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ANNOUNCE: levmar-1.0
by Bas van Dijk 18 May '11

18 May '11

Dear all, I released levmar-1.0, an implementation of the Levenberg-Marquardt minimization algorithm that can be used for least squares, curve fitting and nonlinear programming. The most important change in this release is the use of vectors and matrices from the hmatrix package (which uses the high performance vector package). An application at work became 25 times faster when switching to the new levmar! I'm not sure this major speedup can be entirely attributed to the switch from lists to vectors. I also switched the FFI types from CDouble to Double in the internal bindings-levmar package. This made the expensive realToFrac conversions from CDouble to Double unnecessary which I believe had a big impact. API Documentation: http://hackage.haskell.org/package/levmar-1.0 I also switched the repository from darcs to git and hosted it on github: https://github.com/basvandijk/levmar/ Regards, Bas

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ANNOUNCE: Haskell Communities and Activities Report (20th ed., May 2011)
by Janis Voigtländer 18 May '11

18 May '11

On behalf of all the contributors, I am pleased to announce that the Haskell Communities and Activities Report (20th edition, May 2011) is now available in PDF and HTML formats: http://haskell.org/communities/05-2011/report.pdf http://haskell.org/communities/05-2011/html/report.html Many thanks go to all the people that contributed to this report, both directly, by sending in descriptions, and indirectly, by doing all the interesting things that are reported. I hope you will find it as interesting a read as I did. If you have not encountered the Haskell Communities and Activities Reports before, you may like to know that the first of these reports was published in November 2001. Their goal is to improve the communication between the increasingly diverse groups, projects, and individuals working on, with, or inspired by Haskell. The idea behind these reports is simple: Every six months, a call goes out to all of you enjoying Haskell to contribute brief summaries of your own area of work. Many of you respond (eagerly, unprompted, and sometimes in time for the actual deadline ;-) to the call. The editor collects all the contributions into a single report and feeds that back to the community. When I try for the next update, six months from now, you might want to report on your own work, project, research area or group as well. So, please put the following into your diaries now: ========================================== End of October 2011: target deadline for contributions to the November 2011 edition of the HC&A Report ========================================== Unfortunately, many Haskellers working on interesting projects are so busy with their work that they seem to have lost the time to follow the Haskell related mailing lists and newsgroups, and have trouble even finding time to report on their work. If you are a member, user or friend of a project so burdened, please find someone willing to make time to report and ask them to "register" with the editor for a simple e-mail reminder in October (you could point me to them as well, and I can then politely ask if they want to contribute, but it might work better if you do the initial asking). Of course, they will still have to find the ten to fifteen minutes to draw up their report, but maybe we can increase our coverage of all that is going on in the community. Feel free to circulate this announcement further in order to reach people who might otherwise not see it. Enjoy! Janis Voigtlaender <hcar at haskell.org>

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Extended deadline: GPCE 2011 Call for Papers
by Chang Hwan Peter Kim 17 May '11

17 May '11

------------------------------------------------------------------------ **** EXTENDED DEADLINE **** CALL FOR PAPERS Tenth International Conference on Generative Programming and Component Engineering (GPCE 2011) October 22-23, 2011 Portland, Oregon, USA (collocated with SPLASH 2011) http://www.gpce.org http://www.facebook.com/GPCEConference http://twitter.com/GPCECONF LinkedIn: GPCE (http://tinyurl.com/48eoovb) ------------------------------------------------------------------------ IMPORTANT DATES (NEW) * Submission of abstracts: Saturday, May 21, 2011 * Submission of papers: Saturday, May 28, 2011 * Paper notification: Wednesday, July 6, 2011 * Submission of tech talks: Sunday, August 7, 2011 SCOPE Generative and component approaches are revolutionizing software development just as automation and componentization revolutionized manufacturing. Key technologies for automating program development are Generative Programming for program synthesis, Component Engineering for modularity, and Domain-Specific Languages (DSLs) for compact problem-oriented programming notations. The International Conference on Generative Programming and Component Engineering is a venue for researchers and practitioners interested in techniques that use program generation and component deployment to increase programmer productivity, improve software quality, and shorten the time-to-market of software products. In addition to exploring cutting-edge techniques of generative and component-based software, our goal is to foster further cross-fertilization between the software engineering and the programming languages research communities. SUBMISSIONS Research papers: 10 pages in SIGPLAN proceedings style (sigplanconf.cls, see http://www.sigplan.org/authorInformation.htm) reporting original and unpublished results of theoretical, empirical, conceptual, or experimental research that contribute to scientific knowledge in the areas listed below (the PC chair can advise on appropriateness). Tool demonstrations: Tool demonstrations should present tools that implement generative and component-based software engineering techniques, and are available for use. Any of the GPCE'11 topics of interest are appropriate areas for tool demonstrations. Purely commercial tool demonstrations will not be accepted. Submissions should contain a tool description of up to 6 pages in SIGPLAN proceedings style (sigplanconf.cls) and a demonstration outline of up to 2 pages text plus 2 pages screen shots. The six page description will, if the demonstration is accepted, be published in the proceedings. The 2+2 page demonstration outline will only be used by the PC for evaluating the submission. Workshops and tech talks: Workshops are organized by SPLASH - see the SPLASH website for details (http://splashcon.org) Tech talks are organized by GPCE as one or two talks at the end of each day of the conference. The talks will be about an hour in length and, similarly to tutorials, do not (need to) present original new research material. Unlike longer tutorials, these talks cannot be very interactive, and should instead aim to be 'keynote' style presentations. Please see the tech talks call for contributions at www.gpce.org for details. TOPICS GPCE seeks contributions in software engineering and in programming languages related (but not limited) to: * Generative programming o Reuse, meta-programming, partial evaluation, multi-stage and multi-level languages, step-wise refinement, generic programming, automated code generation o Semantics, type systems, symbolic computation, linking and explicit substitution, in-lining and macros, templates, program transformation o Runtime code generation, compilation, active libraries, synthesis from specifications, development methods, generation of non-code artifacts, formal methods, reflection * Generative techniques for o Product-line architectures o Distributed, real-time and embedded systems o Model-driven development and architecture o Resource bounded/safety critical systems. * Component-based software engineering o Reuse, distributed platforms and middleware, distributed systems, evolution, patterns, development methods, deployment and configuration techniques, formal methods * Integration of generative and component-based approaches * Domain engineering and domain analysis o Domain-specific languages including visual and UML-based DSLs * Separation of concerns o Aspect-oriented and feature-oriented programming, o Intentional programming and multi-dimensional separation of concerns * Applications of the above in industrial scenarios or to real-world problems, bridging the gap between theory and practice * Empirical studies o Original work in any of the areas above where there is a substantial empirical dimension to the work being presented. Such contributions might take the form of a case/field study, comparative analysis, controlled experiment, survey or meta-analysis of previous studies. Incremental improvements over previously published work should have been evaluated through systematic, comparative, empirical, or experimental evaluation. Submissions must adhere to SIGPLAN's republication policy (http://www.sigplan.org/republicationpolicy.htm) Please contact the program chair if you have any questions about how this policy applies to your paper (chairs(a)gpce.org) ORGANIZATION Chairs (chairs(a)gpce.org) General Chair: Ewen Denney (SGT/NASA Ames, USA) Program Chair: Ulrik Pagh Schultz (Univ. of Southern Denmark, Denmark) Publicity Chair: Chang Hwan Peter Kim (Univ. of Texas at Austin, USA) Program Committee * Andrzej Wasowski (IT University of Copenhagen, Denmark) * Aniruddha Gokhale (Vanderbilt University, USA) * Bernd Fischer (University of Southampton, UK) * Bruno C. d. S. Oliveira (Seoul National University, Korea) * Christian Kaestner (Philipps Universitat Marburg, Germany) * Chung-Chieh Shan (Rutgers, The State University of New Jersey, USA) * Don Batory (University of Texas at Austin, USA) * Eli Tilevich (Virginia Tech, USA) * Eric Tanter (University of Chile, Chile) * Gorel Hedin (Lund Institute of Technology, Sweden) * Ina Schaefer (TU Braunschweig, Germany) * Jeremiah Willcock (Indiana University, USA) * Jeremy Siek (University of Colorado at Boulder, USA) * Jurgen Vinju (Centrum Wiskunde en Informatica, The Netherlands) * Lionel Seinturier (University of Lille, France) * Marjan Mernik (University of Maribor, Slovenia) * Mat Marcus (Adobe Systems, USA) * Nicolas Loriant (INRIA, France) * Ras Bodik (University of California at Berkeley, USA) * Robert Gluck (University of Copenhagen, Denmark) * Steffen Zschaler (King's College London, UK) * Tudor Girba (netstyle.ch, Switzerland) * Walter Binder (University of Lugano, Switzerland) * Yanhong A. Liu (State University of New York at Stony Brook, USA)

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ANNOUNCE: preview release of diagrams EDSL for declarative drawing
by Brent Yorgey 17 May '11

17 May '11

I am extremely pleased to announce a "developer preview" release of the diagrams framework [1] for declarative drawing. This is a well-thought-out, well-documented, working release with all core functionality in place, but with many planned features still missing (for example, support for rendering text and higher-level tools for constructing curves). If you are interested in - trying out a new way of producing vector graphics, - providing feedback to help drive ongoing development, or - getting involved and contributing some code yourself, please give it a try! On the other hand, if you are looking for a complete, full-featured package that will let you jump right into producing the graphics you need, you may want to wait for the 1.0 release. If you are familiar with the diagrams package [2] already on Hackage, this is a complete rewrite which has been in the works for over a year and a half. What is it? ----------- Diagrams is an embedded domain-specific library (EDSL) for creating diagrams, illustrations, and other sorts of vector graphics. The overall vision is for diagrams to become a viable alternative to systems like MetaPost, Asymptote, and PGF/TikZ. Diagrams is: - Declarative: you specify what a diagram is, not how to draw it. - Compositional: diagrams can be combined in many ways to produce more complex diagrams. Diagrams are scale- and translation-invariant, so you never have to worry about a "global" coordinate system, only "local" ones. - Embedded: the full power of Haskell, including every library on Hackage, is available to help construct and manipulate diagrams. - Extensible: extending diagrams with additional or higher-level functionality is as simple as writing a Haskell module. - Flexible: diagrams is designed from the ground up to be as generic and flexible as possible. Features include: - Pluggable rendering backends -- creating a new rendering backend is as simple as writing a type class instance. - Arbitrary vector spaces -- the core diagrams library data types and primitives work for any vector space, so given a suitable rendering backend you can produce diagrams of any dimension, or even more exotic things... Cool, how can I try it out? --------------------------- Start by reading the quick tutorial [3], which has detailed information about how to install the necessary packages and will introduce you to the fundamentals of the framework. Or, for the truly impatient: cabal install diagrams-core diagrams-lib diagrams-cairo How can I contribute? --------------------- There are lots of ways you can contribute! First, you may want to subscribe to the project mailing list [4], and/or come hang out in the #diagrams IRC channel on freenode.org. - Cairo is the only well-supported backend at the moment, but you might create another backend or contribute to an existing project [5]. - The standard library is in need of additional features. Visit the Google Code site [6] for a list of open tickets. - Create a higher-level module built on top of the diagrams framework (e.g. tree or graph layout, generating Turing machine configuration diagrams, Penrose tilings ... your imagination is the only limit!) and submit it for inclusion in a special diagrams-contrib package which will be created for such higher-level user-contributed modules. - Use diagrams to create some cool graphics and submit them for inclusion in a gallery of examples (to be created soon). - Start your own project built on top of diagrams and let us know how it goes! - Last but certainly not least, just try it out for your pet graphics generation needs and contribute your bug reports and feature requests. Happy diagramming! Brought to you by the diagrams team: - Brent Yorgey - Ryan Yates with contributions from: - Sam Griffin - Vilhelm Sjöberg - Luite Stegeman - Kanchalai Suveepattananont - Scott Walck [1] http://code.google.com/p/diagrams/ [2] http://hackage.haskell.org/package/diagrams [3] http://projects.haskell.org/diagrams/tutorial/DiagramsTutorial.html [4] http://groups.google.com/group/diagrams-discuss [5] http://code.google.com/p/diagrams/wiki/BackendProjects [6] http://code.google.com/p/diagrams/

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ANN: AERN-Real-Double-2011.1
by Michal Konečný 13 May '11

13 May '11

Dear all, I am pleased to announce the first release of (a large part of) a newly designed AERN. AERN (approximating exact real numbers) is a set of Haskell libraries providing arbitrary precision interval arithmetic, polynomial arithmetic and distributed lazy exact real computation. Anyone is welcome to join in the development of AERN via http://code.google.com/p/aern/ . This release contains the following features: * Type classes for rounded arithmetic and rounded interval arithmetic with explicit control of rounding direction and the possibility to increase the rounding precision arbitrarily for types that support it. For example, type classes for types with rounded addition, multiplication, exponentiation etc. * Over 150 QuickCheck properties for these type classes, such as associativity of multiplication modulo rounding. * Interval arithmetic using Double endpoints, rounded outwards or inwards. Outwards rounding allows to safely approximate exact real arithmetic while a combination of both outwards and inwards rounding allows one to safely approximate exact interval arithmetic. Inverted intervals with Kaucher arithmetic are also supported. * For most of the type classes there are also in-place versions that act in the ST monad on mutable variables containing numbers or intervals. This facilitates some explicit memory allocation optimisation, especially for data on the C heap. The best starting point for experimenting with these features are the demo programs included in the bundle and the documentation for the AERN-Real-Double package: http://www-users.aston.ac.uk/~konecnym/aern/AERN-Real-Double (The HackageDB page does not have Haddock documentation because AERN fails to build with ghc 7.0.* due to a compiler bug.) The following features are planned for future releases: * Interval arithmetic with MPFR arbitrary precision endpoints. * Polynomial interval arithmetic with an optimised C core * Distributed exact real and geometric computation with lazy query-driven communication. For those familiar with the old AERN design, the main changes in the new design are: * use of many smaller type classes instead of few large ones * use of associated types instead of multi-parameter type classes * a much more systematic approach to representing the numerical order on real numbers and the information refinement (ie the inverse set inclusion) order on intervals * ability to specify different effort indicator types for each type of operation and each numerical type instead of Int. (For example, Double has () as its effort indicator for almost all operations while MPFR will have Precision as the effort indicator type.) * a more systematic approach to specifying QuickCheck properties and applying them to form test suites * a unified implementation of interval elementary operations (only sqrt and exp at the moment) that is efficient when applied to Double intervals as well as polynomial intervals * new support for in-place rounded numerical operations The current development team will be grateful for any feedback and suggestions. Best regards, Michal -- |o| Michal Konecny <mikkonecny(a)gmail.com> |o| http://www-users.aston.ac.uk/~konecnym/ |o| office: (+42) (0)121 204 3462 |o| PGP key http://www-users.aston.ac.uk/~konecnym/ki.aston

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Haskell Weekly News: Issue 181
by Daniel Santa Cruz 12 May '11

12 May '11

Welcome to issue 181 of the HWN, a newsletter covering developments in the Haskell community. This release covers the week of May 1 to 7, 2011. Announcements Last week I failed to note the announcement [http://goo.gl/ApClU] of a new version of Leksah (0.10.0). If you haven't yet, give Leksha a test run and send some feedback! Ketil Malde started a thread [http://goo.gl/Prlu2] about Robert Harper's thoughts on monads and laziness. Hakim Cassimally extended an invitation [http://goo.gl/QIjcF] to anyone living in the Northwest UK for Tuesday May 31st to Geekup's first ever "Functional Programming Night". Andy announced [http://goo.gl/uCEn1] a new release of Manatee (0.2.1). Quotes of the Week * hpc: [SPOILER] You can check wikipedia for the definition of fibonacci sequences if you get stuck after half an hour * pmetzger: it is always possible to make an algorithm slower. just give it to a CS freshman to code up. * kmc: ghc -XMixfixOperators -XDependentTypes -XMakeMeASandwich * pmetzger: I have my password tattooed to my forehead. that way when I forget it others can tell me what it is. * alexbagel: i find that my first 26 variables are always easy to name. after that it becomes a bit harder. * Eric Kow: Haskell is a good fit for me because I tend to practise Doh!-oriented programming Top Reddit Stories * More points for lazy evaluation Domain: augustss.blogspot.com, score: 56, comments: 24 On Reddit: http://goo.gl/qecQ1 Original: http://goo.gl/OnJXx * iterIO: iteratee-based IO with pipe operators, courtesy David Mazieres Domain: haskell.org, score: 43, comments: 15 On Reddit: http://goo.gl/YzPJn Original: http://goo.gl/6WQAk * Monad comprehensions are finally in GHC Domain: self.haskell, score: 37, comments: 32 On Reddit: http://goo.gl/1Rjnw * Horner's Rule Domain: patternsinfp.wordpress.com, score: 34, Comments: 2 On Reddit: http://goo.gl/A1wYo Original: http://goo.gl/zeC1f * Patent 5,893,120 reduced to mathematical formulae (via Haskell) Domain: paulspontifications.blogspot.com, score: 31, comments: 13 On Reddit: http://goo.gl/PmB4K Original: http://goo.gl/QknmV * Custom Haskell mug! Domain: imgur.com, score: 31, comments: 6 On Reddit: http://goo.gl/lD388 Original: http://goo.gl/bzZR8 * Differences between 'data' and 'newtype' ... in pictures Domain: stackoverflow.com, score: 31, comments: 2 On Reddit: http://goo.gl/5YaSo Original: http://goo.gl/KQiJv * Haskell: not pure enough? Domain: blog.ezyang.com, score: 30, comments: 19 On Reddit: http://goo.gl/6v28x Original: http://goo.gl/zsfSq * Galois is hiring computer scientists Domain: corp.galois.com,score: 27, comments: 28 On Reddit: http://goo.gl/ToeJ0 Original: http://goo.gl/osjJY * Fancy comparison of Data values Domain: pnyf.inf.elte.hu, score: 26, comments: 18 On Reddit: http://goo.gl/BlFVl Original: http://goo.gl/RuMKT Top StackOverflow Questions * Ordering of parameters to make use of currying votes: 43, answers: 3 Read on SO: http://goo.gl/7LnBJ * Difference between 'data' and 'newtype' in Haskell votes: 29, answers: 2 Read on SO: http://goo.gl/KQiJv * Haskell: why the convention to name a helper function "go"? votes: 24, answers: 3 Read on SO: http://goo.gl/CE1O7 * How do you design programs in Haskell or other functional programming languages? [migrated] votes: 24, answers: 0 Read on SO: http://goo.gl/IW7Z5 * Haskell Graphics Library that works in GHCi on MacOS X votes: 19, answers: 3 Read on SO: http://goo.gl/VZGAK About the Haskell Weekly News To help create new editions of this newsletter, please send stories to dstcruz(a)gmail.com. Until next time, Daniel Santa Cruz

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ANNOUNCE: time-1.2.0.5
by Ashley Yakeley 11 May '11

11 May '11

I've uploaded time-1.2.0.5 to Hackage. Version 1.2.0.5 fixes two parsing issues in 1.2.0.4. Firstly, the default century (in the absence of %C or %Y) is 1969-2068. Formerly it was 1900-1999. http://hackage.haskell.org/trac/ghc/ticket/2671 Secondly, %-, %_ and %0 specifiers can now be used. For instance, parseTime defaultTimeLocale "%-m/%e/%Y" "3/9/2011" :: Maybe Day = Just 2011-03-09 -- Ashley

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GTTSE 2011: Call for Participation
by Vadim Zaytsev 10 May '11

10 May '11

GTTSE 2011, 3–9 July, 2011, Braga, Portugal 4th International Summer School on Generative and Transformational Techniques in Software Engineering http://gttse.wikidot.com/ SCIENTIFIC PROGRAM SUMMARY 8 Long Tutorials 8 Short Tutorials Participants Workshop REGISTRATION DEADLINE: May 27 (early registration) June 17 (late registration) SCOPE AND FORMAT The summer school brings together PhD students, lecturers, technology presenters, as well as other researchers and practitioners who are interested in the generation and the transformation of programs, data, software models, data models, meta-models, documentation, and entire software systems. This concerns many areas of software engineering: software reverse and re-engineering, model-driven approaches, automated software engineering, generic language technology, aspect-oriented programming, feature-oriented development, compiler construction, to name a few. These areas differ with regard to the specific sorts of meta-models (or grammars, schemas, formats etc.) that underlie the involved artifacts, and with regard to the specific techniques that are employed for the generation and the transformation of the artifacts. The tutorials are given by renowned representatives of complementary approaches and problem domains. Each tutorial combines foundations, methods, examples, and tool support. The program of the summer school also features invited technology presentations, which present setups for generative and transformational techniques. These presentations complement each other in terms of the chosen application domains, case studies, and the underlying concepts. The program of the school also features a participants workshop. All summer school material will be collected in proceedings that are handed out to the participants. Formal proceedings will be compiled after the summer school, where all contributions are subjected to additional reviewing. The formal proceedings of the previous three instances of the summer school (2005, 2007 and 2009) were published as volumes 4143, 5235 and 6491 in the Lecture Notes in Computer Science series of Springer-Verlag. LONG TUTORIALS Compilation in the 21st century—Too Real for Comfort Darius Blasband (RainCode, Belgium) Tips & Tricks for Communication in CS: Reviews, Papers and Talks Olivier Danvy (Aarhus University, Denmark) Test Automation: An Empirical Perspective Arie van Deursen (Delft University of Technology, The Netherlands) Variation Programming with the Choice Calculus Martin Erwig (Oregon State University, USA) Exposing and Exploiting Program Analyses in an IDE Robert Fuhrer (IBM Research, USA) Model Management in the Wild: Foundations & Applications Richard Paige (University of York, UK) Methods and Tools for Analyzing Software Evolution Eleni Stroulia (University of Alberta, Canada) Bidirectional by Necessity James F. Terwilliger (Microsoft Corporation, USA) SHORT TUTORIALS Requirements for Self-adaptation Nelly Bencomo (INRIA, France) Dynamic Program Analysis for Database Reverse Engineering Anthony Cleve (University of Namur, Belgium) Tooling Research Tudor Girba (netstyle.ch GmbH, Switzerland) Model-based Language Engineering Florian Heidenreich (Technische Universität Dresden, Germany) Christian Wende (Technische Universität Dresden, Germany) Re(verse)engineering Tim Janssen (Cornerstone, Netherlands) Feature-oriented Software Development (FOSD) Christian Kästner (Philipps University Marburg, Germany) Sven Apel (University of Passau, Germany) Managing the Evolution of F/OSS with Model-Driven Techniques Alfonso Pierantonio (University of L’Aquila, Italy) Davide Di Ruscio (University of L’Aquila, Italy) Language & IDE Development, Modularization and Composition with MPS Markus Völter (independent/itemis, Germany) ORGANIZATION COMMITTEE Ralf Lämmel (Universität Koblenz-Landau, Germany) João Saraiva (Universidade do Minho, Portugal) Joost Visser (Software Improvement Group, The Netherlands) ADDITIONAL INFORMATION For additional information on the program, venue, and other details of the summer school, please consult the web page: http://gttse.wikidot.com/ Or engage in direct contact with: Jácome Cunha (Universidade do Minho, Portugal) — local arrangements and registration Vadim Zaytsev (Centrum Wiskunde & Informatica, The Netherlands) — publicity chair

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ANN: syntactic-0.1
by Emil Axelsson 10 May '11

10 May '11

I'm happy to announce the first release of syntactic: http://hackage.haskell.org/package/syntactic providing generic abstract syntax and utilities for embedded languages. To get an idea of what it's about, check out the tiny(!) implementation of (simplified) Feldspar in the Examples directory: http://projects.haskell.org/syntactic/Examples/MuFeldspar The library is intended to provide a growing set of utilities for embedded languages. In particular, I hope to be able to provide safe interfaces to various unsafe techniques for speeding things up. Comments, patches and clients are welcome! / Emil

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An update on ICFP'11 in Tokyo (September 18-24, 2011)
by Wouter Swierstra 10 May '11

10 May '11

Given the fairly recent severe earthquake and tsunami in Japan, you may wonder how this affects the preparations for ICFP'11 in Tokyo. Luckily, Tokyo was significantly less affected by these saddening events than the regions further north. In fact, the situation in Tokyo is almost back to normal, after only two months, with another four months until ICFP. Moreover, all major embassies have in the meantime lifted their travel advisories for the Tokyo metropolitan region (while they still maintain active advisories for some other regions.) Our local organisational team has completed major parts of the preparations and recently summarised the most important facts on a local information page for ICFP'11: http://www.biglab.org/icfp11local/index.html The main conference site is at http://www.icfpconference.org/icfp2011/ We are looking forward to seeing you in Tokyo in September! Manuel Chakravarty Zhenjiang Hu (General Chairs of ICFP'11)

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