April 2003 - Haskell - Haskell.org

compilation problem in glibc 2.3.2-27.9 RedHat 9
by Kenny Lu Zhuo Ming 17 Apr '03

17 Apr '03

Hi, recently I've upgraded my RedHat box from 8 to 9. This immediately gave rise to a lot of problem due to incompatibility (I guess). When I try to compile my haskell library, for example (HaXml), it halted with this error message /usr/local/lib/ghc-5.02.3/libHSrts.a(RtsFlags.o)(.text+0x1b0): In function `setupRtsFlags': : undefined reference to `__ctype_b' collect2: ld returned 1 exit status I then try to recompile my ghc from source, the compilation terminates with the same error. for which I thought it is due to update on static links from glibc version 2.2 to 2.3. But I think this has already been fixed by some previous version. This problem is resolved until I reverted my glibc package back to 2.3.2-4.80 Any of you have ever encoutered the same issue? Regards, Kenny

1 0

ANNOUNCE: HaWiki, the Haskell Wiki
by Keith Wansbrough 16 Apr '03

16 Apr '03

Hi all... following recent discussions, the Haskell Wiki has been upgraded. It is now running MoinMoin http://moin.sourceforge.net/, and has been renamed HaWiki. You can access it from the Haskell homepage, http://www.haskell.org, or directly at http://www.haskell.org/hawiki/ The old Wiki has been replaced by a redirection page; this is intentionally not automatic. Please update your old links. All the old content has been copied across (as of about an hour ago). The following have been lost: * external [1]-style links. * some formatting * the change history Please could people look at the various pages, and fix any problems they find, or let me know directly. I expect the new wiki to be *much* more stable than the old one, but let me know if there are any problems. The new Wiki has many more features, and looks a lot cooler. I hope it will continue to be a useful resource for the Haskell community. As the front page says, A WikiWikiWeb is a collaborative hypertext environment, with an emphasis on easy access to and modification of information. Everyone should feel free to add pages and information. This should be a repository for answers to all FAQs, for useful code fragments and techniques, for discussion and documents related to Haskell projects, and so on. Cheers, --KW 8-) -- Keith Wansbrough <kw217(a)cl.cam.ac.uk> http://www.cl.cam.ac.uk/users/kw217/ University of Cambridge Computer Laboratory.

1 0

Arrows and the IO monad
by Peter Simons 16 Apr '03

16 Apr '03

Hi, after reading the excellent paper "Generalising Monads to Arrows" from John Hughes, I am trying to use an arrow-based stream processor of type 'SP a b' to implement a network daemon. So far I have defined the arrow successfully: > data SP a b = Put b (SP a b) > | Get (a -> SP a b) > | Null > deriving (Show) > > instance Arrow SP where > arr f = get (\x -> put (f x) (arr f)) > > _ >>> Null = Null > sp1 >>> Put c sp2 = Put c (sp1 >>> sp2) > Null >>> Get _ = Null > Put c sp1 >>> Get f2 = sp1 >>> f2 c > Get f1 >>> Get f2 = Get (\c -> f1 c >>> Get f2) > > first f = bypass [] f > where > bypass ds (Get f) = Get (\(b,d) -> bypass (ds ++ [d]) (f b)) > bypass [] (Put c sp) = Get (\(_,d) -> Put (c,d) (bypass [] sp)) > bypass (d:ds) (Put c sp) = Put (c,d) (bypass ds sp) But now I have to make the stream processors interact with the IO monad, because I want the actual reading and writing to take place in the processor arrow. Is there any good way to achieve that without being forced to use the type 'SP (IO a) (IO b)' throughout the arrow? Can I maybe split the data flow for simple non-IO processors off the I/O monad temporarily? Or is there a way to combine my SP arrow with the IO monad in way that IO actions can be lifted to my SP arrow? Can anyone recommend some further reading material concerning this topic? Any feedback is appreciated! Peter

2 1

update fun->pdf?
by Kenny Lu Zhuo Ming 15 Apr '03

15 Apr '03

Hi all, I've found that the fun->pdf link in www.haskell.org/libraries/ broken, does anyone know whether there is an update of it? or any other library that equivalent? Regards, Kenny

3 2

Summer School and Workshop on Proof Theory, Computation and Complexity - Announcement
by Janis Voigtlaender 14 Apr '03

14 Apr '03

Summer School and Workshop on Proof Theory, Computation and Complexity Technische Universitaet Dresden June 23-July 4, 2003 <http://www.ki.inf.tu-dresden.de/~guglielm/WPT2> Preliminary Program and Call for Participation We plan the following courses and workshop for graduate students and researchers. Like for last year's events on Proof Theory and Computation (Dresden) and Proof, Computation, Complexity (Tuebingen), we aim at a meeting where people have plenty of time to exchange ideas. The summer school consists of eight advanced courses; the workshop takes place in the last two days. For participating in the summer school we ask for a small fee (currently undetermined). We are looking into the possibility of providing grants to participants who ask for them. Registration is requested, please send an email to <mailto:PTEvent@Janeway.Inf.TU-Dresden.DE>, making sure you include a very brief bio (5-10 lines) stating your experience, interests, home page, etc. We will select applicants in case of excessive demand. We will provide assistance in finding an accommodation in Dresden. Week 1, June 23-27: courses on Denotational Semantics of Lambda Calculi Achim Jung (Birmingham, UK) Proof Theory with Deep Inference Alessio Guglielmi (Dresden, Germany) Five Lectures on Proof-Analysis Sara Negri (University of Helsinki and Academy of Finland) Mass Problems Stephen Simpson (Penn State, USA) Week 2, June 30-July 2: courses on Natural Deduction: Some Recent Developments Jan von Plato (Helsinki, Finland) Semantics and Cut-elimination for Church's (Intuitionistic) Theory of Types, with Applications to Higher-order Logic Programming Jim Lipton (Wesleyan, USA) Dependent Type Theories Peter Aczel (Manchester, UK) Term-rewriting and Termination in Proof Theory Roy Dyckhoff (St Andrews, Scotland) July 3-4: workshop (consult the web site for details) Dresden, on the river Elbe, is one of the most important art cities of Germany. You can find world-class museums and wonderful architecture and surroundings. We will organize trips and social events. This program is still subject to variation, please check the web site. Please distribute this message broadly.

1 0

Help Support
by edgar cubides 11 Apr '03

11 Apr '03

Hi, i'm doing my undergraduate project about a HUGS tool. I have right now the following components: - A software client/server that is compilable on runHUGS. The problem is if i compile this software using GHC, can i run it on line.? How can i do this? I apreciate any documentation about it. Thanks for your time. _________________________________________________________________ The new MSN 8: advanced junk mail protection and 2 months FREE* http://join.msn.com/?page=features/junkmail

1 0

RDP'03 - Call for participation
by Salvador Lucas 11 Apr '03

11 Apr '03

[Apologies for multiple copies of this announcement] ****************************************************************** ****************** Call for participation ****************** ****************************************************************** Federated Conference on Rewriting, Deduction and Programming (RDP) including RTA - TLCA - FTP - IFIP WG 1.6 - RULE - UNIF - WFLP - WRS - WST http://www.dsic.upv.es/~rdp03 Valencia, Spain, June 8 - 14, 2003 ------------------------------------------------------------------ We are pleased to announce that the registration and hotel reservation procedures for attending RDP 2003 are open now. Please, follow this link http://www.dsic.upv.es/~rdp03/org/registration_info.html to formalize your registration. A number of rooms have been booked in various hotels near the Conference venue. Please remember that the number of rooms is limited. Requests will be processed on a first come first served basis and will be subject to space availability. Please, follow this link http://www.dsic.upv.es/~rdp03/org/hotel_info.html to eventually formalize your accomodation in one of such hotels. IMPORTANT: The deadline for early registration/accomodation is M a y 1 5, 2 0 0 3 RDP 2003 will take place at the ADEIT building of the "Fundacio Universitat Empresa de Valencia": Plaza Virgen de la Paz, 3 E-46001 Valencia Spain Please, look at the conference WWW site for further travelling information (available soon). The conference will be hosted by the Departamento de Sistemas Informaticos y Computacion (DSIC) at the Universidad Politecnica de Valencia. PARTICIPANTS 14th Int. Conf. on Rewriting Techniques and Applications, RTA'03 6th Int. Conf. on Typed Lambda Calculi and Applications, TLCA'03 4th Int. Workshop on First Order Theorem Proving, FTP'03 IFIP Working Group 1.6 on Term Rewriting 4th Int. Workshop on Rule Based Programming, RULE'03 17th Int. Workshop on Unification, UNIF'03 12th Int. Workshop on Functional and (Constraint) Logic Prog., WFLP'03 3rd Int. Workshop on Red. Strat. in Rewriting and Programming, WRS'03 6th Int. Workshop on Termination, WST'03 DATES RDP : June 8 - 14, 2003 RTA'03 : June 9 - 11 TLCA'03: June 10 - 12 FTP'03 : June 12 - 14 WG 1.6 : June 12 RULE'03: June 9 UNIF'03: June 8 - 9 WFLP'03: June 12 - 13 WRS'03 : June 8 WST'03 : June 13 - 14 ORGANIZERS The ELP group at the Universidad Politecnica de Valencia Officials: Salvador Lucas (chair of the organizing committee) Maria Alpuente (workshops chair) Jose Hernandez (local arrangements) Javier Oliver (secretary) Maria Jose Ramirez (local arrangements chair) German Vidal (publicity chair) CONTACT Salvador Lucas Departamento de Sistemas Informaticos y Computacion (DSIC) Universidad Politecnica de Valencia Camino de Vera, s/n E-46022 Valencia (Spain) phone: + 34 96 387 7353 (73531) fax: + 34 96 387 7359 e-mail: slucas(a)dsic.upv.es URL: http://www.dsic.upv.es/users/elp/slucas.html FURTHER INFORMATION RDP website: http://www.dsic.upv.es/~rdp03 The ELP group: http://www.dsic.upv.es/users/elp/elp.html ******************************************************************

1 0

setenv?
by Johannes Waldmann 11 Apr '03

11 Apr '03

We have System.getEnv - is there setEnv as well? in System? in Posix? -- -- Johannes Waldmann ---- http://www.informatik.uni-leipzig.de/~joe/ -- -- joe(a)informatik.uni-leipzig.de -- phone/fax (+49) 341 9732 204/207 --

2 1

ANNOUNCE: New Chameleon relase
by Martin Sulzmann 11 Apr '03

11 Apr '03

New features: * Interactive Debugging in Haskell See http://www.comp.nus.edu.sg/~sulzmann/chameleon/ for details. Martin

1 0

ANNOUNCE: Haskell/Java VM Bridge 0.2 Release
by Ashley Yakeley 10 Apr '03

10 Apr '03

Release 0.2 of Haskell/Java VM Bridge is now available in source-code form. New in Version 0.2: Haskell: * 'Haskell' now a separate Autotools project installing in /usr/lib/jvm-bridge/ * New array region access functions * Correct array types in autogenerated class interfaces * Subtype parameters in autogenerated class interfaces * VMLayer 'env' parameter now implicit * Various changes in the BasicLayer * new native StartExecuteFunction function called by getExecuteFunctionClass, defineCallbackClass Native: * Mac OS X support * Beginnings of MinGW32/Cygwin support * New Sun 1.4 JVM * Now installs in /usr/lib/jvm-bridge/ * ExecuteFunction bindings now done at run-time Haskell/Java VM Bridge allows Haskell programs access to the Java Virtual Machine. It comes in two parts: the 'Native' part, that abstracts away differences in the various Java VMs, and the 'Haskell' part that provides a Haskell API. The Native part is not Haskell-specific, and could potentially be used by other languages wishing to access the Java VM. Features include: * Calling of Java methods, access to fields, array-handling; * Integration of garbage collectors; * Reconciliation of exception models; * Reconciliation of thread models, including 'synchronized' monitor support and the ability to fork Haskell actions as Java threads; * Strong typing for Java classes and method argument lists (as tuples), and use of Haskell lists as arrays; * Creation of Java classes 'on the fly' (using DefineClass and the Java Class File Format) that can have Haskell callback methods; * Lifted monads which do all the necessary JNI class and method/field ID preloading and 'JNIEnv'-pointer variable handling for you -- these can be automatically generated via a tool (MakeJVMModule); * Layered design includes lower-level IO-based interface; * Automatic generation of modules for Java API classes; * All relevant imports, flags and libraries etc. handled by a single GHC package 'javavm'; * No 'unsafe' Haskell calls or pure function FFI anywhere; * Easy to port to new Java VMs. This release should be 'beta' quality, but has undergone little testing. You will need: * An x86 machine running some form of Unix, or a Mac OS X machine; * GHC 5.02.4 or later; In particular, GHC 5.02.2 and earlier will not work on Mac OS X. * A Java VM. It's been tested only with Sun's JVM, but should (may?) work with a number of others. Haddock documentation is currently blocked on a bug in Haddock ("implicit parameters"). Should that be fixed, you will be able to build API documentaion by doing "make doc". Some simple examples have been included such as a program that shows a Java Frame containing an instance of a Haskell-defined subclass of Canvas that has a Haskell 'paint' method that draws an oval. You should be able to figure out most of it from that. Haskell/JVM Bridge and source code is licensed under the GNU Lesser GPL. <http://sourceforge.net/projects/jvm-bridge/> Future plans: * port to Cygwin * use hierarchical module structure * separate out pure (non-FFI) Haskell into a separate package * better typing for the IO-based layer -- Ashley Yakeley, Seattle WA Almost empty page: <http://semantic.org/>

1 0