- Haskell - Haskell.org

Instantiating MonadPlus from ArrowApply and ArrowPlus
by Daniel Franke 01 May '07

01 May '07

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Is there any reason that the following is not defined in Control.Arrow? instance (ArrowApply a, ArrowPlus a) => MonadPlus (ArrowMonad a) where mzero = ArrowMonad zeroArrow mplus (ArrowMonad a) (ArrowMonad b) = ArrowMonad (a <+> b) - -- Daniel Franke df(a)dfranke.us http://www.dfranke.us |----| =|\ \\\\ || * | -|-\--------- Man is free at the instant he wants to be. -----| =| \ /// --Voltaire -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFGNsTlKTA17JAC/eYRAjE4AJ9QSyjYXGs2ZNgGLp6rh3Gc3qP5hgCfXMYW mOU9DtZ0A54h1KIJ35q2HsQ= =2Rs0 -----END PGP SIGNATURE-----

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how to include GHC/Hugs specific module/function?
by Paul L 30 Apr '07

30 Apr '07

What I'm trying to do is something like below, except that #ifdef doesn't really work.. #ifdef __GLASGOW_HASKELL__ import GHC.Prim unsafePtrEq = reallyUnsafePtrEquality# #endif #ifdef __HUGS__ import Hugs.IOExts (unsafePtrEq) #endif Any help is greated appreciated! Regards, Paul Liu

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ANN: The Monad.Reader - Issue7
by Wouter Swierstra 30 Apr '07

30 Apr '07

I am pleased to announce that the latest issue of The Monad.Reader is now available: http://www.haskell.org/haskellwiki/The_Monad.Reader Issue 7 consists of the following four articles: * Matthew Naylor A Recipe for controlling Lego using Lava * Yaron Minsky Caml Trading: Experiences in Functional Programming on Wall Street * Duncan Coutts Book Review: “Programming in Haskell” by Graham Hutton * Dimitry Golubovsky, Neil Mitchell, Matthew Naylor Yhc.Core – from Haskell to Core The Monad.Reader is a quarterly magazine about functional programming. It is less-formal than journal, but somehow more enduring than a wiki page or blog post. If you'd like to submit something to the next issue of The Monad.Reader, please get in touch. I haven't fixed the deadline for the next issue just yet; I hope to send out an official call for copy in the coming weeks. Wouter This message has been checked for viruses but the contents of an attachment may still contain software viruses, which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation.

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Newbie: what are the advantages of Haskell?
by phiroc＠free.fr 30 Apr '07

30 Apr '07

Hello, what are the advantages of haskell over semi-functional programming languages such as Perl, Common Lisp, etc.? What are the mysterious "side effects" which are avoided by using Haskell, which everyone talks about? Null pointers? Don't you ever get null pointers in Haskell, including when doing IO? Aren't Haskell's advantages outweighed by its complexity (Monads, etc.) and rigidity? Last but not least, I would like to learn from those among you who are former PERL developers, why you switched to Haskell. Many thanks. phiroc

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ANNOUNCE: photoname
by Dino Morelli 29 Apr '07

29 Apr '07

photoname - rename and move photo files based on EXIF data photoname is a command-line utility for renaming/moving photo image files. The new folder location and naming are determined by two things: the photo shoot date information contained within the file's EXIF tags and the usually-camera-assigned serial number, often appearing in the filename. This software requires Bjorn Bringert's exif binding library to build. (http://www.cs.chalmers.se/~bringert/darcs/haskell-exif/doc/) get photoname: darcs get http://ui3.info/darcs/photoname http://ui3.info/d/proj/photoname.html Binary available as well for Debian i386 users: http://ui3.info/d/proj/photoname/photoname_002-1_i386.deb -- .~. Dino Morelli /V\ email: dino(a)ui3.info /( )\ irc: dino- ^^-^^ preferred distro: Debian GNU/Linux http://www.debian.org

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Re: Newbie: what are the advantages of Haskell?
by Taillefer, Troy (EXP) 28 Apr '07

28 Apr '07

Mike, It has affected my Java/C/C++ programming a lot. 1. I am much more careful how I combine ( inherit, compose, aggregate ) code because of potential side affects 2. It has helped to find certain types of bugs in Java code more easily that come up because of subtle effects introduced by combining code together 3. It has helped me to write code that is more composable 4. Haskell has increased my awareness of how important type safety is So I use Java Generics more now to enforce more type safety when I can (sometimes I am stuck deploying to java 1.4) (I also use C++ templates to do the same thing for C++) But these are often feel like hacks Haskell's type system is a thing of pure beauty haven't seen anything quite like it in any other PL (ML and OCAML are as close as I have seen but still fall short) and Generics and Templates really can't compare You really want the compiler to help you out as much it can. Have it tell you when you are doing something that you shouldn't be doing. By the way Mike thanks you just totally cheered me up I guess I just needed to sit back and think about what I have learned and how valuable it is to me. Troy -----Original Message----- From: haskell-bounces(a)haskell.org [mailto:haskell-bounces@haskell.org] On Behalf Of mike clemow Sent: Friday, April 27, 2007 4:16 PM To: haskell(a)haskell.org Subject: Re: [Haskell] Re: Newbie: what are the advantages of Haskell? Troy, As a Java chimp embarking on the Haskell journey myself, I'd be interested in hearing about specific ways that learning Haskell has changed the way you program Java. How do you employ the "very interesting concepts" that you have learned through your study of Haskell in your Java programming? Do you employ them at all? _Can_ they be employed in Java? Has it made you a better Java programmer? Cheers, Mike On 4/27/07, Taillefer, Troy (EXP) <troy.taillefer(a)lmco.com> wrote: > >Admittedly, this is phrased in an inflammatory manner, however, the > original sentiment >>is actually pointing out an advantage of Java > over Haskell. Here is the original >>>.paragraph in context: > > This not the first inflammatory comment he has made > > >>But, Sebastian is right. > Sebastian will be right when I see Chimpanzees coding in Java :) > > >> The leap is worth it. > I am not so sure it was for me. > I guess It depends on what you are looking for I have spent the last > year learning Haskell and I have learned some very interesting concepts. > I can't help but wish that Haskell turned out to be a more practical > language for me to code something useful in every time I looked for > Haskell libraries I was a disappointed. > I can't help feeling that last year might have been better spent > learning Erlang (which is this years language for me to learn). > > I really enjoy Functional programming (at least until I try to do > something serious then frustration sets in). I can't produce software > in a timely and cost effective fashion without a large body of high > quality, documented and maintained libraries. > > I get the feeling that Haskell is for researchers to explore ideas > about programming in but no one is interested in doing The grind work > of cranking out useful basic libraries. > I guess you need borrow some of those Java Chimps :). > > Am I the only person on the list that feels this way ? > > I guess I am feeling a bit bitter of spending so much time on Haskell > and having so little to show for it. > > Troy > > > -----Original Message----- > From: haskell-bounces(a)haskell.org [mailto:haskell-bounces@haskell.org] > On Behalf Of Al Falloon > Sent: Friday, April 27, 2007 12:19 PM > To: haskell(a)haskell.org > Cc: haskell(a)haskell.org > Subject: [Haskell] Re: Newbie: what are the advantages of Haskell? > > Taillefer, Troy (EXP) wrote: > > Java sense (i.e. "cut out any feature that can't be understood in > > five > > > minutes by a chimp") > > > > Got to love comments like this they are constructive, objective, > > mature and accurate. > > > > Glad we have your expert opinion to give us the gospel. > > > > Can I get an amen? How about a Hallelujah ? > > Admittedly, this is phrased in an inflammatory manner, however, the > original sentiment is actually pointing out an advantage of Java over > Haskell. Here is the original paragraph in context: > > Sebastian Sylvan wrote: > > I can sometimes feel that Haskell looses out on not being user > > friendly in the Java sense (i.e. "cut out any feature that can't be > > understood in five minutes by a chimp"). Some things do take some > > effort to learn, but there is a huge payoff for it (it's really > > powerful!). But yeah, there might be plenty of folks who will never > > bother learning about them, and they won't understand your code. > > IOW: Java's advanced features are separable from its basic features. > I.e. you can teach Java without teaching generics or anonymous inner > classes. In Haskell, OTOH, you can't even learn how to do IO without > learning Monads, or at least glossing over oddities like a new syntax. > And thats not even getting into issues like statelessness and lazy > evaluation. > > So for a new user, Java is the better language. You can get into its > features slowly and as you see the need for them. Haskell requires you > to learn a number of mind-bending concepts right up front. Java has a > gentle learning curve and Haskell has a vertical jump. > > But, Sebastian is right. The leap is worth it. Its the same as what > someone once said about LISP: even if you never get to use Haskell > regularly, you will be a better programmer when you finally "get it". > > _______________________________________________ > Haskell mailing list > Haskell(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell > _______________________________________________ > Haskell mailing list > Haskell(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell > -- http://clembie.livejournal.com http://shadowofaculture.blogspot.com http://deadlylittlepills.com _______________________________________________ Haskell mailing list Haskell(a)haskell.org http://www.haskell.org/mailman/listinfo/haskell

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Re: [Haskell] Re: Newbie: what are the advantages of Haskell?
by mike clemow 28 Apr '07

28 Apr '07

On 4/27/07, Taillefer, Troy (EXP) <troy.taillefer(a)lmco.com> wrote: [snip] > By the way Mike thanks you just totally cheered me up I guess I just > needed to sit back and think about what I have learned and how valuable > it is to me. There had to be some reason you were still hanging around on this list. ;-) I think that one can make a really good case for learning Haskell on the basis that knowing how to program in Haskell will make you a better programmer in any language. There's some recognition about that regarding functional programming in business; I know Jane St. Capital only hires programmers with FP experience and uses Ocaml on the inside because they know that programmers who can program in these languages produce good code. I'm glad to hear that your experience with Haskell has made you a better Java programmer and it cheers me up to think that there's something inherently beneficial to learning the language per se, even if there aren't a lot of libraries to make it as productive as other languages _yet_. Cheers, Mike

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ANNOUNCE: Haskell mode for Vim (was: Haskell IDE)
by Claus Reinke 28 Apr '07

28 Apr '07

I am happy to announce the Haskell mode for Vim.. just kidding, of course!-) there is no single best Haskell mode for Vim, but there are certainly numerous Vimmers out there with their own personalized Haskell mode settings for Vim, and there are certainly numerous Haskellers out there looking for the kind of IDE functionality that some Vimmers have at their fingertips already. this announcement is really about three things: 1. there is a section at haskell.org listing several people's Vim files: http://www.haskell.org/haskellwiki/Libraries_and_tools/Program_development#… 2. my own Vim scripts and plugins are available here (just updated): http://www.cs.kent.ac.uk/people/staff/cr3/toolbox/haskell/Vim/ 3. since Vim is about getting things done, there isn't much mouse-waving, browser tabs, gui buttons, etc. to show off (well, you can have all of those, either built-in or via plugins, but in my settings, i prefer less gui clutter), and there is so much code editing functionality that could be specialised to Haskell that it is difficult to get that message across to Haskellers who don't like to browse the online help, or who are just at the beginning of their Vim learning curve. but, there are a few things that do have menues or other easily visible effects, and i've created a short tour of some such for Haskell editing (warning: large screenshots): http://www.cs.kent.ac.uk/people/staff/cr3/toolbox/haskell/Vim/vim.html i hope that mentioning (1) might encourage more Haskell Vimmers to link to their own tricks and tips (perhaps there should be a top-level 'Haskell modes for Vim' section at haskell.org, similar to the 'Haskell mode for Emacs' section that is already there), (2) might be useful to some of you, and (3) might help to motivate some of you to give Vim a try. it is really not as if Vim (or Emacs, for that matter) didn't have more IDE functionality than most of us ever use, it is more that there is so much of it to learn and to fine-tune to your personal preferences. hth & enjoy!-) claus

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Code snippet: constraint a heterogenous list by a deterministic finite automaton
by Marcel Manthe 27 Apr '07

27 Apr '07

{-# OPTIONS -fglasgow-exts #-} data HNil = HNil data HCons a s b = Delta s b => HCons a s b data One = One data Two = Two data Three = Three data Four = Four data A = A data B = B data C = C class Delta st sy -- you can use HaLeX to generate minimal DFA's from -- regular expressions. -- http://www.di.uminho.pt/~jas/Research/HaLeX/HaLeX.html -- the minimal deterministic finite automaton for "AB?C" instance Delta HNil One -- One is the start state instance Delta One (HCons A Two n) instance Delta Two (HCons B Three n) instance Delta Two (HCons C Four n) instance Delta Three (HCons C Four n) instance Delta Four HNil -- Four is an end state -- there are two valid full sequences x = HCons HNil One $ HCons A Two $ HCons B Three $ HCons C Four HNil y = HCons HNil One $ HCons A Two $ HCons C Four HNil -- if you do not terminate and/or start with HNil, you can have -- partitial matches z = HCons B Three $ HCons C Four HNil -- invalid sequences do not type-check -- b = HCons HNil One $ HCons B Three $ HCons C Four HNil -- b' = HCons A Two $ HCons B Three HNil -- View this message in context: http://www.nabble.com/Code-snippet%3A-constraint-a-heterogenous-list-by-a-d… Sent from the Haskell - Haskell mailing list archive at Nabble.com.

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Haskell Weekly News: April 27, 2007
by dons＠cse.unsw.edu.au 27 Apr '07

27 Apr '07

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20070427 Issue 61 - April 27, 2007 --------------------------------------------------------------------------- Welcome to issue 61 of HWN, a weekly newsletter covering developments in the [1]Haskell community. The last week was a very exciting week for the Haskell community, with a new GHC release, the first release of Xmonad, a window manager written in Haskell, and DisTract, a new distributed bug tracker, written in Haskell. A number of new Haskell jobs were announced, and several new user groups were formed! 1. http://haskell.org/ Announcements GHC 6.6.1. Ian Lynagh [2]announced a new patchlevel release of GHC. This release contains a significant number of bugfixes relative to 6.6, so we recommend upgrading. Release notes are [3]here. GHC is a state-of-the-art programming suite for Haskell. Included is an optimising compiler generating good code for a variety of platforms, together with an interactive system for convenient, quick development. The distribution includes space and time profiling facilities, a large collection of libraries, and support for various language extensions, including concurrency, exceptions, and foreign language interfaces. 2. http://article.gmane.org/gmane.comp.lang.haskell.glasgow.user/12075 3. http://haskell.org/ghc/docs/6.6.1/html/users_guide/release-6-6-1.html Xmonad 0.1. Spencer Janssen [4]announced the inaugural release of [5]Xmonad. Xmonad is a minimalist tiling window manager for X, written in Haskell. Windows are managed using automatic layout algorithms, which can be dynamically reconfigured. At any time windows are arranged so as to maximise the use of screen real estate. All features of the window manager are accessible purely from the keyboard: a mouse is entirely optional. Xmonad is configured in Haskell, and custom layout algorithms may be implemented by the user in config files. 4. http://article.gmane.org/gmane.comp.lang.haskell.general/15131 5. http://xmonad.org/ DisTract: Distributed Bug Tracker implemented in Haskell. Matthew Sackman [6]announced DisTract, a [7]Distributed Bug Tracker. We're all now familiar with working with distributed software control systems, such as Monotone, Git, Darcs, Mercurial and others, but bug trackers still seem to be fully stuck in the centralised model: Bugzilla and Trac both have single centralised servers. This is clearly wrong, as if you're able to work on the Train, off the network and still perform local commits of code then surely you should also be able to locally close bugs too. DisTract allows you to manage bugs in a distributed manner through your web-browser. The distribution is achieved by making use of a distributed software control system, Monotone. Thus Monotone is used to move files across the network, perform merging operations and track the development of every bug. Finally, the glue in the middle that generates the HTML summaries and modifies the bugs is written in Haskell. 6. http://article.gmane.org/gmane.comp.lang.haskell.cafe/21857 7. http://www.distract.wellquite.org/ IOSpec 0.1. Wouter Swierstra [8]announced the first release of the [9]Test.IOSpec library, that provides a pure specification of some functions in the IO monad. This may be of interest to anyone who wants to debug, reason about, analyse, or test impure code. Essentially, by importing libraries from IOSpec you can the same code you would normally write in the IO monad. Once you're satisfied that your functions are reasonably well-behaved, you can remove the Test.IOSpec import and replace it with the 'real' functions instead. 8. http://article.gmane.org/gmane.comp.lang.haskell.general/15134 9. http://www.cs.nott.ac.uk/~wss/repos/IOSpec wl-pprint-1.0: Wadler/Leijen pretty printer. Stefan O'Rear [10]announced wl-pprint-1.0, the classic Wadler / Leijen pretty printing combinators, now in 100% easier to use [11]Cabalised form! PPrint is an implementation of the pretty printing combinators described by Philip Wadler (1997). In their bare essence, the combinators of Wadler are not expressive enough to describe some commonly occurring layouts. The PPrint library adds new primitives to describe these layouts and works well in practice. 10. http://thread.gmane.org/gmane.comp.lang.haskell.general/15112 11. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/wl-pprint-1.0 London Haskell User Group. Neil Bartlett [12]announced the first meeting of the [13]London Haskell User Group on Wednesday 23rd May from 6:30PM. The meeting will be held at City University's main campus in central London, and Simon Peyton Jones will be coming to give a talk. 12. http://article.gmane.org/gmane.comp.lang.haskell.cafe/21955 13. http://www.londonhug.net/2007/04/26/announcement-first-meeting-of-the-londo… New York Functional Programmers Network. Howard Mansell [14]announced a New York area-based network for Haskell (and functional) programmers. The idea is to have a regular meeting through which functional programmers can meet to discuss experiences, get and give information, find jobs. 14. http://article.gmane.org/gmane.comp.lang.haskell.cafe/21856 Data.Proposition 0.1. Neil Mitchell [15]announced the release of [16]Data.Proposition, a library that handles propositions, logical formulae consisting of literals without quantification. It automatically simplifies a proposition as it is constructed using simple rules provided by the programmer. Implementations of propositions in terms of an abstract syntax tree and as a Binary Decision Diagram (BDD) are provided. A standard interface is provided for all propositions. 15. http://article.gmane.org/gmane.comp.lang.haskell.general/15117 16. http://www-users.cs.york.ac.uk/~ndm/proposition/ Book reviews for the Journal of Functional Programming. Simon Thompson [17]sought interested contributors for book reivews for the Journal of Functional Programming. There is a list of books [18]currently available for review. 17. http://article.gmane.org/gmane.comp.lang.haskell.general/15136 18. http://www.cs.kent.ac.uk/people/staff/sjt/JFP/available.html Reminder: HCAR May 2007. Andres Loeh [19]reminded us that the deadline for the May 2007 edition of the Haskell Communities and Activities Report is only a few days away -- but this is still enough time to make sure that the report contains a section on your project, on the interesting stuff that you've been doing; using or affecting Haskell in some way. 19. http://article.gmane.org/gmane.comp.lang.haskell.general/15161 Template 0.1: Simple string substitution. Johan Tibell [20]announced a simple [21]string substitution library that supports substitution ala Perl or Python. 20. http://article.gmane.org/gmane.comp.lang.haskell.general/15135 21. http://darcs.johantibell.com/template hpaste for emacs. David House [22]announced hpaste.el, an Emacs Lisp library that integrates [23]hpaste, the Haskell pastebin, into Emacs. It provides two functions, hpaste-paste-region and hpaste-paste-buffer, which send the region or buffer to the hpaste server as required. 22. http://thread.gmane.org/gmane.comp.lang.haskell.glasgow.user/12046 23. http://hpaste.org/ Haskell' This section covers the [24]Haskell' standardisation process. * [25]General pattern bindings * [26]Relax the restriction on Bounded derivation * [27]data syntax * [28]Mathematical preludes * [29]Literate Haskell specification 24. http://hackage.haskell.org/trac/haskell-prime 25. http://thread.gmane.org/gmane.comp.lang.haskell.prime/2178 26. http://thread.gmane.org/gmane.comp.lang.haskell.prime/2183 27. http://thread.gmane.org/gmane.comp.lang.haskell.prime/2184 28. http://thread.gmane.org/gmane.comp.lang.haskell.prime/2189 29. http://thread.gmane.org/gmane.comp.lang.haskell.prime/2190 Libraries This week's proposals and extensions to the [30]standard libraries. * [31]Add a MonadState instance for the Parsec monad * [32]Use 'Wide' API if System has it 30. http://haskell.org/haskellwiki/Library_submissions 31. http://thread.gmane.org/gmane.comp.lang.haskell.libraries/6778 32. http://thread.gmane.org/gmane.comp.lang.haskell.libraries/6848 Hackage This week's new libraries in [33]the Hackage library database. * [34]X11-extras-0.1 * [35]hinstaller-2007.4.24 * [36]IOSpec-0.1.1 * [37]gd-3000.0.1 * [38]xmonad-0.1 * [39]YamlReference-0.3 * [40]parsedate-2006.11.10 * [41]chunks-2007.4.18 * [42]wl-pprint-1.0 * [43]Emping-0.1 * [44]hsns-0.5.1 * [45]htar-0.1 * [46]cabal-upload-0.3 * [47]unix-compat-0.1 * [48]tar-0.1 33. http://hackage.haskell.org/ 34. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/X11-extras-0.1 35. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hinstaller-2007.… 36. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/IOSpec-0.1.1 37. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/gd-3000.0.1 38. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/xmonad-0.1 39. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/YamlReference-0.3 40. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/parsedate-2006.1… 41. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/chunks-2007.4.18 42. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/wl-pprint-1.0 43. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Emping-0.1 44. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hsns-0.5.1 45. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/htar-0.1 46. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/cabal-upload-0.3 47. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/unix-compat-0.1 48. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/tar-0.1 Discussion GHC Release Plans. Simon Marlow [49]initiated a discussion on possibe release timelines for upcoming GHC versions. 49. http://thread.gmane.org/gmane.comp.lang.haskell.glasgow.user/12014 More inlining. Duncan Coutts [50]asked about more fine grained control over inlining in GHC, to ease term rewriting with RULES 50. http://thread.gmane.org/gmane.comp.lang.haskell.glasgow.user/12046 Haskell version of Norvig's Python Spelling Corrector. Pete Kazmier [51]spawned a long thread covering various implementations of spelling correctors in Haskell 51. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/21780 Jobs Quantitative Functional Programmer. Credit Suisse. [52]The Global Modelling and Analytics Group (GMAG) is responsible for producing state-of-the-art pricing, trading and hedging models for Credit Suisse. These models are used across a range of businesses in the Fixed Income and Equity Divisions. The groups mandate covers all major asset classes including Credit Derivatives, Commodities, Emerging Markets, Equity Derivatives and Convertibles, Exotics, Foreign Exchange, Fund Linked Products, Interest Rate Products and Mortgage Derivatives. GMAG operates globally with 85 members located in New York, London, Hong Kong and Tokyo. We are currently building a Domain Specific Language (embedded in Haskell) that will be used within GMAG. We require intelligent, motivated people to develop and extend this language. These individuals will also work with modellers to aid them in effectively applying these new tools. 52. http://tinyurl.com/2lqoq9 Haskell programmer positions. HAppS. HAppS LLC has [53]part-time and full-time positions open for Haskell programmers to: improve the open source Haskell codebase at HAppS.org; implement infrastructure to make it work well in Amazon S3/EC2 environments; make http://pass.net reliable enough to be used by live apps; build the mass market apps we want to run on top of the HAppS/Pass.net platform. We are looking for people who: have substantial experience programming Haskell; have experience building Internet apps (not necessarily in Haskell but would be good), and live in any of these places: the Internet, New York, San Francisco Los Angeles. 53. http://article.gmane.org/gmane.comp.lang.haskell.cafe/21951 Vacancy for a PhD student. Johan Jeuring [54]announced a vacancy for a PhD student in the Strategy Feedback project. Knowledge of Haskell is a big plus; implementation of most of the tools will be done in Haskell. Length: 1+3 years, Open University the Netherlands, Location: Heerlen. 54. http://article.gmane.org/gmane.comp.lang.haskell.cafe/21740 Blog noise [55]Haskell news from the blogosphere. * [56]Overloading Haskell numbers, part 1, symbolic expressions * [57]Overloading Haskell numbers, part 2, Forward Automatic Differentiation * [58]Overloading Haskell numbers, part 3, Fixed Precision * [59]More Haskell parallelism * [60]Haskell status: impressed * [61]On haskell: writing a packet sniffer * [62]Must-see Haskell talks at OSCON 07 * [63]Zen and the Art of Functional Programming * [64]Playing with sections in Haskell * [65]More playing with sections (and flip) * [66]Thinking in objects * [67]Robot localization using a particle system monad * [68]21 open problems in typed lambda calculus * [69]Arrows and security in Haskell * [70]Haskell GUI Programing * [71]Splitting a string in Haskell * [72]Introduction to Haskell: I like it a lot * [73]Haskell (ish) code, Java gui * [74]Haskell wikibook blurb * [75]Functional and Object-Oriented Programming * [76]Xmonad: a lightweight window manager * [77]Xmonad: a tiling window manager written in Haskell * [78]Xmonad: Haskell window management has arrived * [79]Xmonad: a minimal window manager in Haskell * [80]Xmonad: in the footsteps of wmii * [81]Xmonad: a new window manager * [82]Haskell code * [83]IO in Haskell * [84]Haskell records considered grungy 55. http://planet.haskell.org/ 56. http://augustss.blogspot.com/2007/04/overloading-haskell-numbers-part-1.html 57. http://augustss.blogspot.com/2007/04/overloading-haskell-numbers-part-2.html 58. http://augustss.blogspot.com/2007/04/overloading-haskell-numbers-part-3.html 59. http://mikeburrell.wordpress.com/2007/04/16/more-haskell-parallelism/ 60. http://austin.youareinferior.net/?q=node/21 61. http://austin.youareinferior.net/?q=node/24 62. http://www.serpentine.com/blog/2007/04/16/must-see-haskell-talks-at-oscon-0… 63. http://azaidi.blogspot.com/2007/04/zen-and-art-of-functional-programming.ht… 64. http://gimbo.org.uk/blog/2007/04/13/playing-with-sections-in-haskell/ 65. http://gimbo.org.uk/blog/2007/04/19/more-playing-with-sections-and-flip-in-… 66. http://braindump.dk/tech/2007/04/16/thinking-in-objects/ 67. http://www.randomhacks.net/articles/2007/04/19/robot-localization-particle-… 68. http://tlca.di.unito.it/opltlca/ 69. http://abstractabsurd.blogspot.com/2007/04/arrows-security.html 70. http://araujoluis.blogspot.com/2007/04/haskell-gui-programing.html 71. http://gimbo.org.uk/blog/2007/04/20/splitting-a-string-in-haskell/ 72. http://www.noulakaz.net/weblog/2007/04/20/i-like-haskell-a-lot/ 73. http://jpmoresmau.blogspot.com/2007/04/haskell-code-java-ui.html 74. http://koweycode.blogspot.com/2007/04/haskell-wikibook-blurb.html 75. http://weblog.raganwald.com/2007/04/we-dont-need-no-stinkin-scientific.html 76. http://lennartkolmodin.blogspot.com/2007/04/xmonad.html 77. http://www.osnews.com/story.php/17744/Xmonad-a-Tiling-Window-Manager-Writte… 78. http://existentialtype.net/?p=113 79. http://gimbo.org.uk/blog/2007/04/22/xmonad-a-minimal-window-manager-in-hask… 80. http://ephemient.livejournal.com/38438.html 81. http://jpatrao-online.blogspot.com/2007/04/xmonad-new-windowmanager.html 82. http://www.wardtek.ca/2007/04/haskell-code-number-one/ 83. http://www.friendofthepigeon.co.uk/wordpress/?p=54 84. http://bloggablea.wordpress.com/2007/04/24/haskell-records-considered-grung… Quotes of the Week * apfelmus: Programming in Haskell is like dual-wielding two light sabers whereas programming in imperative languages is like being equipped with a blunt kitchen knife. * mwc: C++ is multiparadigm in the same way a dog with 4 table legs nailed onto it is an octopus * ptolomy: Sometimes Haskell feels like a personal trainer for proper program construction. You half-ass something, and the compiler doesn't let you get away with it and won't let you move on until you do it right. * dons: I wish you success and may your lambdas always beta reduce * quicksilver: May your years be long and your type inference algorithms sound. * inverselimit: So I tried as my first project in Haskell to write something that decomposes modules of polynomials using Schur-Weyl duality. This turned out to be a little tricky without being comfortable with the syntax * jcreigh: Could not find instance Ord for type ProgrammingLanguage Code Watch Apr 19 07:23:58 PDT 2007. Simon Marlow. [85]More debugger improvements. :list shows the code around the current breakpoint. Also it highlights the current expression in bold (the bold/unbold codes are hardwired to the ANSI codes right now, I'll provide a way to change them later). :set stop cmd' causes cmd to be run each time we stop at a breakpoint. In particular, :set stop :list is particularly useful. 85. http://article.gmane.org/gmane.comp.lang.haskell.cvs.ghc/20269 Wed Apr 25 03:18:32 PDT 2007. simonpj. [86]Add -fwarn-monomorphism-restriction (on by default) to warn when the MR is used. Users often trip up on the Dreaded Monomorphism Restriction. This warning flag tells you when the MR springs into action. Currently it's on by default, but we could change that. 86. http://article.gmane.org/gmane.comp.lang.haskell.cvs.ghc/20359 Thu Apr 26 02:37:19 PDT 2007. Pepe Iborra. New section on [87]debugging lambdas in the ghci user guide 87. http://article.gmane.org/gmane.comp.lang.haskell.cvs.ghc/20404 About the Haskell Weekly News Each week, new editions are posted to [88]the Haskell mailing list as well as to [89]the Haskell Sequence and [90]Planet Haskell. [91]RSS is also available, and headlines appear on [92]haskell.org. Headlines are available as [93]PDF. To help create new editions of this newsletter, please see the [94]contributing information. Send stories to dons at cse.unsw.edu.au. The darcs repository is available at darcs get [95]http://www.cse.unsw.edu.au/~dons/code/hwn 88. http://www.haskell.org/mailman/listinfo/haskell 89. http://sequence.complete.org/ 90. http://planet.haskell.org/ 91. http://sequence.complete.org/node/feed 92. http://haskell.org/ 93. http://www.cse.unsw.edu.au/~dons/code/hwn/archives/20070427.pdf 94. http://haskell.org/haskellwiki/HWN 95. http://www.cse.unsw.edu.au/~dons/code/hwn

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