[Haskell-cafe] Beginners Question: Problem with Data Type Declaration
I try to create an own data type containing Vector Double from the H-Matrix package. The code: ## data PowerSig = PowerSig Int Double Vector Double main = do let p5 = PowerSig 1 0.1 (fromList [1,2,3]) ## When compiling with ghci, I get however the following message: `Vector' is not applied to enough type arguments Expected kind `?', but `Vector' has kind `* - *' In the type `Vector' In the definition of data constructor `PowerSig' In the data type declaration for `PowerSig' I don't understand the compilers message and couldn't find any wiki-page/other material to help me. The Data Declaration somehow seems not to understand that Vector Double belongs together, but brackets don't help either. Cheers Phil -- View this message in context: http://haskell.1045720.n5.nabble.com/Beginners-Question-Problem-with-Data-Type-Declaration-tp4494012p4494012.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Beginners Question: Problem with Data Type Declaration
Hi, On Thu, Jun 16, 2011 at 9:53 AM, kaffeepause73 kaffeepaus...@yahoo.de wrote: I try to create an own data type containing Vector Double from the H-Matrix package. The code: ## data PowerSig = PowerSig Int Double Vector Double You need to put parenthesis around (Vector Double). Otherwise this is interpreted as a constructor with 4 fields (instead of 3). Johan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Best platform for development with GHC?
Dmitri O.Kondratiev doko...@gmail.com writes: Let me know if you would like opinions on Emacs vs vi! I know vi, but it is just that I got used to Emacs which is my main IDE for most PL that I work with and for many years already ) No, no! Stop, it was just a joke, really. I regret it already. :-) -k -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Best platform for development with GHC?
John D. Ramsdell ramsde...@gmail.com writes: Developers should be using older versions of GHC because they cannot be sure users will have an up-to-date GHC. I wonder, how hard would it be to have, say Amazon images of various Linux distributions with ghc and cabal-install available? Currently, I have a discontious integration server that checks my stuff by pulling off hackage, but this is a bit limited, as well as a security risk. I'd consider running something off Amazon instead - perhaps it could even be automated, so that I could do 'cabal install whatever' in parallel on a slew of configurations? And, although I could probably pay for my own stuff, perhaps Amazon could contribute (som of) the CPU time? -k -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Beginners Question: Problem with Data Type Declaration
Hi Johan, actually quite obvious. Code works now, many thanks. :-) import Data.Packed.Vector data PowerSig = PowerSig Int Double (Vector Double) -- signal Index timeStep data instance Show PowerSig where show (PowerSig idx dt vector) = PowerSignal Nr: ++ show idx ++ dt: ++ show dt ++ val: ++ show vector main = do let p = PowerSig 5 0.1 (fromList [0..10::Double]) putStrLn (show p) -- View this message in context: http://haskell.1045720.n5.nabble.com/Beginners-Question-Problem-with-Data-Type-Declaration-tp4494012p4494166.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Win32: cabal install --prefix=$HOME --user ?
On win32 cabal install --prefix=$HOME --user fails: cabal install --prefix=$HOME --user Resolving dependencies... Configuring split-0.1.4... cabal: expected an absolute directory name for --prefix: $HOME cabal: Error: some packages failed to install: split-0.1.4 failed during the configure step. The exception was: ExitFailure 1 What is the right equivalent of cabal install --prefix=$HOME --user on Win32? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Build failure on Hackage, missing syb
Hi all, What causes the following build failure on Hackage? *** setup configure Configuring instant-generics-0.3.2... cabal-setup: At least the following dependencies are missing: syb 0.4 This is in package instant-generics-0.3.2http://hackage.haskell.org/packages/archive/instant-generics/0.3.2/logs/failure/ghc-7.0. The syb package built fine on Hackage. Previously, packages depending on syb built fine too (e.g. http://hackage.haskell.org/package/syz). So why is instant-generics-0.3.2 not building? Thanks, Pedro ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Parsing Haskell in Parsec
You may browse my source code (quite unpolished) ... updated locations: http://dfa.imn.htwk-leipzig.de/cgi-bin/gitweb.cgi?p=ws10-cb.git;a=summary git clone git://dfa.imn.htwk-leipzig.de/srv/git/ws10-cb ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Best platform for development with GHC?
Hi, let me chime in as someone who wanted to deploy a Haskell app on a fairly popular hosting environment (Slicehost). The support of GHC on the Ubuntu server front is tragic - there's no official Haskell Platform for the currently suggested server version of Ubuntu, which is Ubuntu 10.04 LTS (Long Term Support). It will still have to be supported for the next about-five years. Setting aside arguments of whether Ubuntu is the best choice for a server, it is fairly popular, and easy to use. You can expect any developer who wants to jump into Haskell for e.g. web-related servers to use Ubuntu, because it's easy. 10.04 LTS only has single GHC packages and some other stuff, but the Platform is missing. It is impossible to compile HP on a virtual server, and cross-compiling is beyond the casual user's skill. The solution would be to have a PPA with binaries that people can use - PPA usage is well documented and popular among Ubuntu folks. In the end this project died off because I simply could not get HP into the box. Notice that - ironically - Ubuntu 10.10 and further versions, none of which are Long Term Support versions, do have HP as a package. I hope this can happen and that it can be officially backed - as opposed to a halfway-effort which will be someone hosting a private PPA, getting bored of it after 3 months/weeks/hours, and the whole situation returning to an even worse state than it was before. I hope we can get good Haskell support for the most popular server version of one of the most popular Linux distribution, because frankly the current options are just terrible and useless. Cheers, D. On Thu, Jun 16, 2011 at 08:40, Ketil Malde ke...@malde.org wrote: John D. Ramsdell ramsde...@gmail.com writes: Developers should be using older versions of GHC because they cannot be sure users will have an up-to-date GHC. I wonder, how hard would it be to have, say Amazon images of various Linux distributions with ghc and cabal-install available? Currently, I have a discontious integration server that checks my stuff by pulling off hackage, but this is a bit limited, as well as a security risk. I'd consider running something off Amazon instead - perhaps it could even be automated, so that I could do 'cabal install whatever' in parallel on a slew of configurations? And, although I could probably pay for my own stuff, perhaps Amazon could contribute (som of) the CPU time? -k -- If I haven't seen further, it is by standing in the footprints of giants ___ 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] Data Type Inheritance ala OO - Inheritence -- howto best in Haskell ?
Dear all, I'm created a timeSignal datatype as container around a Vector Double data type (see simple code below) and subsequently started to instanciate Num Eq to be able to perform operations on it. Additionally I want store ifno like an index, time information and eventually an inheritence log (the log is not yet in there). As I will in the end need up to 10 different datatypes, however using slightly different content (time signal, single value, distribution, ...) I ask myself, how I could define a super data-type with sub-data-types to inherit, but then also overload certain functions (like u would do in OO). What is best way in haskell to achieve this ? (I'm unsure wether haskell classes are what I'm looking for) Cheers Phil ## Code below import qualified Data.Vector.Unboxed as V data TimeSig = TimeSig Int Double (V.Vector Double) -- signal Index timeStep data getVect :: TimeSig - (V.Vector Double) getVect (TimeSig idx dt vect)= vect getIdx :: TimeSig - Int getIdx (TimeSig idx dt vect) = idx getdt :: TimeSig - Double getdt (TimeSig idx dt vect) = dt pzipWith :: (Double - Double - Double) - TimeSig - TimeSig - TimeSig pzipWith f p1 p2 = TimeSig idx dt vect where vect = V.zipWith f (getVect p1) (getVect p2) idx = getIdx p1 dt = getdt p1 pmap :: (Double - Double) - TimeSig - TimeSig pmap f p = TimeSig (getIdx p) (getdt p) (V.map f (getVect p)) instance Num TimeSig where (+) p1 p2 = pzipWith (+) p1 p2 (-) p1 p2 = pzipWith (-) p1 p2 negate p1 = pmap negate p1 abs p1 = pmap abs p1 (*) p1 p2 = pzipWith (*) p1 p2 instance Eq TimeSig where (==) p1 p2 = (==) (getVect p1) (getVect p2) instance Show TimeSig where show (TimeSig idx dt vect) = TimeSignal Nr: ++ show idx ++ dt: ++ show dt ++ val: ++ show vect main = do let p = TimeSig 5 0.1 (V.fromList [0..10::Double]) putStrLn (show p) putStrLn (show (p+p)) -- View this message in context: http://haskell.1045720.n5.nabble.com/Data-Type-Inheritance-ala-OO-Inheritence-howto-best-in-Haskell-tp4494800p4494800.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Data.Map: Values to keys and keys to values
Hi, Data.Map has many great functions, yet I could not find the one that allows from one map create another map where keys are values and values are keys of the first one. Something like: transMap:: (Ord k, Ord a) = Map k a - Map a k Does such function exist? Thanks! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Map: Values to keys and keys to values
On Thu, Jun 16, 2011 at 3:01 PM, Dmitri O.Kondratiev doko...@gmail.com wrote: Hi, Data.Map has many great functions, yet I could not find the one that allows from one map create another map where keys are values and values are keys of the first one. Something like: transMap:: (Ord k, Ord a) = Map k a - Map a k Does such function exist? Note that such a function would be lossy as there might be duplicate values in the map. Cheers, Johan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Map: Values to keys and keys to values
Why not make it unlossy and have: trans :: (Ord k, Ord a) = Map k a - Map a (Set k) On Thu, Jun 16, 2011 at 9:10 AM, Johan Tibell johan.tib...@gmail.comwrote: On Thu, Jun 16, 2011 at 3:01 PM, Dmitri O.Kondratiev doko...@gmail.com wrote: Hi, Data.Map has many great functions, yet I could not find the one that allows from one map create another map where keys are values and values are keys of the first one. Something like: transMap:: (Ord k, Ord a) = Map k a - Map a k Does such function exist? Note that such a function would be lossy as there might be duplicate values in the map. Cheers, Johan ___ 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] Data.Map: Values to keys and keys to values
On 16/06/11 15:01, Dmitri O.Kondratiev wrote: Hi, Data.Map has many great functions, yet I could not find the one that allows from one map create another map where keys are values and values are keys of the first one. Something like: transMap:: (Ord k, Ord a) = Map k a - Map a k Does such function exist? Thanks! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe What about something like transMap :: (Ord k, Ord a) = Map k a - Map a k transMap = M.fromList . map swap . M.toList ? Francesco. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Map: Values to keys and keys to values
On Thu, Jun 16, 2011 at 3:01 PM, Dmitri O.Kondratiev doko...@gmail.com wrote: Hi, Data.Map has many great functions, yet I could not find the one that allows from one map create another map where keys are values and values are keys of the first one. Something like: transMap:: (Ord k, Ord a) = Map k a - Map a k I don't think implementing this function in the library would add much as it cannot be implemented more efficiently with access to the internal representation than it can using the public API. Just write transMap = M.fromList . map swap . M.toList and stick it in some utility file. Johan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Map: Values to keys and keys to values
On Thu, Jun 16, 2011 at 5:38 PM, Johan Tibell johan.tib...@gmail.comwrote: On Thu, Jun 16, 2011 at 3:01 PM, Dmitri O.Kondratiev doko...@gmail.com wrote: Hi, Data.Map has many great functions, yet I could not find the one that allows from one map create another map where keys are values and values are keys of the first one. Something like: transMap:: (Ord k, Ord a) = Map k a - Map a k I don't think implementing this function in the library would add much as it cannot be implemented more efficiently with access to the internal representation than it can using the public API. Just write transMap = M.fromList . map swap . M.toList and stick it in some utility file. Johan Yes, this is a good one. Thanks! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Win32: cabal install --prefix=$HOME --user ?
There is a nice table in the cabal docs that explains how prefix gets used:
http://www.haskell.org/ghc/docs/7.0.4/html/Cabal/builders.html#simple-paths
For Vista and above C:\Documents and settings\myusername\ is
C:\Users\myusername. The equivalent to $HOME on Windows would be
$USERPROFILE but the syntax of expanding an environment variable is
going to depend on the shell you are using:
cmd window: cabal install --prefix=%USERPROFILE% --user
PowerShell: cabal install --prefix=${env:USERPROFILE} --user
msys window: cabal install --prefix=$USERPROFILE --user
Note that msys does define $HOME and it is a different physical path
than $USERPROFILE.
Ryan
On Thu, Jun 16, 2011 at 5:48 AM, Dmitri O.Kondratiev doko...@gmail.com wrote:
On win32 cabal install --prefix=$HOME --user fails:
cabal install --prefix=$HOME --user
Resolving dependencies...
Configuring split-0.1.4...
cabal: expected an absolute directory name for --prefix: $HOME
cabal: Error: some packages failed to install:
split-0.1.4 failed during the configure step. The exception was:
ExitFailure 1
What is the right equivalent of cabal install --prefix=$HOME --user on
Win32?
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Re: [Haskell-cafe] Win32: cabal install --prefix=$HOME --user ?
On Thu, Jun 16, 2011 at 6:18 PM, Ryan Yates fryguy...@gmail.com wrote:
There is a nice table in the cabal docs that explains how prefix gets used:
http://www.haskell.org/ghc/docs/7.0.4/html/Cabal/builders.html#simple-paths
For Vista and above C:\Documents and settings\myusername\ is
C:\Users\myusername. The equivalent to $HOME on Windows would be
$USERPROFILE but the syntax of expanding an environment variable is
going to depend on the shell you are using:
cmd window: cabal install --prefix=%USERPROFILE% --user
PowerShell: cabal install --prefix=${env:USERPROFILE} --user
msys window: cabal install --prefix=$USERPROFILE --user
Note that msys does define $HOME and it is a different physical path
than $USERPROFILE.
Ryan, thanks!
This win32 $HOME story is clear now.
And why not just use:
cabal install
instead of:
cabal install --prefix=%USERPROFILE% --user
for win32 platform?
Where in this case cabal install root will be?
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Re: [Haskell-cafe] Win32: cabal install --prefix=$HOME --user ?
I never set the prefix manually and just use the default. The default
for Windows is $APPDATA/Cabal. Where that ends up depends on your
version of Windows. On Windows --user is also the default.
On Thu, Jun 16, 2011 at 10:47 AM, Dmitri O.Kondratiev doko...@gmail.com wrote:
On Thu, Jun 16, 2011 at 6:18 PM, Ryan Yates fryguy...@gmail.com wrote:
There is a nice table in the cabal docs that explains how prefix gets
used:
http://www.haskell.org/ghc/docs/7.0.4/html/Cabal/builders.html#simple-paths
For Vista and above C:\Documents and settings\myusername\ is
C:\Users\myusername. The equivalent to $HOME on Windows would be
$USERPROFILE but the syntax of expanding an environment variable is
going to depend on the shell you are using:
cmd window: cabal install --prefix=%USERPROFILE% --user
PowerShell: cabal install --prefix=${env:USERPROFILE} --user
msys window: cabal install --prefix=$USERPROFILE --user
Note that msys does define $HOME and it is a different physical path
than $USERPROFILE.
Ryan, thanks!
This win32 $HOME story is clear now.
And why not just use:
cabal install
instead of:
cabal install --prefix=%USERPROFILE% --user
for win32 platform?
Where in this case cabal install root will be?
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Re: [Haskell-cafe] Data Type Inheritance ala OO - Inheritence -- howto best in Haskell ?
Look into Oleg's HList (heterogeneous list) and OOHaskell http://homepages.cwi.nl/~ralf/HList/ http://homepages.cwi.nl/~ralf/OOHaskell/ On Thu, Jun 16, 2011 at 5:08 AM, kaffeepause73 kaffeepaus...@yahoo.dewrote: Dear all, I'm created a timeSignal datatype as container around a Vector Double data type (see simple code below) and subsequently started to instanciate Num Eq to be able to perform operations on it. Additionally I want store ifno like an index, time information and eventually an inheritence log (the log is not yet in there). As I will in the end need up to 10 different datatypes, however using slightly different content (time signal, single value, distribution, ...) I ask myself, how I could define a super data-type with sub-data-types to inherit, but then also overload certain functions (like u would do in OO). What is best way in haskell to achieve this ? (I'm unsure wether haskell classes are what I'm looking for) Cheers Phil ## Code below import qualified Data.Vector.Unboxed as V data TimeSig = TimeSig Int Double (V.Vector Double) -- signal Index timeStep data getVect :: TimeSig - (V.Vector Double) getVect (TimeSig idx dt vect)= vect getIdx :: TimeSig - Int getIdx (TimeSig idx dt vect) = idx getdt :: TimeSig - Double getdt (TimeSig idx dt vect) = dt pzipWith :: (Double - Double - Double) - TimeSig - TimeSig - TimeSig pzipWith f p1 p2 = TimeSig idx dt vect where vect = V.zipWith f (getVect p1) (getVect p2) idx = getIdx p1 dt = getdt p1 pmap :: (Double - Double) - TimeSig - TimeSig pmap f p = TimeSig (getIdx p) (getdt p) (V.map f (getVect p)) instance Num TimeSig where (+) p1 p2 = pzipWith (+) p1 p2 (-) p1 p2 = pzipWith (-) p1 p2 negate p1 = pmap negate p1 abs p1 = pmap abs p1 (*) p1 p2 = pzipWith (*) p1 p2 instance Eq TimeSig where (==) p1 p2 = (==) (getVect p1) (getVect p2) instance Show TimeSig where show (TimeSig idx dt vect) = TimeSignal Nr: ++ show idx ++ dt: ++ show dt ++ val: ++ show vect main = do let p = TimeSig 5 0.1 (V.fromList [0..10::Double]) putStrLn (show p) putStrLn (show (p+p)) -- View this message in context: http://haskell.1045720.n5.nabble.com/Data-Type-Inheritance-ala-OO-Inheritence-howto-best-in-Haskell-tp4494800p4494800.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ 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] Data.Map: Values to keys and keys to values
On Thu, Jun 16, 2011 at 04:17:55PM +0200, Francesco Mazzoli wrote: On 16/06/11 15:01, Dmitri O.Kondratiev wrote: Hi, Data.Map has many great functions, yet I could not find the one that allows from one map create another map where keys are values and values are keys of the first one. Something like: transMap:: (Ord k, Ord a) = Map k a - Map a k Does such function exist? Thanks! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe What about something like transMap :: (Ord k, Ord a) = Map k a - Map a k transMap = M.fromList . map swap . M.toList ? Or, if you want to keep duplicates, import qualified Data.Set as S import Control.Arrow (second) transMap = M.fromListWith S.union . map (second S.singleton . swap) . M.toList -Brent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell Parallel Digest 3
Parallel Haskell Digest === Edition 3 2011-06-16 http://www.well-typed.com/blog/55 Hello Haskellers! Welcome to the third edition of the Parallel Haskell Digest, bringing you news, discussions and tasters of parallelism and concurrency in Haskell. The digest is made possible by the Parallel GHC project. More news about how we're doing below. This digest is brought to you by Eric Kow and Nicolas Wu. Nick will be taking over as maintainer of the Parallel Digest for the next few months. It's tutorial season in the Parallel Haskell world, with Simon Marlow's [Parallel and Concurrent Programming in Haskell][1], and Don Stewart's [Numeric Haskell: A Repa Tutorial][2]. The former gives a broad tour of parallelism and concurrency techniques in Haskell and the latter focuses on the Repa parallel array library. Both are very concrete and focus on real working code. Give them a try! News -- * Haskell in the Economist! The Economist article [Parallel Bars][3] discusses the rise of multicore computing, and the essential obstacle that programs have to be specially written with parallelism in mind. The article gives a tour of some problems (overhead and dependencies between subtasks, programmers being trained for sequential programming, debugging parallel programs) and possible solutions, among which is functional programming: Meanwhile, a group of obscure programming languages used in academia seems to be making slow but steady progress, crunching large amounts of data in industrial applications and behind the scenes at large websites. Two examples are Erlang and Haskell, both of which are “functional programming” languages. Are we doomed to succeed? Word of the Month -- The word of the month (well, phrase really!) for this digest is *parallel arrays*. Parallel array manipulation fits nicely into Haskell's arsenal of parallel processing techniques. In fact, you might have seen the Repa library, as mentioned above, in the news a while back. And now there's a new tutorial on the [Haskell Wiki][2]. So what's all the fuss? Parallel arrays manipulation is a particularly nice way of writing parallel programs: it's pure and it has the potential to scale very well to large numbers of CPUs. The main limitation is that not all programs can be written in this style. Parallel arrays are a way of doing *data parallelism* (as opposed to *control parallelism*). Repa (REgular Parallel Arrays) is a Haskell library for high performance, regular, multi-dimensional parallel arrays. All numeric data is stored unboxed and functions written with the Repa combinators are automatically parallel. This means that you can write simple array code and get parallelism for free. As an example, Repa has been used for real time edge detection using a [Canny edge algorithm][12], which has resulted in performance comparable to the standard OpenCV library, an industry standard library of computer vision algorithms written in C and C++ (a single threaded Haskell implementation is about 4 times slower than the OpenCV implementation, but is on par when using 8 threads on large images). While the Canny algorithm written with Repa doesn't quite match the speed of its procedural counterparts, it benefits from all of Haskell's built in support for purity and type safety, and painlessly scales to multiple cores. You can find more details on Ben Lippmeier's [blog][10]. Parallel GHC project news -- The Parallel GHC Project is an MSR-funded project to promote the real-world use of parallel Haskell. Part of this project involves effort by Well-Typed to provide tools for use by the general community. Last week, Well-Typed were excited to [announce][11] that we have capacity to support another partner for the parallel project for at least another 12 months. So, if you have a project that involves scaling up to multiple cores, or that deals with some heavy duty concurrency, then we'd love to hear from you. In return for your time and commitment to the parallel project, we'll unleash our team of expert programmers to help build tools and provide support that will help you and the community towards making parallel Haskell even more accessible. For more information on the Parallel GHC project, on the [Parallel GHC Project wiki page][27]. Blogs, papers and packages -- * [Parallel and Concurrent Programming in Haskell (19 May)][1] Simon Marlow released version 1.1 of his tutorial introducing the main programming models available for concurrent and parallel programming in Haskell. This tutorial takes a deliberately practical approach: most of the examples are real Haskell programs that you can compile, run, measure, modify and experiment with. The tutorial covers a
Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
I seem to still be missing some things. I found mt19937 in GSL.Random.Gen, but there are two evalMCs, one in Control.Monad.MC and another in Control.Monad.MC.GSL. Which? Michael - Registering monte-carlo-0.4.1...Installing library in /home/michael/.cabal/lib/monte-carlo-0.4.1/ghc-7.0.2Registering monte-carlo-0.4.1...[michael@sabal ~]$ ghciGHCi, version 7.0.2: http://www.haskell.org/ghc/ :? for helpLoading package ghc-prim ... linking ... done.Loading package integer-gmp ... linking ... done.Loading package base ... linking ... done.Prelude :m + Control.Monad.MC.ClassPrelude Control.Monad.MC.Class evalMC (sampleSubset [1..20] 5) (mt19937 0) interactive:1:1: Not in scope: `evalMC' interactive:1:34: Not in scope: `mt19937'Prelude Control.Monad.MC.Class --- On Mon, 6/13/11, Felipe Almeida Lessa felipe.le...@gmail.com wrote: From: Felipe Almeida Lessa felipe.le...@gmail.com Subject: Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints To: michael rice nowg...@yahoo.com Cc: haskell-cafe@haskell.org Date: Monday, June 13, 2011, 9:38 PM On Mon, Jun 13, 2011 at 8:56 PM, michael rice nowg...@yahoo.com wrote: Is there an (existing) way to select 5 Ints randomly (no duplicates) from a population, say 1-20 (inclusive)? Yes, already implemented in the monte-carlo package as sampleSubset [1], sampleSubset :: MonadMC m = [a] - Int - m [a] Complete example code for your example: evalMC (sampleSubset [1..20] 5) (mt19937 0) Cheers! [1] http://hackage.haskell.org/packages/archive/monte-carlo/0.4.1/doc/html/Control-Monad-MC-Class.html#v:sampleSubset -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
On Thu, Jun 16, 2011 at 3:04 PM, michael rice nowg...@yahoo.com wrote: I seem to still be missing some things. I found mt19937 in GSL.Random.Gen, but there are two evalMCs, one in Control.Monad.MC and another in Control.Monad.MC.GSL. Which? Both are actually the same, because Control.Monad.MC reexports from Control.Monad.MC.GSL. =) GHCi, version 6.12.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package ffi-1.0 ... linking ... done. Prelude :m + Control.Monad.MC Prelude Control.Monad.MC evalMC (sampleSubset [1..20] 5) (mt19937 0) Loading package mtl-1.1.1.1 ... linking ... done. Loading package primitive-0.3.1 ... linking ... done. Loading package vector-0.7.0.1 ... linking ... done. Loading package gsl-random-0.4.2 ... linking ... done. Loading package monte-carlo-0.4.1 ... linking ... done. [20,4,6,17,19] Prelude Control.Monad.MC evalMC (sampleSubset [1..20] 5) (mt19937 42) [8,16,18,4,12] Prelude Control.Monad.MC evalMC (sampleSubset [1..20] 5) (mt19937 2938420) [18,3,2,9,14] Prelude Control.Monad.MC evalMC (sampleSubset [1..20] 5) (mt19937 0) [20,4,6,17,19] Cheers, -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANNOUNCE: doctest-0.3.0
I just uploaded a new version of doctest[1] to Hackage. WHAT IS doctest? doctest is a port of Python's doctest[2] to Haskell. It can be used to verify, that examples in Haddock comments[3] do still work. This also provides you with a simple mechanism to write unit test, without the burden of maintaining a dedicated test suite. A basic example of usage is at [4]. WHAT'S NEW IN THIS VERSION? === It is now possible to intersperse comments between a longer, continuing example. All examples within the same comment now share a namespace. The following now works : -- | Calculate Fibonacci number of given 'Num'. -- -- First let's set `n` to ten: -- -- let n = 10 -- -- And now calculate the 10th Fibonacci number: -- -- fib n -- 55 fib :: Integer - Integer fib 0 = 0 fib 1 = 1 fib n = fib (n - 1) + fib (n - 2) Thanks to Sakari Jokinen for this contribution! In addition I changed the name from DocTest to doctest. I think using all lower-case package names is a good thing. And as we will use doctest as a library in the near future, this was the last chance for this change. Cheers, Simon [1] http://hackage.haskell.org/cgi-bin/hackage-scripts/package/doctest [2] http://docs.python.org/library/doctest.html [3] http://www.haskell.org/haddock/doc/html/ch03s08.html#id566093 [4] http://haskell.org/haskellwiki/DocTest ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data Type Inheritance ala OO - Inheritence -- howto best in Haskell ?
Hi David, thanks for the links. I had a lok at the OO-paper some time ago already, heard however that its quite unusual and rather tricky to do OO-style programming in Haskell. So I'm looking for suggestions how to tackle this problem in a functional way. Cheers Phil -- View this message in context: http://haskell.1045720.n5.nabble.com/Data-Type-Inheritance-ala-OO-Inheritence-howto-best-in-Haskell-tp4494800p4496726.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Simple CSV parser?
Hi, This time I am looking for a simple CSV parser that supports commas and quotes. I have no time now to learn Parsec, so I hope to find something simple and easy to use. Thanks! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
Do any of the ones on hackage work for you? http://hackage.haskell.org/package/csv-0.1.2 http://hackage.haskell.org/package/bytestring-csv http://hackage.haskell.org/package/csv-enumerator (note: hackage supports search via google it works reasonably well) On Jun 16, 2011, at 5:21 PM, Dmitri O.Kondratiev wrote: Hi, This time I am looking for a simple CSV parser that supports commas and quotes. I have no time now to learn Parsec, so I hope to find something simple and easy to use. Thanks! ___ 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] Simple CSV parser?
On Thu, Jun 16, 2011 at 6:21 PM, Dmitri O.Kondratiev doko...@gmail.com wrote: This time I am looking for a simple CSV parser that supports commas and quotes. I have no time now to learn Parsec, so I hope to find something simple and easy to use. 1. Go to http://hackage.haskell.org/packages/archive/pkg-list.html 2. Press Ctrl+F, look for CSV. 3. Find many packages [1,2,3,4,5] 4. See which one suits better your needs. [1] http://hackage.haskell.org/package/bytestring-csv [2] http://hackage.haskell.org/package/csv-enumerator [3] http://hackage.haskell.org/package/spreadsheet [4] http://hackage.haskell.org/package/csv [5] http://hackage.haskell.org/package/ssv -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] 8th Ghent Functional Programming Group Meeting on Thursday, the 30th of June, 2011
(apologies if you receive multiple postings) Dear All, We are pleased to announce the 8th Ghent Functional Programming Group (GhentFPG) meeting, which takes place on Thursday, the 30th of June, 2011 at 19:30 in the Technicum building of Ghent University (Sint-Pietersnieuwstraat 41, 9000 Gent). As before, the electronic sliding doors will be locked, but a phone number that you can call to get in will be provided at the doors on the far left of the building. The structure of the meeting is a bit different than before: we begin with two short talks and end with a small problem solving activity where everyone tries to solve a given problem in his favorite functional language. The exact problem will be given at the meeting. The abstracts for the talks are as follows: Pieter Wuille - I'll talk about the monadic constraint programming (MCP) framework, and in particular the Finite Domain layer i've developed for it. As explained by Tom Schrijvers in a previous talk, MCP is a general Haskell framework for Constraint Programming (CP), allowing users to search for assignments to variables that satisfy given constraints, while abstracting from the actual algorithm used to find these solutions. Finite Domain problems are a subset of CP where the variable's initial domains are finite, typically small integers. Problems that can be expressed elegantly in FD include Sudoku and N-Queens. MCP's FD layer provides an embedded Domain Specific Language (DSL) to describe these problems declaratively, some backend solvers, and an intermediate translation layer. I'll introduce the features and possibilities of the system by showing some examples, and explain some implementation details along the way. Jasper Van der Jeugt I will give a talk about the techniques and patterns used in the Text library. Text is quickly becoming the de-facto standard type for presenting human-readable text in Haskell. My current work focuses on improving the performance of this library by porting the internally used encoding from UTF-16 to UTF-8. The talk will present a high-level overview of some tools and techniques to study and improve the performance of a Haskell program, including: strictness analysis, pitfalls for benchmarking, fusion frameworks, unboxed type representations, and GHC core. If you would like to receive updates on our activities, you can follow us on twitter (@ghentfpg), google groups (http://groups.google.com/group/ghent-fpg?pli=1) or linked.in (http://t.co/cjXbGyT) Hope to see you there! Andy Georges Jasper Van der Jeugt Jeroen Janssen The GhentFPG Organizing Committee ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Thu, 16 Jun 2011, Daniel Patterson wrote: Do any of the ones on hackage work for you? http://hackage.haskell.org/package/csv-0.1.2 http://hackage.haskell.org/package/bytestring-csv http://hackage.haskell.org/package/csv-enumerator (note: hackage supports search via google it works reasonably well) How could it miss my lovely package named spreadsheet? It provides a lazy parser. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
That was my (lazy) fault. I saw the name and (faultily) assumed that it provided functionality on top of another CSV parser. On Jun 16, 2011, at 5:33 PM, Henning Thielemann wrote: On Thu, 16 Jun 2011, Daniel Patterson wrote: Do any of the ones on hackage work for you? http://hackage.haskell.org/package/csv-0.1.2 http://hackage.haskell.org/package/bytestring-csv http://hackage.haskell.org/package/csv-enumerator (note: hackage supports search via google it works reasonably well) How could it miss my lovely package named spreadsheet? It provides a lazy parser. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Fri, Jun 17, 2011 at 1:27 AM, Felipe Almeida Lessa felipe.le...@gmail.com wrote: On Thu, Jun 16, 2011 at 6:21 PM, Dmitri O.Kondratiev doko...@gmail.com wrote: This time I am looking for a simple CSV parser that supports commas and quotes. I have no time now to learn Parsec, so I hope to find something simple and easy to use. 1. Go to http://hackage.haskell.org/packages/archive/pkg-list.html 2. Press Ctrl+F, look for CSV. 3. Find many packages [1,2,3,4,5] 4. See which one suits better your needs. [1] http://hackage.haskell.org/package/bytestring-csv [2] http://hackage.haskell.org/package/csv-enumerator [3] http://hackage.haskell.org/package/spreadsheet [4] http://hackage.haskell.org/package/csv [5] http://hackage.haskell.org/package/ssv -- Felipe. Now I know where and how to search, sorry for trivial questions ) Thanks! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Fri, Jun 17, 2011 at 1:33 AM, Henning Thielemann lemm...@henning-thielemann.de wrote: How could it miss my lovely package named spreadsheet? It provides a lazy parser. Installing spreadsheet: cabal install Resolving dependencies... cabal: cannot configure explicit-exception-0.1.6. It requires transformers ==0.2.* For the dependency on transformers ==0.2.* there are these packages: transformers-0.2.0.0, transformers-0.2.1.0 and transformers-0.2.2.0. However none of them are available. transformers-0.2.0.0 was excluded because spreadsheet-0.1 requires transformers ==0.0.* transformers-0.2.1.0 was excluded because spreadsheet-0.1 requires transformers ==0.0.* transformers-0.2.2.0 was excluded because spreadsheet-0.1 requires transformers ==0.0.* How to make cabal install all the dependencies? I couldn't find this in the docs at: http://www.haskell.org/haskellwiki/Cabal-Install ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell on NUMA
Hi, what ist the current state of Haskell's parallel performance on NUMA machines? I've (probably) run into some performance problems using a 2x8 cores machine and am unsure how to fix them (if it's possible at all at the moment). I've only found two (helpful?) resources on the web, namely - an old ticket which is closed [1] - a current talk (13. May 2011) about a new runtime system for GHC7 for NUMA machines [2] Are any other informations available? Kind regards, Michael [1] http://hackage.haskell.org/trac/summer-of-code/ticket/1123 [2] http://www.dcs.gla.ac.uk/~jsinger/mmnet11_talks/orczyk.pdf ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Fri, 17 Jun 2011, Dmitri O.Kondratiev wrote: How to make cabal install all the dependencies? I couldn't find this in the docs at: http://www.haskell.org/haskellwiki/Cabal-Install Usually, 'cabal install' automatically installs all imported packages. But it will certainly not do, if a dependency problem cannot be solved by downloading packages. In your case it may be, that installed packages are compiled with respect to different versions of the same package, say 'transformers'. I found out, that you get more useful cabal messages if you force cabal-install to use a specific version of a package. Say, run $ ghc-pkg list transformers transformers-0.2.2.0 Then call $ cabal install spreadsheet --constraint=transformers==0.2.2.0 What does 'cabal' tell you? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Thu, Jun 16, 2011 at 3:05 PM, Henning Thielemann lemm...@henning-thielemann.de wrote: On Fri, 17 Jun 2011, Dmitri O.Kondratiev wrote: How to make cabal install all the dependencies? I couldn't find this in the docs at: http://www.haskell.org/haskellwiki/Cabal-Install Usually, 'cabal install' automatically installs all imported packages. But it will certainly not do, if a dependency problem cannot be solved by downloading packages. In your case it may be, that installed packages are compiled with respect to different versions of the same package, say 'transformers'. I found out, that you get more useful cabal messages if you force cabal-install to use a specific version of a package. Say, run $ ghc-pkg list transformers transformers-0.2.2.0 Then call $ cabal install spreadsheet --constraint=transformers==0.2.2.0 Nicer still, is to use cabal-dev: http://www.reddit.com/r/haskell/comments/f3ykj/psa_use_cabaldev_to_solve_dependency_problems/ Jason ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Fri, Jun 17, 2011 at 2:05 AM, Henning Thielemann lemm...@henning-thielemann.de wrote: On Fri, 17 Jun 2011, Dmitri O.Kondratiev wrote: How to make cabal install all the dependencies? I couldn't find this in the docs at: http://www.haskell.org/haskellwiki/Cabal-Install Usually, 'cabal install' automatically installs all imported packages. But it will certainly not do, if a dependency problem cannot be solved by downloading packages. In your case it may be, that installed packages are compiled with respect to different versions of the same package, say 'transformers'. I found out, that you get more useful cabal messages if you force cabal-install to use a specific version of a package. Say, run $ ghc-pkg list transformers transformers-0.2.2.0 Then call $ cabal install spreadsheet --constraint=transformers==0.2.2.0 What does 'cabal' tell you? ghc-pkg list transformers /Library/Frameworks/GHC.framework/Versions/612/usr/lib/ghc-6.12.3/package.conf.d: /Users/user/.ghc/i386-darwin-6.12.3/package.conf.d: transformers-0.2.2.0 cabal install spreadsheet --constraint=transformers==0.2.2.0 Resolving dependencies... cabal: cannot configure spreadsheet-0.1. It requires transformers ==0.0.* For the dependency on transformers ==0.0.* there are these packages: transformers-0.0.0.0 and transformers-0.0.1.0. However none of them are available. transformers-0.0.0.0 was excluded because of the top level dependency transformers ==0.2.2.0 transformers-0.0.1.0 was excluded because of the top level dependency transformers ==0.2.2.0 Compilation exited abnormally with code 1 at Fri Jun 17 02:12:30 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Fri, Jun 17, 2011 at 2:13 AM, Dmitri O.Kondratiev doko...@gmail.comwrote: On Fri, Jun 17, 2011 at 2:05 AM, Henning Thielemann lemm...@henning-thielemann.de wrote: On Fri, 17 Jun 2011, Dmitri O.Kondratiev wrote: How to make cabal install all the dependencies? I couldn't find this in the docs at: http://www.haskell.org/haskellwiki/Cabal-Install Usually, 'cabal install' automatically installs all imported packages. But it will certainly not do, if a dependency problem cannot be solved by downloading packages. In your case it may be, that installed packages are compiled with respect to different versions of the same package, say 'transformers'. I found out, that you get more useful cabal messages if you force cabal-install to use a specific version of a package. Say, run $ ghc-pkg list transformers transformers-0.2.2.0 Then call $ cabal install spreadsheet --constraint=transformers==0.2.2.0 What does 'cabal' tell you? ghc-pkg list transformers /Library/Frameworks/GHC.framework/Versions/612/usr/lib/ghc-6.12.3/package.conf.d: /Users/user/.ghc/i386-darwin-6.12.3/package.conf.d: transformers-0.2.2.0 cabal install spreadsheet --constraint=transformers==0.2.2.0 Resolving dependencies... cabal: cannot configure spreadsheet-0.1. It requires transformers ==0.0.* For the dependency on transformers ==0.0.* there are these packages: transformers-0.0.0.0 and transformers-0.0.1.0. However none of them are available. transformers-0.0.0.0 was excluded because of the top level dependency transformers ==0.2.2.0 transformers-0.0.1.0 was excluded because of the top level dependency transformers ==0.2.2.0 Compilation exited abnormally with code 1 at Fri Jun 17 02:12:30 I really have no choice, but install Data.Spreadsheet, because this is the only library that allows split a _single_ CSV string into chunks (which is exactly what I need). All other libs work with CSV files or provide a DSL to do such a simple thing! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Fri, 17 Jun 2011, Dmitri O.Kondratiev wrote: cabal install spreadsheet --constraint=transformers==0.2.2.0 Resolving dependencies... cabal: cannot configure spreadsheet-0.1. It requires transformers ==0.0.* For the dependency on transformers ==0.0.* there are these packages: transformers-0.0.0.0 and transformers-0.0.1.0. However none of them are available. transformers-0.0.0.0 was excluded because of the top level dependency transformers ==0.2.2.0 transformers-0.0.1.0 was excluded because of the top level dependency transformers ==0.2.2.0 I see. I had fixed the problem locally long time ago, but somehow missed upload to Hackage. Try the updated package, please. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Fri, Jun 17, 2011 at 2:27 AM, Henning Thielemann lemm...@henning-thielemann.de wrote: I see. I had fixed the problem locally long time ago, but somehow missed upload to Hackage. Try the updated package, please. Ok great! Installed (with some warnings, see below), thank you! I'll try it tomorrow (now here is 2:34 am) on a file of about 4000 lines. Thanks! Compilation started at Fri Jun 17 02:29:59 cabal install Resolving dependencies... Downloading explicit-exception-0.1.6... Configuring explicit-exception-0.1.6... Preprocessing library explicit-exception-0.1.6... Preprocessing executables for explicit-exception-0.1.6... Building explicit-exception-0.1.6... [1 of 9] Compiling Control.Monad.Label ( src/Control/Monad/Label.hs, dist/build/Control/Monad/Label.o ) [2 of 9] Compiling Control.Monad.Exception.Synchronous ( src/Control/Monad/Exception/Synchronous.hs, dist/build/Control/Monad/Exception/Synchronous.o ) [3 of 9] Compiling Control.Monad.Exception.Warning ( src/Control/Monad/Exception/Warning.hs, dist/build/Control/Monad/Exception/Warning.o ) [4 of 9] Compiling Control.Monad.Exception.Label ( src/Control/Monad/Exception/Label.hs, dist/build/Control/Monad/Exception/Label.o ) [5 of 9] Compiling System.IO.Straight ( src/System/IO/Straight.hs, dist/build/System/IO/Straight.o ) src/System/IO/Straight.hs:61:9: Warning: orphan instance: instance (MonadSIO m, ContainsIOException e) = MonadIO (ExceptionalT e m) [6 of 9] Compiling System.IO.Exception.File ( src/System/IO/Exception/File.hs, dist/build/System/IO/Exception/File.o ) [7 of 9] Compiling System.IO.Exception.BinaryFile ( src/System/IO/Exception/BinaryFile.hs, dist/build/System/IO/Exception/BinaryFile.o ) [8 of 9] Compiling Control.Monad.Exception.Asynchronous ( src/Control/Monad/Exception/Asynchronous.hs, dist/build/Control/Monad/Exception/Asynchronous.o ) [9 of 9] Compiling System.IO.Exception.TextFile ( src/System/IO/Exception/TextFile.hs, dist/build/System/IO/Exception/TextFile.o ) src/System/IO/Exception/TextFile.hs:8:0: Warning: In the use of `Async.manySynchronousT' (imported from Control.Monad.Exception.Asynchronous): Deprecated: use manyMonoidT with appropriate Monad like LazyIO and result Monoid like Endo instead Registering explicit-exception-0.1.6... Installing library in /Users/user/.cabal/lib/explicit-exception-0.1.6/ghc-6.12.3 Registering explicit-exception-0.1.6... Configuring spreadsheet-0.1.1... Preprocessing library spreadsheet-0.1.1... Building spreadsheet-0.1.1... [1 of 3] Compiling Data.Spreadsheet.CharSource ( src/Data/Spreadsheet/CharSource.hs, dist/build/Data/Spreadsheet/CharSource.o ) [2 of 3] Compiling Data.Spreadsheet.Parser ( src/Data/Spreadsheet/Parser.hs, dist/build/Data/Spreadsheet/Parser.o ) [3 of 3] Compiling Data.Spreadsheet ( src/Data/Spreadsheet.hs, dist/build/Data/Spreadsheet.o ) Registering spreadsheet-0.1.1... Installing library in /Users/user/.cabal/lib/spreadsheet-0.1.1/ghc-6.12.3 Registering spreadsheet-0.1.1... Compilation finished at Fri Jun 17 02:30:05 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple CSV parser?
On Thu, 16 Jun 2011, Felipe Almeida Lessa wrote: [1] http://hackage.haskell.org/package/bytestring-csv [2] http://hackage.haskell.org/package/csv-enumerator [3] http://hackage.haskell.org/package/spreadsheet [4] http://hackage.haskell.org/package/csv [5] http://hackage.haskell.org/package/ssv I have updated http://www.haskell.org/haskellwiki/Spreadsheet ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Can one drop GHC 7.0.4 into the Haskell Platform or does the platform need to be updated?
-- -- Regards, KC ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data Type Inheritance ala OO - Inheritence -- howto best in Haskell ?
I've done something perhaps similar in that I have a couple of signal types, backed by (X, Y) vectors with Y values of different types, but the same X type. So they can share a fair amount of implementation that depends only on X. Still more could be shared if I could know a zero value for each Y, so I wrote a SignalBase module: class (Eq y) = Y y where zero_y :: y -- anything else that lets you share code class (Storable.Storable (X, y), Y y) = Signal y type SigVec y = V.Vector (X, y) Now the SignalBase functions take '(Signal y) = SigVec y'. The specific signals contain a SigVec, and the functions whose implementations can be shared are just one line: at :: X - Signal y - Y at x sig = SignalBase.at x (sig_vec sig) The 'y' parameter to Signal is unrelated, I use it for a phantom type to distinguish between signals of the same implementation but different logical meaning, but 'at' applies to all of them. On Thu, Jun 16, 2011 at 2:16 PM, gutti philipp.guttenb...@gmx.net wrote: Hi David, thanks for the links. I had a lok at the OO-paper some time ago already, heard however that its quite unusual and rather tricky to do OO-style programming in Haskell. So I'm looking for suggestions how to tackle this problem in a functional way. Cheers Phil -- View this message in context: http://haskell.1045720.n5.nabble.com/Data-Type-Inheritance-ala-OO-Inheritence-howto-best-in-Haskell-tp4494800p4496726.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ 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] Haskell: The Craft of Functional Programming 3rd ed is out.
http://www.haskellcraft.com/craft3e/Home.html -- -- Regards, KC ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: doctest-0.3.0
On Thu, Jun 16, 2011 at 12:22 PM, Simon Hengel simon.hen...@wiktory.orgwrote: I just uploaded a new version of doctest[1] to Hackage. Sweet! I think using all lower-case package names is a good thing. I'm just curious -- why? Luke ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: doctest-0.3.0
On 17 June 2011 14:36, Luke Palmer lrpal...@gmail.com wrote: On Thu, Jun 16, 2011 at 12:22 PM, Simon Hengel simon.hen...@wiktory.org wrote: I just uploaded a new version of doctest[1] to Hackage. Sweet! I think using all lower-case package names is a good thing. I'm just curious -- why? One reason: if that's the convention, then you don't have the problem of how do I list that package in my .cabal file, is it doctest, Doctest or DocTest? Also, some distro package managers prefer lowercase package names. -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] type signature of parsec functions and how to warp them up.
I have some different parsers of Parsec to use in a project, and I want to make a warp function to make the testing easy. here is some of my body of parser : they all has type of parsecT *** stringSet :: ParsecT String u Identity [String] intSet :: ParsecT String u Identity [Integer] tupleSet :: ParsecT String u Identity [(String, String)] all of the returned type are instance of 'Show'. then I write these warp function: -- import System.IO import Data.Functor.Identity (Identity) import Text.Parsec.Prim (ParsecT, runParserT, parse, Stream) runIOParse :: (Show a) = ParsecT String u Identity a - String - IO () runIOParse pa fn = do inh - openFile fn ReadMode outh - openFile (fn ++ .parseout) WriteMode instr - hGetContents inh let result = show $ parse pa fn instr hPutStr outh result hClose inh hClose outh --- :l RunParse.hs --- RunParse.hs:12:31: Could not deduce (u ~ ()) from the context (Show a) bound by the type signature for runIOParse :: Show a = ParsecT String u Identity a - String - IO () at RunParse.hs:(7,1)-(15,15) `u' is a rigid type variable bound by the type signature for runIOParse :: Show a = ParsecT String u Identity a - String - IO () at RunParse.hs:7:1 Expected type: Text.Parsec.Prim.Parsec String () a Actual type: ParsecT String u Identity a In the first argument of `parse', namely `pa' In the second argument of `($)', namely `parse pa fn instr' Failed, modules loaded: none. --- then I modify the type signature of 'runIOParse': runIOParse :: (Show a) = ParsecT String () Identity a - String - IO () then load again :l RunParse.hs --- RunParse.hs:12:25: Could not deduce (Stream String Identity t0) arising from a use of `parse' from the context (Show a) bound by the type signature for runIOParse :: Show a = ParsecT String () Identity a - String - IO () at RunParse.hs:(7,1)-(15,15) Possible fix: add (Stream String Identity t0) to the context of the type signature for runIOParse :: Show a = ParsecT String () Identity a - String - IO () or add an instance declaration for (Stream String Identity t0) In the second argument of `($)', namely `parse pa fn instr' In the expression: show $ parse pa fn instr In an equation for `result': result = show $ parse pa fn instr Failed, modules loaded: none. --- I also tried some 'possible fix' in the information, but it still failed to pass the compiler. Main Question: How can I warp a parsec function interface for do the IO test with different 'ParsecT String u Identity a'? -- 吴兴博 Wu Xingbo ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] type signature of parsec functions and how to warp them up.
It seems weird:
first ghci failed to load this file:
file: RunParse.hs
---
module RunParse where
import System.IO
import Data.Functor.Identity (Identity)
import Text.Parsec first, no this
line---what about this line ???
import Text.Parsec.Prim (Parsec, parse, Stream)
runIOParse :: (Show a) = Parsec String () a - String - IO ()
runIOParse pa fn =
do
inh - openFile fn ReadMode
outh - openFile (fn ++ .parseout) WriteMode
instr - hGetContents inh
let result = case parse pa fn instr of
Right rs - show rs
Left err - error
hPutStr outh result
hClose inh
hClose outh
--
ghci tell me:
-
RunParse.hs:13:23:
Could not deduce (Stream String Identity t0)
arising from a use of `parse'
from the context (Show a)
bound by the type signature for
runIOParse :: Show a = Parsec String () a - String - IO ()
at Sim/Std/RunParse.hs:(8,1)-(18,15)
Possible fix:
add (Stream String Identity t0) to the context of
the type signature for
runIOParse :: Show a = Parsec String () a - String - IO ()
or add an instance declaration for (Stream String Identity t0)
In the expression: parse pa fn instr
In the expression:
case parse pa fn instr of {
Right rs - show rs
Left err - error }
In an equation for `result':
result
= case parse pa fn instr of {
Right rs - show rs
Left err - error }
--
I just add one line of import and ghci:
import Text.Parsec
then ghci loaded it succeed!
It seems I didn't uses any functions from this import.
what goes wrong?
2011/6/17 吴兴博 wux...@gmail.com:
I have some different parsers of Parsec to use in a project, and I
want to make a warp function to make the testing easy.
--
吴兴博 Wu Xingbo
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