Re: [Haskell-cafe] What is the rank of a polymorphic type?

2009-12-05 Thread Dan Doel
On Sunday 06 December 2009 1:42:34 am Eugene Kirpichov wrote: > OK, thanks. > However, isn't the type (forall a . a) -> String impredicative because > it instantiates a type variable of the type constructor (->) p q with > p = forall a . a? There's probably no clear cut answer to this independent

[Haskell-cafe] Re: universal binary version of Haskell Platform?

2009-12-05 Thread Benjamin L . Russell
On Thu, 03 Dec 2009 10:52:35 +, Duncan Coutts wrote: >[...] > >There no binary platform installer for OSX PPC. You'll have to grab >ghc-6.10.4 for PPC from the ghc download page and then install the >platform from the generic source tarball. Ah, that's too bad. That means that I won't be ab

Re: [Haskell-cafe] What is the rank of a polymorphic type?

2009-12-05 Thread Eugene Kirpichov
2009/12/6 Stefan Holdermans : > Eugene, > >> 1) Does there exist an authoritative source saying the same? Not that >> I'm doubting, just supposing that the source would have other >> interesting information, too :) > > You may want to have a look at the already mentioned JFP-article by Peyton > Jon

Re: [Haskell-cafe] ANNOUNCE: error-message

2009-12-05 Thread Ariel J. Birnbaum
> In particular, the motivation for this package was that I have written > a build system, and I wanted to collect as many errors in the build as > possible and show them all to the user at once. YMMV, but at least for me a deluge of errors is less helpful than a short list I can fix quickly, then

Re: [Haskell-cafe] When are undecidables ok?

2009-12-05 Thread Michael Snoyman
On Sun, Dec 6, 2009 at 7:36 AM, Luke Palmer wrote: > On Sat, Dec 5, 2009 at 10:04 PM, Michael Snoyman > wrote: > > I know this is basically a rewording of a previous e-mail, but I realized > > this is the question I *really* wanted to ask. > > > > We have this language extension UndecidableInsta

Re: [Haskell-cafe] When are undecidables ok?

2009-12-05 Thread Luke Palmer
On Sat, Dec 5, 2009 at 10:04 PM, Michael Snoyman wrote: > I know this is basically a rewording of a previous e-mail, but I realized > this is the question I *really* wanted to ask. > > We have this language extension UndecidableInstances (not to mention > OverlappingInstances), which seem to divid

[Haskell-cafe] When are undecidables ok?

2009-12-05 Thread Michael Snoyman
I know this is basically a rewording of a previous e-mail, but I realized this is the question I *really* wanted to ask. We have this language extension UndecidableInstances (not to mention OverlappingInstances), which seem to divide the Haskell camp into two factions: * Hey, GHC said to turn on

[Haskell-cafe] PortAudio library successfully built on Windows

2009-12-05 Thread M Xyz
John Lask, The steps you enumerated below successfully built portaudio for me! Thank you! I wonder though, you said to rename the dll to libpa19.dll from portaudio_x86.dll and to change the .cabal entry from "extra-Libraries: portaudio" to "extra-Libraries: pa19". Since my .dll name and .cabal

RE: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread M Xyz
I am going to give this a try. Thanks. Where can I get the pexports and dlltool utilities? Google yields: http://www.emmestech.com/software/pexports-0.43/download_pexports.html http://sourceware.org/binutils/ Are those correct? --- On Sat, 12/5/09, john lask wrote: From: john lask Subject: RE

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread M Xyz
--- On Sat, 12/5/09, Daniel Fischer wrote: cd portaudio-0.0.1 ghc --make Setup ../Setup configure --help (choose your options, prefix, profiling, ...) ../Setup configure $OPTIONS ../Setup build Everything went well until "Setup build" which yielded our friend "c2hs.exe does not exist".

Re: [Haskell-cafe] New Hackage category: Error Handling

2009-12-05 Thread Henning Thielemann
On Sat, 5 Dec 2009, Henning Thielemann wrote: On Sun, 6 Dec 2009, Michael Snoyman wrote: I think there are plenty of examples like web servers. A text editor with plugins? I don't want to lose three hours worth of work just because some plugin wasn't written correctly. For many classes of pr

RE: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread john lask
I don't know whether this will help you but I just downloaded an built the haskell portaudio package ... (I had a windows msvc build of portaudio dll already) the process I used ... ghc 6.10.4, portaudio-19 make an import lib for ghc from dll: pexports libpa19.dll > libpa19.def dlltool --input-

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Daniel Fischer
Am Sonntag 06 Dezember 2009 01:49:49 schrieb M Xyz: I just had another idea. da...@linux-mkk1:~> c2hs -o memyself.hs memyself.chs c2hs: does not exist it's not that c2hs isn't found or something, c2hs doesn't find Base.chs! Try installing from the unpacked sources (cd portaudio; cabal install)

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread M Xyz
--- On Sat, 12/5/09, Daniel Fischer wrote: If you have cpphs, hugs, jhc, greencard etc., it is probably something about your environment. If you don't have them, it's clear that they aren't found. I don't know what those things are. I have nothing but what came with HP other than installin

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread M Xyz
--- On Sat, 12/5/09, Andrew Coppin wrote: >> Hell, I even followed a C++ guide to Win32 programming and >> managed to translate an "open a blank window" program to Haskell, and it >> worked. Maybe somebody just needs to sit down and write a nice binding >> for doing native GUI stuff under Win32?

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Daniel Fischer
Am Sonntag 06 Dezember 2009 00:47:38 schrieb M Xyz: > Daniel, Thank you for your thoughtful reply. I didn't know about those > flags. The log is fairly long, and as I'm new to Haskell and Cabal it is > mostly meaningless to me. I see very many incidences of "searching for ___ > in path. Cannot find

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread M Xyz
--- On Sat, 12/5/09, Daniel Fischer wrote: Try cabal install --with-c2hs="C:\path\to\c2hs.exe" portaudio maybe that'll work. If not, run cabal --verbose=3 install portaudio, perhaps that gives more information about what went wrong. Daniel, Thank you for your thoughtful reply. I didn't know

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Daniel Fischer
Am Sonntag 06 Dezember 2009 00:10:05 schrieb M Xyz: > Stephen, > I had no problem compiling the portaudio binaries on Windows. It came with > a msvc project that worked. The problem I'm getting currently is that when > I "cabal install portaudio etc etc" I get a "c2hs.exe does not exist error" > wh

Re: [Haskell-cafe] New Hackage category: Error Handling

2009-12-05 Thread Gregory Crosswhite
On Dec 5, 2009, at 3:00 PM, Michael Snoyman wrote: > I think we can all appreciate why it would be a bad thing is we treat > exceptions as errors. For example, I don't want my program to crash on a file > not found. > > On the other hand, what's so bad about treating errors as exceptions? If

[Haskell-cafe] Re: binding to C libraries on Windows was Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Stephen Tetley
Hi John Fair points - but aren't you always going to 'need' at least MinGW? (for some degree of 'need' of course, I use it quite a bit though prefer Cygwin, I suppose Andrew C. would care not to use either). GHC brings with it gcc and ld, ar ... but not much else, so when a C library isn't all bu

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread M Xyz
Stephen, I had no problem compiling the portaudio binaries on Windows. It came with a msvc project that worked. The problem I'm getting currently is that when I "cabal install portaudio etc etc" I get a "c2hs.exe does not exist error" when c2hs.exe clearly exists and is in my system path. Just

Re: [Haskell-cafe] New Hackage category: Error Handling

2009-12-05 Thread Michael Snoyman
On Sun, Dec 6, 2009 at 12:55 AM, Henning Thielemann < lemm...@henning-thielemann.de> wrote: > > On Sun, 6 Dec 2009, Michael Snoyman wrote: > > I think there are plenty of examples like web servers. A text editor with >> plugins? I >> don't want to lose three hours worth of work just because some

Re: [Haskell-cafe] New Hackage category: Error Handling

2009-12-05 Thread Henning Thielemann
On Sun, 6 Dec 2009, Michael Snoyman wrote: I think there are plenty of examples like web servers. A text editor with plugins? I don't want to lose three hours worth of work just because some plugin wasn't written correctly. For many classes of programs, the distinction between error and exce

Re: [Haskell-cafe] New Hackage category: Error Handling

2009-12-05 Thread Michael Snoyman
On Sun, Dec 6, 2009 at 12:17 AM, Henning Thielemann < lemm...@henning-thielemann.de> wrote: > > On Sat, 5 Dec 2009, Michael Snoyman wrote: > > On Sat, Dec 5, 2009 at 7:41 PM, Ross Paterson >> wrote: >> On Sat, Dec 05, 2009 at 05:52:11PM +0200, Michael Snoyman wrote: >> > For the record

Re: [Haskell-cafe] New Hackage category: Error Handling

2009-12-05 Thread Henning Thielemann
On Sat, 5 Dec 2009, Michael Snoyman wrote: On Sat, Dec 5, 2009 at 7:41 PM, Ross Paterson wrote: On Sat, Dec 05, 2009 at 05:52:11PM +0200, Michael Snoyman wrote: > For the record, I find this pedanticism misplaced, ... I think you'll find that's "pedantry". Hoped someone wo

[Haskell-cafe] binding to C libraries on Windows was Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread john lask
I think there are some misapprehensions here:- many haskell packages binding to c libraries will compile with ghc without problems on windows - without cygwin, without mingw/msys system. Some such packages build "out of the box" on windows, like the zlib package which contains the c source for

Re: [Haskell-cafe] ANNOUNCE: error-message

2009-12-05 Thread Gregory Crosswhite
Recall that the definition of liftM2 is == liftM2 :: (Monad m) => (a1 -> a2 -> r) -> m a1 -> m a2 -> m r liftM2 f m1 m2 = do { x1 <- m1; x2 <- m2; return (f x1 x2) } == which, if I understand

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Andrew Coppin
Miguel Mitrofanov wrote: Try Mac. You're not the first to suggest this either. ;-) Maybe once I get hired by some financial modelling consultants and get paid shedloads of money to write Haskell all day, I'll be able to afford a Mac. But until then...

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Miguel Mitrofanov
Try Mac. On 6 Dec 2009, at 01:00, Andrew Coppin wrote: Daniel Fischer wrote: I'm constantly amazed by those who manage to use Windows. (In case you want to misunderstand, it's not a Windows bashing, I just never managed to work with it I've not had a lot of luck with Linux. I imagine t

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Stephen Tetley
Compiling the C PortAudio library for either Cygwin or MinGW will be challenging at the moment. The current release doesn't compile as is, and although there should be patch for the configure script as an attachment to this message it seems to have gone amiss: http://music.columbia.edu/pipermail/

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Andrew Coppin
Daniel Fischer wrote: I'm constantly amazed by those who manage to use Windows. (In case you want to misunderstand, it's not a Windows bashing, I just never managed to work with it I've not had a lot of luck with Linux. I imagine this is merely due to having a lot more experience with Windo

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread M Xyz
--- On Sat, 12/5/09, Daniel Fischer wrote: I thought in this case, it was a proposed change in the installer, so you'd only have to change that and could leave the gtk2hs binary untouched. Of course that can only work if Windows installers are some sort of script or otherwise customisable.

[Haskell-cafe] Re: Optimizing Parsec 3 -- was: Wiki software?

2009-12-05 Thread John MacFarlane
+++ Howard B. Golden [Dec 05 09 13:36 ]: > On Friday December 4, 2009, John MacFarlane wrote: > > > I used criterion to compare pandoc compiled with parsec2 to > > pandoc compiled with your version of parsec3. (The benchmark > > is converting testsuite.txt from markdown to HTML.) The difference >

Re: [Haskell-cafe] What is the rank of a polymorphic type?

2009-12-05 Thread Stefan Holdermans
Eugene, 1) Does there exist an authoritative source saying the same? Not that I'm doubting, just supposing that the source would have other interesting information, too :) You may want to have a look at the already mentioned JFP-article by Peyton Jones et al. and perhaps the work of Kfoury a

Re: [Haskell-cafe] Avoiding undecidables

2009-12-05 Thread Daniel Fischer
Am Samstag 05 Dezember 2009 21:51:26 schrieb Michael Snoyman: > On Sat, Dec 5, 2009 at 10:33 PM, José Iborra wrote: > > Since you have already decided MPTCs are ok, in my opinion undecidable > > instances are fine here. > > But I realize this is not the usual stance, so I might be wrong. > > As f

[Haskell-cafe] Re: Optimizing Parsec 3 -- was: Wiki software?

2009-12-05 Thread Howard B. Golden
On Friday December 4, 2009, John MacFarlane wrote: > I used criterion to compare pandoc compiled with parsec2 to > pandoc compiled with your version of parsec3. (The benchmark > is converting testsuite.txt from markdown to HTML.) The difference > was minor: > > parsec2: > mean: 67.66576 ms, lb

Re: [Haskell-cafe] ANNOUNCE: error-message

2009-12-05 Thread Brent Yorgey
On Thu, Dec 03, 2009 at 01:50:06PM -0800, Gregory Crosswhite wrote: > > Or, even more concisely: > > == > sumWithError_3 = liftM2 (+) > == > > Unfortunately though, neither of these definitions ha

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Daniel Fischer
Am Samstag 05 Dezember 2009 21:43:13 schrieb Miguel Mitrofanov: > I'm constantly amused by those who manage to use Windows without   > installing Cygwin. I'm constantly amazed by those who manage to use Windows. (In case you want to misunderstand, it's not a Windows bashing, I just never manage

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread Daniel Fischer
Am Samstag 05 Dezember 2009 21:31:39 schrieb Andrew Coppin: > Daniel Fischer wrote: > > Am Samstag 05 Dezember 2009 20:14:17 schrieb Andrew Coppin: > >> Bulat Ziganshin wrote: > >>> Developer. many Haskell problems is due to the fact that we have a few > >>> volunteers doing things and lot of consu

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Andrew Coppin
Miguel Mitrofanov wrote: I'm constantly amused by those who manage to use Windows without installing Cygwin. I'm constantly puzzled by those who think that Cygwin is a mandatory part of Windows. ;-) ___ Haskell-Cafe mailing list Haskell-Cafe@haskel

Re: [Haskell-cafe] What is the rank of a polymorphic type?

2009-12-05 Thread Eugene Kirpichov
2009/12/5 Stefan Holdermans : > Eugene, > >> Consider the type: (forall a . a) -> String. > > It's of rank 2. > >> What is the definition of rank of a polymorphic type? > > The minimal rank of a type is given by > >  rank (forall a. t) = 1 `max` rank t >  rank (t -> u)      = (if rank t == 0 then 0

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Stephen Tetley
Hi Andrew 2009/12/5 Andrew Coppin : > I don't think it should be necessary to install a Unix emulator just so that > I can write Windows programs. Maybe others disagree. > ... > > I'm by no means an expert here, but isn't it usual for C libraries on > Windows to be supplied as a compiled DLL

Re: [Haskell-cafe] Avoiding undecidables

2009-12-05 Thread Michael Snoyman
On Sat, Dec 5, 2009 at 10:33 PM, José Iborra wrote: > > On Dec 5, 2009, at 6:58 PM, Michael Snoyman wrote: > > > Hi all, > > > > Well, I've got two problems which both want to be solved with undecidable > and overlapping instances. Obviously, I'd like to try and avoid them. For > the record, the

Re: [Haskell-cafe] Haskell-Newbie and Char-Function

2009-12-05 Thread ??????? ??????
fct a n = (snd $ break (==a) ['a'..'z']) !! n Hi guys, I only started learning Haskell some days ago. Maybe one of you can give me a hint on how to implement a function that needs a character in the range (a,b,...z) and an integer number k and returns the k-next neighbor of the character? For exa

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Miguel Mitrofanov
I'm constantly amused by those who manage to use Windows without installing Cygwin. On 5 Dec 2009, at 23:33, Andrew Coppin wrote: Stephen Tetley wrote: Hello Andrew Plenty compile on Windows: Some OpenVG, OpenGL[1] (still? - I'm a bit behind the times) only compile with MinGW. Others are

Re: [Haskell-cafe] Avoiding undecidables

2009-12-05 Thread José Iborra
On Dec 5, 2009, at 6:58 PM, Michael Snoyman wrote: > Hi all, > > Well, I've got two problems which both want to be solved with undecidable and > overlapping instances. Obviously, I'd like to try and avoid them. For the > record, the problems have to do with the control-monad-failure and > con

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Andrew Coppin
Stephen Tetley wrote: Hello Andrew Plenty compile on Windows: Some OpenVG, OpenGL[1] (still? - I'm a bit behind the times) only compile with MinGW. Others are fine with Cygwin provided you have the dev packages installed (readline, pcre-light...). You're talking about MinGW and Cygwin. So

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread Andrew Coppin
Daniel Fischer wrote: Am Samstag 05 Dezember 2009 20:14:17 schrieb Andrew Coppin: Bulat Ziganshin wrote: Developer. many Haskell problems is due to the fact that we have a few volunteers doing things and lot of consumers begging for features :) That *does* in fact seem to be a r

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread Stephen Tetley
2009/12/5 Andrew Coppin : > Interestingly, while you can't compile bindings to external C libraries, Ah Mr Coppin, maybe you should change "you" to "I". I had (Haskell bindings) SDL-0.5.3 working August last year - so I think I would be using GHC 6.8.3 at that time, the version of the SDL C li

Re: [Haskell-cafe] Haskell-Newbie and Char-Function

2009-12-05 Thread Chaddaï Fouché
On Sat, Dec 5, 2009 at 4:48 PM, Jochem Berndsen wrote: > MeAdAstra wrote: >> Hi guys, >> I only started learning Haskell some days ago. Maybe one of you can give me >> a hint on how to implement a function that needs a character in the range >> (a,b,...z) and an integer number k and returns the k-

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread Daniel Fischer
Am Samstag 05 Dezember 2009 20:14:17 schrieb Andrew Coppin: > Bulat Ziganshin wrote: > > Hello Andrew, > > > > Saturday, December 5, 2009, 6:40:23 PM, you wrote: > >> prominent?) Somebody pointed out this bug 6 months ago. Somebody else > >> posted a potential fix a month ago. There is no visible a

Re[2]: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread Bulat Ziganshin
Hello Andrew, Saturday, December 5, 2009, 10:14:17 PM, you wrote: > I did try to get wxHaskell going once or twice. And the SDL binding. (I > wasn't aware we have Qt now...) I've never got any of them to work yet. it depends on when you have tried. wx made significant progress in last year or tw

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread wren ng thornton
Andrew Coppin wrote: Unfortunately, I've yet to find a single Haskell package that binds to C which will actually compile on Windows. :-( Take a look at logfloat[1], it builds cleanly on Windows XP using GHC 6.10.1 without needing Cygwin nor Mingw/Msys (however GHCi has some DLL errors[2]).

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread Andrew Coppin
Bulat Ziganshin wrote: Hello Andrew, Saturday, December 5, 2009, 6:40:23 PM, you wrote: prominent?) Somebody pointed out this bug 6 months ago. Somebody else posted a potential fix a month ago. There is no visible activity from the developers. Developer. many Haskell problems is due

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread Andrew Coppin
M Xyz wrote: - Apart from HP providing GHC 6.10.4 while Gtk2hs currently requires 6.10.3, it appears that the Gtk2hs installer package doesn't like GHC being installed in a path with spaces. Apparently Gtk2hs has a bug tracker. (I only just discovered this, so perhaps it ne

[Haskell-cafe] ANN: readline-statevar-1.0.1.0

2009-12-05 Thread Krzysztof Skrzętnicki
Hello I am happy to announce a release of small package called readline-statevar. It's a small wrapping library around readline, which in turn wraps libreadline. The reason I wrote it is because I wasn't happy with the API of readline. It was composed of tons of functions like setX/getX, where the

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread M Xyz
- Apart from HP providing GHC 6.10.4 while Gtk2hs currently requires 6.10.3, it appears that the Gtk2hs installer package doesn't like GHC being installed in a path with spaces. Apparently Gtk2hs has a bug tracker. (I only just discovered this, so perhaps it needs to be more prominent?) Someb

[Haskell-cafe] Avoiding undecidables

2009-12-05 Thread Michael Snoyman
Hi all, Well, I've got two problems which both want to be solved with undecidable and overlapping instances. Obviously, I'd like to try and avoid them. For the record, the problems have to do with the control-monad-failure and convertible packages. The code below *should* make clear what I'm tryin

Re: [Haskell-cafe] New Hackage category: Error Handling

2009-12-05 Thread Michael Snoyman
On Sat, Dec 5, 2009 at 7:41 PM, Ross Paterson wrote: > On Sat, Dec 05, 2009 at 05:52:11PM +0200, Michael Snoyman wrote: > > For the record, I find this pedanticism misplaced, ... > > I think you'll find that's "pedantry". > Hoped someone would comment exactly that ;). >

Re: [Haskell-cafe] New Hackage category: Error Handling

2009-12-05 Thread Ross Paterson
On Sat, Dec 05, 2009 at 05:52:11PM +0200, Michael Snoyman wrote: > For the record, I find this pedanticism misplaced, ... I think you'll find that's "pedantry". ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinf

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Stephen Tetley
Hello Andrew Plenty compile on Windows: Some OpenVG, OpenGL[1] (still? - I'm a bit behind the times) only compile with MinGW. Others are fine with Cygwin provided you have the dev packages installed (readline, pcre-light...). Yet others - no chance... If you can get the raw C library to work i

[Haskell-cafe] Re: Binding to C in Windows (was: Low Level Audio - Writing bytes to the sound card?)

2009-12-05 Thread Maurí­cio CA
> Unfortunately, I've yet to find a single Haskell package that > binds to C which will actually compile on Windows. :-( Do you know how can we check dependencies to C libraries in Windows? Is pkg-config available? What about packages with no pkg-config configuration? Thanks, Maurício _

Re: [Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread Bulat Ziganshin
Hello Andrew, Saturday, December 5, 2009, 6:40:23 PM, you wrote: > prominent?) Somebody pointed out this bug 6 months ago. Somebody else > posted a potential fix a month ago. There is no visible activity from > the developers. Developer. many Haskell problems is due to the fact that we have a f

Re: [Haskell-cafe] New Hackage category: Error Handling

2009-12-05 Thread Michael Snoyman
Careful Gregory, you've hit a hot-button issue: you have dared to refer to exceptions as errors! For the record, I find this pedanticism misplaced, as the line between the two is rather blurry. Nonetheless, for control-monad-failure and attempt, we purposely refer to the whole slew of "things not

Re: [Haskell-cafe] Haskell-Newbie and Char-Function

2009-12-05 Thread Jochem Berndsen
MeAdAstra wrote: > Hi guys, > I only started learning Haskell some days ago. Maybe one of you can give me > a hint on how to implement a function that needs a character in the range > (a,b,...z) and an integer number k and returns the k-next neighbor of the > character? For example, fct a 5 would r

Re: [Haskell-cafe] Low Level Audio - Writing bytes to the sound card?

2009-12-05 Thread Andrew Coppin
M Xyz wrote: > if you get it to work As a spoiled Java programmer, this new role as pioneer is a bit intimidating, but I will give it a shot. :) I wish there was a multimedia standard library for beginners like me. Writing audio to the speakers shouldn't be such a journey. Unfortunately

[Haskell-cafe] Haskell-Newbie and Char-Function

2009-12-05 Thread MeAdAstra
Hi guys, I only started learning Haskell some days ago. Maybe one of you can give me a hint on how to implement a function that needs a character in the range (a,b,...z) and an integer number k and returns the k-next neighbor of the character? For example, fct a 5 would result in output f. Tobias

[Haskell-cafe] HP + Gtk2hs?

2009-12-05 Thread Andrew Coppin
So I decided to try out the Haskell Platform instead of just installing GHC directly. To be honest, I didn't really notice much difference, except for the files being installed in a different place. But then, initially HP ~= GHC; presumably the plan is for it to grow as time goes on. Anyway, I

Re: [Haskell-cafe] Finding HP

2009-12-05 Thread Andrew Coppin
Malcolm Wallace wrote: The suggestion was to have a single Download button, leading to a *page* of suitably described links, allowing the user to choose whether they only wanted the basics (a choice of compiler/interpreter + cabal), or the whole Platform, or something else. It would be the id

Re: [Haskell-cafe] What is the rank of a polymorphic type?

2009-12-05 Thread Stefan Holdermans
Eugene, Consider the type: (forall a . a) -> String. It's of rank 2. What is the definition of rank of a polymorphic type? The minimal rank of a type is given by rank (forall a. t) = 1 `max` rank t rank (t -> u) = (if rank t == 0 then 0 else rank t + 1) `max` rank u rank _

Re: [Haskell-cafe] Wikipedia article

2009-12-05 Thread Gwern Branwen
On Sat, Dec 5, 2009 at 4:53 AM, Deniz Dogan wrote: > 2009/12/4 Simon Marlow : >> As noted before, the Wikipedia article for Haskell is a disorganised mess. >> >> http://en.wikipedia.org/wiki/Haskell_%28programming_language%29 >> >> earlier this year, dons suggested reorganising it and posted a tem

[Haskell-cafe] ANN: hakyll-0.1

2009-12-05 Thread Jasper van der Jeugt
Hello all, Hakyll is a simple static site generator library, mostly aimed at blogs. It supports markdown, tex and html templates. It is inspired by the ruby Jekyll program. It has a very small codebase because it makes extensive use of the excellent pandoc and Text.Template libraries. More

[Haskell-cafe] Do you need Windows USB in Haskell?

2009-12-05 Thread Maurí­cio CA
Hi, I keep this direct binding to libusb-1.0.x: http://hackage.haskell.org/package/bindings-libusb on top of which Bas maintains a nice USB library: http://hackage.haskell.org/package/usb Work has been done to support libusb-1.0.x in Windows. So, as long as my bindings-libusb works proper

Re: [Haskell-cafe] What is the rank of a polymorphic type?

2009-12-05 Thread Martijn van Steenbergen
Eugene Kirpichov wrote: Hello. Consider the type: (forall a . a) -> String. On one hand, it is rank-2 polymorphic, because it abstracts over a rank-1 polymorphic type. On the other hand, it is monomorphic because it isn't actually quantified itself: in my intuitive view, a parametrically polymo

Re: [Haskell-cafe] SYB <> very, very mysteriously

2009-12-05 Thread Andrea Vezzosi
On Fri, Dec 4, 2009 at 8:51 PM, Jeremy Shaw wrote: > I have stripped things down to the bare minimum, and test under GHC 6.10, > GHC 6.12, Linux, and Mac OS X. Results are consistent. > > In the following code, > >  1. if you load the code into ghci and evaluate e it will hang, but > (defaultValue

Re: [Haskell-cafe] Re: From function over expression (+, *) derive function over expression (+)

2009-12-05 Thread Martijn van Steenbergen
Radek Micek wrote: Hi, thank you for your reply but your MulExpr does not support expressions like (2*3)+5 Oh! You're right, how silly of me. Martijn. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/h

Re: [Haskell-cafe] Wikipedia article

2009-12-05 Thread Deniz Dogan
2009/12/4 Simon Marlow : > As noted before, the Wikipedia article for Haskell is a disorganised mess. > > http://en.wikipedia.org/wiki/Haskell_%28programming_language%29 > > earlier this year, dons suggested reorganising it and posted a template on > the Haskell wiki: > > http://haskell.org/haskell

[Haskell-cafe] What is the rank of a polymorphic type?

2009-12-05 Thread Eugene Kirpichov
Hello. Consider the type: (forall a . a) -> String. On one hand, it is rank-2 polymorphic, because it abstracts over a rank-1 polymorphic type. On the other hand, it is monomorphic because it isn't actually quantified itself: in my intuitive view, a parametrically polymorphic type has infinitely

Re: [Haskell-cafe] Wikipedia article

2009-12-05 Thread Ketil Malde
Simon Marlow writes: >> There's no need to do any page moving or anything; the new version can >> just be pasted in. > Ok, done! > http://en.wikipedia.org/wiki/Haskell_%28programming_language%29 After conferring briefly with people on IRC (yeah, on a Saturday morning, who am I kidding?), I move