, Vasili ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] NVIDIA's CUDA and Haskell
Trevor L. McDonell tmcdonell at cse.unsw.edu.au writes: ... source repo should work: https://github.com/mchakravarty/accelerate I have CUDA in the default location (e.g., /usr/local/cuda/bin/nvcc ) but I can't seem to get the cuda cabal package to build ... checking cuda.h usability... yes checking cuda.h presence... yes checking for cuda.h... yes checking cuda_runtime_api.h usability... yes checking cuda_runtime_api.h presence... yes checking for cuda_runtime_api.h... yes checking for library containing cuDriverGetVersion... no configure: error: could not find CUDA driver library I have nvcc in the PATH, and I also set --extra-include/lib-dirs I can build and run the NVIDIA_GPU_Computing_SDK examples. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Automatic Reference Counting
On 2 Jul 2011, at 18:35, Thomas Davie wrote: It's interesting that you cite that GC is both faster and lower memory overhead – Apple's stated reasons for implementing this were that GC was both too slow and too memory intensive to use sensibly on iDevices and that ARC was both faster and less memory intensive. Reality is probably a little more subtle than this. In general, and specifically for long-running and memory intensive processes (such as used in servers), quality garbage collection (and especially compacting garbage collection) are probably more efficient overall. Apple already supported (and continues to support) garbage collection for Objective-C in their desktop systems. The primary motivation (as I understand it) for developing ARC is to bring (mostly) automatic memory management to the iOS platforms. There are 2 reasons that I've heard why Apple considers ARC a superior solution for the iOS platform: 1. iOS devices are much more resource constrained than a desktop system. Therefore the delay that garbage collection causes before memory is available for re-allocation can have a much greater effects on application. 2. Running a background garbage collector can introduce unpredictable pauses in your application, which would destroy the illusion of immediacy that is one of the prime characteristics of good iOS apps. So for iOS immediate memory release and predictable performance trumps overall average performance. To see if this technique would be at all useful for Haskell, you'll have to evaluate these points in the context of a Haskell application and decide which trade-off brings you the most benefit. Maarten ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Searching of several substrings (with Data.Text ?)
Hi, For my font library I need A function that can handle ligatures. It can be explained best with an example: f [Th, ff, fi, fl, ffi] The fluffiest bunny should be evaluated to [Th, e, , fl, u, ffi, e, s, t, , b, u, n, n, y ] I looked at Data.Text http://hackage.haskell.org/packages/archive/text/0.5/doc/html/Data-Text.html and http://hackage.haskell.org/packages/archive/stringsearch/0.3.3/doc/html/Data-ByteString-Search.html but they don't have a function that can search several substrings in one run. I guess that searching a text again and again for every substring is not very efficient and it can be done in one run. Although I may figure this out myself I think such a function could be so common that someone has done it or can give me some tips. Thanks ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Searching of several substrings (with Data.Text ?)
... a function that can search several substrings in one run. use regular expressions? (the regexp can be compiled into a finite automaton that scans the string just once.) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Searching of several substrings (with Data.Text ?)
On Tuesday 05 July 2011, 20:01:26, Tillmann Vogt wrote: Hi, For my font library I need A function that can handle ligatures. It can be explained best with an example: f [Th, ff, fi, fl, ffi] The fluffiest bunny should be evaluated to [Th, e, , fl, u, ffi, e, s, t, , b, u, n, n, y ] I looked at Data.Text http://hackage.haskell.org/packages/archive/text/0.5/doc/html/Data-Text. html and http://hackage.haskell.org/packages/archive/stringsearch/0.3.3/doc/html/ Data-ByteString-Search.html but they don't have a function that can search several substrings in one run. Well, Data.ByteString[.Lazy].KarpRabin does provide simultaneous search for multiple substrings - it does not, however, provide direct splitting. But in my tests, unless the number of substrings was large, multiple separate (Boyer-Moore) passes with manual merging of the offset lists were much faster [there's a possible space leak for lazy ByteStrings if any pattern does not appear in a long substring of the source, so that would be a point for Data.ByteString.Lazy.KarpRabin], and I didn't know of any real use-case, so I did not pursue it further and considered it just an interesting curiosity. I suppose using a regex package as Johannes Waldmann suggested would be the easiest way (probably also faster). If you submit a feature request, however, I would look into expanding the offered functionality (but I'll be on vacation soon, so performance would have to wait; I suppose something could be gained there). I guess that searching a text again and again for every substring is not very efficient and it can be done in one run. Well, it is surprisingly efficient, compared to (my implementation of) the Karp-Rabin algorithm at least. Although I may figure this out myself I think such a function could be so common that someone has done it or can give me some tips. Thanks Cheers, Daniel ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Searching of several substrings (with Data.Text ?)
On Tue, Jul 5, 2011 at 11:01 AM, Tillmann Vogt tillmann.v...@rwth-aachen.de wrote: I looked at Data.Text http://hackage.haskell.org/** packages/archive/text/0.5/doc/**html/Data-Text.htmlhttp://hackage.haskell.org/packages/archive/text/0.5/doc/html/Data-Text.html and http://hackage.haskell.org/**packages/archive/stringsearch/** 0.3.3/doc/html/Data-**ByteString-Search.htmlhttp://hackage.haskell.org/packages/archive/stringsearch/0.3.3/doc/html/Data-ByteString-Search.html but they don't have a function that can search several substrings in one run. Here's what you want: http://hackage.haskell.org/packages/archive/text-icu/0.6.3.4/doc/html/Data-Text-ICU-Regex.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to ensure code executes in the context of a specific OS thread?
On 04/07/11 06:02, Jason Dagit wrote: Hello, I'm trying to get some GUI code working on OSX and numerous forums around the internet keep reiterating that on OSX to correctly handle GUI events you need to use the original thread allocated to your process to check for events and to call the Cocoa framework functionality. Specifically, using a secondary thread (even a bound thread) is not sufficient with the Cocoa framework. I looked at the threading documentation in Control.Concurrent for GHC and it's not clear to me if this is even possible with GHC without restricting to the non-threaded RTS. This means that using the GUI library from GHCI is not an option and using multiple OS threads in the final application is also not possible. This means that some FFI libraries will be unusable. In a compiled program, the main thread is a bound thread, bound to the main OS thread of the process (i.e. the GUI thread in your case). So you can safely make Cocoa calls using the main thread of your compiled Haskell program, and from other threads if you add some way to forward operations to the main thread, like gtk2hs's postGUI. In GHCi it's a different matter, because the main thread is running GHCi itself, and all the expressions/statements typed at the prompt are run in forkIO'd threads (a new one for each statement, in fact). If you want a way to run command-line operations in the main thread, please submit a feature request. I'm not sure it can be done, but I'll look into it. Cheers, Simon ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Searching of several substrings (with Data.Text ?)
I've been looking into building parsers at runtime (from a config file), and in my case it's beneficial to fit them into the context of a larger parser with Attoparsec.Text. This code is untested for practical use so I doubt you'll see comparable performance to the aforementioned regex packages, but it could be worth exploring if you need to mix and match parsers or if the definitions can change arbitrarily at runtime. import qualified Data.Text as T import Data.Attoparsec.Text import Control.Applicative ((|)) parseLigature x = string (T.pack x) charToText = do c - anyChar return (T.singleton c) buildChain [x]= parseLigature x buildChain (x:xs) = try (parseLigature x) | buildChain xs -- ordering matters here, so ffi comes before ff or fi ligatures = buildChain [ffi, th, ff, fi, fl] myParser = many (try ligatures | charToText) -- at ghci prompt: parseOnly myParser (T.pack the fluffiest bunny) -- Right [th,e, ,fl,u,ffi,e,s,t, ,b,u,n,n,y] On Tue, Jul 5, 2011 at 12:09 PM, Bryan O'Sullivan b...@serpentine.com wrote: On Tue, Jul 5, 2011 at 11:01 AM, Tillmann Vogt tillmann.v...@rwth-aachen.de wrote: I looked at Data.Text http://hackage.haskell.org/packages/archive/text/0.5/doc/html/Data-Text.html and http://hackage.haskell.org/packages/archive/stringsearch/0.3.3/doc/html/Data-ByteString-Search.html but they don't have a function that can search several substrings in one run. Here's what you want: http://hackage.haskell.org/packages/archive/text-icu/0.6.3.4/doc/html/Data-Text-ICU-Regex.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to ensure code executes in the context of a specific OS thread?
On Tue, Jul 05, 2011 at 08:11:21PM +0100, Simon Marlow wrote: In GHCi it's a different matter, because the main thread is running GHCi itself, and all the expressions/statements typed at the prompt are run in forkIO'd threads (a new one for each statement, in fact). If you want a way to run command-line operations in the main thread, please submit a feature request. I'm not sure it can be done, but I'll look into it. We already have a way: -fno-ghci-sandbox Thanks Ian ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to ensure code executes in the context of a specific OS thread?
On Tue, Jul 5, 2011 at 12:11 PM, Simon Marlow marlo...@gmail.com wrote: On 04/07/11 06:02, Jason Dagit wrote: Hello, I'm trying to get some GUI code working on OSX and numerous forums around the internet keep reiterating that on OSX to correctly handle GUI events you need to use the original thread allocated to your process to check for events and to call the Cocoa framework functionality. Specifically, using a secondary thread (even a bound thread) is not sufficient with the Cocoa framework. I looked at the threading documentation in Control.Concurrent for GHC and it's not clear to me if this is even possible with GHC without restricting to the non-threaded RTS. This means that using the GUI library from GHCI is not an option and using multiple OS threads in the final application is also not possible. This means that some FFI libraries will be unusable. In a compiled program, the main thread is a bound thread, bound to the main OS thread of the process (i.e. the GUI thread in your case). So you can safely make Cocoa calls using the main thread of your compiled Haskell program, and from other threads if you add some way to forward operations to the main thread, like gtk2hs's postGUI. Is my understanding correct that this is only the case for the non-threaded RTS? If so, what do you do when you need to use the threaded RTS? My test was to check if the main thread was bound when compiling with -threaded. I got the impression that I couldn't guarantee that the code was running on the original thread. In GHCi it's a different matter, because the main thread is running GHCi itself, and all the expressions/statements typed at the prompt are run in forkIO'd threads (a new one for each statement, in fact). If you want a way to run command-line operations in the main thread, please submit a feature request. I'm not sure it can be done, but I'll look into it. I'll try Ian's suggestion of -fno-ghci-sandbox when I get a chance. Thanks, Jason ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANNOUNCE: test-framework-doctest 0.1
test-framework-doctest [1] provides a wrapper for running doctests [2] in test-framework [3]. This uses the newly minted API exposed by doctest 0.4 that Simon Hengel just announced [4]. The current incarnation of the package is a very rudimentary. Patches are more than welcome [5]. Many thanks to Simon Hengel for working with me on this. [1] http://hackage.haskell.org/package/test-framework-doctest [2] http://hackage.haskell.org/package/doctest-0.4.0 [3] http://hackage.haskell.org/package/test-framework-0.4.0 [4] http://www.haskell.org/pipermail/haskell-cafe/2011-July/093748.html [5] https://github.com/sakari/test-framework-doctest Sakari ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANN: Monad.Reader Issue 18
I am pleased to announce that Issue 18 of The Monad.Reader is now available [1]. Issue 18 consists of the following three articles: * MapReduce as a Monad by Julian Porter * Fun with Parallel Monad Comprehensions by Tomas Petricek * Attributed Variables: Their Uses and One Implementation by Douglas M. Auclair Feel free to browse the source files. You can check out the entire repository using darcs (or simply visit the below URL in your browser): darcs get http://code.haskell.org/~byorgey/TMR/Issue18 Enjoy! [1] http://themonadreader.files.wordpress.com/2011/07/issue18.pdf ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Searching of several substrings (with Data.Text ?)
Am 05.07.2011 21:29, schrieb Eric Rasmussen: I've been looking into building parsers at runtime (from a config file), and in my case it's beneficial to fit them into the context of a larger parser with Attoparsec.Text. This code is untested for practical use so I doubt you'll see comparable performance to the aforementioned regex packages, but it could be worth exploring if you need to mix and match parsers or if the definitions can change arbitrarily at runtime. import qualified Data.Text as T import Data.Attoparsec.Text import Control.Applicative ((|)) parseLigature x = string (T.pack x) charToText = do c- anyChar return (T.singleton c) buildChain [x]= parseLigature x buildChain (x:xs) = try (parseLigature x)| buildChain xs -- ordering matters here, so ffi comes before ff or fi ligatures = buildChain [ffi, th, ff, fi, fl] myParser = many (try ligatures| charToText) -- at ghci prompt: parseOnly myParser (T.pack the fluffiest bunny) -- Right [th,e, ,fl,u,ffi,e,s,t, ,b,u,n,n,y] Of course parsec! I should have thought of this. icu seems to be the best solution (I already considered it for parsing character references), but it is not so easy to install on windows. So I wait until cabal does this or it is integrated into the haskell platform. Thank you all for your help (especially the attoparsec example) On Tue, Jul 5, 2011 at 12:09 PM, Bryan O'Sullivanb...@serpentine.com wrote: On Tue, Jul 5, 2011 at 11:01 AM, Tillmann Vogt tillmann.v...@rwth-aachen.de wrote: I looked at Data.Text http://hackage.haskell.org/packages/archive/text/0.5/doc/html/Data-Text.html and http://hackage.haskell.org/packages/archive/stringsearch/0.3.3/doc/html/Data-ByteString-Search.html but they don't have a function that can search several substrings in one run. Here's what you want: http://hackage.haskell.org/packages/archive/text-icu/0.6.3.4/doc/html/Data-Text-ICU-Regex.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to ensure code executes in the context of a specific OS thread?
On Tue, Jul 5, 2011 at 12:33 PM, Ian Lynagh ig...@earth.li wrote: On Tue, Jul 05, 2011 at 08:11:21PM +0100, Simon Marlow wrote: In GHCi it's a different matter, because the main thread is running GHCi itself, and all the expressions/statements typed at the prompt are run in forkIO'd threads (a new one for each statement, in fact). If you want a way to run command-line operations in the main thread, please submit a feature request. I'm not sure it can be done, but I'll look into it. We already have a way: -fno-ghci-sandbox I've removed all my explicit attempts to forkIO/forkOS and passed the command line flag you mention. I just tried this but it doesn't change the behavior in my example. Jason ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANNOUNCE: FunPat 0.1
Hello, I've recently uploaded a package that provides some kind of extended pattern matching. For example, one can use (abc ++ xs) as a pattern. The original motivation was to allow pattern matching on expressions of embedded languages in cases when the constructors of the underlying data types are hidden. For more examples, see http://hackage.haskell.org/package/funpat Feedback is very welcome! Cheers, Gergely ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] NVIDIA's CUDA and Haskell
hmm... so libcuda and libcudart are in /usr/local/cuda/lib and the script isn't finding them? Any further information on your system / os combination? What version of the toolkit are you using? I currently use 3.2, haven't tried with 4.x yet. $ nvcc --version nvcc: NVIDIA (R) Cuda compiler driver Copyright (c) 2005-2010 NVIDIA Corporation Built on Thu_Nov_11_15:26:50_PST_2010 Cuda compilation tools, release 3.2, V0.2.1221 On 05/07/2011, at 10:16 PM, Johannes Waldmann wrote: Trevor L. McDonell tmcdonell at cse.unsw.edu.au writes: ... source repo should work: https://github.com/mchakravarty/accelerate I have CUDA in the default location (e.g., /usr/local/cuda/bin/nvcc ) but I can't seem to get the cuda cabal package to build ... checking cuda.h usability... yes checking cuda.h presence... yes checking for cuda.h... yes checking cuda_runtime_api.h usability... yes checking cuda_runtime_api.h presence... yes checking for cuda_runtime_api.h... yes checking for library containing cuDriverGetVersion... no configure: error: could not find CUDA driver library I have nvcc in the PATH, and I also set --extra-include/lib-dirs I can build and run the NVIDIA_GPU_Computing_SDK examples. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Automatic Reference Counting
The important point about reference counting on idevices is the near realtime performance, since stops for collecting garbage are actually very short in comparison to collecting compilers (despite more frequent). Some compilers, I think it was for the pure functional programming language OPAL if I'm not wrong even check at compile time and add code for reusing cells instead of freeing them when it is known to be safe. But OPAL has strict evaluation and no lazy construct. This it does not allow for cycles unlike haskell which makes reference counting a viable and easy implementable option for OPAL. About Apple's ARC. It is actually using the very same mechanisms the clang static analyzer uses. That is at a first stage it works with the typical Objective-C conventions of object ownership. For example if you have a function other than alloc and Co. transferring object ownership to it's caller the static analyzer will complain about a possible space leak. In this case one has to add an attribute to the function telling the compiler that it is intended for the function to work like this. Having a look at the ARC docs it seems to be the very same case. That is if you have a function like just mentioned you need to add this said attribute to the function declaration for ARC to insert correct retains/releases. So there is no real magic going on, but one needs to be really aware of it or bug hunting (especially for external libraries) may become maybe a little less funny... Additionally clang adds some extra commands into the generated LLVM code which LLVM understands. This allows i) for further optimizations at later compiling stages and ii) you don't need to send messages to objects anymore for reference counting (as long as you don't implement retain/release for them by yourself, but by convention you don't do so...), but the counter may be accessed directly in memory. That's why ARC (if you follow Apple's conventions about object ownership) can be much more efficient than the current implementation. - Steffen ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
