August 2002 - Haskell

tuple component functions
by trb＠eastpac.com.au 03 Jan '03

03 Jan '03

S.D.Mechveliani writes: > As Haskell has the standard functions fst, snd to decompose (a,b), > maybe, it worths to provide also > tuple31, tuple31, tuple31, > ... > tuple51, tuple52, tuple53, tuple54, tuple55 > > for the tuples of n = 3,4,5 ? I've found some of these useful, except I named them differently: > fst3 :: (a,b,c) -> a > fst3 (x,_,_) = x > snd3 :: (a,b,c) -> b > snd3 (_,x,_) = x > thd3 :: (a,b,c) -> c > thd3 (_,_,x) = x .... never got around to quadruples etc. I also defined (some of these may be untested): > tripl :: a -> (a,a,a) > tripl x = (x,x,x) > curry3 :: ((a, b, c) -> d) -> a -> b -> c -> d > curry3 f x y z = f (x, y, z) > uncurry3 :: (a -> b -> c -> d) -> ((a, b, c) -> d) > uncurry3 f t = f (fst3 t) (snd3 t) (thd3 t) > applyTriple :: (a -> b, a -> c, a -> d) -> a -> (b,c,d) > applyTriple (f,g,h) x = (f x, g x, h x) > cross3 :: (a -> b, c -> d, e -> f) -> (a,c,e) -> (b,d,f) > cross3 (f,g,h) (x,y,z) = (f x, g y, h z) > mapTriple :: (a -> b) -> (a, a, a) -> (b, b, b) > mapTriple = cross3 . tripl > applyFst3 :: (a -> b) -> (a, c, d) -> (b, c, d) > applyFst3 f = applyTriple (f . fst3, snd3, thd3) > applySnd3 :: (a -> b) -> (c, a, d) -> (c, b, d) > applySnd3 f = applyTriple (fst3, f . snd3, thd3) > applyThd3 :: (a -> b) -> (c, d, a) -> (c, d, b) > applyThd3 f = applyTriple (fst3, snd3, f . thd3) > applyArgs3 :: (a -> b) -> (c -> d) -> (e -> f) -> (b -> d -> f -> g) -> (a -> c -> e -> g) > applyArgs3 af1 af2 af3 f = \x y z -> f (af1 x) (af2 y) (af3 z) > rotl :: (a -> b -> c -> d) -> (b -> c -> a -> d) > rotl f y z x = f x y z > rotr :: (a -> b -> c -> d) -> (c -> a -> b -> d) > rotr f z x y = f x y z > rotl4 :: (a -> b -> c -> d -> e) -> (b -> c -> d -> a -> e) > rotl4 f y z t x = f x y z t > rotr4 :: (a -> b -> c -> d -> e) -> (d -> a -> b -> c -> e) > rotr4 f t x y z = f x y z t Some more combinators (only for pairs so far): > twin :: a -> (a,a) > twin x = (x,x) > swap :: (a,b) -> (b,a) > swap (x,y) = (y,x) -- apply a pair of functions to one argument > applyPair :: (a -> b, a -> c) -> a -> (b, c) > applyPair (f, g) x = (f x, g x) -- apply a pair of functions to a pair > cross :: (a -> b, c -> d) -> (a, c) -> (b, d) > cross (f, g) = applyPair (f . fst, g . snd) -- compose a pair of functions onto one function > dotPair :: (a -> b, a -> c) -> (d -> a) -> (d -> b, d -> c) > dotPair (f, g) h = (f . h, g . h) -- compose a pair of functions onto a pair of functions > dotCross :: (a -> b, c -> d) -> (e -> a, f -> c) -> (e -> b, f -> d) > dotCross (f, g) (h, i) = (f . h, g . i) > mapPair :: (a -> b) -> (a, a) -> (b, b) > mapPair = cross . twin > applyFst :: (a -> b) -> (a, c) -> (b, c) > applyFst f = applyPair (f . fst, snd) > applySnd :: (a -> b) -> (c, a) -> (c, b) > applySnd f = applyPair (fst, f . snd) > applyArgs :: (a -> b) -> (c -> d) -> (b -> d -> e) -> (a -> c -> e) > applyArgs af1 af2 f = \x y -> f (af1 x) (af2 y) > betweenFst :: (a -> b -> c) -> (a, d) -> (b, e) -> c > betweenFst = applyArgs fst fst > betweenSnd :: (a -> b -> c) -> (d, a) -> (e, b) -> c > betweenSnd = applyArgs snd snd I find these combinators useful, and probably other people have their own versions - it would be nice to get them standardised, so we all speak the same language. By standardised, I mean a prominent version that will be adopted by users, not necessarily a committee process. Tim

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ICFP programming contest
by trb＠eastpac.com.au 03 Jan '03

03 Jan '03

Michael Hobbs writes: > Just took a look at the results for the ICFP contest. Am I correct in > assuming that "LA" stands for Lennart Augustsson and that "Si^3" stands > for Simon Marlow, Simon Peyton-Jones, Sigbjorn Finne? Is there a URL for the results ? Tim

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Re: GPH: RE: Concurrency and Haskell
by Phil Trinder 12 Sep '02

12 Sep '02

Murray, There are several parallel Haskell implementations: a survey of them has just appeared in Journal of Func. Prog Vols 4&5 (July & Sept 2002). Implementations are available for o Eden http://www.mathematik.uni-marburg.de/inf/eden/ o GpH http://www.cee.hw.ac.uk/~dsg/gph/ My group works on Glasgow parallel Haskell (GpH) which extends Haskell 98 with a parallel composition combinator. As Simon said the main implemntation, GUM, buys portability using the relatively slow PVM communications library. This doesn't matter so much on distributed memory machines, and we've recently achieved some quite respectable results SunServer shared-memory machines. Simon Marlowe developed an alternative SMP implementation of GpH a couple of years ago that may be more suitable for a Mosix platform, but I'm not sure of the status of that implementation now. Phil On Mon, 19 Aug 2002 18:04:44 +0100 Simon Peyton-Jones <simonpj(a)microsoft.com> wrote: > Hi Murray > > I'm catching up with my email backlog, but I didn't see a reply to your > message, so I thought I'd reply. The parallel-Haskell crew are at > http://www.cee.hw.ac.uk/~dsg/gph/ > There's a mailing list that I'm ccing. > > GHC can be built to run on a shared-memory multiprocessor, but we have > not built and tested that for some time. Untrue - both Eden and GpH are currently used on SunServer SMPs. > GPH is aimed more at > distributed-memory machines, and has quite a bit more code layered on > top of GHC. Details on the GPH page above. > > Let me know if I can help. It'd be great to get some more > parallel-Haskell stuff going. > > Simon > > | A group of us at Brooklyn College (City University of New > | York) are in the latter stages of setting up a Mosix cluster > | that we would like to use for research on, among other > | things, parallel execution of Haskell code and run-time > | optimization of both automatic and programmed parallelization. > | > | I would greatly appreciate hearing from anyone who can > | provide advice on > | an appropriate bibliography on the language implementation and past > | work in this area (other than the code in the Haskell compilers and > | libraries, of course), approaches, ongoing work, etc. > | > | Also, I would be most interested in hearing from anyone > | interested in joining our effort (no problems with remote > | access to the cluster by way of SSH), or making arrangements > | for cooperation in research in this area, although, of > | course, access to our equipment will be subject to approval > | from "higher authorities" (however, note that I really don't > | expect difficulty here, since our administration has already > | shown considerable interest in supporting the project). > | > | Replies to the list will be read, but those who wish may mail > | me directly at mgross(a)dorsai.org. > | > | Thanks in advance for any replies. > | > | Murray Gross > | Adj. Lecturer, Brooklyn College, > | City University of New York > | > | > | > | _______________________________________________ > | Haskell mailing list > | Haskell(a)haskell.org http://www.haskell.org/mailman/listinfo/haskell > | > -------------------------------------------------- Phil Trinder Department of Computing and Electrical Engineering Heriot Watt University Riccarton Edinburgh, EH14 4AS E-mail: trinder(a)cee.hw.ac.uk Teleph: +44 (0)131 451 3435 Depart: +44 (0)131 451 3328 Fasmly: +44 (0)131 451 3327 Intrnt: http://www.cee.hw.ac.uk/~trinder

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RE: Spam
by Simon Marlow 30 Aug '02

30 Aug '02

> Sorry to bother you with a message about spam. > > I have noticed two things about this mailing list: > > * Every once in a while, we get messages like "your e-mail > is under consideration for sending to the list". This > suggests that the mailing list is moderated, and that > there is some person deciding on what can and what cannot > be sent to the list. > > (One could discuss wether it is a good idea to send these > messages to the whole list rather than just to the person > who sent them, but let us not discuss that here.) The list is partly moderated: any message over a certain size, or with too many destination addresses, or with certain keywords, gets held for moderation. The moderation messages you're seeing are caused by viruses (primarily Win32.Klez) which spoof the sender address. The virus messages are always caught by the auto moderation, but sometimes the sender address has been spoofed to be one of the other Haskell lists, so the moderation message gets sent there. Unfortunately causing these messages to be caught by the moderator would lead to an infinite loop... > * Very often, we get spam e-mail. This suggests that nobody > is moderating the list. Spam is supposed to be caught by SpamAssassin on haskell.org. It's doing a pretty good job so far - I get far fewer messages to moderate, but the occasional one does get through. > These two observations are in contradiction with each other. > > Couldn't we allow list subscribers to submit to the list > without problems, whereas non-list subscribers have to be > approved by a list moderator? I've resisted doing that because (a) I'm lazy and (b) lots of people are subscribed to the list using addresses which are different from the ones they post with, so we'd have to gradually build up a list of those addresses which are allowed. Well, maybe I'll give it a go for a while. If it's too much hassle expect an advertisment for the moderator's job soon... Cheers, Simon

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Spam
by Koen Claessen 30 Aug '02

30 Aug '02

Hi all, Sorry to bother you with a message about spam. I have noticed two things about this mailing list: * Every once in a while, we get messages like "your e-mail is under consideration for sending to the list". This suggests that the mailing list is moderated, and that there is some person deciding on what can and what cannot be sent to the list. (One could discuss wether it is a good idea to send these messages to the whole list rather than just to the person who sent them, but let us not discuss that here.) * Very often, we get spam e-mail. This suggests that nobody is moderating the list. These two observations are in contradiction with each other. Couldn't we allow list subscribers to submit to the list without problems, whereas non-list subscribers have to be approved by a list moderator? Just my 2 öre, /Koen.

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Say�n haskell ,
by Green Card 29 Aug '02

29 Aug '02

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Welcome to Floralplanet.com- thanks for stopping By!
by Visit Earth's Largest Garden today! 29 Aug '02

29 Aug '02

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Please reconsider
by rob and lynne rindzevicius 29 Aug '02

29 Aug '02

Please take a few moments to read this. Your very soul is at risk, because you are performing this barbaric form of murder. How can you sleep at night? All the money that you are making from this procedure is not going to help you when you have to stand and face your God. Don't fool yourself and think that nothing will happen to you. I am begging you to stop this practice.Vol. 36 No. 16 - The Blessed Mother Mary - April 18, 1993 (dictated on February 27, 1993) "I am not old-fashioned, I am a realist. And I am telling you of the realities of the karma of abortion. If abortion has entered your life, I say, call upon the violet flame for the healing of the soul in pain for its mission cut off. Call on the law of forgiveness for yourself. Do not condemn yourself, for I, Mary, do not condemn you, but I urge you to seek early the opportunity of serving life and caring for children that you might learn to love your own inner child and balance the karma of abortion. And pray that in due course you might have a family and bring in the soul or souls whom you aborted through ignorance in an hour when you were perhaps distraught, misled, faced with choices without being given the facts about the life that was aborning in your womb-or perhaps you knew and denied what you knew. Blessed ones, America is not fulfilling her mission because millions of souls are not in life, are not growing up, are not taking their places at your side." Vol. 34 No. 18 - Beloved Jesus Christ - May 5, 1991 (dictated on Easter Sunday, March 31, 1991) "Blessed hearts, let us love this day! Let us enter the love feast! And let us release such a powerful love that it does cast out fear in those who are desiring to seek me and know me and to walk on the road to Emmaus with me-and who would walk out of their churches and follow me down the highways of life to bring in those souls who can yet save an age and can yet put to an end the very possibility of nuclear war and earth changes and all of those karmic predictions that will surely come, I tell you, if this nation does not stop the practice of abortion, legalized and government-sponsored and [tax-]supported abortion. Blessed hearts, it is the karma of a people. It is becoming heavy and heavier until no power will be able to stop it from descending. Therefore if you have love for those in embodiment who have been led astray [by the Supreme Court's decision to legalize abortion] and love for those young women who are bringing forth babes, even at an early age, as Mary did bring me forth from her womb, [you must see to it that] these young ones know the Truth, for the Truth is in their hearts. They need be told only once. For these young maidens, beloved, are surely of my Heart and surely desire to truly know me. I present myself to them, beloved, and I present myself to them through you. They must have a teaching they can understand. They must have a spiritual path instead of a path that is of a dead ritual. Religion is not necessarily spirituality. Therefore let the spiritual path be opened unto them! Let their spiritual eyes be opened! So many of them have the courage to carry their young ones in the face of all adversity and obligations. Blessed hearts, I praise the angels who tend them and their pure hearts who are bringing forth souls. And they are bringing forth souls of Light and many of them are being reared in homes where there is Light and where there is opportunity. This is the hour indeed to be on your knees daily in prayer unto my Mother that you might have from her again the empowerment of the Immaculate Heart. It is the day and the hour to do penance on behalf of the sin of a nation, to atone for that sin by speaking the Word and preaching it. Do not fear the reaction of the world! Do not fear to become unpopular! Do not fear to be put down! Only call upon me and upon Archangel Michael and the hosts of the LORD for your protection and the protection of the ears and the hearts who must know this truth! For they are thirsting for it, they are hungering after this truth and they must know that that soul is integral to that body, to that mind, to that memory, to that sheath of desire, all coming together in that embryo, in that fetus in the womb, beloved. Now I say to you, if this entire momentum of Death and Hell be turned around, nothing shall be impossible to the Church of God upon earth, to his people! For this [abortion of unborn children] is the most deadly of all plots against humanity and the children of Light. It is greater than nuclear war itself, for the destruction of the nucleus of life that is God is the most horrendous crime that is (or can be) practiced, that is (or can be) committed against the backdrop of eternity. Before it is too late, beloved, I say to you, take my staff this day, take my hand. I shall walk with you. I AM he! I AM Jesus and I will keep my promise. I will be at your side in the defense of life-all life, any part of life. Wherever you defend the right of life to be the full expression of God in embodiment in a healthy body, a harmonious home and on a path of Light, wherever you defend the right of the individual to know the truth of my message of all ages that is the path of the resurrection and the ascension in the Light, I will be with you! This is my promise. May you not lose it by departing into old patterns." Vol. 33 No. 41 - Beloved Mother Mary - October 21, 1990 (dictated on Friday, October 26, 1990) Think, then, what is the karma of abortion! The karma is that one day, should you pass from the screen of life not having fulfilled your mission [on earth] and not having balanced sufficient karma [to enter heaven's gates], which would have allowed you to pass through [the initiations of] the resurrection and the ascension, you yourself will be seeking entrée to the physical octave through the portals of birth. And at that moment, beloved, the karma of having performed or had an abortion may greet you with the denial [of opportunity] to once again enter earth's schoolroom because you have denied life to another. This is the law of karma. It is real and it is true. Therefore there be souls at inner levels, beloved, who have been denied that life who have a tremendous anguish and frustration that they are not in embodiment to help you meet the crisis of your cities and your nations [and] every [other] crisis that besets you this day. One of the principal reasons why there is such crisis is that those whom God has sent to be here when these challenges were to come upon earth are not in embodiment. They are crying on the astral plane and in the etheric octave because they do not stand [at your side] to assist you. Thus, the woes shall come upon this earth, beloved, for this karma of the nations. Therefore I ask you to pray to my Immaculate Heart and to give the New Age rosary as I have given it to this Messenger, which does avail much for yourself and much for the world. There are things that can be mitigated, beloved, and then there are freewill decisions made in spiritual blindness by those in embodiment that do upset the cycles of the turning of the ages." Vol. 32 No. 14 - Beloved Peace and Aloha - April 2, 1989 (dictated on Sunday, June 10, 1984)

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SAS'02 Call for Participation -- Early Registration: * September 3 *
by SAS2002 28 Aug '02

28 Aug '02

[ Please Distribute -- Apologies for Receiving Multiple Copies ] [ CALL FOR PARTICIPATION: Early Registration Extended: * September 3 * ] [ EU funded student grants available ] -------------------------------------------------------------------------- CALL FOR PARTICIPATION SAS'02 The 9th International Static Analysis Symposium Madrid, Spain 17 - 20 September 2002 -------------------------------------------------------------------------- On-line Registration and Hotel Reservations: http://clip.dia.fi.upm.es/SAS02/ Early registration date is ** September 3, 2002 ** -------------------------------------------------------------------------- SAS'02 is Organized by: Department of Computer Science, Technical University of Madrid ---------------------------------------------------------------------- The Ninth International Static Analysis Symposium (SAS'02) will be held at the Technical University of Madrid (UPM), co-located with Logic-based Program Development and Transformation (LOPSTR'02), the APPIA-GULP-PRODE Joint Conference on Declarative Programming (AGP'02), and a number of workshops. Static Analysis is increasingly recognized as a fundamental tool for high performance implementations and verification systems of high-level programming languages. The series of Static Analysis Symposia has served as the primary venue for presentation of theoretical, practical, and application advances in the area. Invited Talks include: Static Program Analysis via 3-Valued Logic Thomas Reps, University of Wisconsin Open Modeling in Multi-stakeholder Distributed Systems: Research and Tool Challenges Robert J. Hall, AT&T Labs Research An Algebraic Approach to the Static Analysis of Concurrent Software Javier Esparza, University of Edinburgh Secrets of Software Model Checking Thomas Ball, Microsoft Research Accepted papers: Static Analysis of the Numerical Stability of Loops Martel Matthieu Modular Control Flow Analysis for Libraries Christian Probst On termination of programs with real numbers computations Alexander Serebrenik and Danny De Schreye Polynomial Constants are Decidable Markus Müller-Olm and Helmut Seidl Normalizable Horn clauses, Strongly Recognizable Relations and Spi Flemming Nielson, Hanne Riis Nielson, and Helmut Seidl Detecting Optimal Termination Conditions of Logic Programs Fred Mesnard, Etienne Payet, and Ulrich Neumerkel Representing and approximating transfer functions in Abstract Interpretation of hetereogeneous datatypes Bertrand Jeannet Improving the Precision of Equality-Based Dataflow Analyses Erik Ruf >From Secrecy to Authenticity in Security Protocols Bruno Blanchet Checking Safety Properties of Behavioral VHDL Descriptions by Abstract Interpretation Charles Hymans Refinement of LTL Formulas for Abstract Model Checking Maria del Mar Gallardo, Pedro Merino, and Ernesto Pimentel Making Abstract Model Checking Strongly Preserving Francesco Ranzato and Francesco Tapparo Static Confidentiality Enforcement for Distributed Programs Andrei Sabelfeld and Heiko Mantel More Precise Yet Efficient Type Inference for Logic Programs Claudio Vaucheret and Francisco Bueno A Few Graph-Based Relational Numerical Abstract Domains Antoine Mine' Pipeline Modeling for Timing Analysis Marc Langenbach, Stephan Thesing, and Reinhold Heckmann Compactly Representing First-Order Structures for Static Analysis R. Manevich, G.Ramalingam, J. Field, D. Goyal, and M. Sagiv Semantics for Abstract Interpretation-Based Static Analyzes of Temporal Properties Damien Masse States vs. Traces in Model Checking by Abstract Interpretation Roberto Giacobazzi and Francesco Ranzato Speeding Up Dataflow Analysis Using Flow-Insensitive Pointer Analysis Stephen Adams, Thomas Ball, Manuvir Das, Sorin Lerner, Sriram K. Rajamani, Mark Seigle, and Westley Weimer Analysing Approximate Confinement under Uniform Attacks Alessandra Di Pierro, Chris Hankin, and Herbert Wiklicky Reuse of results in termination analysis of typed logic programs Maurice Bruynooghe, Michael Codish, Samir Genaim, and Wim Vanhoof Backward Type Inference Generalises Type Checking Lunjin Lu and Andy King Security Typings by Abstract Interpretation Mirko Zanotti Possibly Not Closed Convex Polyhedra and the Parma Polyhedra Library R. Bagnara, E. Ricci, E. Zaffanella, and P. M. Hill Reliable Optimization for Imperative Languages: Proving Nullspace Properties of Compilers Todd L. Veldhuizen and Andrew Lumsdaine Representation Analysis for Coercion Placement Karl-Filip Faxen Ensuring Termination of Offline Partial Evaluation in Polynomial Time (A New Finiteness Analysis) Chin Soon Lee Automated Verification of Concurrent Linked Lists with Counters Tuba Yavuz-Kahveci and Tevfik Bultan An Efficient Inclusion-Based Points-To Analysis for Strictly-Typed Languages John Whaley and Monica Lam An Improved Constraint-Based System for the Verification of Security Protocols Ricardo Corin and Sandro Etalle Nonuniform Alias Analysis of Recursive Data Structures and Arrays Arnaud Venet -------------------------------------------------------------------------- Organized by: ------------- Department of Computer Science, Technical University of Madrid Program Chair: Conference Chair: -------------- ----------------- Manuel Hermenegildo German Puebla Program Committee ----------------- Manuel Hermenegildo Technical University of Madrid, Spain German Puebla Technical University of Madrid, Spain Radhia Cousot Ecole Polytechnique, France Saumya Debray The University of Arizona, USA Manuel Fahndrich Microsoft Research, USA Roberto Giacobazzi Univerity of Verona, Italy Chris Hankin Imperial College, UK Giorgio Levi Univerity of Pisa, Italy Kim Marriott Monash University, Australia Alan Mycroft Cambridge University, United Kingdom Ganesan Ramalingam IBM T.J. Watson Research Center, USA Martin Rinard Massachusetts Institute of Technology, USA Shmuel Sagiv Tel-Aviv Univerisity, Israel Reinhard Wilhelm Universitat des Saarlandes, Germany -------------------------------------------------------------------------- EU funded grants are available for European full-time students or researchers with limited budget. For more info please visit: http://clip.dia.fi.upm.es/SAS-LOPSTR-AGP/grants.html Grants include accommodation for the days of the conference and a registration waiver. -- ----------------------------------------------------------------------------- 9th International Static Analysis Symposium SAS'02 17-20 September 2002, Madrid Spain Technical University of Madrid http://clip.dia.fi.upm.es/SAS02/ sas02(a)clip.dia.fi.upm.es ----------------------------------------------------------------------------- -- ----------------------------------------------------------------------------- 9th International Static Analysis Symposium SAS'02 17-20 September 2002, Madrid Spain Technical University of Madrid http://clip.dia.fi.upm.es/SAS02/ sas02(a)clip.dia.fi.upm.es -----------------------------------------------------------------------------

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RE: difference between (evaluate . runST) and stToIO
by Simon Peyton-Jones 28 Aug '02

28 Aug '02

They aren't identical. runST guarantees to run a complete state thread that can't interact with any other. stToIO runs some imperative actions that might interact with other stToIO calls. You might find it helpful to read 'State in Haskell' if you havn't already done so. Simon | -----Original Message----- | From: Hal Daume III [mailto:hdaume@ISI.EDU] | Sent: 06 August 2002 18:55 | To: Haskell Mailing List | Subject: difference between (evaluate . runST) and stToIO | | | I can't seem to figure out what the difference is between using | | evaluate (runST action) | | and | | stToIO action | | when in the IO monad and running something in ST...they seem | to behave identically...are they? | | If they are, why do they have different type signatures (one | is ST RealWorld a -> IO a, while the other is (forall s. ST s | a) -> IO a)? | | - Hal | | -- | Hal Daume III | | "Computer science is no more about computers | hdaume(a)isi.edu | than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume | | _______________________________________________ | Haskell mailing list | Haskell(a)haskell.org http://www.haskell.org/mailman/listinfo/haskell |

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