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Fwd: ACL2 2009 Call for Papers
by Simon Marlow 03 Nov '08

03 Nov '08

[ forwarding on behalf of Sandip Ray <sandip(a)cs.utexas.edu> ] [ Apologies if you get several copies of this call for papers. Please share it with students and colleagues who may be interested in the workshop. ] =============================================================================== CALL FOR PAPERS =============================================================================== ACL2 2009 International Workshop on the ACL2 Theorem Prover and Its Applications May 11-12, 2009 Northeastern University, Boston, MA, USA http://www.cs.utexas.edu/~sandip/acl2-09/ In cooperation with ACM SIGPLAN =============================================================================== IMPORTANT DATES Abstract Submission: January 12, 2009 Paper Submission: January 19, 2009 Acceptance Notification: February 23, 2009 Final Version: March 23, 2009 =============================================================================== SCOPE OF CONFERENCE ACL2 2009 is a major forum for the users of the ACL2 theorem proving system to present research related to the ACL2 theorem prover and its application, and is the eighth in the series of workshops, occurring at approximately 18-month intervals. ACL2 is a state-of-the-art automated reasoning system, the latest in the Boyer-Moore family of theorem provers, for which its authors received the 2005 ACM Software Systems Award. ACL2 2009 is planned as a two-day workshop to be held in Boston, MA, USA, on May 11-12, 2009. In addition to paper presentations, ACL2 2009 is anticipated to include two keynote lectures, a panel discussion, and several rump sessions discussing ongoing research. We invite submission of papers on any topic related to ACL2 and its applications. We strongly encourage the participation of users of other theorem provers and researchers and practitioners interested in theorem proving technology. Appropriate topics include, but are not limited to, the following: * Applications of ACL2 in hardware and software system verification * Formalization of mathematics in ACL2 * Use of ACL2 in emerging and novel application areas * New libraries, tools, and interfaces for ACL2 * Connection of ACL2 with other formal (and semi-formal) verification tools * Foundational issues related to ACL2 * Comparison of ACL2 with other formal verification tools * Reports and proposals on improvement of ACL2 * Challenge problems related to implementation and applications of ACL2 * Classroom and pedagogical experiences in the use of ACL2 =============================================================================== PAPER SUBMISSION Submissions must be made electronically in PDF format through the ACL2 2009 Web site. Submissions must use ACM SIG Proceedings format with letter-size paper (see URL http://www.acm.org/sigs/pubs/proceed/template.html) ACL2 2009 is organized in cooperation with ACM SIGPLAN and the proceedings are expected to be published in the ACM Digital Library. Two categories of papers will be accepted: long (at most 10 pages) and short (at most 4 pages). Authors may assume that the audience has a working knowledge of ACL2's syntax, basic commands, and modeling techniques. Papers should contain a short abstract of about 150 words, clearly stating the contribution of the submission. Papers should be self-contained, but we strongly encourage authors to follow the tradition (where applicable) of providing ACL2 "books", or script files, with instructions for their execution. For accepted papers, these books will be mirrored from the ACL2 Home Page and included in the future ACL2 distributions. At least one author of each accepted paper will be required to register for the workshop and present the paper. ============================================================================== ORGANIZATION Co-Chairmen: Sandip Ray, University of Texas at Austin, USA David Russinoff, Advanced Micro Devices, Inc., USA Local Arrangements: Panagiotis Manolios, Northeastern University, USA Publications: Ruben Gamboa, University of Wyoming Steering Committee: John Cowles, University of Wyoming, USA Ruben Gamboa, University of Wyoming, USA Matt Kaufmann, University of Texas at Austin, USA Panagiotis Manolios, Northeastern University, USA J Strother Moore, University of Texas at Austin, USA Jun Sawada, IBM Austin Research Laboratory, USA Matt Wilding, Rockwell Collins, Inc., USA ============================================================================== PROGRAM COMMITTEE * John Cowles, University of Wyoming, USA * Ruben Gamboa, University of Wyoming, USA * Mike Gordon, Cambridge University, UK * Matt Kaufmann, University of Texas at Austin, USA * Francisco Palomo Lozano, Universidad de Cadiz, Spain * Panagiotis Manolios, Northeastern University, USA * John Matthews, Galois, Inc., USA * J Strother Moore, University of Texas at Austin, USA * Rex Page, University of Oklahoma, USA * Jun Sawada, IBM Austin Research Laboratory, USA * Julien Schmaltz, Radboud University, Nijmegen, the Netherlands * Natarajan Shankar, SRI International, USA * Rob Sumners, Advanced Micro Devices, Inc., USA * Freek Wiedijk, Radboud University, Nijmegen, the Netherlands * Matt Wilding, Rockwell Collins, Inc., USA

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ANNOUNCE: Graphalyze-0.5 and SourceGraph-0.3
by Ivan Lazar Miljenovic 03 Nov '08

03 Nov '08

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I've just submitted my thesis this morning (w00t!!!) and as such I'm announcing the latest versions of Graphalyze [1,2] and SourceGraph [3,4], which fix a couple of bugs in the previous versions (these bugs were fixed whilst waiting for my supervisor to finish reading through my draft, and as such I had to re-write bits of my thesis that talked about the limitations of the software :s ). [1] http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Graphalyze [2] http://code.haskell.org/Graphalyze [3] http://hackage.haskell.org/cgi-bin/hackage-scripts/package/SourceGraph [4] http://code.haskell.org/SourceGraph Briefly, SourceGraph is a utility that uses the Graphalyze library to analyse Cabalized Haskell software. Its input/output is rather restrictive at the moment: it takes a single argument, which is the path to a .cabal file, and then produces an HTML report in: <project directory>/SourceGraph/<project name>.html This report contains visualisation of the code for each module, for the imports (similar to what graphmod [5] does) as well as the entire code base. Furthermore, the entire code base is also visualised with functions grouped by the modules they're defined in, as well some simple analyses (such as comparing the export list to what functions are actually roots, similar to the output for top-level functions returned by GHC when using -fwarn-unused-binds). Main changes in Graphalyze since version 0.4: * When writing my thesis, I found some obvious silly mistakes (such as copying the rootsOf function definition to leavesOf, but not changing the function definition). * Images in the document representation are now inline elements. * When using Pandoc [6] for document generation, the size of generated graphs is now customisable on a per-format basis; furthermore, for web pages graph visualisations link to larger versions. Also, graph visualisations can now be created in a sub-directory. Main changes in SourceGraph since version 0.2: * Now uses Cabal 1.6 * Improve visual layout of generated HTML report (still no CSS though). * "Smarter" analysis: don't show trivial analysis results, and when analysing the entire code base don't return cliques, etc. that contain functions all in the same module (as they would have been reported in the per-module section). Note, however, that the parsing limitations for version 0.2 still apply: cpp is still as-yet unsupported (as I'm not sure what I'll do about choosing cpp flags); Template Haskell, HaRP and HXML are still ignored and functions in class declarations/records are still ignored (the former because it's ambiguous which actual function you want, the latter because they're boring :p ). Also, SourceGraph is _still_ not a refactoring tool ;-) If anyone's interested, I'll soon be uploading the final version of my thesis to my blog. Also, if anyone is interested in hacking on any of this, feel free! I'll probably leave it for a while (I'm going to be doing Java coding over summer, blech :s ), but I intend to come back to it later on. - -- Ivan Lazar Miljenovic Ivan.Miljenovic(a)gmail.com IvanMiljenovic.wordpress.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEARECAAYFAkkOcaAACgkQfEfFJ9JhvyjhIwCeM9VXsJeSVK2CdWURJDer6zoA A5YAoIfayHtjpw0qt/gyPZhhhypOwzSh =x+/X -----END PGP SIGNATURE-----

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Need help with VXML again (fun deps and forall types)
by Marc Weber 02 Nov '08

02 Nov '08

Some time I've announced that I'm working on VXML, a validating xml library. The use case which makes trouble is elem+ (one or more) <!ELEMENT root (a|b|(c,d+))*> This example is encoded in this way: root -> St 1 id :1 endable : True a -> St 1 b -> St 1 c -> St 12 id :11 endable : True (a|b|c) -> St 1 d -> St 11 id :12 endable : False d -> St 11 to be read as: When creating a new root element start with state 1, then expect one of a,b,c subelemnts. If subelement c is added continue with state 12. The element may not be finalized (endable false because a "d" is expected). Following that we end in a loop at state 11 which is endable when only adding more d subelemnts. in VXML it looks like this print $ fStr $ runRoot $ vdo -- forceElements c e d e -- first, result has state 12 A d e -- second, result has state 11 X d e -- thrd, result has state 11 d e -- fourth, result has state 11 Y -- ... Now I'd like to do something convinient such as foldr1 (>>) print $ [1..10] I've called the corresponding function in VXML vxmlgtgt because it can be used like a monad and even do notation is supported using the vdo cpp macro rebinding (>>), (>>=) and return. Obviously I can only use foldr from X up to Y because A has a different return type. If you download the latest version of the library (git clone git://mawercer.de/vxml; git checkout fc160ab # is master branch ) you see that it actually works quite fine -- helper function: vxmlSeqPlus_ (f,fl) = f `vxmlgtgt` (foldr1 vxmlgtgt fl) -- usage example from testSimple.hs, note that both (d e) have different types vxmlSeqPlus_ ((d e), replicate 9 (d e)) d is actually a function creating the d element requiring a function as first argument which adds attrubutes and subelemnts (e is a nop here) This all makes d having a type which looks rather complicated: el*: the result type (String only in the current implementation) data VXML st el_ st2 el2_ st3 el3_ a = VXML { runVVXML :: (PT st el_ -> PT st2 el2_) -- [1] -> (a, PT st el_ -> PT st3 el3_) -- [2] } [1] : st -> st2 : The function which is passed [2] : st -> st3 : The type of function which is returned taking a function modyfiying the parent and adding "d" resulting in st3 (st3 is either State12 in A, or State11 in Y talking about the example given above) Its even getting more interesting now: Because I'd like to use different result types (String, ByteString, ...) I've used a type var to represent that type. I've called them el el2 el3 etc. When finally creating the document by using runRoot the result types propagates through the xml tree by functional dependencies. An example is the AddElT class which actually does add a subelement: class AddElT est el_ estc elc_ est2 el2_ | est estc -> est2 -- result state is determined by parent and child element state , est est2 estc el2_ -> el_ -- the result type of child and parent privious sibling are determined by the el2_ return type and the element states , est est2 estc el2_ -> elc_ where addElT :: PT est el_ -> PT estc elc_ -> PT est2 el2_ The instance has constraints like this determining el_ elc_ and st2 instance ( , DetermineElAddEl (NYV (Element elType AttrsOk st hchs)) el2 cest2 elc2 (NYV (Element elType AttrsOk st2 HTrue)) el3 , Consume st (Elem celType) st2 [..] ) => AddElT [..] Determining states form leafs to the root then propagating String or ByteString result type form the root to the leaf depending on states works fine until I start trying to use shortcut for the foldr1 example above. Instead of vxmlSeqPlus_ ((d e), replicate 9 (d e)) I'd like to write this. Of course the lamba here is polymorphic because it must return State 12 the first time and State 11 in the following cases. vxmlMapSeqPlus_ (\_ -> d e) [1..10] -- Ex I It's implementation is straight forward: vxmlMapSeqPlus_ f (x:xs) = vxmlSeqPlus_ (f x, map f xs) vxmlMapSeqPlus_ _ [] = error "vxmlSeqPlus has been called with empty list" My attempt to assign a type looks like this: vxmlMapSeqPlus_ :: ( VXMLMonad m st el st2 el2 st3 el3 st3 el3 , VXMLMonad m st el st3 el3 st3 el3 st3 el3 ) => (forall st' elA st'' elB . t -> m st el st' elA st'' elB ()) -> [t] -> m st el st2 el2 st3 el3 () vxmlMapSeqPlus_ f (x:xs) = vxmlSeqPlus_ (f x , map f xs) vxmlMapSeqPlus_ _ [] = error "vxmlSeqPlus has been called with empty list" where class VXMLMonad m st el_ st2 el2_ st3 el3_ st4 el4_ where vxmlgtgt :: m st el_ st2 el2_ st3 el3_ a -> m st el_ st3 el3_ st4 el4_ b -> m st el_ st2 el2_ st4 el4_ b vxmlgtgt a b = vxmlbind a $ const b vxmlbind :: m st el_ st2 el2_ st3 el3_ a -> (a -> m st el_ st3 el3_ st4 el4_ b) -> m st el_ st2 el2_ st4 el4_ b However when compiling the example (Ex I) there are a bunch of errors telling me that ghc can't find the matching instances caused by missing specialization of st.. That is ghc does no longer determine the resulting state based on parent and previous childs. Without state it can't propagate the el type ... You can see both examples in testSimple.hs vxmlSeqPlus_ ((d e), replicate 9 (d e)) vxmlMapSeqPlus_ (\n -> d e ) [1..10] So my question is: The second line does work fine, the first one dosen't. How to write vxmlMapSeqPlus_ so that I can compile the example? vxmlMapSeqPlus_ (\n -> d e ) [1..10] (d e) `vxmlgtgt` (foldr1 vxmlgtgt $ map (const $ d e) [2..10]) If you want to try this with ghc older than 6.10 you'll have to rewrite the vdo notation using vxmlbind and vxmlgtgt.. Do you have any idea how to make this work as expected? That's the last issue preventing me from trying to use it in real life projects. Sincerly Marc Weber

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Publication of InputYourData.com + Project Announcement
by Enzo Haussecker 02 Nov '08

02 Nov '08

I would like to announce the publication of InputYourData.com (beta) − the online resource tool for financial, mathematical and scientific calculations. All web applications found at http://inputyourdata.com/ are written solely in Haskell and based on the Network.CGI framework. This website began as an experiment to familiarize myself with the monadic features of Haskell and their use in web programming. Namely, the mapping and manipulation of user inputs as typed objects. Through these experiments I found that Haskell allows for an efficient system where a variety of operations can be preformed while minimizing as many resources (such as time and memory space) as possible. I am now interested in developing a similar type of website, except wiki style − where all web applications are created by the user. Essentially, I am designing a web application where users can symbolically declare the arguments of a function and that function's call based on arbitrary variables. For example, say a user would like to create a web application to compute the roots of a second degree polynomial. He/she would simply declare the arguments to her function − three complex numbers a b and c, and the call of that function − (-b ± sqrt (b^2 - 4*a*c))/(2*a). The product of that users inputs will render a web application that looks similar to http://inputyourdata.com/cgi-bin/quadratic.cgi (all text is to be updated by the user as well). As one could imagine, other, more complex functions involving vectors, matrices, stock prices, and other arguments can also be defined in terms of arbitrary variables and declared as an inputs to my wiki-style web application. If you are intrigued by this project and you have substantial experience in designing Haskell-based web applications, please send me your resume and a brief summery of why you are interested. Regards, Enzo Haussecker ehaussecker(a)gmail.com

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Haskell Weekly News: Issue 91 - November 1, 2008
by Brent Yorgey 01 Nov '08

01 Nov '08

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20081101 Issue 91 - November 01, 2008 --------------------------------------------------------------------------- Welcome to issue 91 of HWN, a newsletter covering developments in the [1]Haskell community. Announcements blas version 0.6. Patrick Perry [2]announced a [3]new version of the Haskell BLAS bindings, now with support for the ST monad! darcs hacking sprint #1 (report). Eric Y. Kow [4]summarized the [5]progress made during the darcs hacking sprint last weekend. Looks like exciting stuff! Much more detail and links can be found in Eric's original email. LAST CALL: Haskell Communities and Activities Report. Janis Voigtlaender [6]is extending the submission deadline for the 15th edition of the Haskell Community and Activities Report by a few days. If you haven't already, please [7]write an entry for your new project or update your old entry. Data.TCache 0.5.1. Alberto G. Corona [8]announced the release of [9]Data.TCache, which implements a transactional cache with configurable persistence. It tries to simulate Hibernate for Java or Rails for Ruby; the main difference is that transactions are done in memory trough STM. multirec-0.1. Andres Loeh [10]announced the release of the [11]multirec package, which provides a mechanism to talk about fixed points of systems of datatypes that may be mutually recursive. On top of this representations, generic functions such as the fold or the Zipper can then be defined. Making 'Super Nario Bros.' in Haskell. Korcan Hussein [12]linked to a [13]super mario brothers clone which was [14]written in Haskell! Chart-0.9. Tim Docker [15]announced the 0.9 release of the [16]Chart library, a library for drawing 2D charts. Publication of InputYourData.com + Project Announcement. Enzo Haussecker [17]announced the publication of [18]InputYourData.com, an online tool, written in Haskell, for financial, mathematical and scientific calculations. Enzo also described an idea to create a similar website where web applications are created by the user. If you are intrigued by this project and have substantial experience in designing Haskell-based web applications, please send Enzo your resume and a brief summery of why you are interested. Blog noise [19]Haskell news from the [20]blogosphere. * Mark Jason Dominus: [21]Atypical Typing. Mark describes his OOPSLA talk about Haskell's type system. * Eric Kow (kowey): [22]official darcs blog!. * Ben Moseley: [23]2 Minute intro to Associated Types / Type Families. * Ivan Lazar Miljenovic: [24]Honours + LXDE. Ivan discusses the status of his Haskell-oriented Mathematics Honours thesis. * Jason Dagit: [25]Darcs Hacking Sprint - Summary from Portland Team. * Eric Kow (kowey): [26]darcs hacking sprint - Team Brighton Day 2. * Dan Piponi (sigfpe): [27]Operads and their Monads. Quotes of the Week * lispy: I just wanted to make sure that this was illegal first * quicksilver: it doesn't entirely help that SQL is a series of broken standards layered over very poor decisions by large corporations * Baughn: SingInTime> hello world <Baughn> SingInTime: Type mismatch: Expected type: IRC [a], inferred type: IO () About the Haskell Weekly News New editions are posted to [28]the Haskell mailing list as well as to [29]the Haskell Sequence and [30]Planet Haskell. [31]RSS is also available, and headlines appear on [32]haskell.org. To help create new editions of this newsletter, please see the information on [33]how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get [34]http://code.haskell.org/~byorgey/code/hwn/ . References 1. http://haskell.org/ 2. http://article.gmane.org/gmane.comp.lang.haskell.cafe/47117 3. http://quantile95.com/2008/10/31/ann-blas-bindings-for-haskell-version-06/ 4. http://article.gmane.org/gmane.comp.lang.haskell.cafe/47114 5. http://blog.darcs.net/2008/10/darcs-hacking-sprint-1-report.html 6. http://article.gmane.org/gmane.comp.lang.haskell.cafe/47078 7. http://www.haskell.org/pipermail/haskell/2008-October/020651.html 8. http://article.gmane.org/gmane.comp.lang.haskell.cafe/47016 9. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/TCache 10. http://article.gmane.org/gmane.comp.lang.haskell.general/16574 11. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/multirec 12. http://article.gmane.org/gmane.comp.lang.haskell.general/16572 13. http://uk.youtube.com/watch?v=gVLFGQGRsDw 14. http://svn.coderepos.org/share/lang/haskell/nario/ 15. http://article.gmane.org/gmane.comp.lang.haskell.general/16570 16. http://dockerz.net/software/chart.html 17. http://article.gmane.org/gmane.comp.lang.haskell.general/16550 18. http://inputyourdata.com/ 19. http://planet.haskell.org/ 20. http://haskell.org/haskellwiki/Blog_articles 21. http://blog.plover.com/talk/atypical-typing.html 22. http://koweycode.blogspot.com/2008/10/official-darcs-blog.html 23. http://nattermorphisms.blogspot.com/2008/10/2-minute-intro-to-associated-ty… 24. http://ivanmiljenovic.wordpress.com/2008/10/29/honours-lxde/ 25. http://blog.codersbase.com/2008/10/28/darcs-hacking-sprint-summary-from-por… 26. http://koweycode.blogspot.com/2008/10/darcs-hacking-sprint-team-brighton-da… 27. http://sigfpe.blogspot.com/2008/10/operads-and-their-monads.html 28. http://www.haskell.org/mailman/listinfo/haskell 29. http://sequence.complete.org/ 30. http://planet.haskell.org/ 31. http://sequence.complete.org/node/feed 32. http://haskell.org/ 33. http://haskell.org/haskellwiki/HWN 34. http://code.haskell.org/~byorgey/code/hwn/

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ANNOUNCE: multirec-0.1
by Andres Loeh 31 Oct '08

31 Oct '08

multirec: Generic programming with systems of recursive datatypes ================================================================= Many generic programs require information about the recursive positions of a datatype. Examples include the generic fold, generic rewriting or the Zipper data structure. Several generic programming systems allow to write such functions by viewing datatypes as fixed points of a pattern functor. Traditionally, this view has been limited to so-called regular datatypes such as lists and binary trees. In particular, systems of mutually recursive datatypes have been excluded. With the multirec library, we provide a mechanism to talk about fixed points of systems of datatypes that may be mutually recursive. On top of this representations, generic functions such as the fold or the Zipper can then be defined. We expect that the library will be especially interesting for compiler writers, because ASTs are typically systems of mutually recursive datatypes, and with multirec it becomes easy to write generic functions on ASTs. The library is based on ideas described in the paper: Alexey Rodriguez, Stefan Holdermans, Andres Löh, Johan Jeuring Generic programming with fixed points for mutually recursive datatypes Technical Report, Universiteit Utrecht http://www.cs.uu.nl/research/techreps/repo/CS-2008/2008-019.pdf Features -------- * Generalizes the fixed point view from single, regular datatypes to systems of recursive datatypes. * Includes detailed examples: generic fold and generic compos, the latter in the style of Björn Bringert, Arne Ranta A pattern for almost compositional functions ICFP 2006 The Zipper and generic rewriting for systems of datatypes will be released soon as separate libraries that build on multirec. * The generic compos functions do not require the user to modify their existing systems of datatypes. * In its current form, this library does not support nested datatypes. Requirements ------------ * GHC 6.8.3 or later * Cabal 1.2.1 or later Download -------- With cabal-install: cabal install multirec Get the package: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/multirec Get the source: svn checkout https://svn.cs.uu.nl:12443/repos/dgp-haskell/multirec/trunk Bugs & Support -------------- Report issues, request features, or just discuss the library with the authors, maintainers, and other interested persons at: http://www.haskell.org/mailman/listinfo/generics -- Andres Loeh, Universiteit Utrecht mailto:andres@cs.uu.nl mailto:mail@andres-loeh.de http://www.andres-loeh.de

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LAST CALL: Haskell Communities and Activities Report
by Janis Voigtlaender 30 Oct '08

30 Oct '08

Dear Haskellers, It is not yet too late to contribute to the 15th edition of the HC&A Report. In fact, I will wait for a few more days. If you haven't already, please write an entry for your new project or update your old entry. Please mail your entries to hcar(a)haskell.org in plain text or LaTeX format. More information can be found in the original Call for Contributions at http://www.haskell.org/pipermail/haskell/2008-October/020651.html I look forward to receiving your contributions. Thanks a lot, Janis (current editor) -- Dr. Janis Voigtlaender http://wwwtcs.inf.tu-dresden.de/~voigt/ mailto:voigt@tcs.inf.tu-dresden.de

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Making 'Super Nario Bros.' in Haskell‏
by Korcan Hussein 29 Oct '08

29 Oct '08

Hi I haven't seen this posted any where so I'm sorry in advance if this has been mentioned already but I came across this recent video on youtube: http://uk.youtube.com/watch?v=gVLFGQGRsDw it's a mario clone written in haskell with a link to source code repository (http://svn.coderepos.org/share/lang/haskell/nario/) I thought that it maybe useful to some people. Trustworthiness:Vendor reliability:Privacy:Child safety: _________________________________________________________________ Discover Bird's Eye View now with Multimap from Live Search http://clk.atdmt.com/UKM/go/111354026/direct/01/

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Announce: Chart-0.9
by Tim Docker 29 Oct '08

29 Oct '08

Chart-0.9 is now available via hackage and a darcs repository. This is a library for drawing 2D charts. It relies upon the haskell cairo binding that is part of gtk2hs, and hence supports several backend output formats (png, pdf, ps, etc). Further information is available here: http://dockerz.net/software/chart.html Also, there is now a mailing list for discussions about the library: http://groups.google.com/group/haskell-charts Tim

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ANNOUNCE: Data.TCache 0.5.1
by Alberto G. Corona 28 Oct '08

28 Oct '08

I uploaded TCache to hackage.org. Data.Tcache is a transactional cache with configurable persistence. It tries to simulate Hibernate for Java or Rails for Ruby. The main difference is that transactions are done in memory trough STM. There are transactional cache implementations for some J2EE servers like JBOSS. TCache uses STM . It can atomically apply a function to a list of cached objects. The resulting objects go back to the cache (withResources). It also can retrieve these objects (getResources). Persistence can be syncronous (syncCache) or asyncronous, wtih configurable time between cache writes and configurable cache clearance strategy. the size of the cache can be configured too . All of this can be done trough clearSyncCacheProc. Even the TVar variables can be accessed directly (getTVar) to acceess all the semantic of atomic blocks while maintaining the persistence of the TVar updates. Persistence can be defined for each object.: Each object must have a defined key, a default filename path (if applicable). Persistence is pre-defined in files, but the readResource writeResource and delResource methods can be redefined to persist in databases or whatever. There is a sample.hs that explain the main features.

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