November 2007 - Haskell

Announcing Djinn, version 2004-12-11, a coding wizard
by Lennart Augustsson 07 Apr '11

07 Apr '11

Howdy, y'all! I've written a small program that takes a (Haskell) type and gives you back a function of that type if one exists. It's kind of fun, so I thought I'd share it. It's probably best explained with a sample session. calvin% djinn Welcome to Djinn version 2005-12-11. Type :h to get help. # Djinn is interactive if not given any arguments. # Let's see if it can find the identity function. Djinn> f ? a->a f :: a -> a f x1 = x1 # Yes, that was easy. Let's try some tuple munging. Djinn> sel ? ((a,b),(c,d)) -> (b,c) sel :: ((a, b), (c, d)) -> (b, c) sel ((_, v5), (v6, _)) = (v5, v6) # We can ask for the impossible, but then we get what we # deserve. Djinn> cast ? a->b -- cast cannot be realized. # OK, let's be bold and try some functions that are tricky to write: # return, bind, and callCC in the continuation monad Djinn> type C a = (a -> r) -> r Djinn> returnC ? a -> C a returnC :: a -> C a returnC x1 x2 = x2 x1 Djinn> bindC ? C a -> (a -> C b) -> C b bindC :: C a -> (a -> C b) -> C b bindC x1 x2 x3 = x1 (\ c15 -> x2 c15 (\ c17 -> x3 c17)) Djinn> callCC ? ((a -> C b) -> C a) -> C a callCC :: ((a -> C b) -> C a) -> C a callCC x1 x2 = x1 (\ c15 _ -> x2 c15) (\ c11 -> x2 c11) # Well, poor Djinn has a sweaty brow after deducing the code # for callCC so we had better quit. Djinn> :q Bye. To play with Djinn do a darcs get http://darcs.augustsson.net/Darcs/Djinn or get http://darcs.augustsson.net/Darcs/Djinn/Djinn.tar.gz Then just type make. (You need a Haskell 98 implementation and some libraries.) And then start djinn. For the curious, Djinn uses a decision procedure for intuitionistic propositional calculus due to Roy Dyckhoff. It's a variation of Gentzen's LJ system. This means that (in theory) Djinn will always find a function if one exists, and if one doesn't exist Djinn will terminate telling you so. This is the very first version, so expect bugs. :) Share and enjoy. -- Lennart

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Haskell-mode 2.0
by Stefan Monnier 02 Feb '09

02 Feb '09

I have recently taken over maintainership of Haskell-mode, and after making a bunch of changes, I figured it would be a good idea to make a new release. You can find this new release at: http://www-perso.iro.umontreal.ca/~monnier/elisp/ If you think it should also be found at http://www.haskell.org/haskell-mode/, then please tell John Peterson to get back to me (my email to him seem to go straight to the bitbucket. John?). This release has several changes that have all been only lightly tested, especially w.r.t compatibility with various Emacsen. See appended the NEWS file that describes some of the notewirthy changes. Stefan Changes since 1.45: * keybindings C-c <char> have been replaced by C-c C-<char> so as not to collide with minor modes. * The following modules are now automatically activated without having to add anything to haskell-mode-hook: haskell-font-lock (just turn on global-font-lock-mode). haskell-decl-scan (just bind `imenu' to some key). * In recent Emacsen, haskell-doc hooks into eldoc-mode. * haskell-hugs and haskell-ghci are superceded by inf-haskell. * Indentation rules have been improved when using layout inside parens/braces. * Symbols like -> and \ can be displayed as actual arrows and lambdas. See haskell-font-lock-symbols. * Tweaks to the font-lock settings. Among other things paren-matching with things like \(x,y) should work correctly now. * New maintainer <monnier(a)gnu.org>.

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The real Monad Transformer
by Henning Thielemann 13 Nov '08

13 Nov '08

It was argued that people avoid Haskell because of terms from Category theory like 'Monad'. This problem can now be solved by a wrapper which presents all the WWW without monads! Start e.g. at http://saxophone.jpberlin.de/MonadTransformer?source=http%3A%2F%2Fwww%2Ehas… Of course the tool is written in Haskell, that is, Haskell helps solving problems which only exist because of Haskell. Bug reports and feature requests can be tracked at https://sourceforge.net/projects/parallelweb

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ANN: MacOSX - A library some Haskell users on OS X might find useful.
by Corey O'Connor 27 Feb '08

27 Feb '08

I've been working on integrating haskell code with some Objective-C/C++ Cocoa Mac OS X applications. Nothing fancy like a Haskell/Cocoa bridge. Just trying to get the build process smooth. The default cabal build system was incomplete to do this effectively;* Extending XCode was no good either. With some effort I created some Cabal build hooks to fix up the behavior of build on OS X and add support for packaging an executable into a ".app" package. That's not much, but I packaged it up, plus some extras, into a library in case other projects would like to use it: http://tothepowerofdisco.com/repo/HaskellLibraries/ Of course, this is all hackish and very incomplete. EG: * No fat binary support. I only have a PPC Mac and the only fat-binary process usable with GHC I know of requires executing the x86 GHC. * The build hook in MacOSX.Build will only work on the Cabal distributed with GHC 6.6.1 and *completely* replaces the standard GHC build hook. * GHC compiled to use the framework version of GMP installed to /Library/Frameworks is required. * The name is vague... Still, I've used it to add haskell support and replace XCode for building for 3 exisitng Cocoa applications. Maybe somebody else will find it useful as well. -- -Corey O'Connor * I neglected to make a good list of why the default Cabal build hook doesn't work.

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Doctoral and Post-doctoral openings at Rice
by Walid Taha 30 Nov '07

30 Nov '07

The Resource-Aware Programming (RAP) research group at Rice University is seeking qualified doctoral and post-doctoral students. The openings will support work on a wide range of topics, including the Concoqtion programming language, physically safe computing, and device drivers. The full descriptions of these positions can be found at: http://www.resource-aware.org/twiki/bin/view/RAP/OpeningsGraduate and http://www.resource-aware.org/twiki/bin/view/RAP/OpeningsPostdoctoral Funding for these positions is provided by the National Science Foundation (NSF) and by industrial partners including Intel, LogicBlox, and Schlumberger. Walid Taha, http://www.cs.rice.edu/~taha Department of Computer Science Rice University Houston, TX 77025

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Call for Papers - SBLP 2008 (12th BRAZILIAN SYMPOSIUM ON PROGRAMMING LANGUAGES)
by Heron 30 Nov '07

30 Nov '07

12th BRAZILIAN SYMPOSIUM ON PROGRAMMING LANGUAGES <http://www.lia.ufc.br/sblp2008> http://www.lia.ufc.br/sblp2008 Fortaleza, Ceara, Brazil August 27-29, 2008 CALL FOR PAPERS AND TUTORIALS The 12th Brazilian Symposium on Programming Languages, SBLP 2008, will be held in Fortaleza, Ceara, Brazil, on August 27-29, 2008. SBLP provides a venue for researchers and practitioners interested in the fundamental principles and innovations in the design and implementation of programming languages and systems. SBLP 2008 invites authors to contribute with Technical Papers and Tutorial Proposals related (but not limited) to: * Programming language design and implementation * Formal semantics of programming languages * Theoretical foundations of programming languages * Design and implementation of programming language environments * Object-oriented programming languages * Functional programming * Aspect-oriented programming languages * Scripting languages * Domain-specific languages * Programming languages for mobile, web and network computing * New programming models * Program transformations * Program analysis and verification * Compilation and interpretation techniques Contributions can be written in Portuguese or English. Papers should have at most 14 pages. All accepted papers will be published in the conference proceedings. Selected papers will appear in a Special Issue of the Journal of Universal Computer Science (J.UCS). Only papers written in English are eligible to be published in JUCS. Papers should be presented in the language of submission. Tutorial submissions must be in the form of an extended abstract with at most 10 pages. The final version of accepted tutorials should contain at most 30 pages. This final version will be distributed to attendees. An abstract of the tutorial (1-2 pages) will be included in the conference proceedings. Detailed submission guidelines are available at <http://www.lia.ufc.br/sblp2008> http://www.lia.ufc.br/sblp2008. IMPORTANT DATES Paper abstract submission (15 lines): March 28, 2008 Full paper submission: April 4, 2008 Notification of acceptance: June 6, 2008 Final papers due: June 30, 2008 GENERAL CHAIR Francisco Heron de Carvalho Junior, UFC PROGRAMME CHAIRS Marco Tulio Valente, PUC Minas Peter Mosses, Swansea University PROGRAMME COMMITTEE Alberto Pardo, Univ. de La Republica Alex Garcia, IME Alfio Martini, PUC-RS Alvaro Freitas Moreira, UFRGS Andre Rauber Du Bois, UCPel Andre Santos, UFPE Carlos Camarao, UFMG Christiano Braga, Univ. Comp. de Madrid David Naumann, Stevens Tech Eric Tanter, Univ. of Chile Francisco Heron de Carvalho Junior, UFC Isabel Cafezeiro, UFF Johan Jeuring, Utrecht Univ. Joao Saraiva, Univ. do Minho Jose Guimaraes, UFSCAR Jose E. Labra Gayo, Univ. of Oviedo Jose Luiz Fiadeiro, Univ. of Leicester Lucilia Figueiredo, UFOP Luis Soares Barbosa, Univ. do Minho Luis Carlos Meneses, UPE Marcelo A. Maia, UFU Mariza A. S. Bigonha, UFMG Martin A. Musicante, UFRN Nabor Mendonca,UNIFOR Nick Benton, Microsoft Research Noemi Rodriguez, PUC-Rio Paulo Borba, UFPE Rafael Dueire Lins, UFPE Renato Cerqueira, PUC-Rio Ricardo Massa Lima, UPE Roberto S. Bigonha, UFMG Roberto Ierusalimschy, PUC-Rio Rodolfo Jardim de Azevedo, UNICAMP Sandro Rigo, UNICAMP Sergio de Mello Schneider, UFU Sergio Soares, UPE Sergiu Dascalu, Univ. of Nevada Simon Thompson, Univ. of Kent Varmo Vene, Univ. de Tartu Vitor Santos Costa, UFRJ Vladimir Di Iorio, UFV ORGANIZATION Brazilian Computer Society and Federal University of Ceara

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Bug in hugs?
by Damian Nadales 26 Nov '07

26 Nov '07

Hi, I'm sorry to bother. I was using the splitRegex function http://cvs.haskell.org/Hugs/pages/libraries/base/Text-Regex.html#t%3ARegex and it enters an infinite loop when I enter the command (splitRegex (mkRegex "") "hi") I apologize if this is not a bug or if it's the wrong place to submit it. Best regards, damian.

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The Monad.Reader - Call for Copy
by Wouter Swierstra 26 Nov '07

26 Nov '07

Call for Copy The Monad.Reader - Issue 10 I would like to welcome articles for the anniversary issue of The Monad.Reader. * The Monad.Reader * The Monad.Reader is an electronic magazine about all things Haskell. It is less-formal than journal, but somehow more enduring than a wiki- page. There have been a wide variety of articles, including: exciting code fragments, intriguing puzzles, book reviews, tutorials, and even half-baked research ideas. * Submission Details * Get in touch with me if you intend to submit something -- the sooner you let me know what you're up to, the better. Please submit articles for the next issue by e-mail (wss at cs.nott.ac.uk) to me before ** January 25, 2008 ** Articles should be written according to the guidelines available from http://www.haskell.org/haskellwiki/The_Monad.Reader Please submit your article in PDF, together with any source files you used. The sources will be released together with the magazine under a BSD license. If you would like to submit an article, but have trouble with LaTeX please let me know and we'll sort something out. Looking forward to your submission, 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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First Call for Papers TFP 2008, The Netherlands
by Peter Achten 23 Nov '07

23 Nov '07

CALL FOR PAPERS TRENDS IN FUNCTIONAL PROGRAMMING 2008 RADBOUD UNIVERSITY NIJMEGEN, THE NETHERLANDS MAY 26-28, 2008 INVITED SPEAKER: PROF. HENK BARENDREGT http://www.st.cs.ru.nl/AFP_TFP_2008/ The symposium on Trends in Functional Programming (TFP) is an international forum for researchers with interests in all aspects of functional programming languages, focusing on providing a broad view of current and future trends in Functional Programming. It aspires to be a lively environment for presenting the latest research results through acceptance by extended abstracts and full papers. A formal post-symposium refereeing process selects the best articles presented at the symposium for publication in a high-profile volume. TFP 2008 is hosted by the Radboud University Nijmegen, The Netherlands, and will be held in the rural setting of Center Parcs “Het Heijderbos”, Heijen (in the vicinity of Nijmegen), The Netherlands. TFP 2008 is co-located with the 6th Int’l. Summer School on Advanced Functional Programming (AFP’08), which is held immediately before TFP’08. SCOPE OF THE SYMPOSIUM The symposium recognizes that new trends may arise through various routes. As part of the Symposium's focus on trends we therefore identify the following five article categories. High-quality articles are solicited in any of these categories: Research: leading-edge, previously unpublished research. Position: on what new trends should or should not be. Project: descriptions of recently started new projects. Evaluation: what lessons can be drawn from a finished project. Overview: summarizing work with respect to a trendy subject. Articles must be original and not submitted for simultaneous publication to any other forum. They may consider any aspect of functional programming: theoretical, implementation-oriented, or more experience-oriented. Applications of functional programming techniques to other languages are also within the scope of the symposium. Contributions on the following subject areas are particularly welcomed: * Dependently Typed Functional Programming * Validation and Verification of Functional Programs * Debugging for Functional Languages * Functional Programming and Security * Functional Programming and Mobility * Functional Programming to Animate/Prototype/Implement Systems from Formal or Semi-Formal Specifications * Functional Languages for Telecommunications Applications * Functional Languages for Embedded Systems * Functional Programming Applied to Global Computing * Functional GRIDs * Functional Programming Ideas in Imperative or Object-Oriented Settings (and the converse) * Interoperability with Imperative Programming Languages * Novel Memory Management Techniques * Parallel/Concurrent Functional Languages * Program Transformation Techniques * Empirical Performance Studies * Abstract/Virtual Machines and Compilers for Functional Languages * New Implementation Strategies * Any new emerging trend in the functional programming area If you are in doubt on whether your article is within the scope of TFP, please contact the TFP 2008 program chairs, Peter Achten and Pieter Koopman, at afp_tfp_2008(a)cs.ru.nl. SUBMISSION AND DRAFT PROCEEDINGS Acceptance of articles for presentation at the symposium is based on the review of full papers (15 pages) and extended abstracts (3 pages) by the program committee. TFP encourages PhD students to submit papers. PhD students may request the program committee to provide extensive feedback on their full papers at the time of submission. Full papers describing work accepted for presentation must be completed before the symposium for publication in the draft proceedings and on-line. Further details can be found at the TFP 2008 website http://www.st.cs.ru.nl/AFP_TFP_2008/. POST-SYMPOSIUM REFEREEING AND PUBLICATION In addition to the draft symposium proceedings, we continue the TFP tradition of publishing a high-quality subset of contributions in the Intellect series on Trends in Functional Programming. IMPORTANT DATES (ALL 2008) Paper Submission: March 3 Notification of Acceptance: March 31 Early Registration Deadline: April 14 Late Registration Deadline: May 5 Camera Ready Symposium: May 5 TFP Symposium: May 26-28 Post Symposium Paper Submission: June 20 Notification of Acceptance: September 7 Camera Ready Revised Paper: September 21 PROGRAMME COMMITTEE Peter Achten (co-chair) Radboud Univ. Nijmegen, NL Andrew Butterfield Trinity College, IE Manuel Chakravarty Univ. of New South Wales, AU John Clements Cal Poly State Univ., USA Matthias Felleisen Northeastern Univ., USA Jurriaan Hage Utrecht Univ., NL Michael Hanus Christian-Albrechts Univ. zu Kiel, DE Ralf Hinze Univ. of Oxford, UK Graham Hutton Univ. of Nottingham, UK Johan Jeuring Utrecht Univ., NL Pieter Koopman (co-chair) Radboud Univ. Nijmegen, NL Shriram Krishnamurthi Brown Univ., USA Hans-Wolfgang Loidl Ludwig-Maximilians Univ.München, DE Rita Loogen Philipps-Univ. Marburg, DE Greg Michaelson Heriot-Watt Univ., UK Marco T. Morazán (symp. chair) Seton Hall Univ., USA Sven-Bodo Scholz Univ. of Hertfordshire, UK Ulrik Schultz Univ. of Southern Denmark, DK Clara Segura Univ. Complutense de Madrid, ES Olin Shivers Northeastern Univ., USA Phil Trinder Heriot-Watt Univ., UK Varmo Vene Univ. of Tartu, EE Viktória Zsók Eötvös Loránd Univ., HU ORGANIZATION Symposium Chair: Marco T. Morazán, Seton Hall University, USA Programme Chair: Peter Achten, Pieter Koopman, Radboud University Nijmegen, NL Treasurer: Greg Michaelson, Heriot-Watt University, UK

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ANNOUNCE: nhc98-1.20
by Malcolm Wallace 23 Nov '07

23 Nov '07

---------- nhc98-1.20 ---------- http://haskell.org/nhc98/ We are pleased to announce that, contrary to popular belief, there is indeed more than one Haskell compiler in the world. Whilst nhc98 might not receive much love and attention these days, it does at least continue to work. 1.20 is a refreshed release with many of the current core library packages included, and a variety of small bugfixes since the last release. * It successfully compiles and runs more programs from the nobench suite than jhc, hbc, Hugs, or yhc. * It generates an interpreted bytecode that, on the whole runs faster than that generated by Hugs or yhc, and in many cases is also faster than ghci. * Although nhc98 is written in Haskell, you don't need an existing Haskell compiler on your platform to build nhc98 - a C compiler will do. Hence, it is portable to almost any unix-like machine with a 32-bit compatibility mode. * Many useful build tools come included: hmake (the inspiration for ghc --make) hi (interactive read-eval-print, like Hugs or ghci) cpphs (Haskell-aware replacement for cpp) hsc2hs (preprocessor for FFI code) * Supplied with recent versions of these library packages: base, Cabal, directory, filepath, fps, haskell-src, HaXml, html, HUnit, old-locale, old-time, parsec, polyparse, pretty, process, QuickCheck, random, xhtml * Supports the Haskell'98 language standard, with the following language extensions: pattern guards (new) existential types named field puns hierarchical module names foreign function interface no monomorphism restriction empty data declarations Regards, Malcolm

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