[Haskell-cafe] Iteratee, parsec co.
I read a lot about iteratee IO and it seemed very interesting
(Unfortunately it lacks tutorial). Especially features like 'no input
yet' in network programming (with lazy IO + parsec I run into problems
as it tried to evaluate the first response character before sending
output).
I decided first write a simple program and then attempt write a Stream
implementation for parsec.
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
import Data.Iteratee
import Text.Parse
data Buffer a = Buffer
instance Monad m = Stream (Buffer a) (IterateeG [] a m) a where
uncons Buffer = IterateeG loop
where loop (Chunk []) =
return $! Cont (IterateeG loop) Nothing
loop (Chunk (x:xs)) =
return $! Done (Just (x, Buffer))
(Chunk xs)
loop (EOF Nothing) =
return $! Done Nothing (EOF Nothing)
loop (EOF (Just e)) =
return $! throwErr e
1. I'm not quite sure what Cursor was suppose to do from A Parsing
Trifecta presentation.
2. Is there any package which contains this stream definition?
3. Why Seek FileOffset is error message?
Regards
PS. I guess iteratee does qualify as cafe but if beginner would be more
appropriate group then I'm sorry - I'll remember next time.
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[Haskell-cafe] various dependencies breakages
Hi there. I'm trying to reinstall gitit after updating to ghc 6.12 and it's driving me crazy. I hope you will be able to help me troubleshoot this mess ... I'm starting from scratch again, using cabal. I will post more problems as they appears. $ cabal install gitit Resolving dependencies... cabal: cannot configure datetime-0.2. It requires QuickCheck ==2.* For the dependency on QuickCheck ==2.* there are these packages: QuickCheck-2.1, QuickCheck-2.1.0.1, QuickCheck-2.1.0.2 and QuickCheck-2.1.0.3. However none of them are available. QuickCheck-2.1 was excluded because happstack-util-0.4.1 requires QuickCheck 2 QuickCheck-2.1.0.1 was excluded because happstack-util-0.4.1 requires QuickCheck 2 QuickCheck-2.1.0.2 was excluded because happstack-util-0.4.1 requires QuickCheck 2 QuickCheck-2.1.0.3 was excluded because happstack-util-0.4.1 requires QuickCheck 2 Can't cabal handle several versions of the same library in parallel ? If not, how can I solve this problem ? cheers tom ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] various dependencies breakages
Cabal can handle multiple versions of libraries, but you need to find a consistent set of libraries when building any one executable, since they are all going to be linked together. In this case Cabal has apparently failed to find such a set. You might be able to get this to work with cabal instal gitit --constraint='datetime==0.1', since that version only demands QuickCheck 1.2, and gitit doesn't specify a datetime version. I haven't tried this though. Happstack-util should probably not depend on QuickCheck at all if the tests flag is False -- this appears to be an omission in their Cabal file (http://hackage.haskell.org/packages/archive/happstack-util/0.4.1/happstack-util.cabal). The datetime package doesn't appear to make this a configurable dependency at all... Cheers, Max On 9 February 2010 10:40, Thomas Girod tho...@0xc29.net wrote: Hi there. I'm trying to reinstall gitit after updating to ghc 6.12 and it's driving me crazy. I hope you will be able to help me troubleshoot this mess ... I'm starting from scratch again, using cabal. I will post more problems as they appears. $ cabal install gitit Resolving dependencies... cabal: cannot configure datetime-0.2. It requires QuickCheck ==2.* For the dependency on QuickCheck ==2.* there are these packages: QuickCheck-2.1, QuickCheck-2.1.0.1, QuickCheck-2.1.0.2 and QuickCheck-2.1.0.3. However none of them are available. QuickCheck-2.1 was excluded because happstack-util-0.4.1 requires QuickCheck 2 QuickCheck-2.1.0.1 was excluded because happstack-util-0.4.1 requires QuickCheck 2 QuickCheck-2.1.0.2 was excluded because happstack-util-0.4.1 requires QuickCheck 2 QuickCheck-2.1.0.3 was excluded because happstack-util-0.4.1 requires QuickCheck 2 Can't cabal handle several versions of the same library in parallel ? If not, how can I solve this problem ? cheers tom ___ 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] Compiling on Windows - using a particular Manifest file
Hello Günther, Tuesday, February 9, 2010, 4:03:48 AM, you wrote: how can I make ghc use a particular manifest file for embedding? (on Windows) compile.cmd: windres.exe -I. Register.rc res.o g++.exe Register.cpp res.o Register.rc: 1 24 Register.exe.manifest windres is standard mingw tool alternatively: mt.exe -manifest Register64.exe.manifest -outputresource:Register64.exe where mt.exe is MSVS tool (probably available in free MSVS Express) -- Best regards, Bulatmailto:bulat.zigans...@gmail.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Iteratee, parsec co.
Am Dienstag 09 Februar 2010 10:03:46 schrieb Maciej Piechotka: Sorry, I haven't looked at iteratees at all, so I can't answer your questions. PS. I guess iteratee does qualify as cafe but if beginner would be more appropriate group then I'm sorry - I'll remember next time. It's not that one kind of question is for the beginners list and only more advanced questions are to be posted in the cafe, the distinction is - the beginners list is lower traffic, so your questions are less likely to be overlooked there (though it's unlikely to be overlooked in the cafe either) - questions on beginners are less likely to get answers involving terms like zygohistomorphic prepromorphism So it's more a decision of what kind of answer do you want where to post your question. Another aspect is that your question and the answers are more visible on beginners (especially to beginners), so if you think your question is something many beginners would wrestle with, that's a reason to post it on beginners (or both lists), so other beginners may profit more from it. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Generate random UArray in constant memory space.
Hello Cafe, I tried to generate memory-efficient list of random numbers, so I've used uvector library for this task. But it doesn't work, it still allocates more than 6Gb of memory for the random list of 10 million elements. Here is the code: import Text.Printf import System.Random import Control.Applicative import System.Environment import Data.Array.Vector randomListU :: (Int, Int) - StdGen - Int - (UArr Int) randomListU b g size = unfoldU size gen g where gen g = let (x, g') = randomR b g in JustS (x :*: g') main = do [size] - map read $ getArgs let ints = randomListU (-10, 10) (mkStdGen 1) size printf %d\n (sumU ints) Could someone give a hint, how to implement this function in constant memory space? Thank you in advance. Best regards, Vasyl Pasternak ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] various dependencies breakages
thanks Lars and Max. It did the trick, except for one small detail : MissingH needs the testpack -any dependency, but cabal does not install it automatically. tom ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Lazy language on JVM/CLR
About a year ago, Jeroen Leeuwenstein and I worked on CLR backend for
the Utrecht Haskell Compiler (UHC) [1].
That was a one-month project for a seminar at Utrecht University, and
the backend is far from being complete. But we did make some
interesting observations.
A particular caveat of the UHC is that it does whole program analysis,
so we had access to the entire program and all libraries at compile
time.
A benefit of using the CLR was that it does support tail calls. So a
mutual recursive function definition can loop a million times without
creating a stack overflow.
Our main problem (in efficiency) was lazy evaluation, not knowing the
difference between an evaluated `int` and a possible thunk
`Lazyint`. That meant we had to wrap _everything_ in a layer of
indirection, e.g.:
add :: Int - Int - Int
add x y = x + y
add 2 4
Becomes something equivalent to:
public int add(Lazyint x, Lazyint y)
{
return x.Force() + y.Force();
}
add(new Lazy(() = 2), new Lazy(() = 4));
Having a strictness analyser would have helped tremendously.
Also, I wonder if there is some efficient way of implementing the Lazy
class, perhaps by having the Force method using runtime code
generation to override itself. I don't know if this is possible, but I
vaguely remember the Dynamic Language Runtime on .NET doing something
like that.
I find this an interesting topic, so when you do have something more,
please let us know on this list.
- Tom Lokhorst
[1]: http://tom.lokhorst.eu/ehc/clr/ehc-clr-handout.pdf
On Tue, Feb 9, 2010 at 1:42 AM, Tony Morris tonymor...@gmail.com wrote:
I have hypothesised a pure, lazy language on the JVM and perhaps the
.NET CLR with FFI to .NET/Java libraries. I foresee various problems but
none that are catastrophic; just often requiring a compromises,
sometimes very unattractive compromises. I have authored several
libraries in the same vain as pure, lazy programming to run on the JVM
in Java and Scala programming languages.
I expect others have forethought and perhaps even experimented with such
a language. Are there any dangers to be wary of that undo the entire
endeavour?
Thanks for any insights.
--
Tony Morris
http://tmorris.net/
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Re: [Haskell-cafe] Generate random UArray in constant memory space.
Am Dienstag 09 Februar 2010 13:18:23 schrieb Vasyl Pasternak: Hello Cafe, I tried to generate memory-efficient list of random numbers, so I've used uvector library for this task. But it doesn't work, it still allocates more than 6Gb of memory for the random list of 10 million elements. Here is the code: Hmm, $ ghc -O2 --make ranVec [1 of 1] Compiling Main ( ranVec.hs, ranVec.o ) Linking ranVec ... $ ./ranVec 1000 +RTS -sstderr 5130 4,919,912,080 bytes allocated in the heap 883,256 bytes copied during GC 26,896 bytes maximum residency (1 sample(s)) 25,620 bytes maximum slop 1 MB total memory in use (0 MB lost due to fragmentation) maximum residency is just eight bytes more than for 100,000 or 1,000,000 numbers. I think that is constant space. The ~5 GB total allocation is sequential, ten million new StdGens are produced and allocated, then immediately garbage collected. I see no problem (except that StdGen is slow, e.g. the Mersenne twister is much faster [and allocates less, but still linear in size]). import Text.Printf import System.Random import Control.Applicative import System.Environment import Data.Array.Vector randomListU :: (Int, Int) - StdGen - Int - (UArr Int) randomListU b g size = unfoldU size gen g where gen g = let (x, g') = randomR b g in JustS (x :*: g') main = do [size] - map read $ getArgs let ints = randomListU (-10, 10) (mkStdGen 1) size printf %d\n (sumU ints) Could someone give a hint, how to implement this function in constant memory space? Thank you in advance. Best regards, Vasyl Pasternak ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: haskelldb in-memory driver?
Hello Johannes, no, sorry, HaskellDB is only meant for RDBM back ends, it eventually generates SQL (Strings). I tried to create an EDSL for relational algebra in the finally tagless style. This would theoretically allow to create entirely abstract expressions which could then be evaluated to either SQL or in-memory code or whatever. Of course I don't even know how to get started and at the moment it's on the very top of my wish-list because I really need it badly. All my code eventually turned into spaghetti code and without being able to express the algorithm abstractly(but correctly) and decide on implementation later I don't think will even try to untangle my mess, because at least it works. Günther Am 07.02.10 16:44, schrieb Johannes Waldmann: Is there a haskelldb-driver that works with a datasource that is in memory, as a Haskell object? (like LINQ can work on C# collections) - J. ___ 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] Re: haskelldb in-memory driver?
Günther == Günther Schmidt gue.schm...@web.de writes: Günther Hello Johannes, no, sorry, HaskellDB is only meant for RDBM Günther back ends, it eventually generates SQL (Strings). I recall that there WAS an experimental in-memory backend. -- Colin Adams Preston Lancashire ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Lazy language on JVM/CLR
Tom Lokhorst wrote: Also, I wonder if there is some efficient way of implementing the Lazy class, perhaps by having the Force method using runtime code generation to override itself. I don't know if this is possible, but I vaguely remember the Dynamic Language Runtime on .NET doing something like that. .NET 4 (final release due in the next few months) will have a built-in lazy type. Ganesh === Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html === ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Using Cabal during development
Cabal/cabal-install are good tools for distribution and installation, but I was wondering -- as I was starting to learn how to use Cabal -- how do usually Haskell developpers build their softwares (and especially medium or big libraries) while they are still developping them ? With cabal-install, by doing one 'cabal configure' once and 'cabal build' each time they have altered their code ? With only Cabal, through some 'runhaskell Setup.hs build's ? The point is that I am currently writing a binding for an SDL-like library called SFML. My project is now 55-file wide (and I will have to add some more), uses hsc2hs and has a little executable (for testing purposes) in which I add some code each time I add functionnalities to my binding. What I mean is that it would be a pain to have to compile it by hand whenever I add something to my code. Currently, I compile it by using a simple shell script, but it's a little bit lousy, I think. -- View this message in context: http://old.nabble.com/Using-Cabal-during-development-tp27515446p27515446.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] Using Cabal during development
With cabal-install, usually. Limestraël wrote: Cabal/cabal-install are good tools for distribution and installation, but I was wondering -- as I was starting to learn how to use Cabal -- how do usually Haskell developpers build their softwares (and especially medium or big libraries) while they are *still developping them* ? With cabal-install, by doing one 'cabal configure' once and 'cabal build' each time they have altered their code ? With only Cabal, through some 'runhaskell Setup.hs build's ? The point is that I am currently writing a binding for an SDL-like library called SFML. My project is now 55-file wide (and I will have to add some more), uses hsc2hs and has a little executable (for testing purposes) in which I add some code each time I add functionnalities to my binding. What I mean is that it would be a pain to have to compile it by hand whenever I add something to my code. Currently, I compile it by using a simple shell script, but it's a little bit lousy, I think. View this message in context: Using Cabal during development http://old.nabble.com/Using-Cabal-during-development-tp27515446p27515446.html Sent from the Haskell - Haskell-Cafe mailing list archive http://old.nabble.com/Haskell---Haskell-Cafe-f13132.html 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] Using Cabal during development
(This is a same message, but with newlines. Sorry for the double post) Cabal/cabal-install are good tools for distribution and installation, but I was wondering -- as I was starting to learn how to use Cabal -- how do usually Haskell developpers build their softwares (and especially medium or big libraries) while they are still developping them ? With cabal-install, by doing one 'cabal configure' once and 'cabal build' each time they have altered their code ? With only Cabal, through some 'runhaskell Setup.hs build's ? The point is that I am currently writing a binding for an SDL-like library called SFML. My project is now 55-file wide (and I will have to add some more), uses hsc2hs and has a little executable (for testing purposes) in which I add some code each time I add functionnalities to my binding. What I mean is that it would be a pain to have to compile it by hand whenever I add something to my code. Currently, I compile it by using a simple shell script, but it's a little bit lousy, I think. -- View this message in context: http://old.nabble.com/Using-Cabal-during-development-tp27515446p27515487.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] Iteratee, parsec co.
On Tue, Feb 9, 2010 at 4:03 AM, Maciej Piechotka uzytkown...@gmail.comwrote:
I read a lot about iteratee IO and it seemed very interesting
(Unfortunately it lacks tutorial). Especially features like 'no input
yet' in network programming (with lazy IO + parsec I run into problems
as it tried to evaluate the first response character before sending
output).
I decided first write a simple program and then attempt write a Stream
implementation for parsec.
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
import Data.Iteratee
import Text.Parse
data Buffer a = Buffer
instance Monad m = Stream (Buffer a) (IterateeG [] a m) a where
uncons Buffer = IterateeG loop
where loop (Chunk []) =
return $! Cont (IterateeG loop) Nothing
loop (Chunk (x:xs)) =
return $! Done (Just (x, Buffer))
(Chunk xs)
loop (EOF Nothing) =
return $! Done Nothing (EOF Nothing)
loop (EOF (Just e)) =
return $! throwErr e
1. I'm not quite sure what Cursor was suppose to do from A Parsing
Trifecta presentation.
Note that my parsing trifecta Iteratee differs from the iteratees defined by
Oleg et al; it has access to the entire input so far (accumulated in a
fingertree). The Cursor is the index into that finger tree, and is tracked
as the 'remaining input' by Parsec, allowing backtracking. The presentation
up to that point centers on the changes necessary to Iteratee to make this
possible.
2. Is there any package which contains this stream definition?
Not that I'm aware of, but I hardly qualify as an expert in the mainline
Iteratee implementation.
3. Why Seek FileOffset is error message?
I'm not quite sure what you're asking here.
-Edward Kmett
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Re: [Haskell-cafe] Generate random UArray in constant memory space.
Sorry, maybe I should ask more clearer. I've looked at dons article Haskell as fast as C[1], and tried to implement similar algorithm but for list of random numbers. Please look at code: import Text.Printf import Control.Applicative import System.Environment import Data.Array.Vector main = do [size] - map read $ getArgs let ints = enumFromToU 0 size :: UArr Int printf %d\n (sumU ints) This code runs in constant space (on my pc ~25kb allocates on the heap) regardless of array size. So I tried to achieve similar with random list, just to replace `enumFromToU` with my own list generator. So the question - is it possible to implement random list similary to enumFromToU? [1]http://donsbot.wordpress.com/2008/06/04/haskell-as-fast-as-c-working-at-a-high-altitude-for-low-level-performance/ Thank you, Vasyl Pasternak 2010/2/9 Daniel Fischer daniel.is.fisc...@web.de: Am Dienstag 09 Februar 2010 13:18:23 schrieb Vasyl Pasternak: Hello Cafe, I tried to generate memory-efficient list of random numbers, so I've used uvector library for this task. But it doesn't work, it still allocates more than 6Gb of memory for the random list of 10 million elements. Here is the code: Hmm, $ ghc -O2 --make ranVec [1 of 1] Compiling Main ( ranVec.hs, ranVec.o ) Linking ranVec ... $ ./ranVec 1000 +RTS -sstderr 5130 4,919,912,080 bytes allocated in the heap 883,256 bytes copied during GC 26,896 bytes maximum residency (1 sample(s)) 25,620 bytes maximum slop 1 MB total memory in use (0 MB lost due to fragmentation) maximum residency is just eight bytes more than for 100,000 or 1,000,000 numbers. I think that is constant space. The ~5 GB total allocation is sequential, ten million new StdGens are produced and allocated, then immediately garbage collected. I see no problem (except that StdGen is slow, e.g. the Mersenne twister is much faster [and allocates less, but still linear in size]). import Text.Printf import System.Random import Control.Applicative import System.Environment import Data.Array.Vector randomListU :: (Int, Int) - StdGen - Int - (UArr Int) randomListU b g size = unfoldU size gen g where gen g = let (x, g') = randomR b g in JustS (x :*: g') main = do [size] - map read $ getArgs let ints = randomListU (-10, 10) (mkStdGen 1) size printf %d\n (sumU ints) Could someone give a hint, how to implement this function in constant memory space? Thank you in advance. Best regards, Vasyl Pasternak ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: haskelldb in-memory driver?
Hello, for completeness there is also CoddFish, which is not based on HaskellDB, but rather on Oleg's HList. Günther Am 09.02.10 14:33, schrieb Colin Paul Adams: Günther == Günther Schmidtgue.schm...@web.de writes: Günther Hello Johannes, no, sorry, HaskellDB is only meant for RDBM Günther back ends, it eventually generates SQL (Strings). I recall that there WAS an experimental in-memory backend. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] haskelldb in-memory driver?
On Sun, Feb 7, 2010 at 6:44 PM, Johannes Waldmann waldm...@imn.htwk-leipzig.de wrote: Is there a haskelldb-driver that works with a datasource that is in memory, as a Haskell object? (like LINQ can work on C# collections) - J. SQLite could make it, take a look at http://www.sqlite.org/inmemorydb.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Using Cabal during development
Limestraël limestr...@gmail.com writes: how do usually Haskell developpers build their softwares (and especially medium or big libraries) while they are still developping them ? With cabal-install, by doing one 'cabal configure' once and 'cabal build' each time they have altered their code ? With only Cabal, through some 'runhaskell Setup.hs build's ? Generally, the first thing I do is hit C-c C-l in Emacs to load the current file into a haskell process. Then back to fix the type errors (click on the error to jump to the code), and iterate until it loads correctly. Then I can play with expressions in the Haskell buffer until I'm satisfied things work as expected. Now I can use darcsum to record the changes. For libraries, I switch to an xterm to do the ./Setup.hs build; sudo ./Setup.hs install routine. I guess I could be using cabal-install for this, but I haven't really gotten around to installing it everywhere yet. For binaries, I sometimes build executables using ghc --make in the shell, using -optl-static -oplt-pthread to build static executables for distribution to different machines. This process could probably be improved, but that's how it stands at the moment. -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] Using Cabal during development
Okay, so then I have so troubles regarding the compilation of my executable: First, what do you think is the simpler : (1) build only the library through cabal-install and then the executable with ghc (it isn't to be distributed with the lib), or (2) add both to my http://old.nabble.com/file/p27515830/HSFML.cabal .cabal file and build them in the same time with a 'cabal build' ? Because I've tried both methods, and have had issues with both : (1) after a 'cabal build', ghc doesn't know where to find my library -- whereas cabal-install displays 'Registering HSFL-1.5...' at the end of the build -- when I do 'ghc --make main.hs'. I'm not gonna do a 'cabal install' whenever I alter my code, am I? (2) well, then, when building, if I don't specify that my executable depends on my lib, I got: SFML/Direct/Graphics.hs:51:7: Could not find module `SFML.Direct.Types.Enums': It is a member of the hidden package `HSFML-1.5'. Perhaps you need to add `HSFML' to the build-depends in your .cabal file. it is a hidden module in the package `HSFML-1.5' Use -v to see a list of the files searched for. and if I do what I asks me to add (I add the line 'Build-Depends: HSFML' in the 'Executable' section of my .cabal file), I'm told when 'cabal build'ing: cabal: internal error: could not construct a valid install plan. The proposed (invalid) plan contained the following problems: The following packages are involved in a dependency cycle HSFML-1.5 Miguel Mitrofanov wrote: With cabal-install, usually. -- View this message in context: http://old.nabble.com/Using-Cabal-during-development-tp27515446p27515830.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] Lazy language on JVM/CLR
Perhaps this is similar to what you're looking for. http://openquark.org/Open_Quark/Welcome.html It's a pure, lazy language for the JVM. I haven't used it myself, but I would imagine that it would have a Java FFI. Cheers, - Tim On Mon, Feb 8, 2010 at 6:42 PM, Tony Morris tonymor...@gmail.com wrote: I have hypothesised a pure, lazy language on the JVM and perhaps the .NET CLR with FFI to .NET/Java libraries. I foresee various problems but none that are catastrophic; just often requiring a compromises, sometimes very unattractive compromises. I have authored several libraries in the same vain as pure, lazy programming to run on the JVM in Java and Scala programming languages. I expect others have forethought and perhaps even experimented with such a language. Are there any dangers to be wary of that undo the entire endeavour? Thanks for any insights. -- Tony Morris http://tmorris.net/ ___ 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] Lazy language on JVM/CLR
On Mon, Feb 8, 2010 at 8:16 PM, John Meacham j...@repetae.net wrote: I expect others have forethought and perhaps even experimented with such a language. Are there any dangers to be wary of that undo the entire endeavour? There have been a couple papers published on it, the main sticking point seems to be tail call elimination. When targeting real hardware you always had the option of dropping to assembly to do a direct jump, but there isn't an equivalent in the JVM. If you look up tail call + jvm you will probably get a few hits. I believe there are even a couple haskell specific papers on the issue. One of the easiest approaches to this comes from the scheme folks and I've been able to employ it fairly effectively in toy compilers. It doesn't require anything from the host language except exceptions and you can use it to evaluate spineless tagless g-machine frames mostly on the native/VM stack fairly easily. The biggest problem is the generated code bloat factor of about 2-3x. http://www.ccs.neu.edu/scheme/pubs/stackhack4.html http://www.cs.brown.edu/~sk/Publications/Papers/Published/pcmkf-cont-from-gen-stack-insp/ -Edward Kmett ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Using Cabal during development
Okay, I juste solved issue (1) : The package compiled through Cabal has its information stored in the dist/package.conf.inplace file. I can then compile my main by doing : ghc --make -package-conf dist/package.conf.inplace main.hs I just don't know if it's really the way I'm supposed to do this. Nevertheless, issue (2) remains... Limestraël wrote: Okay, so then I have some troubles regarding the compilation of my executable: First, what do you think is the simpler : (1) build only the library through cabal-install and then the executable with ghc (it isn't to be distributed with the lib), or (2) add both to my http://old.nabble.com/file/p27515830/HSFML.cabal .cabal file and build them in the same time with a 'cabal build' ? Because I've tried both methods, and have had issues with both : (1) after a 'cabal build', ghc doesn't know where to find my library -- whereas cabal-install displays 'Registering HSFL-1.5...' at the end of the build -- when I do 'ghc --make main.hs'. I'm not gonna do a 'cabal install' whenever I alter my code, am I? (2) well, then, when building, if I don't specify that my executable depends on my lib, I got: SFML/Direct/Graphics.hs:51:7: Could not find module `SFML.Direct.Types.Enums': It is a member of the hidden package `HSFML-1.5'. Perhaps you need to add `HSFML' to the build-depends in your .cabal file. it is a hidden module in the package `HSFML-1.5' Use -v to see a list of the files searched for. and if I do what it asks me to do (to add the line 'Build-Depends: HSFML' in the 'Executable' section of my .cabal file), I'm told when 'cabal build'ing: cabal: internal error: could not construct a valid install plan. The proposed (invalid) plan contained the following problems: The following packages are involved in a dependency cycle HSFML-1.5 Miguel Mitrofanov wrote: With cabal-install, usually. -- View this message in context: http://old.nabble.com/Using-Cabal-during-development-tp27515446p27516610.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] Iteratee, parsec co.
| 3. Why Seek FileOffset is error message? Are you talking about John Lato's implementation [1]? Well, `Seek' is not an error message. It is one of constructors for ErrMsg, and ErrMsg is [2] ---- a message to the stream producer (e.g., to rewind the stream) -- or an error indication. You know the overall idea behind Seek, don't you? It is an instrument to implement random IO [3]. Compare Oleg's code [4] data SeekException = SeekException FileOffset deriving Show instance Typeable SeekException where typeOf _ = mkTyConApp (mkTyCon SeekException) [] instance Exception SeekException and [2] type ErrMsg = SomeException data Stream el = EOF (Maybe ErrMsg) | Chunk [el] deriving Show with John Lato's implementation [1]: data StreamG c el = EOF (Maybe ErrMsg) | Chunk (c el) data ErrMsg = Err String | Seek FileOffset deriving (Show, Eq) John makes Err and Seek to be the distinct constructors of ErrMsg. Errors (Err) in `iteratee' package are always Strings. Oleg's ErrMsg is SomeException. One of its instances (SeekException) is a ``rewind the stream'' message to the stream producer. And the user is free to have as many different ErrMsg'es as he needs to do the job. [1] http://inmachina.net/~jwlato/haskell/iteratee/src/Data/Iteratee/Base.hs [2] http://okmij.org/ftp/Haskell/Iteratee/IterateeM.hs [3] http://okmij.org/ftp/Streams.html#random-bin-IO [4] http://okmij.org/ftp/Haskell/Iteratee/RandomIO.hs -- vvv ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Generate random UArray in constant memory space.
Am Dienstag 09 Februar 2010 14:51:31 schrieb Vasyl Pasternak:
Sorry, maybe I should ask more clearer.
I've looked at dons article Haskell as fast as C[1], and tried to
implement similar algorithm but for list of random numbers.
Please look at code:
import Text.Printf
import Control.Applicative
import System.Environment
import Data.Array.Vector
main = do
[size] - map read $ getArgs
let ints = enumFromToU 0 size :: UArr Int
printf %d\n (sumU ints)
This code runs in constant space (on my pc ~25kb allocates on the
heap) regardless of array size.
The random number thing runs in constant space, too.
The difference is that the enumFromToU produces a tight loop with variables
which never leave the registers, while in the random number thing at least
the StdGens are allocated in the heap (the produced Ints may stay in the
registers, too, I don't know).
But enumFromToU and friends were written for that to happen, there are a
ton of rewrite rules to help the compiler create tight loops. StdGen has no
such thing, randomR has no {-# INLINE #-} pragma, so you have a call to
randomR (well, to randomIValInteger, actually) for each element.
Maybe if you had the source for the PRNG in the same file, it could be
inlined to give an allocation-free loop.
So I tried to achieve similar with
random list, just to replace `enumFromToU` with my own list generator.
So the question - is it possible to implement random list similary to
enumFromToU?
[1]http://donsbot.wordpress.com/2008/06/04/haskell-as-fast-as-c-working-
at-a-high-altitude-for-low-level-performance/
Thank you,
Vasyl Pasternak
2010/2/9 Daniel Fischer daniel.is.fisc...@web.de:
Am Dienstag 09 Februar 2010 13:18:23 schrieb Vasyl Pasternak:
Hello Cafe,
I tried to generate memory-efficient list of random numbers, so I've
used uvector library for this task. But it doesn't work,
it still allocates more than 6Gb of memory for the random list of 10
million elements. Here is the code:
Hmm,
$ ghc -O2 --make ranVec
[1 of 1] Compiling Main ( ranVec.hs, ranVec.o )
Linking ranVec ...
$ ./ranVec 1000 +RTS -sstderr
5130
4,919,912,080 bytes allocated in the heap
883,256 bytes copied during GC
26,896 bytes maximum residency (1 sample(s))
25,620 bytes maximum slop
1 MB total memory in use (0 MB lost due to
fragmentation)
maximum residency is just eight bytes more than for 100,000 or
1,000,000 numbers. I think that is constant space.
The ~5 GB total allocation is sequential, ten million new StdGens are
produced and allocated, then immediately garbage collected. I see no
problem (except that StdGen is slow, e.g. the Mersenne twister is much
faster [and allocates less, but still linear in size]).
import Text.Printf
import System.Random
import Control.Applicative
import System.Environment
import Data.Array.Vector
randomListU :: (Int, Int) - StdGen - Int - (UArr Int)
randomListU b g size = unfoldU size gen g
where gen g = let (x, g') = randomR b g
in JustS (x :*: g')
main = do
[size] - map read $ getArgs
let ints = randomListU (-10, 10) (mkStdGen 1) size
printf %d\n (sumU ints)
Could someone give a hint, how to implement this function in constant
memory space?
Thank you in advance.
Best regards,
Vasyl Pasternak
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Re: [Haskell-cafe] Lazy language on JVM/CLR
I don't think it's pure. I would definitely use a pure language on the JVM, but IIRC Open Quark / Cal is an impure language. For example, from the library documentation: printLine :: String - (). -chris On 9 feb 2010, at 15:31, Tim Wawrzynczak wrote: Perhaps this is similar to what you're looking for. http://openquark.org/Open_Quark/Welcome.html It's a pure, lazy language for the JVM. I haven't used it myself, but I would imagine that it would have a Java FFI. Cheers, - Tim On Mon, Feb 8, 2010 at 6:42 PM, Tony Morris tonymor...@gmail.com wrote: I have hypothesised a pure, lazy language on the JVM and perhaps the .NET CLR with FFI to .NET/Java libraries. I foresee various problems but none that are catastrophic; just often requiring a compromises, sometimes very unattractive compromises. I have authored several libraries in the same vain as pure, lazy programming to run on the JVM in Java and Scala programming languages. I expect others have forethought and perhaps even experimented with such a language. Are there any dangers to be wary of that undo the entire endeavour? Thanks for any insights. -- Tony Morris http://tmorris.net/ ___ 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] Lazy language on JVM/CLR
Oops, you're right. It's not pure. Mea cupla for not reading more closely. I wonder how it deals with I/O, then? I don't see anything like Haskell's monads or Clean's uniqueness typing... but at a closer look it does appear to have an excellent Java FFI. On Tue, Feb 9, 2010 at 9:44 AM, Chris Eidhof ch...@eidhof.nl wrote: I don't think it's pure. I would definitely use a pure language on the JVM, but IIRC Open Quark / Cal is an impure language. For example, from the library documentation: printLine :: String - (). -chris On 9 feb 2010, at 15:31, Tim Wawrzynczak wrote: Perhaps this is similar to what you're looking for. http://openquark.org/Open_Quark/Welcome.html It's a pure, lazy language for the JVM. I haven't used it myself, but I would imagine that it would have a Java FFI. Cheers, - Tim On Mon, Feb 8, 2010 at 6:42 PM, Tony Morris tonymor...@gmail.com wrote: I have hypothesised a pure, lazy language on the JVM and perhaps the .NET CLR with FFI to .NET/Java libraries. I foresee various problems but none that are catastrophic; just often requiring a compromises, sometimes very unattractive compromises. I have authored several libraries in the same vain as pure, lazy programming to run on the JVM in Java and Scala programming languages. I expect others have forethought and perhaps even experimented with such a language. Are there any dangers to be wary of that undo the entire endeavour? Thanks for any insights. -- Tony Morris http://tmorris.net/ ___ 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] Using Cabal during development
On Tue, Feb 9, 2010 at 6:10 AM, Ketil Malde ke...@malde.org wrote: Limestraël limestr...@gmail.com writes: how do usually Haskell developpers build their softwares (and especially medium or big libraries) while they are still developping them ? With cabal-install, by doing one 'cabal configure' once and 'cabal build' each time they have altered their code ? With only Cabal, through some 'runhaskell Setup.hs build's ? Generally, the first thing I do is hit C-c C-l in Emacs to load the current file into a haskell process. Then back to fix the type errors (click on the error to jump to the code), and iterate until it loads correctly. It's really unfortunate that this approach doesn't work for .hsc files. When writing low level libraries I often have a couple of these which forces me out of my nice Emacs workflow into an Emacs + terminal + Cabal workflow. -- Johan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Strange Haddock output
I was browsing Hackage pointlessly and came across what appears to be strange Haddock formatting here: http://hackage.haskell.org/packages/archive/pointless-haskell/0.0.3/doc/html/Generics-Pointless-Functors.html#v%3Afmap The following source -- | Polytypic 'Prelude.Functor' class for functor representations class Functor (f :: * - *) where fmap :: Fix f -- ^ For desambiguation purposes, the type of the functor must be passed as an explicit paramaeter to 'fmap' - (x - y) - Rep f x - Rep f y -- ^ The mapping over representations produces the following view from the browser class Functor f where Polytypic Prelude.Functor class for functor representations Methods fmap :: = Fix f - x - y - Rep f xThe mapping over representations - Rep f y with the Haddock 2.6.0 on Hackage. There seems to be an extraneous = in the signature of fmap, and the comment on Fix f does not show up. Sean ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Haskell-Cafe Digest, Vol 78, Issue 14
Edward's reply was quite good. I'll just try to fill in a few items
he didn't address.
From: Maciej Piechotka uzytkown...@gmail.com
I read a lot about iteratee IO and it seemed very interesting
(Unfortunately it lacks tutorial). Especially features like 'no input
yet' in network programming (with lazy IO + parsec I run into problems
as it tried to evaluate the first response character before sending
output).
I decided first write a simple program and then attempt write a Stream
implementation for parsec.
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
import Data.Iteratee
import Text.Parse
data Buffer a = Buffer
instance Monad m = Stream (Buffer a) (IterateeG [] a m) a where
uncons Buffer = IterateeG loop
where loop (Chunk []) =
return $! Cont (IterateeG loop) Nothing
loop (Chunk (x:xs)) =
return $! Done (Just (x, Buffer))
(Chunk xs)
loop (EOF Nothing) =
return $! Done Nothing (EOF Nothing)
loop (EOF (Just e)) =
return $! throwErr e
2. Is there any package which contains this stream definition?
I believe this Stream instance is incorrect. According to the parsec-3.0.1 docs,
A Stream instance is responsible for maintaining the 'position within
the stream' in the stream state s. This is trivial unless you are
using the monad in a non-trivial way.
This is necessary for referential integrity. That is, uncons s
needs to always evaluate to the same result for the same 's'. Your
Stream instance doesn't preserve this. As an example,
testIter = let b = Buffer in uncons b uncons b
should be an iteratee that returns a Maybe (t, buffer) where t is
the first element in the enumeration, but with your instance it will
return the second.
See http://inmachina.net/~jwlato/haskell/ParsecIteratee.hs for a valid
Stream instance using iteratee. Also Gregory Collins recently posted
an iteratee wrapper for Attoparsec to haskell-cafe. To my knowledge
these are not yet in any packages, but hackage is vast.
3. Why Seek FileOffset is error message?
Version 3 of iteratee is somewhat experimental, one of the ideas on
trial is that of resumable exceptions. This framework is perfectly
suited to handle control messages as well, which is why Seek is
included as an error message.
I don't want to make a major release just to fix this, but both error
handling and control messages will undergo a substantial cleanup in
the next major version. Included in this will be a proper separation
between control messages and true exceptions, most likely based upon
the extensible-exceptions framework.
Cheers,
John
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Re: [Haskell-cafe] various dependencies breakages
The latest darcs head for happstack has changed the quickcheck dependency to 2. You might try that. On Tue, Feb 9, 2010 at 7:13 AM, Thomas Girod tho...@0xc29.net wrote: thanks Lars and Max. It did the trick, except for one small detail : MissingH needs the testpack -any dependency, but cabal does not install it automatically. tom ___ 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] Iteratee, parsec co.
From: Edward Kmett ekm...@gmail.com 3. Why Seek FileOffset is error message? I'm not quite sure what you're asking here. One of the infelicities of iteratee-0.3 is that it defines a data type: data ErrMsg = Err String | Seek FileOffset deriving (Show, Eq) I believe this is what the OP is referring to. Oleg originally implemented seek using IORefs; I wanted to try this and didn't know if it would work so I used a minimal implementation. I've decided this is the correct approach, but the details need to be tweaked a bit. Cheers, John ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Using Cabal during development
My development environment is a Screen with Bash, Vim and GHCi running. If I can just load the files in GHCi or compile them with GHC without specifying many options or extensions, then I just do it that way. As soon as I feel a need to write a Makefile or a little build script, I write a Cabal file instead and switch to using `cabal-install'. When I say many options or extensions, I nearly mean any. Most projects of mine get a Cabal file at the point where I feel the need for the first `LANGUAGE' pragma. (I usually omit `LANGUAGE' pragmas, delegating to Cabal for that. I'm not sure whether this is good or bad practice.) -- Jason Dusek ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Using Cabal during development
Okay, but have you ever felt the need to make in the same project a library and an executable which depends on this library (even just like me, for testing purpose)? How would you do it? Jason Dusek wrote: My development environment is a Screen with Bash, Vim and GHCi running. If I can just load the files in GHCi or compile them with GHC without specifying many options or extensions, then I just do it that way. As soon as I feel a need to write a Makefile or a little build script, I write a Cabal file instead and switch to using `cabal-install'. When I say many options or extensions, I nearly mean any. Most projects of mine get a Cabal file at the point where I feel the need for the first `LANGUAGE' pragma. (I usually omit `LANGUAGE' pragmas, delegating to Cabal for that. I'm not sure whether this is good or bad practice.) -- Jason Dusek ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- View this message in context: http://old.nabble.com/Using-Cabal-during-development-tp27515446p27518960.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] automatically exclude unused modules at compile time
I did not use -split-objs. This option did help after I tried it. Thanks. Hong On Mon, Feb 8, 2010 at 11:57 AM, Felipe Lessa felipe.le...@gmail.comwrote: On Mon, Feb 08, 2010 at 11:25:13AM -0600, Hong Yang wrote: Can we make GHC a little bit more intelligent to automatically exclude unused modules at compile time as in case 4)? (Am I just too lazy to add several dashes?) Did you use -split-objs? Does it help? -- Felipe. ___ 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] Using Cabal during development
Cabal/cabal-install are good tools for distribution and installation, but I was wondering -- as I was starting to learn how to use Cabal -- how do usually Haskell developpers build their softwares (and especially medium or big libraries) while they are still developping them ? The first thing I always do is create a skeletal cabal file for my project and add Library and Executable sections to it. The executable might be a test/demo program, or it might be a real app. I usually try to put whatever I can into a library to keep my executable source lightweight. My development flow relies heavily on some emacs integration with darcs that I wrote, which allows me to press C-c C-t to run the darcs test hook preference in am emacs buffer, which happens to be bound to something like cabal build some_test_command in most of my Haskell repositories. That way I don't usually have to leave my editor to see the build failures and address them. -- Jonathan Daugherty ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Generate random UArray in constant memory space.
On Tue, Feb 9, 2010 at 4:18 AM, Vasyl Pasternak vasyl.paster...@gmail.comwrote: I tried to generate memory-efficient list of random numbers, so I've used uvector library for this task. Use the mwc-random package. It provides a function that does exactly this, and produces better quality random numbers with much higher performance (1000x faster) than System.Random or even mersenne-random. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Using Cabal during development
Okay, but have you ever felt the need to make in the same project a library and an executable which depends on this library (even just like me, for testing purpose)? How would you do it? Specifying the modules under test in other-modules section for the executable does the trick for me. I can email you a suitable elided cabal file for one of my projects if you want. Also another really helpful thing for testing is adding a .ghci file in your project I usually check in the .ghci with my source. Standard commands that I define in .ghci usually include :test to run the Test Suite. I also use .ghci set up the correct source paths and to start up with the test module loaded. So recompiles are usually just as simple as :reload. I still run the complete cabal configure -ftest cabal configure build ./dist//test before commits. Rahul ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Using Cabal during development
Then how does the 'Executable' section of your .cabal look like? That's what I can't get working. Jonathan Daugherty-4 wrote: The first thing I always do is create a skeletal cabal file for my project and add Library and Executable sections to it. The executable might be a test/demo program, or it might be a real app. I usually try to put whatever I can into a library to keep my executable source lightweight. -- View this message in context: http://old.nabble.com/Using-Cabal-during-development-tp27515446p27520110.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] Using Cabal during development
Then how does the 'Executable' section of your .cabal look like? That's what I can't get working. Suitably elided. Executable test hs-source-dirs: src, tests other-modules:Text.Yaml.Yay, Text.Yaml.Yay.Syck main-is: Main.hs build-depends:base, HsSyck, syb if flag(test) build-depends: QuickCheck = 2.1 2.2, test-framework-quickcheck2 = 0.2 0.3, test-framework = 0.2 0.3 else buildable: False Library Hs-Source-Dirs: src Exposed-Modules: Text.Yaml.Yay, Text.Yaml.Yay.Syck Other-Modules:Text.Yaml.Yay.Internal.Utils, Text.Yaml.Yay.Syck.Encoder, Text.Yaml.Yay.Syck.Decoder Build-Depends:base, HsSyck, syb if flag(test) -- Faster builds ghc-options:-O0 else -- Optimized builds ghc-options:-O2 if flag(nolib) buildable: False ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Using Cabal during development
Then how does the 'Executable' section of your .cabal look like? That's what I can't get working. Executable vty-ui-demo Hs-Source-Dirs: src Main-is: Demo.hs Build-Depends: mtl = 1.1 1.2 The Main-is refers to src/Demo.hs. This example is from: http://hackage.haskell.org/packages/archive/vty-ui/0.2/vty-ui.cabal The package description link on any Hackage package page will link to the release's cabal file, so you can see how other folks have written their Executable sections. Hope that helps, -- Jonathan Daugherty ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Using Cabal during development
Executable test hs-source-dirs: src, tests other-modules:Text.Yaml.Yay, Text.Yaml.Yay.Syck ... In general, it's not advisable to name your test executable test due to a naming collision with the typical test utility. You might consider naming it $package_name-test. (This is also more cabal-install-friendly.) -- Jonathan Daugherty ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Using Cabal during development
Johan Tibell johan.tib...@gmail.com writes: It's really unfortunate that this approach doesn't work for .hsc files. When writing low level libraries I often have a couple of these which forces me out of my nice Emacs workflow into an Emacs + terminal + Cabal workflow. I use the elisp code below to run cabal without leaving emacs, with its output going into a compilation buffer (so that one can jump to the errors). C-c c will find the cabal file nearest to the current buffer and invoke cabal. HTH, jao --8---cut here---start-8--- (defun jao-locate-dominating-files (regexp optional file) Look up the directory hierarchy from FILE for a file matching REGEXP. Stop at the first parent where a matching file is found and return the list of files that that match in this directory. (catch 'found (let ((dir (file-name-as-directory (or file (buffer-file-name files) (while (and dir (not (string-match locate-dominating-stop-dir-regexp dir))) (if (setq files (condition-case nil (directory-files dir 'full regexp 'nosort) (error nil))) (throw 'found files) (if (equal dir (setq dir (file-name-directory (directory-file-name dir (setq dir nil nil))) (defun jao-haskell-locate-cabal-file () Find the cabal file associated with current buffer. (car (jao-locate-dominating-files .+\\.cabal))) (eval-after-load 'haskell-mode '(add-hook 'haskell-mode-hook (lambda () (set (make-local-variable 'compile-command) cabal build (defun jao-haskell-cabal-build () Run, in a compilation buffer, a cabal command, after finding the cabal file associated with this buffer. (interactive) (let ((cabal-file (jao-haskell-locate-cabal-file))) (unless cabal-file (error Couldn't find associated cabal file)) (let ((default-directory (file-name-directory cabal-file))) (call-interactively 'compile (eval-after-load 'haskell-mode '(define-key haskell-mode-map [?\C-c ?c] 'jao-haskell-cabal-build)) --8---cut here---end---8--- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Strange Haddock output
2010/2/9 Sean Leather leat...@cs.uu.nl: I was browsing Hackage pointlessly and came across what appears to be strange Haddock formatting here: http://hackage.haskell.org/packages/archive/pointless-haskell/0.0.3/doc/html/Generics-Pointless-Functors.html#v%3Afmap The following source -- | Polytypic 'Prelude.Functor' class for functor representations class Functor (f :: * - *) where fmap :: Fix f -- ^ For desambiguation purposes, the type of the functor must be passed as an explicit paramaeter to 'fmap' - (x - y) - Rep f x - Rep f y -- ^ The mapping over representations produces the following view from the browser class Functor f where Polytypic Prelude.Functor class for functor representations Methods fmap :: = Fix f - x - y - Rep f xThe mapping over representations - Rep f y with the Haddock 2.6.0 on Hackage. There seems to be an extraneous = in the signature of fmap, and the comment on Fix f does not show up. I think this is an instance of a bug introduced when implementing cross-package documentation. It has been fixed already and will be in the next minor release. David ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Strange Haddock output
I think this is an instance of a bug introduced when implementing cross-package documentation. It has been fixed already and will be in the next minor release. Sorry, I should have said that the /fix/ will be in the next minor release, and not the bug, of course :-) David ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Generate random UArray in constant memory space.
Am Tuesday 09 February 2010 19:19:18 schrieben Sie:
Daniel,
I've just run venum2 program locally and here is my results:
$ ./venum2 1000 +RTS -s
./venum2 1000 +RTS -s
500500
22,736 bytes allocated in the heap
688 bytes copied during GC
17,184 bytes maximum residency (1 sample(s))
19,680 bytes maximum slop
1 MB total memory in use (0 MB lost due to fragmentation)
$ ./venum2 10 +RTS -s
./venum2 10 +RTS -s
55
24,152 bytes allocated in the heap
688 bytes copied during GC
17,184 bytes maximum residency (1 sample(s))
19,680 bytes maximum slop
1 MB total memory in use (0 MB lost due to fragmentation)
So my PC shows that there is constant memory allocation. Maybe I'm
doing something wrong ?
Unlikely.
However, I notice that you seem to have a 64-bit system.
I don't know the details, but usually those have more registers than a 32-
bit system, so you can get more complicated loops to run completely in the
registers.
I think that's what happens here, enumFromToU' is just complicated enough
to not run in the registers on my 32-bit system, but still runs in the
registers on your 64-bit system.
The PRNG code is too complicated (too many temporary variables) to run in
the registers on either system (BTW, have you tried it with the specialised
PRNG code in the source file? I'm not sure whether that might be just small
enough to run in the registers on a 64-bit system.).
2010/2/9 Daniel Fischer daniel.is.fisc...@web.de:
Am Tuesday 09 February 2010 15:43:13 schrieben Sie:
Update:
I've implemented `enumFromToU` through `unfoldU`:
enumFromToU' from to = unfoldU (to - from) f from
where f i = let i' = i + 1 in JustS (i' :*: i')
This code behaves similarly to `enumFromToU` (i.e. constantly uses
~25 kb of memory, runs in the same time as above).
Wait,
$ cat venum2.hs
module Main (main) where
import Text.Printf
import Control.Applicative
import System.Environment
import Data.Array.Vector
main = do
[size] - map read $ getArgs
let ints = enumFromToU' 0 size :: UArr Int
printf %d\n (sumU ints)
enumFromToU' from to = unfoldU (to - from) f from
where f i = let i' = i + 1 in JustS (i' :*: i')
$ ghc -O2 --make venum2
[1 of 1] Compiling Main ( venum2.hs, venum2.o )
Linking venum2 ...
$ ./venum2 +RTS -sstderr -RTS 100
./venum2 100 +RTS -sstderr
1784293664
48,256,384 bytes allocated in the heap
6,256 bytes copied during GC
26,804 bytes maximum residency (1 sample(s))
25,524 bytes maximum slop
1 MB total memory in use (0 MB lost due to
fragmentation)
$ ./venum2 +RTS -sstderr -RTS 1000
./venum2 1000 +RTS -sstderr
-2004260032
481,937,552 bytes allocated in the heap
19,516 bytes copied during GC
26,804 bytes maximum residency (1 sample(s))
25,512 bytes maximum slop
1 MB total memory in use (0 MB lost due to
fragmentation)
So we have constant memory, but linear allocation, just like with the
random numbers.
With enumFromToU, also the allocation is constant, so unfoldU
allocates, enumFromToU not.
So the question is why random number list generator eats O(n) memory
?
It doesn't, not here, at least. Using System.Random, the allocation
figures are about ten times as high, but the residency is about the
same. Putting the PRNG code in the same file and tweaking things a bit
(eliminating all intermediate Integers, e.g.), I get
$ cat ran2Vec.hs
{-# LANGUAGE BangPatterns #-}
module Main (main) where
import Text.Printf
import Control.Applicative
import System.Environment
import Data.Array.Vector
randomListU :: (Int, Int) - StdGen - Int - (UArr Int)
randomListU b@(l,h) g size = unfoldU size gen g
where
!k = h-l+1
!b' = 2147483561 `rem` k
gen !g = let (!x, !g') = stdNext g
in JustS ((l+ (x+b') `rem` k) :*: g')
main = do
[size] - map read $ getArgs
let ints = randomListU (-10, 10) (mkStdGen 1) size
printf %d\n (sumU ints)
data StdGen = StdGen {-# UNPACK #-} !Int {-# UNPACK #-} !Int
mkStdGen :: Int - StdGen
mkStdGen s
| s 0 = mkStdGen (-s)
| otherwise = StdGen (s1+1) (s2+1)
where
(q, s1) = s `divMod` 2147483562
s2 = q `mod` 2147483398
{-# INLINE stdNext #-}
stdNext :: StdGen - (Int, StdGen)
-- Returns values in the range stdRange
stdNext (StdGen s1 s2) = z' `seq` g' `seq` (z', g')
where
!g' = StdGen s1'' s2''
!z' = if z 1 then z + 2147483562 else z
!z = s1'' - s2''
!k = s1 `quot` 53668
!s1' = 40014 * (s1 - k * 53668) - k * 12211
!s1'' = if s1' 0 then s1' + 2147483563 else s1'
!k' = s2 `quot`
Re: [Haskell-cafe] Generate random UArray in constant memory space.
Am Dienstag 09 Februar 2010 19:27:58 schrieb Bryan O'Sullivan:
On Tue, Feb 9, 2010 at 4:18 AM, Vasyl Pasternak
vasyl.paster...@gmail.comwrote:
I tried to generate memory-efficient list of random numbers, so I've
used uvector library for this task.
Use the mwc-random package. It provides a function that does exactly
this, and produces better quality random numbers with much higher
performance (1000x faster) than System.Random or even mersenne-random.
Not here.
I may be doing it wrong, but
{-# LANGUAGE BangPatterns #-}
module Main (main) where
import Text.Printf
import System.Random.MWC
import Control.Applicative
import System.Environment
import Data.Array.Vector
import Control.Monad.ST
randomListU :: (Int, Int) - Int - Int -- (UArr Int)
randomListU b@(l,h) size = runST $ do
let !k = h-l+1
f !m = m `mod` k + l
sg - create
sumU . mapU f $ uniformArray sg size
main = do
[size] - map read $ getArgs
let int = randomListU (-10, 10) size
printf %d\n int
gives
$ ghc -O2 -funfolding-use-threshold=32 -fforce-recomp --make mwcRanVec.hs -
o mwcRanVec3
[1 of 1] Compiling Main ( mwcRanVec.hs, mwcRanVec.o )
Linking mwcRanVec3 ...
$ ./mwcRanVec3 +RTS -s -RTS 1000
./mwcRanVec3 1000 +RTS -s
22784
40,966,820 bytes allocated in the heap
3,696 bytes copied during GC
27,128 bytes maximum residency (1 sample(s))
26,940 bytes maximum slop
40 MB total memory in use (0 MB lost due to fragmentation)
Generation 0: 1 collections, 0 parallel, 0.00s, 0.00s elapsed
Generation 1: 1 collections, 0 parallel, 0.00s, 0.00s elapsed
INIT time0.00s ( 0.00s elapsed)
MUT time1.09s ( 1.15s elapsed)
GCtime0.00s ( 0.00s elapsed)
EXIT time0.00s ( 0.00s elapsed)
Total time1.10s ( 1.15s elapsed)
%GC time 0.0% (0.0% elapsed)
Alloc rate37,376,166 bytes per MUT second
Productivity 99.6% of total user, 95.2% of total elapsed
, System.Random.Mersenne
$ ./mtRanVec +RTS -s -RTS 1000
./mtRanVec 1000 +RTS -s
-24541
280,609,188 bytes allocated in the heap
17,404 bytes copied during GC
26,776 bytes maximum residency (1 sample(s))
25,724 bytes maximum slop
1 MB total memory in use (0 MB lost due to fragmentation)
Generation 0: 535 collections, 0 parallel, 0.00s, 0.00s elapsed
Generation 1: 1 collections, 0 parallel, 0.00s, 0.00s elapsed
INIT time0.00s ( 0.00s elapsed)
MUT time1.10s ( 1.10s elapsed)
GCtime0.00s ( 0.00s elapsed)
EXIT time0.00s ( 0.00s elapsed)
Total time1.10s ( 1.10s elapsed)
%GC time 0.4% (0.4% elapsed)
Alloc rate255,083,261 bytes per MUT second
Productivity 99.3% of total user, 99.5% of total elapsed
more or less the same, the System.Random code gives
$ ./uRanVec +RTS -s -RTS 1000./uRanVec 1000 +RTS -s
5130
4,515,826,700 bytes allocated in the heap
803,132 bytes copied during GC
26,852 bytes maximum residency (1 sample(s))
25,716 bytes maximum slop
1 MB total memory in use (0 MB lost due to fragmentation)
Generation 0: 8680 collections, 0 parallel, 0.10s, 0.10s elapsed
Generation 1: 1 collections, 0 parallel, 0.00s, 0.00s elapsed
INIT time0.00s ( 0.00s elapsed)
MUT time9.12s ( 9.17s elapsed)
GCtime0.10s ( 0.10s elapsed)
EXIT time0.00s ( 0.00s elapsed)
Total time9.22s ( 9.27s elapsed)
%GC time 1.1% (1.1% elapsed)
Alloc rate495,342,570 bytes per MUT second
Productivity 98.9% of total user, 98.3% of total elapsed
(so a factor of a little above 8), and the specialised System.Random code
in the source file,
{-# LANGUAGE BangPatterns #-}
module Main (main) where
import Text.Printf
import Control.Applicative
import System.Environment
import Data.Array.Vector
randomListU :: (Int, Int) - StdGen - Int - (UArr Int)
randomListU b@(l,h) g size = unfoldU size gen g
where
!k = h-l+1
!b' = 2147483561 `rem` k
gen !g = let (!x, !g') = stdNext g
in JustS ((l+ (x+b') `rem` k) :*: g')
main = do
[size] - map read $ getArgs
let ints = randomListU (-10, 10) (mkStdGen 1) size
printf %d\n (sumU ints)
data StdGen = StdGen {-# UNPACK #-} !Int {-# UNPACK #-} !Int
mkStdGen :: Int - StdGen
mkStdGen s
| s 0 = mkStdGen (-s)
| otherwise = StdGen (s1+1) (s2+1)
where
(q, s1) = s `divMod` 2147483562
s2 = q `mod` 2147483398
{-# INLINE stdNext #-}
stdNext :: StdGen - (Int, StdGen)
-- Returns values in the range stdRange
stdNext (StdGen s1 s2) = z' `seq` g' `seq` (z', g')
where
!g' = StdGen s1'' s2''
!z' = if z 1 then z + 2147483562 else z
!z= s1'' -
Re: [Haskell-cafe] Generate random UArray in constant memory space.
Daniel,
Yes, I have 64 bit system.
Maybe you're right. The PRNG code with the same vector size allocates
two times more memory at my PC. (~ 1 Gb)
Thank you,
Vasyl
2010/2/9 Daniel Fischer daniel.is.fisc...@web.de:
Am Tuesday 09 February 2010 19:19:18 schrieben Sie:
Daniel,
I've just run venum2 program locally and here is my results:
$ ./venum2 1000 +RTS -s
./venum2 1000 +RTS -s
500500
22,736 bytes allocated in the heap
688 bytes copied during GC
17,184 bytes maximum residency (1 sample(s))
19,680 bytes maximum slop
1 MB total memory in use (0 MB lost due to fragmentation)
$ ./venum2 10 +RTS -s
./venum2 10 +RTS -s
55
24,152 bytes allocated in the heap
688 bytes copied during GC
17,184 bytes maximum residency (1 sample(s))
19,680 bytes maximum slop
1 MB total memory in use (0 MB lost due to fragmentation)
So my PC shows that there is constant memory allocation. Maybe I'm
doing something wrong ?
Unlikely.
However, I notice that you seem to have a 64-bit system.
I don't know the details, but usually those have more registers than a 32-
bit system, so you can get more complicated loops to run completely in the
registers.
I think that's what happens here, enumFromToU' is just complicated enough
to not run in the registers on my 32-bit system, but still runs in the
registers on your 64-bit system.
The PRNG code is too complicated (too many temporary variables) to run in
the registers on either system (BTW, have you tried it with the specialised
PRNG code in the source file? I'm not sure whether that might be just small
enough to run in the registers on a 64-bit system.).
2010/2/9 Daniel Fischer daniel.is.fisc...@web.de:
Am Tuesday 09 February 2010 15:43:13 schrieben Sie:
Update:
I've implemented `enumFromToU` through `unfoldU`:
enumFromToU' from to = unfoldU (to - from) f from
where f i = let i' = i + 1 in JustS (i' :*: i')
This code behaves similarly to `enumFromToU` (i.e. constantly uses
~25 kb of memory, runs in the same time as above).
Wait,
$ cat venum2.hs
module Main (main) where
import Text.Printf
import Control.Applicative
import System.Environment
import Data.Array.Vector
main = do
[size] - map read $ getArgs
let ints = enumFromToU' 0 size :: UArr Int
printf %d\n (sumU ints)
enumFromToU' from to = unfoldU (to - from) f from
where f i = let i' = i + 1 in JustS (i' :*: i')
$ ghc -O2 --make venum2
[1 of 1] Compiling Main ( venum2.hs, venum2.o )
Linking venum2 ...
$ ./venum2 +RTS -sstderr -RTS 100
./venum2 100 +RTS -sstderr
1784293664
48,256,384 bytes allocated in the heap
6,256 bytes copied during GC
26,804 bytes maximum residency (1 sample(s))
25,524 bytes maximum slop
1 MB total memory in use (0 MB lost due to
fragmentation)
$ ./venum2 +RTS -sstderr -RTS 1000
./venum2 1000 +RTS -sstderr
-2004260032
481,937,552 bytes allocated in the heap
19,516 bytes copied during GC
26,804 bytes maximum residency (1 sample(s))
25,512 bytes maximum slop
1 MB total memory in use (0 MB lost due to
fragmentation)
So we have constant memory, but linear allocation, just like with the
random numbers.
With enumFromToU, also the allocation is constant, so unfoldU
allocates, enumFromToU not.
So the question is why random number list generator eats O(n) memory
?
It doesn't, not here, at least. Using System.Random, the allocation
figures are about ten times as high, but the residency is about the
same. Putting the PRNG code in the same file and tweaking things a bit
(eliminating all intermediate Integers, e.g.), I get
$ cat ran2Vec.hs
{-# LANGUAGE BangPatterns #-}
module Main (main) where
import Text.Printf
import Control.Applicative
import System.Environment
import Data.Array.Vector
randomListU :: (Int, Int) - StdGen - Int - (UArr Int)
randomListU b@(l,h) g size = unfoldU size gen g
where
!k = h-l+1
!b' = 2147483561 `rem` k
gen !g = let (!x, !g') = stdNext g
in JustS ((l+ (x+b') `rem` k) :*: g')
main = do
[size] - map read $ getArgs
let ints = randomListU (-10, 10) (mkStdGen 1) size
printf %d\n (sumU ints)
data StdGen = StdGen {-# UNPACK #-} !Int {-# UNPACK #-} !Int
mkStdGen :: Int - StdGen
mkStdGen s
| s 0 = mkStdGen (-s)
| otherwise = StdGen (s1+1) (s2+1)
where
(q, s1) = s `divMod` 2147483562
s2 = q `mod` 2147483398
{-# INLINE stdNext #-}
stdNext :: StdGen - (Int, StdGen)
-- Returns values in the range stdRange
stdNext (StdGen s1 s2) = z' `seq` g' `seq` (z', g')
where
!g' = StdGen s1'' s2''
!z' = if z 1 then z +
[Haskell-cafe] If monads are single/linearly threaded, doesn't that reduce parallelism?
___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] If monads are single/linearly threaded, doesn't that reduce parallelism?
In what exact sense are monads single threaded, and of which exactly parallelism are you talking about? 2010/2/10 cas...@istar.ca: ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Eugene Kirpichov Web IR developer, market.yandex.ru ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Using Cabal during development
I think I must be dumb or something. I did my SFML.cabal exactly the way the packager of vty-ui did vty-ui.cabal, and I still have got the error when building: hs_src/SFML/Direct/Graphics.hs:51:7: Could not find module `SFML.Direct.Types.Enums': It is a member of the hidden package `SFML-1.5'. Perhaps you need to add `SFML' to the build-depends in your .cabal file. it is a hidden module in the package `SFML-1.5' Use -v to see a list of the files searched for. My cabal file is http://old.nabble.com/file/p27522604/SFML.cabal here . Il you get to know why it doesn't work, please tell me, because I'm lost... I have a hs_src directory, which contains an SFML directory (the lib) and a demo.hs file. (the simple main) It's the way vty-ui package is done. Jonathan Daugherty-4 wrote: Then how does the 'Executable' section of your .cabal look like? That's what I can't get working. Executable vty-ui-demo Hs-Source-Dirs: src Main-is: Demo.hs Build-Depends: mtl = 1.1 1.2 The Main-is refers to src/Demo.hs. This example is from: http://hackage.haskell.org/packages/archive/vty-ui/0.2/vty-ui.cabal The package description link on any Hackage package page will link to the release's cabal file, so you can see how other folks have written their Executable sections. Hope that helps, -- Jonathan Daugherty ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- View this message in context: http://old.nabble.com/Using-Cabal-during-development-tp27515446p27522604.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] If monads are single/linearly threaded, doesn't that reduce parallelism?
Monads are not commutative. A structure that would tell the compiler that it's commutative, would give it more leeway for optimization (and parallel execution). ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Navigating Graphs
Using something like zippers it is easy to navigate an acyclic graph in O(1) operations per arc you follow. Inspired by Chris Okasaki's work on queues I wondered if there is a similar approach to navigating cyclic graphs. If the graph you are navigating is static (i.e. does not have to support addition or removal of vertices in any reasonable amount of time), I guess you can get away with Tying the know (http://www.haskell.org/haskellwiki/Tying_the_Knot). But is there a technique that allows navigation, insertion and removal at focus in (at least amortised) O(1) operations each? As a generalisation being able to have multiple points of focus (in an acyclic graph for a start) would also be interesting. Any thoughts? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: sendfile leaking descriptors on Linux?
On Sun, Feb 7, 2010 at 9:22 AM, Bardur Arantsson s...@scientician.netwrote: True, it is perhaps technically not a bug, but it is certainly a misfeature since there is no easy way (at least AFAICT) to discover that something bad has happened for the file descriptor and act accordingly. AFAICT any solution would have to be based on a separate thread which either 1) checks the FD periodically somehow, or 2) simply lets the thread doing the threadWaitWrite time out after a set period of inactivity. Neither is very optimal. Either way, I'd certainly expect the sendfile library to work around this somehow such that this situation doesn't occur. I'm just having a hard time thinking up a good solution :). Well, it is certainly a bug in sendfile that needs to be fixed. I'm not sure how to fix it either. If we can simplify the test case, we can ask Simon Marlow.. - jeremy ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Generate random UArray in constant memory space.
Bryan, mwc-random is really fast. But it eats to much memory. My previous attempts were to reduce total number of allocations. This package made this possible, but it increases total memory usage. Here is the code: import Text.Printf import System.Random.MWC import Control.Applicative import System.Environment import Data.Array.Vector import Control.Monad.ST randomListU size = runST $ flip uniformArray size = create main = do [size] - map read $ getArgs printf %d\n $ (sumU (randomListU size) :: Int) And sample tests: ./mwcvec 1000 +RTS -s -9198901858466039191 165,312 bytes allocated in the heap 688 bytes copied during GC 17,184 bytes maximum residency (1 sample(s)) 19,680 bytes maximum slop 78 MB total memory in use (1 MB lost due to fragmentation) ./mwcvec 1 +RTS -s 2242701120799374676 165,704 bytes allocated in the heap 688 bytes copied during GC 17,184 bytes maximum residency (1 sample(s)) 19,680 bytes maximum slop 764 MB total memory in use (12 MB lost due to fragmentation) ./mwcvec 10 +RTS -s mwcvec: out of memory (requested 8000634880 bytes) I don't know exactly, but is this a normal behavior ? Thank you, Vasyl 2010/2/9 Bryan O'Sullivan b...@serpentine.com: On Tue, Feb 9, 2010 at 4:18 AM, Vasyl Pasternak vasyl.paster...@gmail.com wrote: I tried to generate memory-efficient list of random numbers, so I've used uvector library for this task. Use the mwc-random package. It provides a function that does exactly this, and produces better quality random numbers with much higher performance (1000x faster) than System.Random or even mersenne-random. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Generate random UArray in constant memory space.
On Tue, Feb 9, 2010 at 3:48 PM, Vasyl Pasternak vasyl.paster...@gmail.comwrote: mwc-random is really fast. But it eats to much memory. It creates and returns a vector, so if you ask it to give you a billion items, it's going to require north of 8 gigabytes of memory. This should not come as a surprise, I'd hope :-) Assuming that's not what you actually want, you should look at other entry points in the API, which you can use to generate a single value at a time in constant space. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: sendfile leaking descriptors on Linux?
Matt, have you seen this thread? Jeremy, are you saying this a bug in the sendfile library on hackage, or something underlying? thomas. 2010/2/9 Jeremy Shaw jer...@n-heptane.com: On Sun, Feb 7, 2010 at 9:22 AM, Bardur Arantsson s...@scientician.net wrote: True, it is perhaps technically not a bug, but it is certainly a misfeature since there is no easy way (at least AFAICT) to discover that something bad has happened for the file descriptor and act accordingly. AFAICT any solution would have to be based on a separate thread which either 1) checks the FD periodically somehow, or 2) simply lets the thread doing the threadWaitWrite time out after a set period of inactivity. Neither is very optimal. Either way, I'd certainly expect the sendfile library to work around this somehow such that this situation doesn't occur. I'm just having a hard time thinking up a good solution :). Well, it is certainly a bug in sendfile that needs to be fixed. I'm not sure how to fix it either. If we can simplify the test case, we can ask Simon Marlow.. - jeremy ___ 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] Generate random UArray in constant memory space.
On Tue, Feb 09, 2010 at 04:27:57PM -0800, Bryan O'Sullivan wrote: It creates and returns a vector, so if you ask it to give you a billion items, it's going to require north of 8 gigabytes of memory. This should not come as a surprise, I'd hope :-) Assuming that's not what you actually want, you should look at other entry points in the API, which you can use to generate a single value at a time in constant space. He thought the vector would be fused away by the library, which is one of the selling points of uvector. Sadly the implementation of uniformArray wasn't done with this purpose in mind. -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Jobs
We need two developers at the company I work for; that is, I am NOT a recruiter. My boss is asking me to search for developers for me to work with ... like minded, haskell loving, driven, c/c++ (c# if we have to) for an INITIALLY c# full-time salaried position in Arizona (or FL or UT). He is open to starting new projects using Haskell, where applicable. So, he is involving me in the interview process, and I've been less than pleased with candidate selection so far. I told him we need to find people that see the beauty of mathematics and Haskell. If you have a resume you want me to forward on, reply to me directly and I will forward on through the review process. Here is a clip from posting 1 (don't take too literally): Software Engineer with strong 'Design, Programming, Debugging' experience Required Experience 3+yrs MS C# *AND* C++ MS SQL Server MS ASP.NET MS SQL Applicants must have at least 3 years practical work experience designing and building commercial software products that have shipped on the Windows OS platform. Requires proven experience building Web GUI on Windows platform, familiarity with distributed programming and networking. Must also be able to write and debug SQL Stored Procedures. Developer will be required to take ownership of the assigned modules through design, code unit test. Past team lead experience would be valuable. Familiarity with gcc and Linux / Unix programming would be a plus. 4 year degree in a Computer Science related field with at least 5-7 years of experience in a software development environment or similar combination of education/work experience. This position is available in the following offices: Scottsdale, Arizona Provo, Utah Melbourne, Florida Here is a clip from posting 2: Job Description As a Senior C# - Asp.net Software Engineer in this position you will operate within a group of engineers, engaged in product design and implementation of enterprise applications. This role has a very high level of technical and product knowledge spanning multiple development technologies and target platforms. The Senior Software Engineer operates unsupervised and is a self-starter. Essential Duties and Responsibilities: Performs OOD, implementation and maintenance for products composed with a variety of technologies, mostly for Windows platforms but also Linux and other platforms Provides expertise for multiple software layers and levels of abstraction: UI, business layer, database, and distributed operations. Builds a tactical consensus with the development team whilst demonstrating strong technical leadership skills Experience working in a scrum agile environment a plus Performs highly complex product design activities which may require extensive research and analysis Performs complex bug verification, release testing and beta support for assigned products Researches problems discovered by QA or product support and identifies solutions to the problems Conducts unit testing and integration testing for functionality and performance limits In absence of product architects, may serve as a product architect Researches and understands non-functional requirements beyond the marketing requirements for a product Researches new technology or development tools to remain informed of current technology Required Skills Advanced technical knowledge in software development methodologies, design and implementation in C#. Expert analytical and design skills at multi-product/multi-environment level. Understands cross-platform and/or internationalisation development. In-depth experience in research and analysis, project planning and implementation. Excellent understanding of entire development process, including specification, documentation and quality assurance. Aware of business issues as they impact overall project plans. Recognised reference and central point for technical issues across groups and products. Strong communications and interpersonal skills. Advanced PC skills. Required Experience A university degree in computer science or software engineering, preferably a masters or higher, is desireable. Requires 10 to 15 years of experience in product design Good knowledge of .Net, and ASP.NET, for C# developers. Minimum 5 Years Experience of C# language and Asp.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Lazy language on JVM/CLR
On 10/02/2010, at 2:52 AM, Tim Wawrzynczak wrote: Oops, you're right. It's not pure. Mea cupla for not reading more closely. I wonder how it deals with I/O, then? I don't see anything like Haskell's monads or Clean's uniqueness typing... but at a closer look it does appear to have an excellent Java FFI. On Tue, Feb 9, 2010 at 9:44 AM, Chris Eidhof ch...@eidhof.nl wrote: I don't think it's pure. I would definitely use a pure language on the JVM, but IIRC Open Quark / Cal is an impure language. For example, from the library documentation: printLine :: String - (). CAL is pure as long as you don't call Java functions with side effects, or functions like printLine -- rather like avoiding unsafePerformIO in Haskell. For my experimentation I use my own IO monad implementation, but you can generally use `seq` to control when IO happens. The Java FFI is good, although arguably verbose. Tom___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Category Theory woes
Mark Spezzano mark.spezzano at chariot.net.au writes: Does anyone know what Hom stands for? 'Hom' stands for 'homomorphism' --a way of changing (morphism) between two structures while keeping some information the same (homo-). Any algebra text will define morphisms aplenty --homomorphisms, epimorphisms, monomorphisms, and the like. These are maps on groups that preserve group operations (or on rings that preserve ring operations, etc.) In a topology text, you will find information on what are called continuous functions; they're morphisms too, in disguise. You can find a thinner disguise when you look at continuously invertible continuous functions, which are called homeomorphisms. If you proceed to differential geometry, you'll see smooth maps --they're morphisms too, and the invertible ones are called diffeomorphisms. This-morphisms, that-morphisms --if you're trying to come up with a general theory that describes all of them, it's natural just to call them 'morphisms'; but, as with the word 'colonel', the word and the symbol come to us via different routes, so that 'Hom(omorphism)' survives instead as the abbreviation. The crucial point in learning category theory is the realisation that, despite all the fancy terminology, it is at heart nothing but a way of talking about groups, rings, topological spaces, partial orders, etc. --all at once, so no wonder it seems abstract! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
