Re: [Haskell-cafe] Re: Haskell Logo write-in candidate
I propose to use concordet voting to appoint a new king from the 100 aspiring candidates ... ;) Good point.. Just noticed that I managed to misspell Don Stewart's name :( Sorry! And thanks for pointing that out! Speaking of Concordet voiting.. :) Have you checked out Arrow's impossibility theorem? http://en.wikipedia.org/wiki/Arrow%27s_impossibility_theorem Dictatorship is the best! And to help appoint a king, I suggest this procedure: First, everyone who wants to be a king puts his name on a wiki page. Then, king = candidates ! maxBound `mod` length candidates --A ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Ease of Haskell development on OS X?
On 21 Mar 2009, at 01:10, Brandon S. Allbery KF8NH wrote: On 2009 Mar 20, at 17:02, Hans Aberg wrote: Therefore, as mentioned before, it might be best to install the GHC binaries and install libraries like Gtk+ from MacPorts. There is also Intel Gtk+ that binds directly to Aqua, the This won;t work as you expect: since there's a dependency on ghc, the ports version of ghc will be installed. (No, it doesn't behave like BSD ports, and can't: breaking base, which is outside of their control, could have severe consequences, so it doesn't simply accept installed versions of programs.) I'm not sure what you are saying here: installing MacPorts Gtk does not cause its GHC to be installed, nor does it bind to it. The way it works with Gnat, is that there is a GtkAda package which binds to Gtk, and the paths of this package must be set to whatever Gtk one is using. Using an external Gnat binding to MacPorts Gtk works just fine. As for the Intel Gtk package that binds to to Aqua, it is integrated with the Xcode GCC. So one must do some extra tweaking there. Hans Aberg ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Haskell Logo write-in candidate
Warren Harris warrensomeb...@gmail.com writes: Hi Jon, I agree with much of your rant, and would agree that the logo is probably the least interesting about haskell, but I think that it's worth spending a little time to spiffy up haskell's image from a marketing perspective. I don't disagree with that. I'm complaining about the method... Although I downplayed much of my design decisions by focusing on the logo's t-shirt potential, I just wanted to say that a lot of thought did go into the design aspects of what I sent out. I don't dispute that either. My point (about lack of justification) was not that people didn't put thought into their efforts, but that there's no mention of it on the listing. A logo needs to be a crisp graphic, needs to draw people in who don't yet understand (pure lazy fun-- huh? or what's with that Amtrak symbol?) That's where that particular design falls down. = is an ugly symbol in the first place, and while the pun with a lambda in the middle provides some intellectual satisfaction, it doesn't outweigh the fussiness of its shape or the irrelevant associations. I hadn't thought of Amtrak, but it made me think of the flags of Mozambique and South Africa. This is all off in the realm of marketing psychology, which is a far cry from programming language design, but important in the overall product perception nonetheless. Again, I don't dispute the importance, but... The other thing about this logo design that is so great is the community process that's creating it. It's the open source process in a nutshell -- the brightest minds playing off each other to build something bigger than the sum of the parts. That could happen, but a vote by people who haven't been given a clue isn't the way to get there. So even if the new logo ends up looking like something that rolled down hill collecting rubbish, the story behind it will be brilliant -- like a family photo reflecting who we are and how we do things here. Maybe so, but the story isn't what's important as far as your first point is concerned. I hesitated in sending my write-in candidate in the first place because I didn't want to derail the process that's underway, derailing it is necessary if we are to get the brightest minds playing off each other Now at the risk of further muddling things, I'll just say that I like your idea of focusing on the :: symbol, and just wanted to provide my interpretation: That design is more like it! I would vote for that. I think that's not bad either, although I think it loses a little of the distinction and intrigue of Pollard's lovely monad/lambda symbol with its curved edges. In the absence of the :: version, I'd might go for that one, but I think it really isn't simple enough, though to properly decide between them, we'd have to try them out on non-Haskellers. -- Jón Fairbairn jon.fairba...@cl.cam.ac.uk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Haskell Logo write-in candidate
Jon Fairbairn jon.fairba...@cl.cam.ac.uk wrote: That's where that particular design falls down. = is an ugly symbol in the first place, and while the pun with a lambda in the middle provides some intellectual satisfaction, it doesn't outweigh the fussiness of its shape or the irrelevant associations. I hadn't thought of Amtrak, but it made me think of the flags of Mozambique and South Africa. I had to google for Amtrak, I didn't know they even existed. I did know that Mozambique and South Africa exist, and googling up their flags I discovered that there are as many resemblances to lambda-bind as there are to the Logo to the Deutsche Bank. Amtrak looks wholly different to me: It doesn't even have straight lines, and it's 3d. :: might be truly Haskell in the sense that everybody else uses plain :, but I don't want Haskell to be associated with squareness, and typing, by itself, is hardly a distinguishing property of Haskell. Furthermore, squares are inherently unstable. Choosing some form of a lambda would be the equivalent of a resistance group choosing a fist as logo: It's been done way to often. Uhh we could use -- . Implies do-notation. Lambda-bind ISN'T UGLY. I wouldn't only wear it as a t-shirt, I'd even paint it on a spaceship. If it's busy, then too are the Windoze and Sun logos, and if non-business is the sole criterion, we should go with a blank logo, saying Haskell is the Zen of Programming. I bet there are some design-experienced people involved in all this, there are way too many well-balanced proposals on the logo list for this not to be true: They just didn't out themselves explicitely. Some time ago, my proposal was to do two votes: First choose the logo, then colour scheme and layout with text etc. Right now, doing three seems wiser: The current, first one to weed out a bulk of unpopular logos, the second to choose one of the popular ones after we've made up our minds about what those logos signify, and finally the third, colour/layout vote. Condorcet voting _should_ actually get rid of the need for the second one, but then, as always, people start to notice that they want to go on a train only after it has left the station. Furthermore, some people seem to be of the oppinion that choosing a couple of favourites and moving them to the top involves dealing with 100+ options, which it of course does, but doesn't. Ignorance is Strength. Voting for a slogan would be a good Idea, too. There's the quite old We put the funk in function, pure - lazy - fun, pure - lazy - fun(ctional) purely functional (functionally pure? pure functionality?), being lazy with class, warm and fuzzy, bind the real world, YEEEAAAHH, Freedom from state, Just Haskell, and probably a couple of others. Then there's the mascot topic: We could have Monica Monad sitting on a lamda-bind, a sloth hanging from it... It makes the whole thing more alive, and can be left out at small scales and on space ships. Maybe we can bribe Tux with some fish, he's on forced vacation right now. -- (c) this sig last receiving data processing entity. Inspect headers for copyright history. All rights reserved. Copying, hiring, renting, performance and/or quoting of this signature prohibited. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Haskell Logo write-in candidate
On Sat, Mar 21, 2009 at 12:52:49PM +0100, Achim Schneider wrote: Jon Fairbairn jon.fairba...@cl.cam.ac.uk wrote: That's where that particular design falls down. = is an ugly symbol in the first place, and while the pun with a lambda in the middle provides some intellectual satisfaction, it doesn't outweigh the fussiness of its shape or the irrelevant associations. I hadn't thought of Amtrak, but it made me think of the flags of Mozambique and South Africa. I had to google for Amtrak, I didn't know they even existed. I did know that Mozambique and South Africa exist, and googling up their flags I discovered that there are as many resemblances to lambda-bind as there are to the Logo to the Deutsche Bank. Amtrak looks wholly different to me: It doesn't even have straight lines, and it's 3d. Amtrak changed their logo in 2000; the old logo looked like =. See the wikipedia article. Amusingly, I also learned from the wikipedia article that critics dubbed this logo the pointless arrow. =) -Brent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Ease of Haskell development on OS X?
On Fri, 2009-03-20 at 14:10 -0400, Jeff Heard wrote: cabal-install works for me. The one thing that would be REALLY REALLY nice (and I'm cc-ing Duncan on this) is a .dmg for Gtk2Hs on Mac OS X. I'm sorry I can't directly help with this. I have no access to any hardware running OS X. I presume you've also asked on the gtk2hs-users mailing list? Duncan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Ease of Haskell development on OS X?
On Fri, 2009-03-20 at 15:22 -0400, Jeff Heard wrote: As this continues to build, I guess the issue for me, and I'm willing to help with it, is trying to figure out how to redistribute programs written with gtk2hs. on Windows, people can just install the gtk2hs libraries via the installer -- although this does bork a little because it assumes you have a haskell compiler on the machine. It's quite possible to make a Windows installer that just bundles the Gtk+ dlls and does not need ghc etc. For example, here's a demo: http://haskell.org/~duncan/gtk2hs/LSystemSetup.exe It's an installer (built using InnoSetup - which is Free software) for a Haskell program that uses gtk2hs and opengl. It installs on a clean machine, no gtk2hs or ghc is required. Constructing such an installer is not hard. The zip files containing all the necessary gtk dlls are available so it's just a matter of the installing them all along with your application .exe file. Duncan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Cabal properties with conditionals
Hi. Assuming this configuration fragment: library xxx cc-options: -Wall if flag(HAVE_URANDOM) cc-options:-DHAVE_URANDOM In case the HAVE_URANDOM flag is defined, what will be the value of the used cc-options? 1) -DHAHE_URANDOM 2) -Wall -DHAHE_URANDOM Thanks Manlio ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell Weekly News: Issue 110 - March 21, 2009
--- Haskell Weekly News http://sequence.complete.org/hwn/20090321 Issue 110 - March 21, 2009 --- Welcome to issue 110 of HWN, a newsletter covering developments in the [1]Haskell community. [2]Facebook apps with Happstack, [3]Sudoku with Cryptol, what next? Tic-tac-toe with darcs? Anyway, lots of neat stuff this week, including new releases of [4]GHC, [5]jhc, and the [6]Monad.Reader, some [7]fun [8]visualizations, and more. Also, students: apply to work on a [9]Haskell project for the Google Summer of Code! Announcements GHC 6.10.2 Release Candidate 1. Ian Lynagh [10]announced the [11]first release candidate for GHC 6.10.2. Please test as much as possible; bugs are much cheaper if we find them before the release! jhc 0.6.0 Haskell Compiler. John Meacham [12]announced the release of [13]jhc 0.6.0. Safe Lazy IO in Haskell. Nicolas Pouillard [14]announced the [15]safe-lazy-io package that provides special types and combinators for performing safe lazy I/O. game-tree - a library for searching game trees. Colin Paul Adams [16]announced [17]game-tree 0.1.0.0, which provides a class for dynamic game trees, and purely functional algorithms for searching them. random-shuffle package. Manlio Perillo [18]announced the availability of the [19]random-shuffle package, which is based on [20]Oleg's description. random-stream package. Manlio Perillo [21]announced the [22]random-stream package, which provides a portable interface for the operating system source of pseudo random data. Supported sources are Unix /dev/urandom, Win32 CryptGenRandom and OpenSSL pseudo random numbers generator. language-python. Bernie Pope [23]announced the [24]language-python package, which provides a parser (and lexer) for Python, written in Haskell. Currently it only supports version 3 of Python (the most recent version), but it will support version 2 in the future. Google Summer of Code. Malcolm Wallace [25]announced that haskell.org has once again been accepted as a mentoring organisation for the 2009 Google Summer of Code. Student applications open on Monday (23rd March) at 1900 UTC, for a period of 12 days (until Fri 3rd April, also at 1900 UTC). Students applicants are encouraged to interact with the community via mailing lists, prior, during, and after the submission of their ideas for projects. Because (sadly) the darcs community did not get accepted as a separate organisation this year, haskell.org will be willing to accept proposals relating to darcs. regex-tdfa-1.1.0. ChrisK [26]announced the release of [27]regex-tdfa-1.1.0. This version is a small performance update to the old regex-tdfa-1.0.0 version. Previously all text (e.g. ByteString) being search was converted to String and sent through a single engine; the new version uses a type class and SPECIALIZE pragmas to avoid converting to String. This should make adding support for searching other Char containers easy to do. Haskell on your system? Information wanted!. Don Stewart [28]announced that haskell.org now features links to wiki pages explaining how to obtain Haskell on windows, mac osx and linux and bsd. If you're a distro maintainer for these systems, please consider adding relevant pointers to the pages, so that users of these systems can find all the info they need. libffi 0.1 released. Remi Turk [29]announced the release of [30]libffi 0.1, bindings to the C library libffi, allowing C functions to be called whose types are not known before run-time. Haskell Logo Voting has started!. Eelco Lempsink [31]announced that voting has begun to choose the new Haskell logo. All subscribed to haskell-cafe should have received a ballot; if you are not directly subscribed, you can still send ballot requests until the end of the competition (March 24, 12:00 UTC). Make sure the message contains 'haskell logo voting ballot request' in the subject. A long discussion of what color to paint the bike shed and why this particular bike shed will not do for storing bikes ensued. The Monad.Reader (13). Wouter Swierstra [32]announced that a new issue of [33]The Monad.Reader, a quarterly magazine about functional programming, is now available. Issue 13 consists of the following four articles: Rapid Prototyping in TEX by Stephen Hicks; The Typeclassopedia by Brent Yorgey; a Real World Haskell book review by Chris Eidhof and Eelco Lempsink; and Calculating Monads with Category Theory by Derek Elkins. dzen-utils 0.1. Felipe Lessa [34]announced the release of [35]dzen-utils 0.1, which contains various utilities for creating dzen input strings in a type-safe way using some combinators, including the ability to apply colors
Re: [Haskell-cafe] Ease of Haskell development on OS X?
Ross == Ross Mellgren rmm-hask...@z.odi.ac writes: Ross While there is not a .dmg for Gtk2Hs, you can use a .dmg Ross installed GHC with a .dmg installed Gtk, and then build Ross gtk2hs straight on top of that, without having to deal with Ross the dual-GHC macports mess.. Ross http://www.haskell.org/haskellwiki/Gtk2hs#Using_the_GTK.2B_OS_X_Framework I just tried this. The configure enables cairo, but does not enable svgcairo. Is there anyway round this, or do I have to revert to the macports gtk? (my application uses svgcairo) -- Colin Adams Preston Lancashire ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: A guess on stack-overflows - thunks build-up and tail recursion
Hi Bas, I'd like to share some thoughts with you. Let's say I'm unable, for whatever reason, to force full evaluation of the accumulator during a foldl. So I have this huge build up of thunks, which causes a stack overflow when the thunks are being reduced. I wonder if I could write some sort of chunked fold which basically still produces the same amount of thunks but in a way so that the do not go on the stack all at once for reduction and thus do not cause a stack overflow. Kind of a tree. I'd sincerely appreciate your thoughts on this. Günther Bas van Dijk schrieb: On Fri, Mar 20, 2009 at 2:01 PM, GüŸnther Schmidt gue.schm...@web.de wrote: The problem occurs when the result value is needed and thus the thunks need to be reduced, starting with the outermost, which can't be reduced without reducing the next one etc and it's these reduction steps that are pushed on the stack until its size cause a stack-overflow. Oh yes of course! Indeed a foldl: foldl f z [] = z foldl f z (x:xs) = foldl f (z `f` x) xs Is compiled to: foldl f z xs = case xs of [] - z (x:xs) - let z' = f z x in foldl f z' x So the z' is allocated on the heap. So it turns out that in my Foldr Foldl Foldl' article the stack overflow message is listed to soon. It should actually be lised after the: ((0 + 1) + 2) + 3) + 4) + ...) + 99) + 100 I will fix it when I get home from work and nobody has beat me to it. Thanks for pointing this out! regards, Bas ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [Haskell-beginners] appropriateness of haskell for GUIs
Am 21.03.2009 um 13:30 schrieb Michael Mossey: Thomas Davie wrote: On 21 Mar 2009, at 00:16, Michael P Mossey wrote: Hello, I'm totally new to Haskell. I'm thinking of using it for a personal project, which is a gui-based musical score editor. The rough situation of GUI programming on Haskell is that it works just as well as in any imperative programming language. This is rather disappointing, simply because so many other things are massively easier in Haskell, and this isn't true of GUI programming (yet). Hi Bob, I can imagine that GUI programming is no easier (yet). It is inherently very stateful. GUI's have modes, such as which screens are displayed, which dialogs are displayed, which options within those dialogs are valid given the other state of the program, etc. When I write GUIs, I often diagram them as state machines to get a handle on what's going on. So, I'm not familiar with GUI programming on Haskell, but would you say the statefulness of GUIs (in their typical implementations) is the reason they are no easier on Haskell? I strongly prefer to use qtHaskell because I'm familiar with Qt, and Qt is extremely capable. For example, it can draw text and shapes with antialiasing, which will be great for a music score editor. Music scores have lots of small shapes to fit on the screen, and antialiasing will provide ease of reading. I don't know how much of Qt is implemented in qtHaskell, or whether the latest version of Qt (4.4) is implemented. Thanks, Mike The main problem is, as far as I know, the complete lack of any usable GUI designer. You have to type everything yourself. That's very annoying. It's a lot easier in other languages because your tools take away the cumbersome twiddling with widgets. However, I haven't googled. Maybe the situation has changed since I last looked. Regards, Adrian PGP.sig Description: Signierter Teil der Nachricht ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [Haskell-beginners] laziness and optimization
You should not rely on the compiler to spot such things. As far as I know GHC doesn't do automatic caching (in many cases that would hurt performance, I think). Have a look at http://haskell.org/haskellwiki/ Memoization perhaps. Am 21.03.2009 um 14:02 schrieb Michael Mossey: I understand a bit about the concept of lazy evaluation. I think of that as saying an imperative language would always make one evaluation, whereas Haskell might make 0 evaluations. I have another similar situation where an imperative language would make N evaluations of the same expression, and I would like Haskell to make only 1. This is the situation: the graphical score editor displays LayoutItems. A LayoutItem can be a single displayed entity, like a round notehead, or it can be composed of several entities. A common situation in my code is the need to determine the size and shape of a LayoutItem. For a fundamental item, this can be looked up in a table or read from the font properties. For a composite item, some computation is required: the code must determine the positions of each sub-item and compute the bounds of a shape containing all of them. It's this latter computation, finding the bounds of a composite item, which might come up multiple times. Consider that I ask for the bounds of a composite-composite item (a composite item composed of composite items). It will run the computation associated with each composite sub-item, even though it is very likely I already make that computation when I first constructed and placed that sub- item. In an imperative language, one might cache values for later lookup. This raises the problem of keeping the cache current to the current state. So I'm wondering to what extent the haskell compiler recognizes computations it's done before. In a purely functional language this should be pretty easy, right? If it sees the same expression, it knows it will have the same value. That's my understanding, so far. Thanks, Mike ___ Beginners mailing list beginn...@haskell.org http://www.haskell.org/mailman/listinfo/beginners PGP.sig Description: Signierter Teil der Nachricht ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: [Haskell-beginners] appropriateness of haskell for GUIs
2009/3/21 Adrian Neumann aneum...@inf.fu-berlin.de Am 21.03.2009 um 13:30 schrieb Michael Mossey: Thomas Davie wrote: On 21 Mar 2009, at 00:16, Michael P Mossey wrote: Hello, I'm totally new to Haskell. I'm thinking of using it for a personal project, which is a gui-based musical score editor. The rough situation of GUI programming on Haskell is that it works just as well as in any imperative programming language. This is rather disappointing, simply because so many other things are massively easier in Haskell, and this isn't true of GUI programming (yet). Hi Bob, I can imagine that GUI programming is no easier (yet). It is inherently very stateful. GUI's have modes, such as which screens are displayed, which dialogs are displayed, which options within those dialogs are valid given the other state of the program, etc. When I write GUIs, I often diagram them as state machines to get a handle on what's going on. So, I'm not familiar with GUI programming on Haskell, but would you say the statefulness of GUIs (in their typical implementations) is the reason they are no easier on Haskell? I strongly prefer to use qtHaskell because I'm familiar with Qt, and Qt is extremely capable. For example, it can draw text and shapes with antialiasing, which will be great for a music score editor. Music scores have lots of small shapes to fit on the screen, and antialiasing will provide ease of reading. I don't know how much of Qt is implemented in qtHaskell, or whether the latest version of Qt (4.4) is implemented. Thanks, Mike The main problem is, as far as I know, the complete lack of any usable GUI designer. You have to type everything yourself. That's very annoying. It's a lot easier in other languages because your tools take away the cumbersome twiddling with widgets. http://en.wikipedia.org/wiki/Glade_Interface_Designer -- Sebastian Sylvan +44(0)7857-300802 UIN: 44640862 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: [Haskell-beginners] appropriateness of haskell for GUIs
On 2009 Mar 21, at 10:59, Sebastian Sylvan wrote: 2009/3/21 Adrian Neumann aneum...@inf.fu-berlin.de Am 21.03.2009 um 13:30 schrieb Michael Mossey: Thomas Davie wrote: On 21 Mar 2009, at 00:16, Michael P Mossey wrote: Hello, I'm totally new to Haskell. I'm thinking of using it for a personal project, which is a gui-based musical score editor. The rough situation of GUI programming on Haskell is that it works just as well as in any imperative programming language. This is rather disappointing, simply because so many other things are massively easier in Haskell, and this isn't true of GUI programming (yet). So, I'm not familiar with GUI programming on Haskell, but would you say the statefulness of GUIs (in their typical implementations) is the reason they are no easier on Haskell? The main problem is, as far as I know, the complete lack of any usable GUI designer. You have to type everything yourself. That's very annoying. It's a lot easier in other languages because your tools take away the cumbersome twiddling with widgets. http://en.wikipedia.org/wiki/Glade_Interface_Designer Glade works fine if all you want is to place widgets; but it won't generate template code in Haskell (it will for C and C++) to connect the widgets together, which is what I understand from you have to type everything yourself. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: [Haskell-beginners] laziness and optimization
Yep. Michael: Haskell doesn't do miracles. It has a well-defined (however, very cool) evaluation model, and the compiler in 99.9% realistic cases optimizes it only by a constant factor. Things can't be much better than that because it is extremely hard or theoretically impossible (probably by some kind of Rice's theorem) to guarantee that certain algorithm-changing optimizations won't hurt. (Same thing for Prolog: when I didn't know it at all, I thought that it was a magic allmighty theorem prover; turned out that it also had a well-defined, however very cool, evaluation model) So, use the strictly-defined lazy evaluation model to its whole extent, and build your own memoization :) 2009/3/21 Adrian Neumann aneum...@inf.fu-berlin.de: You should not rely on the compiler to spot such things. As far as I know GHC doesn't do automatic caching (in many cases that would hurt performance, I think). Have a look at http://haskell.org/haskellwiki/Memoization perhaps. Am 21.03.2009 um 14:02 schrieb Michael Mossey: I understand a bit about the concept of lazy evaluation. I think of that as saying an imperative language would always make one evaluation, whereas Haskell might make 0 evaluations. I have another similar situation where an imperative language would make N evaluations of the same expression, and I would like Haskell to make only 1. This is the situation: the graphical score editor displays LayoutItems. A LayoutItem can be a single displayed entity, like a round notehead, or it can be composed of several entities. A common situation in my code is the need to determine the size and shape of a LayoutItem. For a fundamental item, this can be looked up in a table or read from the font properties. For a composite item, some computation is required: the code must determine the positions of each sub-item and compute the bounds of a shape containing all of them. It's this latter computation, finding the bounds of a composite item, which might come up multiple times. Consider that I ask for the bounds of a composite-composite item (a composite item composed of composite items). It will run the computation associated with each composite sub-item, even though it is very likely I already make that computation when I first constructed and placed that sub-item. In an imperative language, one might cache values for later lookup. This raises the problem of keeping the cache current to the current state. So I'm wondering to what extent the haskell compiler recognizes computations it's done before. In a purely functional language this should be pretty easy, right? If it sees the same expression, it knows it will have the same value. That's my understanding, so far. Thanks, Mike ___ Beginners mailing list beginn...@haskell.org http://www.haskell.org/mailman/listinfo/beginners ___ 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
[Haskell-cafe] [ANN] I/O library for Windows
Hi all, winio is an I/O library for Windows using Windows API functions and has I/O completion port support. The main goal of this library is to support Simon Marlow's new Handle API once he has added that to GHC. The library also has a compatibility module for socket functions from the network-bytestring package. Because the library uses IOCP instead of select it is not limited to 1024 open sockets. Try for example the thread-ring program where each Haskell thread passes a UDP message around (Change the MaxUserPort field in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters to 65534 to enable all ports). The winio package is available on Hackage. Notice that it uses a development version of the network package which is available at http://darcs.haskell.org/packages/network/. The library has not been tested much and should be considered experimental so please try it if you use Windows and notify me of any issue or corner case. Kind Regards, Felix ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] [GSOC] About Implementing Maps using generalized tries project idea
Hi, I was looking at the list of Haskell GSOC 2009 project ideas, and I came across the one in which we have to implement maps using generalized tries. However, I also found this as one of the GSOC 2008 projects. I want to know if this project is still open, or the required work has been done last year. If it's open, what exactly needs to be done further. Regards Gautam ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Ease of Haskell development on OS X?
I tried making this work, but librsvg requires pango, and pango is a huge pain in the ass -- I managed to get the whole thing to compile, but now it can't find any fonts, apparently due to some dynaloading issues. I think if you need any of the extended modules (e.g. svgcairo, gl) that the DMG doesn't directly support then you're best served by shedding a couple tears and going with macports. The steps I used to get the broken version were (FYI -- doing this causes all fonts to load as the no-character square in all gtk2hs apps): export PKG_CONFIG_PATH=/usr/X11/lib/pkgconfig:/usr/local/lib/ pkgconfig:/Library/Frameworks/Cairo.framework/Resources/dev/lib/ pkgconfig:/Library/Frameworks/GLib.framework/Resources/dev/lib/ pkgconfig:/Library/Frameworks/Gtk.framework/Resources/dev/lib/pkgconfig export PATH=$PATH:/Library/Frameworks/GLib.framework/Resources/dev/bin cd pango-1.24.0 CFLAGS=-DFC_WEIGHT_EXTRABLACK=215 ./configure --prefix=/usr/local make -j4 sudo make install cd librsvg-2.26.0 ./configure --prefix=/usr/local make -j4 sudo make install cd gtk2hs-0.10.0 ./configure --disable-gio make -j4 sudo make install Running apps linked with this version of gtk2hs gets: (svgviewer:43314): Pango-CRITICAL **: No modules found: No builtin or dynamically loaded modules were found. PangoFc will not work correctly. This probably means there was an error in the creation of: '/usr/local/etc/pango/pango.modules' You should create this file by running: pango-querymodules '/usr/local/etc/pango/pango.modules' (svgviewer:43314): Pango-WARNING **: failed to choose a font, expect ugly output. engine-type='PangoRenderATSUI', script='latin' So if anyone knows what Pango is trying to do, maybe they could help resolve this. I'm probably going to ditch the use of GTK in my own project and use FFI bindings to Carbon/Win32, since I don't really need widgets for my own stuff and the whole family of GTK related packages is a total pain in the ass (as are most things in the GNU family of software, IMO) -Ross On Mar 21, 2009, at 10:13 AM, Colin Paul Adams wrote: Ross == Ross Mellgren rmm-hask...@z.odi.ac writes: Ross While there is not a .dmg for Gtk2Hs, you can use a .dmg Ross installed GHC with a .dmg installed Gtk, and then build Ross gtk2hs straight on top of that, without having to deal with Ross the dual-GHC macports mess.. Ross http://www.haskell.org/haskellwiki/Gtk2hs#Using_the_GTK.2B_OS_X_Framework I just tried this. The configure enables cairo, but does not enable svgcairo. Is there anyway round this, or do I have to revert to the macports gtk? (my application uses svgcairo) -- Colin Adams Preston Lancashire ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Ease of Haskell development on OS X?
Minor correction -- pango in general is installed with the .DMG of Gtk... it's pangoft2 (the freetype2 bindings) that librsvg requires and aren't provided. -Ross On Mar 21, 2009, at 12:35 PM, Ross Mellgren wrote: I tried making this work, but librsvg requires pango, and pango is a huge pain in the ass -- I managed to get the whole thing to compile, but now it can't find any fonts, apparently due to some dynaloading issues. I think if you need any of the extended modules (e.g. svgcairo, gl) that the DMG doesn't directly support then you're best served by shedding a couple tears and going with macports. The steps I used to get the broken version were (FYI -- doing this causes all fonts to load as the no-character square in all gtk2hs apps): export PKG_CONFIG_PATH=/usr/X11/lib/pkgconfig:/usr/local/lib/ pkgconfig:/Library/Frameworks/Cairo.framework/Resources/dev/lib/ pkgconfig:/Library/Frameworks/GLib.framework/Resources/dev/lib/ pkgconfig:/Library/Frameworks/Gtk.framework/Resources/dev/lib/ pkgconfig export PATH=$PATH:/Library/Frameworks/GLib.framework/Resources/dev/bin cd pango-1.24.0 CFLAGS=-DFC_WEIGHT_EXTRABLACK=215 ./configure --prefix=/usr/local make -j4 sudo make install cd librsvg-2.26.0 ./configure --prefix=/usr/local make -j4 sudo make install cd gtk2hs-0.10.0 ./configure --disable-gio make -j4 sudo make install Running apps linked with this version of gtk2hs gets: (svgviewer:43314): Pango-CRITICAL **: No modules found: No builtin or dynamically loaded modules were found. PangoFc will not work correctly. This probably means there was an error in the creation of: '/usr/local/etc/pango/pango.modules' You should create this file by running: pango-querymodules '/usr/local/etc/pango/pango.modules' (svgviewer:43314): Pango-WARNING **: failed to choose a font, expect ugly output. engine-type='PangoRenderATSUI', script='latin' So if anyone knows what Pango is trying to do, maybe they could help resolve this. I'm probably going to ditch the use of GTK in my own project and use FFI bindings to Carbon/Win32, since I don't really need widgets for my own stuff and the whole family of GTK related packages is a total pain in the ass (as are most things in the GNU family of software, IMO) -Ross On Mar 21, 2009, at 10:13 AM, Colin Paul Adams wrote: Ross == Ross Mellgren rmm-hask...@z.odi.ac writes: Ross While there is not a .dmg for Gtk2Hs, you can use a .dmg Ross installed GHC with a .dmg installed Gtk, and then build Ross gtk2hs straight on top of that, without having to deal with Ross the dual-GHC macports mess.. Ross http://www.haskell.org/haskellwiki/Gtk2hs#Using_the_GTK.2B_OS_X_Framework I just tried this. The configure enables cairo, but does not enable svgcairo. Is there anyway round this, or do I have to revert to the macports gtk? (my application uses svgcairo) -- Colin Adams Preston Lancashire ___ 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] [ANN] ansi-terminal, ansi-wl-pprint - ANSI terminal support for Haskell
2009/3/21 Manlio Perillo manlio_peri...@libero.it: Max Bolingbroke ha scritto: These two packages allow Haskell programs to produce much richer console output by allowing colorisation, emboldening and so on. Do you plan to extend the package to any terminal, using terminfo database? Manlio, I don't plan on an extension like this myself, as assuming ANSI support is enough for all the applications I'm interested in, and I suspect dealing with terminfo stuff will be a headache. Sorry! Cheers, Max ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [ANN] ansi-terminal, ansi-wl-pprint - ANSI terminal support for Haskell
Manlio Perillo manlio_peri...@libero.it wrote: Do you plan to extend the package to any terminal, using terminfo database? Are there any non-ansi terminals left? I assumed they were extinct... it'd come close to using EBCDIC. -- (c) this sig last receiving data processing entity. Inspect headers for copyright history. All rights reserved. Copying, hiring, renting, performance and/or quoting of this signature prohibited. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] [ANN] ansi-terminal, ansi-wl-pprint - ANSI terminal support for Haskell
These two packages allow Haskell programs to produce much richer console output by allowing colorisation, emboldening and so on. Both Unix-like (OS X, Linux) and Windows operating systems are supported (via a pure Haskell ANSI emulation layer for Windows). Examples, screenshots, and lots more information about how to get the packages are available at the freshly-minted homepages: http://batterseapower.github.com/ansi-terminal/ http://batterseapower.github.com/ansi-wl-pprint/ These two packages have actually been in stealth release mode on Hackage for some time. However, they seem to be getting some use and I'm not getting any bug reports, so I figure that they /must/ be stable enough to make a proper announcement :-) Cheers, Max (p.s: the GitHub pages feature seems to be absolutely ace - highly reccomended! http://pages.github.com/) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [ANN] ansi-terminal, ansi-wl-pprint - ANSI terminal support for Haskell
Max Bolingbroke wrote: These two packages allow Haskell programs to produce much richer console output by allowing colorisation, emboldening and so on. This will be a big help in my MUD driver. Thanks! :-) Martijn. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Ease of Haskell development on OS X?
If I try this, pango fails to compile with lots of error messages about error: macro names must be identifiers. I think I've seen this before - some well-known Mac OSX problem? (I'm a linux man myself - so I'm not used to the mac) 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: I tried making this work, but librsvg requires pango, and pango is a huge pain in the ass -- I managed to get the whole thing to compile, but now it can't find any fonts, apparently due to some dynaloading issues. I think if you need any of the extended modules (e.g. svgcairo, gl) that the DMG doesn't directly support then you're best served by shedding a couple tears and going with macports. The steps I used to get the broken version were (FYI -- doing this causes all fonts to load as the no-character square in all gtk2hs apps): export PKG_CONFIG_PATH=/usr/X11/lib/pkgconfig:/usr/local/lib/pkgconfig:/Library/Frameworks/Cairo.framework/Resources/dev/lib/pkgconfig:/Library/Frameworks/GLib.framework/Resources/dev/lib/pkgconfig:/Library/Frameworks/Gtk.framework/Resources/dev/lib/pkgconfig export PATH=$PATH:/Library/Frameworks/GLib.framework/Resources/dev/bin cd pango-1.24.0 CFLAGS=-DFC_WEIGHT_EXTRABLACK=215 ./configure --prefix=/usr/local make -j4 sudo make install cd librsvg-2.26.0 ./configure --prefix=/usr/local make -j4 sudo make install cd gtk2hs-0.10.0 ./configure --disable-gio make -j4 sudo make install Running apps linked with this version of gtk2hs gets: (svgviewer:43314): Pango-CRITICAL **: No modules found: No builtin or dynamically loaded modules were found. PangoFc will not work correctly. This probably means there was an error in the creation of: '/usr/local/etc/pango/pango.modules' You should create this file by running: pango-querymodules '/usr/local/etc/pango/pango.modules' (svgviewer:43314): Pango-WARNING **: failed to choose a font, expect ugly output. engine-type='PangoRenderATSUI', script='latin' So if anyone knows what Pango is trying to do, maybe they could help resolve this. I'm probably going to ditch the use of GTK in my own project and use FFI bindings to Carbon/Win32, since I don't really need widgets for my own stuff and the whole family of GTK related packages is a total pain in the ass (as are most things in the GNU family of software, IMO) -Ross On Mar 21, 2009, at 10:13 AM, Colin Paul Adams wrote: Ross == Ross Mellgren rmm-hask...@z.odi.ac writes: Ross While there is not a .dmg for Gtk2Hs, you can use a .dmg Ross installed GHC with a .dmg installed Gtk, and then build Ross gtk2hs straight on top of that, without having to deal with Ross the dual-GHC macports mess.. Ross http://www.haskell.org/haskellwiki/Gtk2hs#Using_the_GTK.2B_OS_X_Framework I just tried this. The configure enables cairo, but does not enable svgcairo. Is there anyway round this, or do I have to revert to the macports gtk? (my application uses svgcairo) -- Colin Adams Preston Lancashire ___ 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] Ease of Haskell development on OS X?
I didn't get any errors like that (nor do I remember ever having them), though if you want to paste them here maybe I can help with them. -Ross On Mar 21, 2009, at 1:27 PM, Colin Adams wrote: If I try this, pango fails to compile with lots of error messages about error: macro names must be identifiers. I think I've seen this before - some well-known Mac OSX problem? (I'm a linux man myself - so I'm not used to the mac) 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: I tried making this work, but librsvg requires pango, and pango is a huge pain in the ass -- I managed to get the whole thing to compile, but now it can't find any fonts, apparently due to some dynaloading issues. I think if you need any of the extended modules (e.g. svgcairo, gl) that the DMG doesn't directly support then you're best served by shedding a couple tears and going with macports. The steps I used to get the broken version were (FYI -- doing this causes all fonts to load as the no-character square in all gtk2hs apps): export PKG_CONFIG_PATH=/usr/X11/lib/pkgconfig:/usr/local/lib/pkgconfig:/ Library/Frameworks/Cairo.framework/Resources/dev/lib/pkgconfig:/ Library/Frameworks/GLib.framework/Resources/dev/lib/pkgconfig:/ Library/Frameworks/Gtk.framework/Resources/dev/lib/pkgconfig export PATH=$PATH:/Library/Frameworks/GLib.framework/Resources/dev/ bin cd pango-1.24.0 CFLAGS=-DFC_WEIGHT_EXTRABLACK=215 ./configure --prefix=/usr/local make -j4 sudo make install cd librsvg-2.26.0 ./configure --prefix=/usr/local make -j4 sudo make install cd gtk2hs-0.10.0 ./configure --disable-gio make -j4 sudo make install Running apps linked with this version of gtk2hs gets: (svgviewer:43314): Pango-CRITICAL **: No modules found: No builtin or dynamically loaded modules were found. PangoFc will not work correctly. This probably means there was an error in the creation of: '/usr/local/etc/pango/pango.modules' You should create this file by running: pango-querymodules '/usr/local/etc/pango/pango.modules' (svgviewer:43314): Pango-WARNING **: failed to choose a font, expect ugly output. engine-type='PangoRenderATSUI', script='latin' So if anyone knows what Pango is trying to do, maybe they could help resolve this. I'm probably going to ditch the use of GTK in my own project and use FFI bindings to Carbon/Win32, since I don't really need widgets for my own stuff and the whole family of GTK related packages is a total pain in the ass (as are most things in the GNU family of software, IMO) -Ross On Mar 21, 2009, at 10:13 AM, Colin Paul Adams wrote: Ross == Ross Mellgren rmm-hask...@z.odi.ac writes: Ross While there is not a .dmg for Gtk2Hs, you can use a .dmg Ross installed GHC with a .dmg installed Gtk, and then build Ross gtk2hs straight on top of that, without having to deal with Ross the dual-GHC macports mess.. Ross http://www.haskell.org/haskellwiki/Gtk2hs#Using_the_GTK.2B_OS_X_Framework I just tried this. The configure enables cairo, but does not enable svgcairo. Is there anyway round this, or do I have to revert to the macports gtk? (my application uses svgcairo) -- Colin Adams Preston Lancashire ___ 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] Ease of Haskell development on OS X?
In file included from ../pango/pango.h:31, from pango-impl-utils.h:28, from fonts.c:30: ../pango/pango-enum-types.h:12:9: error: macro names must be identifiers ../pango/pango-enum-types.h:14:9: error: macro names must be identifiers ../pango/pango-enum-types.h:17:9: error: macro names must be identifiers ../pango/pango-enum-types.h:19:9: error: macro names must be identifiers ../pango/pango-enum-types.h:22:9: error: macro names must be identifiers ../pango/pango-enum-types.h:25:9: error: macro names must be identifiers ../pango/pango-enum-types.h:27:9: error: macro names must be identifiers ../pango/pango-enum-types.h:29:9: error: macro names must be identifiers ../pango/pango-enum-types.h:31:9: error: macro names must be identifiers ../pango/pango-enum-types.h:33:9: error: macro names must be identifiers ../pango/pango-enum-types.h:36:9: error: macro names must be identifiers ../pango/pango-enum-types.h:38:9: error: macro names must be identifiers ../pango/pango-enum-types.h:41:9: error: macro names must be identifiers ../pango/pango-enum-types.h:43:9: error: macro names must be identifiers ../pango/pango-enum-types.h:45:9: error: macro names must be identifiers ../pango/pango-enum-types.h:48:9: error: macro names must be identifiers ../pango/pango-enum-types.h:51:9: error: macro names must be identifiers ../pango/pango-enum-types.h:54:9: error: macro names must be identifiers In file included from ../pango/pango.h:31, from pango-impl-utils.h:28, from glyphstring.c:26: ../pango/pango-enum-types.h:12:9: error: macro names must be identifiers ../pango/pango-enum-types.h:14:9: error: macro names must be identifiers ../pango/pango-enum-types.h:17:9: error: macro names must be identifiers ../pango/pango-enum-types.h:19:9: error: macro names must be identifiers ../pango/pango-enum-types.h:22:9: error: macro names must be identifiers ../pango/pango-enum-types.h:25:9: error: macro names must be identifiers ../pango/pango-enum-types.h:27:9: error: macro names must be identifiers ../pango/pango-enum-types.h:29:9: error: macro names must be identifiers ../pango/pango-enum-types.h:31:9: error: macro names must be identifiers ../pango/pango-enum-types.h:33:9: error: macro names must be identifiers ../pango/pango-enum-types.h:36:9: error: macro names must be identifiers ../pango/pango-enum-types.h:38:9: error: macro names must be identifiers ../pango/pango-enum-types.h:41:9: error: macro names must be identifiers ../pango/pango-enum-types.h:43:9: error: macro names must be identifiers ../pango/pango-enum-types.h:45:9: error: macro names must be identifiers ../pango/pango-enum-types.h:48:9: error: macro names must be identifiers ../pango/pango-enum-types.h:51:9: error: macro names must be identifiers ../pango/pango-enum-types.h:54:9: error: macro names must be identifiers 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: I didn't get any errors like that (nor do I remember ever having them), though if you want to paste them here maybe I can help with them. -Ross On Mar 21, 2009, at 1:27 PM, Colin Adams wrote: If I try this, pango fails to compile with lots of error messages about error: macro names must be identifiers. I think I've seen this before - some well-known Mac OSX problem? (I'm a linux man myself - so I'm not used to the mac) 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: I tried making this work, but librsvg requires pango, and pango is a huge pain in the ass -- I managed to get the whole thing to compile, but now it can't find any fonts, apparently due to some dynaloading issues. I think if you need any of the extended modules (e.g. svgcairo, gl) that the DMG doesn't directly support then you're best served by shedding a couple tears and going with macports. The steps I used to get the broken version were (FYI -- doing this causes all fonts to load as the no-character square in all gtk2hs apps): export PKG_CONFIG_PATH=/usr/X11/lib/pkgconfig:/usr/local/lib/pkgconfig:/Library/Frameworks/Cairo.framework/Resources/dev/lib/pkgconfig:/Library/Frameworks/GLib.framework/Resources/dev/lib/pkgconfig:/Library/Frameworks/Gtk.framework/Resources/dev/lib/pkgconfig export PATH=$PATH:/Library/Frameworks/GLib.framework/Resources/dev/bin cd pango-1.24.0 CFLAGS=-DFC_WEIGHT_EXTRABLACK=215 ./configure --prefix=/usr/local make -j4 sudo make install cd librsvg-2.26.0 ./configure --prefix=/usr/local make -j4 sudo make install cd gtk2hs-0.10.0 ./configure --disable-gio make -j4 sudo make install Running apps linked with this version of gtk2hs gets: (svgviewer:43314): Pango-CRITICAL **: No modules found: No builtin or dynamically loaded modules were found. PangoFc will not work correctly. This probably means there was an error in the creation of: '/usr/local/etc/pango/pango.modules' You should create this file by running: pango-querymodules '/usr/local/etc/pango/pango.modules' (svgviewer:43314):
Re: [Haskell-cafe] [GSOC] About Implementing Maps using generalized tries project idea
http://hackage.haskell.org/cgi-bin/hackage-scripts/package/gmap-0.1 Everything in the release is working. There's some fast map/trie implementations and a bunch of map combinators. In Test.GMap there are ~800 lines of quickcheck properties. The tests use some undocumented type hackery to allow them to run on any instance of the GMap class. Some of the strictness invariants demanded by the test suite are not documented. There are no real benchmarks. I'm still not even sure how to effectively benchmark haskell code. If you want to suggest this as a project for 2009 I think the priorities should be: Documentation + examples (which I'm willing to help with if there is interest) Systematic benchmarks Integration with the edison api, to encourage a single collection api on hackage Jamie ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Binary, Data.Text and errors
On Sun, Mar 15, 2009 at 9:13 PM, Bryan O'Sullivan b...@serpentine.com wrote: On Sun, Mar 15, 2009 at 8:40 PM, Alexander Dunlap alexander.dun...@gmail.com wrote: I have noticed that in both Data.Binary and Data.Text (which is still experimental, but still), the decode functions can be undefined (i.e. bottom) if they encounter malformed input. For decoding Unicode, it's typical to provide a flexible API that can do one of the following on a bad encoding: Substitute a character Skip it Return the partial decode Throw an exception I just haven't gotten there yet. Thanks! I guess we'll see how this comes together. Does anyone know about error handling options in Data.Binary? Are there plans to add an error handling mechanism? Alex ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] [ANN] random-stream 0.1.1
I'm pleased to announce a new version of random-stream package. In this version I have rewritten the internal API. Now the package exposes a new System.Random.URandom module, with the function: urandom :: Int - IO S.ByteString This function is an interface to the system pseudo random numbers generator. The API of the module System.Random.Stream is left unchanged, but it now uses the urandom function, internally. System.Random.Stream provides a pure interface over urandom, using a lazy ByteString of random bytes. Since it provides an infinite stream of random data, things should be ok. I have also added support to Windows (older versions may not be supported, however [1]). The package should be available on Hackage. Mercurial repository is at: http://hg.mperillo.ath.cx/haskell/random-stream/ Example usage: http://hpaste.org/fastcgi/hpaste.fcgi/view?id=2738 [1] It is possible to use OpenSSL, as a fallback. Just set the HAVE_SSL flag, during package configuration. The OpenSSL DLL should be placed where the linker can find it. I tried to test this, but without success (but I did not put much effort in it). Regards Manlio Perillo ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ghci + hopengl
Hello, I'm writing a program for plotting vectorial functions and maybe something else in the future. My goal is to be able to have the following usage: Prelude :l Galo.hs Prelude Galo show3Dvec (\t - (t, t, 0)) [0.0,0.01 .. 1.0] * shows graph * Prelude Galo show3Dvec (\t - (t, t**2, 0)) [0.0,0.01 .. 1.0] * shows new graph * I already done something, the main module can be found here: http://github.com/aflag/galo/blob/0a54a53db0f66384cfc0775f12582931d0fb4205/Galo.hs The whole project is found here: http://github.com/aflag/galo/tree/master I think mainLoop is somehow responsible to exit the whole thing. I tried to even call that function through forkIO. But didn't work quite well: my terminal started behaving really weird after I closed the window. Could you explain me what is going on and what should I look into for understanding how to solve the issue? []'s Rafael ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] about beta NF in lambda calculus
hi, What is the different between 'in beta normal form' and 'has beta normal form' ? Does the former means the current form of the term is already in normal form but the latter means that it is not a normal form yet and can be reduced to be normal form? Like \x.x is in NF and (\x.x) (\x.x) has NF? If above is true, I am confused why we have to distinguish the terms which have NF and be in NF? isn't the terms have NF will eventually become in NF? or there are some way to avoid them becoming in NF? Thanks Alg ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: [ANN] ansi-terminal, ansi-wl-pprint - ANSI terminal support for Haskell
Achim Schneider ha scritto: Manlio Perillo manlio_peri...@libero.it wrote: Do you plan to extend the package to any terminal, using terminfo database? Are there any non-ansi terminals left? I assumed they were extinct... it'd come close to using EBCDIC. http://groups.google.com/group/comp.unix.shell/browse_thread/thread/a1a088da1032f336/b3862f039688f0f8 Regards Manlio ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [ANN] ansi-terminal, ansi-wl-pprint - ANSI terminal support for Haskell
Max Bolingbroke ha scritto: 2009/3/21 Manlio Perillo manlio_peri...@libero.it: Max Bolingbroke ha scritto: These two packages allow Haskell programs to produce much richer console output by allowing colorisation, emboldening and so on. Do you plan to extend the package to any terminal, using terminfo database? Manlio, I don't plan on an extension like this myself, as assuming ANSI support is enough for all the applications I'm interested in, and I suspect dealing with terminfo stuff will be a headache. Sorry! I think, instead, that it should not be that hard. After all the C API can be wrapper in pure functions. And you can also write a pure Haskell interface to terminfo database. Cheers, Max Regards Manlio ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] about beta NF in lambda calculus
Given the Y combinator, Y (\x.x) has no normal form. However, (\a. (\x. x)) (Y (\x. x)) does have a normal form; (\x. x). But it only reduces to that normal form if you reduce the (\a. ...) redex, not if you reduce its argument. So depending on evaluation order you might not reach a normal form. -- ryan 2009/3/21 Algebras Math algebras2...@googlemail.com: hi, What is the different between 'in beta normal form' and 'has beta normal form' ? Does the former means the current form of the term is already in normal form but the latter means that it is not a normal form yet and can be reduced to be normal form? Like \x.x is in NF and (\x.x) (\x.x) has NF? If above is true, I am confused why we have to distinguish the terms which have NF and be in NF? isn't the terms have NF will eventually become in NF? or there are some way to avoid them becoming in NF? Thanks Alg ___ 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] Ease of Haskell development on OS X?
(back to the list) Answers inline: On Mar 21, 2009, at 2:42 PM, Colin Adams wrote: Yes, that was the problem, and swapping the PATH order does the trick. Thanks. no prob. I must still have the macports stuff installed. Can you tell me how to get rid of it? if you really want to get rid of it I believe you just have to rm -rf / opt/local and remove any initialization hooks for /opt/local out of / etc/profile and ~/.bash_profile However I still can't install my program - I get missing dependencies for gtk glib cairo and svgcairo. I'm not really that savvy with the package registration magics -- on my system after doing sudo make install for gtk2hs, I get the packages properly registered. You can check the registered packages with ghc- pkg list. It could be that the package is registered local for your user, but the cabal install line you're using for the application includes --global (or your cabal configuration) so it won't look in the user config. I think Duncan answered some questions about this same problem recently, though I don't have a mailing list reference. I tried some of the gtk2hs demos - they work, but, for instance, the actionmenu demo does not put the menus up at the top of the screen, so it doesn't look like the framework integration has worked. Even with the integration everything is still GTK-ish. There's a separate framework that comes with the .dmg called ige-mac-integration that allows applications to meld with the mac environment better, but no gtk2hs bindings for this exist at the moment. Bindings would have to be created, and then you'd have to modify the application to make use of them (presumably with CPP or similar switch to control whether you want mac support, or just plain GTK) -Ross 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: I think there must be a version inconsistency with your GLib framework -- either not the most recent copy of the GTK+ DMG, or your path is flipped around and you're using a ports version. Run glib-mkenums --version to see what version you have... I have r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums --version glib-mkenums version glib-2.18.1 glib-mkenums comes with ABSOLUTELY NO WARRANTY. You may redistribute copies of glib-mkenums under the terms of the GNU General Public License which can be found in the GLib source package. Sources, examples and contact information are available at http://www.gtk.org Particularly, the error you're getting is because your version of glib-mkenums doesn't expand @ENUMPREFIX@ -- if I run glib-mkenums with no arguments, my version reports @ENUMPREFIX@ as a valid subtitution: r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums Usage: glib-mkenums [options] [files...] --fhead text output file header --fprod text per input file production --ftail text output file trailer --eprod text per enum text (produced prior to value itarations) --vhead text value header, produced before iterating over enum values --vprod text value text, produced for each enum value --vtail text value tail, produced after iterating over enum values --comments text comment structure --template filetemplate file -h, --help show this help message -v, --version print version informations Production text substitutions: @EnumName@ PrefixTheXEnum @enum_name@prefix_the_xenum @ENUMNAME@ PREFIX_THE_XENUM @ENUMSHORT@THE_XENUM @ENUMPREFIX@ PREFIX @VALUENAME@PREFIX_THE_XVALUE @valuenick@the-xvalue @type@ either enum or flags @Type@ either Enum or Flags @TYPE@ either ENUM or FLAGS @filename@ name of current input file Does yours? You might try moving /Library/Frameworks/GLib.framework/Resources/ dev/bin to the front of your path before make'ing pango -- cd pango-1.24.0 export PATH=/Library/Frameworks/GLib.framework/Resources/dev/bin: $PATH make Hope this helps, -Ross On Mar 21, 2009, at 1:52 PM, Colin Adams wrote: Attached. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: (taking this off list, to avoid noise) Could you attach pango-1.24.0/pango/pango-enum-types.h? Something hokey is going on -- this file is shipped with pango-1.24.0 but may be overwritten if your glib-mkenums does it differently. In any case, since it's (possibly) machine generated I would have to see what's going on at those lines to make progress. Also, if you could cd pango-1.24.0/pango, and run: gcc -E -DHAVE_CONFIG_H -I. -I.. -DG_LOG_DOMAIN=\Pango\ -DPANGO_ENABLE_BACKEND -DPANGO_ENABLE_ENGINE -DSYSCONFDIR=\/usr/local/etc\ -DLIBDIR=\/usr/local/lib\ -I.. -DG_DISABLE_CAST_CHECKS -I/Library/Frameworks/GLib.framework/Headers
Re: [Haskell-cafe] about beta NF in lambda calculus
Thus, if you use normal-order evaluation (which Haskell uses), you will inevitably reach the normal form if and only if it exists at all. So, if all you care about is the normal form (if you don't care about computation time), then terms that *have* an NF and terms that *are* in NF are indistinguishable for you in Haskell. 2009/3/21 Ryan Ingram ryani.s...@gmail.com: Given the Y combinator, Y (\x.x) has no normal form. However, (\a. (\x. x)) (Y (\x. x)) does have a normal form; (\x. x). But it only reduces to that normal form if you reduce the (\a. ...) redex, not if you reduce its argument. So depending on evaluation order you might not reach a normal form. -- ryan 2009/3/21 Algebras Math algebras2...@googlemail.com: hi, What is the different between 'in beta normal form' and 'has beta normal form' ? Does the former means the current form of the term is already in normal form but the latter means that it is not a normal form yet and can be reduced to be normal form? Like \x.x is in NF and (\x.x) (\x.x) has NF? If above is true, I am confused why we have to distinguish the terms which have NF and be in NF? isn't the terms have NF will eventually become in NF? or there are some way to avoid them becoming in NF? Thanks Alg ___ 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 -- 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] about beta NF in lambda calculus
On Sat, Mar 21, 2009 at 07:29:05PM +, Algebras Math wrote: If above is true, I am confused why we have to distinguish the terms which have NF and be in NF? isn't the terms have NF will eventually become in NF? or there are some way to avoid them becoming in NF? Spoken like a mathematician :) (Well, only sort of.) The way to avoid it is not to perform the work of beta conversion. Similarly, you may say that people are either dead or will eventually die, so why distinguish between a person who is dead and a mortal, live person? -- Antti-Juhani Kaijanaho, Jyväskylä, Finland http://antti-juhani.kaijanaho.fi/newblog/ http://www.flickr.com/photos/antti-juhani/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANNOUNCE: Haddock 2.4.2
-- Haddock 2.4.2 A new version of Haddock, the Haskell documentation tool, is out. This is a bug fix release only, and it's the same version that will ship with GHC 6.10.2, unless any important problems are discovered before the GHC release. Because the .haddock file format has changed, links to previously installed documentation will not work when generating documentation using this version. Please use the bug tracker to submit bug reports or feature requests. -- Changes in version 2.4.2 * Support for GHC 6.10.2 * Haddock no longer crashes on Template Haskell modules (#68) (only with GHC 6.10.2 or above) * Fix problem with Template Haskell-generated declarations disappearing (#59) * Generate two anchors for each link for compatibility between IE and Opera (#45) * Improved error messages * Show re-exports from external packages again (GHC ticket #2746) * Store hidden modules in .haddock files again (needed by the haddock library) * Avoid processing boot modules * Pragmas may exist between document comments and declarations * Do not indicate that a constructor argument is unboxed * Fix problem with non-working links to ghc-prim * Allow referring to a specific section within a module in a module link (#65) * Fixes to the Hoogle backend * Improvements to the haddock library * Many other fixes (including #67, #69, #58, #57) -- Links Homepage: http://www.haskell.org/haddock Hackage page: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/haddock-2.4.2 Bugtracker and wiki: http://trac.haskell.org/haddock Mailing list: hadd...@projects.haskell.org Code repository: http://code.haskell.org/haddock -- Contributors The following people contributed patches to this release: Joachim Breitner Roman Cheplyaka Ian Lynagh Neil Mitchell Simon Peyton-Jones Thomas Schilling David Waern -- Get Involved We welcome new contributors. To get involved, start by grabbing the code: http://code.haskell.org/haddock Then take a look at the bug and feature tracker for things to work on: http://trac.haskell.org/haddock ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] about beta NF in lambda calculus
Actually I was also going to provide exactly the same example, but hesitated to :) 2009/3/21 Antti-Juhani Kaijanaho antti-juh...@kaijanaho.fi: On Sat, Mar 21, 2009 at 07:29:05PM +, Algebras Math wrote: If above is true, I am confused why we have to distinguish the terms which have NF and be in NF? isn't the terms have NF will eventually become in NF? or there are some way to avoid them becoming in NF? Spoken like a mathematician :) (Well, only sort of.) The way to avoid it is not to perform the work of beta conversion. Similarly, you may say that people are either dead or will eventually die, so why distinguish between a person who is dead and a mortal, live person? -- Antti-Juhani Kaijanaho, Jyväskylä, Finland http://antti-juhani.kaijanaho.fi/newblog/ http://www.flickr.com/photos/antti-juhani/ ___ 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] Ease of Haskell development on OS X?
OK - I added the --with-user-pkginfo flag. It nearly all works now - but still no svgcairo - ./configure doesn't find it. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: (back to the list) Answers inline: On Mar 21, 2009, at 2:42 PM, Colin Adams wrote: Yes, that was the problem, and swapping the PATH order does the trick. Thanks. no prob. I must still have the macports stuff installed. Can you tell me how to get rid of it? if you really want to get rid of it I believe you just have to rm -rf /opt/local and remove any initialization hooks for /opt/local out of /etc/profile and ~/.bash_profile However I still can't install my program - I get missing dependencies for gtk glib cairo and svgcairo. I'm not really that savvy with the package registration magics -- on my system after doing sudo make install for gtk2hs, I get the packages properly registered. You can check the registered packages with ghc-pkg list. It could be that the package is registered local for your user, but the cabal install line you're using for the application includes --global (or your cabal configuration) so it won't look in the user config. I think Duncan answered some questions about this same problem recently, though I don't have a mailing list reference. I tried some of the gtk2hs demos - they work, but, for instance, the actionmenu demo does not put the menus up at the top of the screen, so it doesn't look like the framework integration has worked. Even with the integration everything is still GTK-ish. There's a separate framework that comes with the .dmg called ige-mac-integration that allows applications to meld with the mac environment better, but no gtk2hs bindings for this exist at the moment. Bindings would have to be created, and then you'd have to modify the application to make use of them (presumably with CPP or similar switch to control whether you want mac support, or just plain GTK) -Ross 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: I think there must be a version inconsistency with your GLib framework -- either not the most recent copy of the GTK+ DMG, or your path is flipped around and you're using a ports version. Run glib-mkenums --version to see what version you have... I have r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums --version glib-mkenums version glib-2.18.1 glib-mkenums comes with ABSOLUTELY NO WARRANTY. You may redistribute copies of glib-mkenums under the terms of the GNU General Public License which can be found in the GLib source package. Sources, examples and contact information are available at http://www.gtk.org Particularly, the error you're getting is because your version of glib-mkenums doesn't expand @ENUMPREFIX@ -- if I run glib-mkenums with no arguments, my version reports @ENUMPREFIX@ as a valid subtitution: r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums Usage: glib-mkenums [options] [files...] --fhead text output file header --fprod text per input file production --ftail text output file trailer --eprod text per enum text (produced prior to value itarations) --vhead text value header, produced before iterating over enum values --vprod text value text, produced for each enum value --vtail text value tail, produced after iterating over enum values --comments text comment structure --template file template file -h, --help show this help message -v, --version print version informations Production text substitutions: �...@enumname@ PrefixTheXEnum �...@enum_name@ prefix_the_xenum �...@enumname@ PREFIX_THE_XENUM �...@enumshort@ THE_XENUM �...@enumprefix@ PREFIX �...@valuename@ PREFIX_THE_XVALUE �...@valuenick@ the-xvalue �...@type@ either enum or flags �...@type@ either Enum or Flags �...@type@ either ENUM or FLAGS �...@filename@ name of current input file Does yours? You might try moving /Library/Frameworks/GLib.framework/Resources/dev/bin to the front of your path before make'ing pango -- cd pango-1.24.0 export PATH=/Library/Frameworks/GLib.framework/Resources/dev/bin:$PATH make Hope this helps, -Ross On Mar 21, 2009, at 1:52 PM, Colin Adams wrote: Attached. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: (taking this off list, to avoid noise) Could you attach pango-1.24.0/pango/pango-enum-types.h? Something hokey is going on -- this file is shipped with pango-1.24.0 but may be overwritten if your glib-mkenums does it differently. In any case, since it's (possibly) machine generated I would have to see what's going on at those lines to make progress. Also, if you could cd pango-1.24.0/pango, and run: gcc
Re: [Haskell-cafe] Ease of Haskell development on OS X?
Did the configure for gtk2hs claim that it was going to build svgcairo? If something is wrong with the librsvg install, it won't. -Ross On Mar 21, 2009, at 4:49 PM, Colin Adams wrote: OK - I added the --with-user-pkginfo flag. It nearly all works now - but still no svgcairo - ./configure doesn't find it. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: (back to the list) Answers inline: On Mar 21, 2009, at 2:42 PM, Colin Adams wrote: Yes, that was the problem, and swapping the PATH order does the trick. Thanks. no prob. I must still have the macports stuff installed. Can you tell me how to get rid of it? if you really want to get rid of it I believe you just have to rm -rf /opt/local and remove any initialization hooks for /opt/local out of /etc/profile and ~/.bash_profile However I still can't install my program - I get missing dependencies for gtk glib cairo and svgcairo. I'm not really that savvy with the package registration magics -- on my system after doing sudo make install for gtk2hs, I get the packages properly registered. You can check the registered packages with ghc-pkg list. It could be that the package is registered local for your user, but the cabal install line you're using for the application includes --global (or your cabal configuration) so it won't look in the user config. I think Duncan answered some questions about this same problem recently, though I don't have a mailing list reference. I tried some of the gtk2hs demos - they work, but, for instance, the actionmenu demo does not put the menus up at the top of the screen, so it doesn't look like the framework integration has worked. Even with the integration everything is still GTK-ish. There's a separate framework that comes with the .dmg called ige-mac-integration that allows applications to meld with the mac environment better, but no gtk2hs bindings for this exist at the moment. Bindings would have to be created, and then you'd have to modify the application to make use of them (presumably with CPP or similar switch to control whether you want mac support, or just plain GTK) -Ross 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: I think there must be a version inconsistency with your GLib framework -- either not the most recent copy of the GTK+ DMG, or your path is flipped around and you're using a ports version. Run glib-mkenums --version to see what version you have... I have r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums --version glib-mkenums version glib-2.18.1 glib-mkenums comes with ABSOLUTELY NO WARRANTY. You may redistribute copies of glib-mkenums under the terms of the GNU General Public License which can be found in the GLib source package. Sources, examples and contact information are available at http://www.gtk.org Particularly, the error you're getting is because your version of glib-mkenums doesn't expand @ENUMPREFIX@ -- if I run glib-mkenums with no arguments, my version reports @ENUMPREFIX@ as a valid subtitution: r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums Usage: glib-mkenums [options] [files...] --fhead text output file header --fprod text per input file production --ftail text output file trailer --eprod text per enum text (produced prior to value itarations) --vhead text value header, produced before iterating over enum values --vprod text value text, produced for each enum value --vtail text value tail, produced after iterating over enum values --comments text comment structure --template filetemplate file -h, --help show this help message -v, --version print version informations Production text substitutions: @EnumName@ PrefixTheXEnum @enum_name@prefix_the_xenum @ENUMNAME@ PREFIX_THE_XENUM @ENUMSHORT@THE_XENUM @ENUMPREFIX@ PREFIX @VALUENAME@PREFIX_THE_XVALUE @valuenick@the-xvalue @type@ either enum or flags @Type@ either Enum or Flags @TYPE@ either ENUM or FLAGS @filename@ name of current input file Does yours? You might try moving /Library/Frameworks/GLib.framework/Resources/ dev/bin to the front of your path before make'ing pango -- cd pango-1.24.0 export PATH=/Library/Frameworks/GLib.framework/Resources/dev/bin: $PATH make Hope this helps, -Ross On Mar 21, 2009, at 1:52 PM, Colin Adams wrote: Attached. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: (taking this off list, to avoid noise) Could you attach pango-1.24.0/pango/pango-enum-types.h? Something hokey is going on -- this file is shipped with pango-1.24.0 but may be overwritten if your glib-mkenums does it differently. In any case, since it's (possibly) machine
Re: [Haskell-cafe] Ease of Haskell development on OS X?
It didn't. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: Did the configure for gtk2hs claim that it was going to build svgcairo? If something is wrong with the librsvg install, it won't. -Ross On Mar 21, 2009, at 4:49 PM, Colin Adams wrote: OK - I added the --with-user-pkginfo flag. It nearly all works now - but still no svgcairo - ./configure doesn't find it. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: (back to the list) Answers inline: On Mar 21, 2009, at 2:42 PM, Colin Adams wrote: Yes, that was the problem, and swapping the PATH order does the trick. Thanks. no prob. I must still have the macports stuff installed. Can you tell me how to get rid of it? if you really want to get rid of it I believe you just have to rm -rf /opt/local and remove any initialization hooks for /opt/local out of /etc/profile and ~/.bash_profile However I still can't install my program - I get missing dependencies for gtk glib cairo and svgcairo. I'm not really that savvy with the package registration magics -- on my system after doing sudo make install for gtk2hs, I get the packages properly registered. You can check the registered packages with ghc-pkg list. It could be that the package is registered local for your user, but the cabal install line you're using for the application includes --global (or your cabal configuration) so it won't look in the user config. I think Duncan answered some questions about this same problem recently, though I don't have a mailing list reference. I tried some of the gtk2hs demos - they work, but, for instance, the actionmenu demo does not put the menus up at the top of the screen, so it doesn't look like the framework integration has worked. Even with the integration everything is still GTK-ish. There's a separate framework that comes with the .dmg called ige-mac-integration that allows applications to meld with the mac environment better, but no gtk2hs bindings for this exist at the moment. Bindings would have to be created, and then you'd have to modify the application to make use of them (presumably with CPP or similar switch to control whether you want mac support, or just plain GTK) -Ross 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: I think there must be a version inconsistency with your GLib framework -- either not the most recent copy of the GTK+ DMG, or your path is flipped around and you're using a ports version. Run glib-mkenums --version to see what version you have... I have r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums --version glib-mkenums version glib-2.18.1 glib-mkenums comes with ABSOLUTELY NO WARRANTY. You may redistribute copies of glib-mkenums under the terms of the GNU General Public License which can be found in the GLib source package. Sources, examples and contact information are available at http://www.gtk.org Particularly, the error you're getting is because your version of glib-mkenums doesn't expand @ENUMPREFIX@ -- if I run glib-mkenums with no arguments, my version reports @ENUMPREFIX@ as a valid subtitution: r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums Usage: glib-mkenums [options] [files...] --fhead text output file header --fprod text per input file production --ftail text output file trailer --eprod text per enum text (produced prior to value itarations) --vhead text value header, produced before iterating over enum values --vprod text value text, produced for each enum value --vtail text value tail, produced after iterating over enum values --comments text comment structure --template file template file -h, --help show this help message -v, --version print version informations Production text substitutions: �...@enumname@ PrefixTheXEnum �...@enum_name@ prefix_the_xenum �...@enumname@ PREFIX_THE_XENUM �...@enumshort@ THE_XENUM �...@enumprefix@ PREFIX �...@valuename@ PREFIX_THE_XVALUE �...@valuenick@ the-xvalue �...@type@ either enum or flags �...@type@ either Enum or Flags �...@type@ either ENUM or FLAGS �...@filename@ name of current input file Does yours? You might try moving /Library/Frameworks/GLib.framework/Resources/dev/bin to the front of your path before make'ing pango -- cd pango-1.24.0 export PATH=/Library/Frameworks/GLib.framework/Resources/dev/bin:$PATH make Hope this helps, -Ross On Mar 21, 2009, at 1:52 PM, Colin Adams wrote: Attached. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: (taking this off list, to avoid noise) Could you attach pango-1.24.0/pango/pango-enum-types.h? Something hokey is going on -- this file is shipped with
Re: [Haskell-cafe] Ease of Haskell development on OS X?
And the reason is that librsvg fails to find cairo, pangocairo and cairo-png. Where is it supposed to find them? 2009/3/21 Colin Adams colinpaulad...@googlemail.com: It didn't. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: Did the configure for gtk2hs claim that it was going to build svgcairo? If something is wrong with the librsvg install, it won't. -Ross On Mar 21, 2009, at 4:49 PM, Colin Adams wrote: OK - I added the --with-user-pkginfo flag. It nearly all works now - but still no svgcairo - ./configure doesn't find it. 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: (back to the list) Answers inline: On Mar 21, 2009, at 2:42 PM, Colin Adams wrote: Yes, that was the problem, and swapping the PATH order does the trick. Thanks. no prob. I must still have the macports stuff installed. Can you tell me how to get rid of it? if you really want to get rid of it I believe you just have to rm -rf /opt/local and remove any initialization hooks for /opt/local out of /etc/profile and ~/.bash_profile However I still can't install my program - I get missing dependencies for gtk glib cairo and svgcairo. I'm not really that savvy with the package registration magics -- on my system after doing sudo make install for gtk2hs, I get the packages properly registered. You can check the registered packages with ghc-pkg list. It could be that the package is registered local for your user, but the cabal install line you're using for the application includes --global (or your cabal configuration) so it won't look in the user config. I think Duncan answered some questions about this same problem recently, though I don't have a mailing list reference. I tried some of the gtk2hs demos - they work, but, for instance, the actionmenu demo does not put the menus up at the top of the screen, so it doesn't look like the framework integration has worked. Even with the integration everything is still GTK-ish. There's a separate framework that comes with the .dmg called ige-mac-integration that allows applications to meld with the mac environment better, but no gtk2hs bindings for this exist at the moment. Bindings would have to be created, and then you'd have to modify the application to make use of them (presumably with CPP or similar switch to control whether you want mac support, or just plain GTK) -Ross 2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac: I think there must be a version inconsistency with your GLib framework -- either not the most recent copy of the GTK+ DMG, or your path is flipped around and you're using a ports version. Run glib-mkenums --version to see what version you have... I have r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums --version glib-mkenums version glib-2.18.1 glib-mkenums comes with ABSOLUTELY NO WARRANTY. You may redistribute copies of glib-mkenums under the terms of the GNU General Public License which can be found in the GLib source package. Sources, examples and contact information are available at http://www.gtk.org Particularly, the error you're getting is because your version of glib-mkenums doesn't expand @ENUMPREFIX@ -- if I run glib-mkenums with no arguments, my version reports @ENUMPREFIX@ as a valid subtitution: r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-mkenums Usage: glib-mkenums [options] [files...] --fhead text output file header --fprod text per input file production --ftail text output file trailer --eprod text per enum text (produced prior to value itarations) --vhead text value header, produced before iterating over enum values --vprod text value text, produced for each enum value --vtail text value tail, produced after iterating over enum values --comments text comment structure --template file template file -h, --help show this help message -v, --version print version informations Production text substitutions: �...@enumname@ PrefixTheXEnum �...@enum_name@ prefix_the_xenum �...@enumname@ PREFIX_THE_XENUM �...@enumshort@ THE_XENUM �...@enumprefix@ PREFIX �...@valuename@ PREFIX_THE_XVALUE �...@valuenick@ the-xvalue �...@type@ either enum or flags �...@type@ either Enum or Flags �...@type@ either ENUM or FLAGS �...@filename@ name of current input file Does yours? You might try moving /Library/Frameworks/GLib.framework/Resources/dev/bin to the front of your path before make'ing pango -- cd pango-1.24.0 export PATH=/Library/Frameworks/GLib.framework/Resources/dev/bin:$PATH make Hope this helps, -Ross On Mar 21, 2009, at 1:52 PM, Colin Adams wrote: Attached. 2009/3/21 Ross Mellgren
Re: [Haskell-cafe] Ease of Haskell development on OS X?
Should be from pkg-config path, make sure your PKG_CONFIG_PATH is set
to include /Library/Frameworks/{GLib,Gtk,Cairo}.framework
Also, I had a problem where it couldn't find libpng -- I had to add /
usr/X11/lib/pkgconfig to my pkg-config path.
-Ross
On Mar 21, 2009, at 5:02 PM, Colin Adams wrote:
And the reason is that librsvg fails to find cairo, pangocairo and
cairo-png.
Where is it supposed to find them?
2009/3/21 Colin Adams colinpaulad...@googlemail.com:
It didn't.
2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac:
Did the configure for gtk2hs claim that it was going to build
svgcairo? If
something is wrong with the librsvg install, it won't.
-Ross
On Mar 21, 2009, at 4:49 PM, Colin Adams wrote:
OK - I added the --with-user-pkginfo flag.
It nearly all works now - but still no svgcairo - ./configure
doesn't find
it.
2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac:
(back to the list)
Answers inline:
On Mar 21, 2009, at 2:42 PM, Colin Adams wrote:
Yes, that was the problem, and swapping the PATH order does the
trick.
Thanks.
no prob.
I must still have the macports stuff installed. Can you tell me
how to
get rid of it?
if you really want to get rid of it I believe you just have to
rm -rf
/opt/local and remove any initialization hooks for /opt/local
out of
/etc/profile and ~/.bash_profile
However I still can't install my program - I get missing
dependencies
for gtk glib cairo and svgcairo.
I'm not really that savvy with the package registration magics
-- on my
system after doing sudo make install for gtk2hs, I get the
packages
properly
registered. You can check the registered packages with ghc-pkg
list. It
could be that the package is registered local for your user, but
the
cabal
install line you're using for the application includes --global
(or your
cabal configuration) so it won't look in the user config.
I think Duncan answered some questions about this same problem
recently,
though I don't have a mailing list reference.
I tried some of the gtk2hs demos - they work, but, for
instance, the
actionmenu demo does not put the menus up at the top of the
screen, so
it doesn't look like the framework integration has worked.
Even with the integration everything is still GTK-ish. There's a
separate
framework that comes with the .dmg called ige-mac-integration
that allows
applications to meld with the mac environment better, but no
gtk2hs
bindings
for this exist at the moment. Bindings would have to be created,
and then
you'd have to modify the application to make use of them
(presumably with
CPP or similar switch to control whether you want mac support,
or just
plain
GTK)
-Ross
2009/3/21 Ross Mellgren rmm-hask...@z.odi.ac:
I think there must be a version inconsistency with your GLib
framework
--
either not the most recent copy of the GTK+ DMG, or your path is
flipped
around and you're using a ports version.
Run glib-mkenums --version to see what version you have... I
have
r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-
mkenums
--version
glib-mkenums version glib-2.18.1
glib-mkenums comes with ABSOLUTELY NO WARRANTY.
You may redistribute copies of glib-mkenums under the terms of
the GNU General Public License which can be found in the
GLib source package. Sources, examples and contact
information are available at http://www.gtk.org
Particularly, the error you're getting is because your version
of
glib-mkenums doesn't expand @ENUMPREFIX@ -- if I run glib-
mkenums with
no
arguments, my version reports @ENUMPREFIX@ as a valid
subtitution:
r...@hugo:~/tmpgtk/GLib.framework/Resources/dev/bin$ ./glib-
mkenums
Usage: glib-mkenums [options] [files...]
--fhead text output file header
--fprod text per input file production
--ftail text output file trailer
--eprod text per enum text (produced prior to
value
itarations)
--vhead text value header, produced before
iterating
over
enum values
--vprod text value text, produced for each enum
value
--vtail text value tail, produced after
iterating over
enum
values
--comments text comment structure
--template filetemplate file
-h, --help show this help message
-v, --version print version informations
Production text substitutions:
@EnumName@ PrefixTheXEnum
@enum_name@prefix_the_xenum
@ENUMNAME@ PREFIX_THE_XENUM
@ENUMSHORT@THE_XENUM
@ENUMPREFIX@ PREFIX
@VALUENAME@PREFIX_THE_XVALUE
@valuenick@the-xvalue
@type@ either enum or flags
@Type@ either Enum or Flags
@TYPE@ either ENUM or FLAGS
@filename@ name of current input file
Does yours?
You might try moving
/Library/Frameworks/GLib.framework/Resources/dev/bin
to
[Haskell-cafe] Re: Ease of Haskell development on OS X?
Ross Mellgren rmm-hask...@z.odi.ac wrote: Way too many, definitely. -- (c) this sig last receiving data processing entity. Inspect headers for copyright history. All rights reserved. Copying, hiring, renting, performance and/or quoting of this signature prohibited. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Haskell Logo write-in candidate
Achim Schneider bars...@web.de writes: :: might be truly Haskell in the sense that everybody else uses plain :, but I don't want Haskell to be associated with squareness, and typing, by itself, is hardly a distinguishing property of Haskell. I guess laziness is the most distinguishing property, and there's no symbol associated with that. How about having no logo, symbolizing laziness? It somehow feels oddly appropriate... -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] ghci + hopengl
I've had issues with ghci and opengl... I usually have to compile my programs before they will run. I'm not sure why that's the case, but I too get strange window behavior (sometimes it freezes, other times it doesn't even show up). If you're on a Mac and would like help compiling to a .app folder, let me know and I can post how I did that. Regards, Duane Johnson http://blog.inquirylabs.com/ On Mar 21, 2009, at 1:27 PM, Rafael Cunha de Almeida wrote: Hello, I'm writing a program for plotting vectorial functions and maybe something else in the future. My goal is to be able to have the following usage: Prelude :l Galo.hs Prelude Galo show3Dvec (\t - (t, t, 0)) [0.0,0.01 .. 1.0] * shows graph * Prelude Galo show3Dvec (\t - (t, t**2, 0)) [0.0,0.01 .. 1.0] * shows new graph * I already done something, the main module can be found here: http://github.com/aflag/galo/blob/0a54a53db0f66384cfc0775f12582931d0fb4205/Galo.hs The whole project is found here: http://github.com/aflag/galo/tree/master I think mainLoop is somehow responsible to exit the whole thing. I tried to even call that function through forkIO. But didn't work quite well: my terminal started behaving really weird after I closed the window. Could you explain me what is going on and what should I look into for understanding how to solve the issue? []'s Rafael ___ 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] Cabal properties with conditionals
On Sat, 2009-03-21 at 14:26 +0100, Manlio Perillo wrote: Hi. Assuming this configuration fragment: library xxx cc-options: -Wall if flag(HAVE_URANDOM) cc-options:-DHAVE_URANDOM In case the HAVE_URANDOM flag is defined, what will be the value of the used cc-options? 1) -DHAHE_URANDOM 2) -Wall -DHAHE_URANDOM The latter. Try it. In general all fields get `mappend`ed which for list-like fields means appending. For single value fields like True/False then latter fields win. Duncan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [ANN] Safe Lazy IO in Haskell
On Fri, 20 Mar 2009, Nicolas Pouillard wrote: Hi folks, We have good news (nevertheless we hope) for all the lazy guys standing there. Since their birth, lazy IOs have been a great way to modularly leverage all the good things we have with *pure*, *lazy*, *Haskell* functions to the real world of files. Maybe you know of my packages lazy-io and explicit-exception which also aim at lazy I/O and asynchronous exception handling. With lazy-io, you are able to write more complicated things than getContents. I needed this for HTTP communication that is run by demand. That is when the HTTP response header is requested, then the function could send a HTTP request first. Is it possible and sensible to combine this with safe-lazy-io? http://hackage.haskell.org/cgi-bin/hackage-scripts/package/lazyio http://hackage.haskell.org/cgi-bin/hackage-scripts/package/explicit-exception I have also code that demonstrates the usage of explicit asynchronous exceptions. I have however still not a set of combinators that makes working with asynchronous exceptions as simple as working with synchronous ones: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/spreadsheet ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] New Cabal FAQ
Hi all, I should have done this ages ago but there's now a Cabal FAQ on the Cabal website: http://haskell.org/cabal/FAQ.html It's not linked in yet, I'm looking for feedback and patches. The Cabal website is now maintained in darcs so it's easy to send in contributions: darcs get http://haskell.org/cabal/ For new pages like the FAQ I've been using markdown via pandoc. If appropriate we can migrate old pages to use that too. The main Cabal home page needs some love. We should have the cabal-install download directly on the front page. We should have quick intro tutorials for using the cabal command line program to install packages. There's lots of good material in the user guide but it is not well sign-posted. Duncan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Haskell Logo write-in candidate
On Fri, 20 Mar 2009, Jon Fairbairn wrote: ::Haskell See the lamp in logo 33 at http://www.haskell.org/logos/poll.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Cabal properties with conditionals
Duncan Coutts ha scritto: On Sat, 2009-03-21 at 14:26 +0100, Manlio Perillo wrote: Hi. Assuming this configuration fragment: library xxx cc-options: -Wall if flag(HAVE_URANDOM) cc-options:-DHAVE_URANDOM In case the HAVE_URANDOM flag is defined, what will be the value of the used cc-options? 1) -DHAHE_URANDOM 2) -Wall -DHAHE_URANDOM The latter. Try it. In general all fields get `mappend`ed which for list-like fields means appending. For single value fields like True/False then latter fields win. Ok, thanks. P.S: I tried to send an email to cabal-devel some days ago, with a feature I would like to see in Cabal. But the mail was never posted to the mailing list. Is that list moderated? Should I simply fill a ticket? Duncan Manlio ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] New Cabal FAQ
As a new Haskell user, I have to heartily agree about the sign-posts. Cabal is a superb, easy-to-use command-line tool for Haskell package management, but browsing various getting started with Haskell pages didn't lead me to clear instructions that cabal exists and that it is really important to install. In addition, may I suggest that the very first thing under Quick Links at http://haskell.org/cabal/ should be the following: Get Cabal Currently, the first link is How to install a Cabal package which was quite confusing for me as a new user, since I knew I wanted the cabal command on my system and that getting it is a prerequisite to installing cabal packages. Next, in a round-about manner, the link sends the user to http://haskell.org/haskellwiki/Cabal/How_to_install_a_Cabal_package which is fairly dense reading considering that the user is just trying to get cabal. At the bottom of the third paragraph of that page, it links to http://haskell.org/haskellwiki/Cabal-Install. The Cabal-Install page itself provides an introduction paragraph stating that there exists a caball-install package which sounds enticing--- but wait, is it a package? Doesn't that mean I need cabal to install cabal-install? What's going on here Strangely, the Usage section is listed before the Installation section which further confounded me until I read everything carefully. So in retrospect, I would have very much appreciated something like this (my blog entry to future Haskellers). Perhaps we could create the Get Cabal page and split it down the middle, one side for Windows and one side for Mac OS X / Linux / Unix. It should be very minimal and have all of the necessary steps first with commentary later in case things go wrong or the visitor decides to return for details. It also might be a good idea to use the cabal-specific pages on the wiki to redirect the user to the official cabal page where the official instructions reside since they show up in Google searches Duane Johnson http://blog.inquirylabs.com/ On Mar 21, 2009, at 3:44 PM, Duncan Coutts wrote: Hi all, I should have done this ages ago but there's now a Cabal FAQ on the Cabal website: http://haskell.org/cabal/FAQ.html It's not linked in yet, I'm looking for feedback and patches. The Cabal website is now maintained in darcs so it's easy to send in contributions: darcs get http://haskell.org/cabal/ For new pages like the FAQ I've been using markdown via pandoc. If appropriate we can migrate old pages to use that too. The main Cabal home page needs some love. We should have the cabal-install download directly on the front page. We should have quick intro tutorials for using the cabal command line program to install packages. There's lots of good material in the user guide but it is not well sign-posted. Duncan ___ 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] Google Summer of Code: Is this idea useful for the community?
I'm planning on applying for the Google Summer of Code and the more I think about it, the more excited I am over a Haskell reddit-alike[1]. I'm interested in web programming, Haskell, and reddit (being an addict for some years now). There's plenty of work to be done on such a project, there are existing code bases to help along with ideas, and it doesn't require the deepest knowledge of Haskell or, say, GHC's guts (not that I don't find those interesting, I'm just no expert). The hang-up I see is that there's not too much of an immediate community benefit if reddit already exists (which, I have on good authority, it does), other than in the interest of eating (or customizing) your own dog food. Any members of the Haskell community (more involved than I am) care to comment? Would the project be useful or otherwise good as a Summer of Code idea? If people don't get too sick of my pestering, I'm also considering opening it up as a ticket on the trac to see if it gets feedback there. Thanks! [1] http://www.reddit.com/r/haskell_proposals/comments/7u48x/a_simple_redditlike_happsbased_proposal_voting/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Cabal properties with conditionals
On Sat, 2009-03-21 at 23:05 +0100, Manlio Perillo wrote: P.S: I tried to send an email to cabal-devel some days ago, with a feature I would like to see in Cabal. But the mail was never posted to the mailing list. Is that list moderated? It's subscriber only, like all the haskell.org mailing lists. We got too much spam otherwise. :-( Should I simply fill a ticket? Yes, thanks very much. Duncan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Cabal properties with conditionals
Duncan Coutts ha scritto: On Sat, 2009-03-21 at 23:05 +0100, Manlio Perillo wrote: P.S: I tried to send an email to cabal-devel some days ago, with a feature I would like to see in Cabal. But the mail was never posted to the mailing list. Is that list moderated? It's subscriber only, like all the haskell.org mailing lists. We got too much spam otherwise. :-( But I did subscribed! Should I simply fill a ticket? Yes, thanks very much. Ok. I posted some details in this thread: http://www.haskell.org/pipermail/haskell-cafe/2009-March/057923.html Duncan Manlio ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Sometimes I wish there was a global variable
Hello, I am writing a OpenGL program in haskell, it can be found in: http://github.com/aflag/galo/tree/master But I hope this e-mail will be self-contained :). My main function goes like this: (...) rotX - newIORef (0.0::GLfloat) rotY - newIORef (0.0::GLfloat) pos - newIORef (0.0::GLfloat, 0.0, 0.0) displayCallback $= display (map f range) rotX rotY pos keyboardMouseCallback $= Just (keyboardMouse rotX rotY pos) (...) Notice that rotX, rotY and pos are meant to be used as comunication between the keyboardMouse and display functions. They need to be set as 0 first, so display won't do anything. Only when they user press a few buttons that those values change, so display behaves accordanly. In a state-based language I would place display and keyboardMouse in one module and let them communcate to each other like they want. In haskell, I'm not quite sure how to do it except by that parameter passing style. I thought about how state-monad may help with that. But I'm not sure how I'd make the state variable to be contained inside a display/keyboardMouse module. []'s Rafael ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Cabal properties with conditionals
On Sun, 2009-03-22 at 01:03 +0100, Manlio Perillo wrote: Duncan Coutts ha scritto: On Sat, 2009-03-21 at 23:05 +0100, Manlio Perillo wrote: P.S: I tried to send an email to cabal-devel some days ago, with a feature I would like to see in Cabal. But the mail was never posted to the mailing list. Is that list moderated? It's subscriber only, like all the haskell.org mailing lists. We got too much spam otherwise. :-( But I did subscribed! Oh, then it should just work. There's nothing stuck in the moderation queue, I've checked (the only things that get moderated are posts from subscribers with very large attachments). Should I simply fill a ticket? Yes, thanks very much. Ok. I posted some details in this thread: http://www.haskell.org/pipermail/haskell-cafe/2009-March/057923.html Ok, great. A feature request ticket about that would be good. Duncan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Haskell Logo write-in candidate
but the rest of it looks like a fat lady bending over. 2009/3/21 Henning Thielemann lemm...@henning-thielemann.de On Fri, 20 Mar 2009, Jon Fairbairn wrote: ::Haskell See the lamp in logo 33 at http://www.haskell.org/logos/poll.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- We can't solve problems by using the same kind of thinking we used when we created them. - A. Einstein ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Sometimes I wish there was a global variable
Notice that rotX, rotY and pos are meant to be used as comunication
between the keyboardMouse and display functions. They need to be set as
0 first, so display won't do anything. Only when they user press a few
buttons that those values change, so display behaves accordanly.
In a state-based language I would place display and keyboardMouse in one
module and let them communcate to each other like they want. In haskell,
I'm not quite sure how to do it except by that parameter passing style.
In one module, you can write:
--
giveMeFunctions = do {
newIORef ...
newIORef ...
newIORef ...
(...)
let f1 = ...
let f2 = ...
return (f1,f2)
--
and in the main:
(keyboardMouse,display) - giveMeFunctions
Best,
Maurício
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Re: [Haskell-cafe] Sometimes I wish there was a global variable
Rafael Cunha de Almeida almeida...@gmail.com writes:
My main function goes like this:
(...)
rotX - newIORef (0.0::GLfloat)
rotY - newIORef (0.0::GLfloat)
pos - newIORef (0.0::GLfloat, 0.0, 0.0)
displayCallback $= display (map f range) rotX rotY pos
keyboardMouseCallback $= Just (keyboardMouse rotX rotY pos)
(...)
...
In a state-based language I would place display and keyboardMouse in one
module and let them communcate to each other like they want. In haskell,
I'm not quite sure how to do it except by that parameter passing style.
You could try something like this: (and apologies in advance for any
typoes)
import Control.Concurrent.MVar
data MyState = MyState {
rotX :: GLFloat
, rotY :: GLFloat
, pos :: (GLFloat,GLFloat)
}
myDisplayCallback :: MVar MyState - IO ()
myDisplayCallback =
flip modifyMVar_ $ \(MyState rx ry p) - do
(newRx, newRy, newP) - yourCodeGoesHere
return $ MyState newRx newRy newP
main = do
mvar - newMVar $ MyState 0 0 (0,0)
displayCallback $= myDisplayCallback mvar
...
Cheers,
G.
--
Gregory Collins g...@gregorycollins.net
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