Re: [Haskell-cafe] can I query if package is in Hackage?

Hi >   Hoogle allows me to query about Haskell functionality. But is there a > mechanism for querying about a package, e.g. Swish? Yes: http://haskell.org/hoogle/?hoogle=hoogle+%2Bhackage http://haskell.org/hoogle/?hoogle=swish+%2Bhackage Answer, swish is not on hackage, but hoogle is. Th

Re: [Haskell-cafe] Functor and Haskell

Daryoush Mehrtash wrote: Thanks this was helpful. In many of Conal Elliot's writings I see that he shows that his semantic function is a natural transformation. Is that just basically showing the polymorphic nature of his semantic functions, or are there other benifits you get by showing a part

[Haskell-cafe] "Search" vs "search" vs "search"

Hi, I have some usability issues with the Haskell homepage. What is the best place to discuss them? 1) "Search" vs "search" vs "search" The front page has 3 search boxes: * at the top with the buttons "Go" and "Search" * the third link on the left called "Search" * the next link below "Search

Re: [Haskell-cafe] Overriding a Prelude function?

As far as referential transparency is concerned, you'd need to keep your reference levels straight, which can seem confusing if you can only communicate via representations(*:-) That came out more confusing than it needs to be, so let me try that again, from scratch: Reduction systems take pro

Re: [Haskell-cafe] "Search" vs "search" vs "search"

I like this idea. Some comments inline. On Fri, Apr 24, 2009 at 1:26 PM, wrote: > I'd propose something like the following grouping: > > * About Haskell > ** What is Haskell? > ** How does Haskell feels like? > ** Haskell success stories > ** Getting Started > *** Installation guide > *** First

Re: [Haskell-cafe] Re: ANNOUNCE: Utrecht Haskell Compiler (UHC) -- first release

Unfortunately I think 4 man years is definitely below the minimum of the guesses I would get if I would ask the people in my group ;-} Doaitse On 23 apr 2009, at 16:13, John A. De Goes wrote: Let's turn this around. You invest 4 months of your life coming out with your own experimental H

Re: Is 78 characters still a good option? Was: [Haskell-cafe] breaking too long lines

2009/4/23 Miguel Mitrofanov : > On 23 Apr 2009, at 12:17, Thomas Davie wrote: > >> Haskell is a very horizontal language, and to limit our horizontal space >> seems pretty weird. > > +1. I sometimes use lines up to 200 characters long, when I feel they would > be more readable. 200 sounds awfully

[Haskell-cafe] Re: Cabal's default install location

"Richard O'Keefe" wrote: > I have never thought, stated, or implied, that only people > without superuser access count! It's just that I and for that > matter, the sysadmin I talk to most are heartily fed up with the > assumption that everyone is a sysadmin. > Yes, but I thought you implied exac

[Haskell-cafe] Re: Is 78 characters still a good option? Was: breaking too long lines

Xiao-Yong Jin wrote: > Gwern Branwen writes: > > > I was cabalizing a package once, and I chucked into the > > build-depends 'ghc' and made it build. About 30 seconds later, it > > occurred to me that this was a geometry library and what the heck > > was it doing with the GHC API? So I go looki

[Haskell-cafe] Re: Cabal's default install location

Edward Middleton wrote: > Could you add this[1] link too, because it highlights the problem with > user installs[1]. i.e. you either have to have root access to install > the dependencies, or install non-haskell dependencies in your home > directory. > > Edward > > 1. http://haskell.org/piperma

Re: [Haskell-cafe] Re: Is 78 characters still a good option? Was: breaking too long lines

On Fri, Apr 24, 2009 at 9:07 AM, Achim Schneider wrote: > Xiao-Yong Jin wrote: > >> Gwern Branwen writes: >> >> > I was cabalizing a package once, and I chucked into the >> > build-depends 'ghc' and made it build. About 30 seconds later, it >> > occurred to me that this was a geometry library an

[Haskell-cafe] (integer) linear programming

Hi. I'm looking for linear programming solvers in Haskell (or a Haskell binding for glpk, or similar). - Thanks, J.W. signature.asc Description: OpenPGP digital signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/ma

[Haskell-cafe] Binary I/O options

I see that there are a few approaches to doing Binary I/O with Haskell, and the one I'm currently looking at using is Data.Binary from Hackage. I was just wondering what folks were choosing for building networked applications and doing Binary I/O. The approach I was about to take was to use Data.B

Re: [Haskell-cafe] Binary I/O options

I use Data.Binary to encode/decode all messages/packets in my P2P VPN application (http://code.google.com/p/scurry/). It's been quite fast and has be suitable for all my needs thus far. On Fri, Apr 24, 2009 at 10:15 AM, David Leimbach wrote: > I see that there are a few approaches to doing Binar

Re: [Haskell-cafe] Binary I/O options

Sounds like the endorsement I was looking for :-) On Fri, Apr 24, 2009 at 7:18 AM, John Van Enk wrote: > I use Data.Binary to encode/decode all messages/packets in my P2P VPN > application (http://code.google.com/p/scurry/). It's been quite fast and > has be suitable for all my needs thus far. >

Re: [Haskell-cafe] Binary I/O options

There is already a network-bytestring package: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/network-bytestring Regards Christopher Skrzętnicki On Fri, Apr 24, 2009 at 16:20, David Leimbach wrote: > Sounds like the endorsement I was looking for :-) > > > On Fri, Apr 24, 2009 at 7

Re: [Haskell-cafe] Binary I/O options

The only caveat I would mention about using Data.Binary is that it traverses lists twice to encode them. Once to determine the length and once to output the list. As a result you may see space-leak-like behavior when encoding very long lists with Data.Binary. -Edward Kmett On Fri, Apr 24, 2009 at

Re: [Haskell-cafe] Binary I/O options

I think I ran across this and somehow thought this was standard, this is what I was planning to use with Data.Binary :-) Dave 2009/4/24 Krzysztof Skrzętnicki > There is already a network-bytestring package: > > > http://hackage.haskell.org/cgi-bin/hackage-scripts/package/network-bytestring > > R

[Haskell-cafe] Template Haskell + Profiling

Hi I'm trying to build some modules that use TH with profiling enabled. The normal build works: $ ghc -fforce-recomp --make -cpp -O -DXQUERY2_TEST Main [1 of 8] Compiling Text.XML.Expat.FormatCustom ( Text/XML/Expat/FormatCustom.hs, Text/XML/Expat/FormatCustom.o ) [2 of 8] Compiling DataStructur

[Haskell-cafe] Re: Template Haskell + Profiling

Lame me, I found the answer here: http://haskell.org/ghc/docs/6.10.2/html/users_guide/template-haskell.html ghc -fforce-recomp --make -cpp -O -DXQUERY2_TEST Main ghc -osuf p_o -prof -auto -auto-all -fforce-recomp --make -cpp -O -DXQUERY2_TEST Main Regards Christopher Skrzętnicki 2009/4/24 Krzy

RE: [Haskell-cafe] Template Haskell + Profiling

Do your profiling builds with "-osuf p_o -hisuf p_hi", and then run a non-profiling build first. This means that both sets of object/hi files are available which placates TH. Ganesh From: haskell-cafe-boun...@haskell.org [mailto:haskell-cafe-boun...@haskell.o

[Haskell-cafe] compilation to C, not via-C

Hi Everyone, It appears the GHC compiler (and other) compile Haskell *via-C* but not *to C*. I've never really understood why there isn't a C generation option, or why GDC ships with its own compulsory copy of gcc. I work in Games middleware, and am very interested in looking at how Haskell could

Re: [Haskell-cafe] compilation to C, not via-C

Have you considered using FFI? On 24 Apr 2009, at 20:36, Sam Martin wrote: Hi Everyone, It appears the GHC compiler (and other) compile Haskell *via-C* but not *to C*. I've never really understood why there isn't a C generation option, or why GDC ships with its own compulsory copy of gcc.

[Haskell-cafe] Confusing change causing space leak

Hi all, I discussed this with a few people in #haskell-in-depth, and we thought I should send this to the list. The following paste shows the only changes required to remove a space leak: http://hpaste.org/fastcgi/hpaste.fcgi/view?id=4185#a4185. Summary: if I reduce a tuple-from-IO to whnf in the

Re: [Haskell-cafe] compilation to C, not via-C

Hello Sam, Friday, April 24, 2009, 8:36:50 PM, you wrote: > I work in Games middleware, and am very interested in looking at how > Haskell could help us. We basically sell C++ libraries. I would like to > be able to write some areas of our libraries in Haskell, compile the > Haskell to C and inco

[Haskell-cafe] darcs hacking sprint 2 and hac5 report

Dear darcs users and Haskellers, Here's our report from the 2nd darcs hacking sprint, held as part of the Haskell Hackathon. http://blog.darcs.net/2009/04/darcs-hacking-sprint-2-report.html Thanks very much to the Hac5 team, to Hac5 sponsors, darcs donors, and to all participants at the Hackatho

Re: [Haskell-cafe] compilation to C, not via-C

Hallo, On 4/24/09, Bulat Ziganshin wrote: > > so, if you just need haskell-C++ interaction, you may look into using > FFI [1,2]. if you believe that you can compile some > java/ruby/haskellwhatever code down to C++ and incorporate it into > your function - sorry, they all have too different c

Re[2]: [Haskell-cafe] compilation to C, not via-C

Hello Alex, Friday, April 24, 2009, 8:57:40 PM, you wrote: >> so, if you just need haskell-C++ interaction, you may look into using >> FFI [1,2]. if you believe that you can compile some >> java/ruby/haskellwhatever code down to C++ and incorporate it into >> your function - sorry, they all h

RE: [Haskell-cafe] compilation to C, not via-C

Thanks Bulat and Miguel. Unless I've missed something, the FFI is an great description of how to bind C and Haskell - I think it's fine. I've read most of the content either on or referenced by the wiki - although I could well be missing something. I believe the problem is with the actual code com

Re: [Haskell-cafe] compilation to C, not via-C

Sam, I work on graphics engine/pipeline for Spore at Electronic Arts, and I've had some similar thoughts as you. But I don't think this is the right path for games right now. The "via C" compiler does generate C code that it puts through GCC. There is a post-process step after the code is conver

Re: [Haskell-cafe] compilation to C, not via-C

On Fri, Apr 24, 2009 at 10:09 AM, Sam Martin wrote: > Thanks Bulat and Miguel. > > Unless I've missed something, the FFI is an great description of how to > bind C and Haskell - I think it's fine. I've read most of the content > either on or referenced by the wiki - although I could well be missin

Re: Re[2]: [Haskell-cafe] compilation to C, not via-C

Hallo, On 4/24/09, Bulat Ziganshin wrote: > > and it supports lazy lists? :) all compiled languages has some FFI, the > problem is that FFI limited to common subset of all those languages - > i.e. primitive types and pointers > I am not saying that Scheme is Haskell. I am just refuting yo

Re: [Haskell-cafe] compilation to C, not via-C

Quoth Alex Queiroz , > Actually some Scheme compilers have a "c-declare" form that lets > you create C functions, which can be called from C, Haskell, Java, > Ruby etc. That would be like what you get with Haskell FFI "export"? When I do this with nhc98, I need a nhc98 "main", and I would e

Re: [Haskell-cafe] compilation to C, not via-C

Hallo, On 4/24/09, Donn Cave wrote: > Quoth Alex Queiroz , > > > > Actually some Scheme compilers have a "c-declare" form that lets > > you create C functions, which can be called from C, Haskell, Java, > > Ruby etc. > > > That would be like what you get with Haskell FFI "export"? > > Wh

Re: [Haskell-cafe] Re: ANNOUNCE: vacuum-cairo: a cairo frontend tovacuum for live Haskell data visualization

Peter Verswyvelen wrote: Something like this? http://en.wikipedia.org/wiki/Force-based_algorithms Yes, I'm all for it :-) The only problem is finding time to do it :-( Although QuickSilver might be able to pull this off easily? A basic version is easy, yes. http://roobarb.jellybean.co.u

Re: [Haskell-cafe] Being impure within a 'pure' function

Well, thanks to all of you. Daniel 2009/4/23 Daniel Fischer > Am Donnerstag 23 April 2009 14:15:16 schrieb Max Rabkin: > > On Wed, Apr 22, 2009 at 10:38 AM, Daniel K. > wrote: > > > Dijkstra's algorithm ... relies heavily on mutating arrays > > > > Well, the imperative implementation does. > >

Re[2]: [Haskell-cafe] compilation to C, not via-C

Hello Sam, Friday, April 24, 2009, 9:09:43 PM, you wrote: well, GHC generates .o files. so you may solve some of your questions. if you can absolutely ignore performance, you can use so-called non-registerized compilation what generates ansi-compatible C code most Haskell libs are written for gh

Re: Re[2]: [Haskell-cafe] compilation to C, not via-C

You may wish to look at Timber. It is a Haskell descendant designed for embedded systems. Its current default output is C which is then compiled. It is a very young language, but given the current list of use cases, I am sure that it will never abandon it's C output model, because most people in em

Re[4]: [Haskell-cafe] compilation to C, not via-C

Hello Rick, Friday, April 24, 2009, 10:12:42 PM, you wrote: what you think about JHC? it seems that Timber is close to it > You may wish to look at Timber. It is a Haskell descendant designed for > embedded systems. > Its current default output is C which is then compiled. It is a > very young

Re: Re[4]: [Haskell-cafe] compilation to C, not via-C

I really like the idea of the region based mem management (and other GC options) in JHC. It could potentially remove the need for any runtime at all, which is nice. Two fundamental differences of Timber is that it is purely strict, and not pure functional. This makes the implementation and use of

[Haskell-cafe] Re: GHC 6.10.2 compatible problem.

Andy Stewart wrote: I saw GHC release new version now, and fix some bug. I want to know below pacakges whether works fine with GHC-6.10.2 before i upgrade it: cabal, gtk2hs, xmonad, yi, leksah Gtk2hs does not work with ghc 6.10.2 yet: http://permalink.gmane.org/gmane.comp.lang.haskell.gtk2h

[Haskell-cafe] Typing efficient folds

I'm trying to write some code to do folds on nested datatypes as in http://web.comlab.ox.ac.uk/people/Jeremy.Gibbons/publications/efolds.pdf but running into trouble getting things to typecheck. Given the types data Nest a = Nil | Cons(a, (Nest (Pair a))) type Pair a = (a,a) and the following

[Haskell-cafe] OT: Good Linux distro for netbook + Haskell?

I've decided to shop around for other options when it comes to a Debian distro to put on my Eee PC 900. Since it has no HDD I want something that isn't too bloated (some is all right) and ideally leaves up to me what to install and what not to. At the same time I'd like to have up-to-date Haskell

Re: [Haskell-cafe] OT: Good Linux distro for netbook + Haskell?

On Fri, Apr 24, 2009 at 4:43 PM, Magnus Therning wrote: > I've decided to shop around for other options when it comes to a Debian > distro to put on my Eee PC 900.  Since it has no HDD I want something > that isn't too bloated (some is all right) and ideally leaves up to me > what to install and w

Re: [Haskell-cafe] OT: Good Linux distro for netbook + Haskell?

Adam Turoff wrote: > On Fri, Apr 24, 2009 at 4:43 PM, Magnus Therning wrote: >> I've decided to shop around for other options when it comes to a Debian >> distro to put on my Eee PC 900. Since it has no HDD I want something >> that isn't too bloated (some is all right) and ideally leaves up to me

Re: [Haskell-cafe] OT: Good Linux distro for netbook + Haskell?

On Fri, Apr 24, 2009 at 4:55 PM, Magnus Therning wrote: > Interesting, but how is it when it comes to availability of up-to-date > Haskell packages?  If it's based on Ubuntu 8.10 then I'd expect out of > date GHC and a need to use cabal-install extensively. Well, my machine just died and I'm wait

Re: [Haskell-cafe] OT: Good Linux distro for netbook + Haskell?

Adam Turoff wrote: > On Fri, Apr 24, 2009 at 4:55 PM, Magnus Therning wrote: >> Interesting, but how is it when it comes to availability of up-to-date >> Haskell packages? If it's based on Ubuntu 8.10 then I'd expect out of >> date GHC and a need to use cabal-install extensively. > > Well, my ma

[Haskell-cafe] Dynamically altering sort order

Hi all, Suppose I have the following interface to a sorting function: sort :: (Ord a) => [a] -> IO [a] -- sort large, on-disk array of records but I don't have a sortBy where you can simply pass a compare function. Wrapped around this is a command-line program which should allow the user to

Re: [Haskell-cafe] Dynamically altering sort order

On Fri, Apr 24, 2009 at 15:22, Martijn van Steenbergen wrote: > Hi Denis, > > Denis Bueno wrote: >> >> where the rCompare field would be a function that is based on the >> flags passed to the command-line problem.  But this has an ugly >> asymmetry.  Does anyone have any other ideas? > > Here's a

Re: [Haskell-cafe] Dynamically altering sort order

Hi Denis, Denis Bueno wrote: where the rCompare field would be a function that is based on the flags passed to the command-line problem. But this has an ugly asymmetry. Does anyone have any other ideas? Here's a solution that is more symmetrical but not necessarily prettier: newtype Wrap =

Re: [Haskell-cafe] Dynamically altering sort order

Denis Bueno wrote: The problem here is that the order is fixed. Statically. I can't change it at runtime based on flags. (Right? Unless I'm missing something) That is right. It might or might not be a problem in your specific case. sortBy :: (a -> a -> Ord) -> [a] -> IO [a] sortBy cmp

RE: [Haskell-cafe] compilation to C, not via-C

Ryan Ingram wrote: > There was > another talk about compiling Haskell into Excel spreadsheets for > finance, but I can't seem to locate it right now. It was an ICFP experience report. http://www.earth.li/~ganesh/research/paradise-icfp08 Ganesh ===

[Haskell-cafe] Takusen, postgres and boolean fields

Let say one has to do something similar to this: execDML $ cmdbind (sql "update some_table set some_boolean_field = ? where ...") [bindP True, ...] When I do it, I have an error: DBError ("42","804") 7 "ERROR: 42804: column \"some_boolean_field\" is of type boolean but expression is of type tex

Re: [Haskell-cafe] OT: Good Linux distro for netbook + Haskell?

Arch is really small. I run it in VMs because it gives me what I need (the ability to compile linux Haskell binaries), plus our very own Don Stewart (hope he doesn't mind if I claim him...) does a lot of Arch stuff making the GHC experience awfully nice :-) Dave On Fri, Apr 24, 2009 at 1:43 PM, M

[Haskell-cafe] ghci debugger problem with :continue. is it broken, or is it me?

In the program below, can someone explain the following debugger output to me? After :continue, shouldn't I hit the f breakpoint two more times? Why do I only hit the f breakpoint once? Is this a problem in the debugger? thart...@ubuntu:~/haskell-learning/debugger>cat debugger.hs -- try t

Re: [Haskell-cafe] compilation to C, not via-C

Sam Martin wrote: In short, I'd like to use Haskell as a code-generator. I can't see that this would be unachievable, particularly given it's generating C already. Have I missed something? For the case of GHC at least, you may be. The "C" that GHC compiles Haskell into isn't C in the normal l

Re: [Haskell-cafe] Dynamically altering sort order

Denis Bueno wrote: Hi all, Suppose I have the following interface to a sorting function: sort :: (Ord a) => [a] -> IO [a] -- sort large, on-disk array of records but I don't have a sortBy where you can simply pass a compare function. Why don't you have sortBy? Wrapped around this is a

Re: [Haskell-cafe] Dynamically altering sort order

On Fri, Apr 24, 2009 at 5:11 PM, Denis Bueno wrote: > Hi all, > > Suppose I have the following interface to a sorting function: > >sort :: (Ord a) => [a] -> IO [a] -- sort large, on-disk array of records > > but I don't have a sortBy where you can simply pass a compare function. > > Wrapped a

[Haskell-cafe] Re: Code reviews Was: Is 78 characters (...) Was: breaking (...)

Maybe we could learn with them: what about if Haskell Weekly News had a section on code review, like many newspapers have book review sections? I'm not sure such a thing is good... At the very least, such reviews should be anonymous, especially if we're going to cover bad code instead of good. H

[Haskell-cafe] Thread priority?

Is there any interest or movement in developing thread priority or any other realtime support in Haskell? Right now, if I have tasks that need to be responsive in real time, even if the realtime needs are very soft, it seems that the only option is to try to ensure that at least one hardware

[Haskell-cafe] "subscribing" to the comments, online Real World Haskell

I love that Real World Haskell is online, here: I love that it has a comment section embedded with every paragraph. However, I would like some ability to subscribe to specific comments. I want to see if people have replied to me or what the latest disc

Re: [Haskell-cafe] "subscribing" to the comments, online Real World Haskell

Michael P Mossey wrote: However, I would like some ability to subscribe to specific comments. I want to see if people have replied to me or what the latest discussion is. Okay, to follow up my own post, I discovered the subscription button for each chapter. That's good. However, using Live Bo

Re: [Haskell-cafe] "subscribing" to the comments, online Real World Haskell

-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 On Fri, Apr 24, 2009 at 10:49 PM, Michael P Mossey wrote: > I love that Real World Haskell is online, here: > > > > I love that it has a comment section embedded with every paragraph. > > However, I would like some ability to subscribe to specific c

Re: [Haskell-cafe] OT: Good Linux distro for netbook + Haskell?

Hi, I've recently tried several different distros on legacy and not so old hardware: AMD 266 MHz Pentium box with BIOS from circa 2000 with 192 MB RAM, AMD Athlon 64 X2 5200 MHz box with 1 GB RAM on ASUS mobo, and Centrino 1600 MHz 5 year old Toshiba notebook with 512 MB RAM. I liked PuppyLinu

RE: [Haskell-cafe] Thread priority?

+1 Incredibly interested if this goes anywhere. Willing to help! -Original Message- From: Christopher Lane Hinson Sent: Friday, April 24, 2009 10:48 PM To: haskell-cafe@haskell.org Subject: [Haskell-cafe] Thread priority? Is there any interest or movement in developing thread priority

[Haskell-cafe] ANN: Cute Hack - Hyena handler + Bamboo Blog Engine :)

Hia, A few interesting progress on Hack: * many middleware ported from Rack, including a lambda! ( just like a pony for wsgi, and a lobster for rack ) * 2 handlers, one for Kibro on fcgi / lighttpd, one for Hyena web server * apps are portable, Bamboo is a port of Panda that runs on Hack, works f

Re: Is 78 characters still a good option? Was: [Haskell-cafe] breaking too long lines

On 24 Apr 2009, at 14:37, Loup Vaillant wrote: 2009/4/23 Miguel Mitrofanov : On 23 Apr 2009, at 12:17, Thomas Davie wrote: Haskell is a very horizontal language, and to limit our horizontal space seems pretty weird. +1. I sometimes use lines up to 200 characters long, when I feel they