December 2001 - 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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CFP : ASIA-PEPM 2002
by Chin Wei Ngan 20 Feb '02

20 Feb '02

CALL FOR PAPERS ACM SIGPLAN ASIAN Symposium on Partial Evaluation and Semantics-Based Program Manipulation (ASIA-PEPM'02) Aizu, JAPAN, September 12-14 2002 (co-located with FLOPS2002) http://www.comp.nus.edu.sg/asia-pepm02 Submission deadline: 1st March 2002 The ASIA-PEPM'02 symposium will bring together researchers working in the areas of semantics-based program manipulation, partial evaluation, and program analysis. The symposium focuses on techniques, supporting theory, and applications for the analysis and manipulation of programs. Technical topics include, but are not limited to: * Program manipulation techniques: transformation, specialization, normalization, reflection, rewriting, run-time code generation, multi-level programming. * Program analysis techniques: abstract interpretation, static analysis, binding-time analysis, type-based analysis. * Related issues in language design and models of computation: imperative, functional, logical, constraint-based, object-oriented, parallel, concurrent, secure, domain-specific. * Programs as data objects: staging, meta-programming, incremental computation, mobility, tools and techniques, prototyping and debugging. * Applications: systems programming, scientific computing, embedded systems, graphics, security, model checking, compiler generation, compiler optimization, decompilation. Original results that bear on these and related topics are solicited. Papers investigating novel uses and applications of program manipulation are especially encouraged. Authors concerned about the appropriateness of a topic are welcome to consult with the program chair prior to submission. SUBMISSION INFORMATION Papers should be submitted electronically via the workshop's Web page. Exceptionally, submissions may be emailed to the program chair: asiapepm(a)comp.nus.edu.sg. Acceptable formats are PostScript or PDF, viewable by gv. Submissions should not exceed 5000 words, excluding bibliography and figures. Submitted papers will be judged on the basis of significance, relevance, correctness, originality, and clarity. They should clearly identify what has been accomplished and why it is significant. The work described should not have been previously published in a major forum. Authors must indicate if a closely related paper is also being considered for another conference or journal. The proceeding of the symposium will be published by ACM Press. A special issue of Higher-Order Symbolic Computation is also planned. LOCAL ARRANGEMENT Mizuhito Ogawa (NTT, Japan) GENERAL CHAIR Kenichi Asai (Ochanomizu University, Japan) PROGRAM CHAIR Wei-Ngan Chin (National University of Singapore, Singapore) PROGRAM COMMITTEE Manuel Chakravarty (University of New South Wales, Australia) Tyng-Ruey Chuang (Academia Sinica, Taiwan) Charles Consel (ENSEIRB, France) Oege de Moor (University of Oxford, UK) Masami Hagiya (University of Tokyo, Japan) Nevin Heintze (Agere Systems, USA) Neil Jones (Univ of Copenhagen, Denmark) Yanhong Annie Liu (SUNY at Stony Brook, USA) Atsushi Ohori (JAIST, Japan) Alberto Pettorossi (University of Roma, Italy) Simon Peyton Jones (Microsoft, UK) Carolyn Talcott (Stanford University, USA) Zhe Yang (University of Pennsylvania, USA)

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RE: punning in GHC?
by Simon Peyton-Jones 02 Jan '02

02 Jan '02

Punning was removed from Haskell some while ago, I believe when Haskell 98 was fixed in Feb 1999. See the Preface section 0.4.1 Simon | -----Original Message----- | From: Iavor S. Diatchki [mailto:diatchki@cse.ogi.edu] | Sent: 26 December 2001 18:55 | To: haskell(a)haskell.org | Subject: punning in GHC? | | | hi there, | | i just discovered that GHC does not support punning with the | -fglasgow-exts | option. is there another flag to turn this on or has it been | completely | removed? if so could we have it back - i really like the feature (in | patterns anyways) and use it (hugs -98 supports it). i don't | particularly | care that it is not in haskell 98 as i rarely write haskell | 98 programs. | | by the way before posting this i did a search on "punning" | through the | mailing list archive to see if someone asked this already. i | couldnt find | anything but it seems that since 1997 there were 7 posts on | "punning" and | all of them seemed to agree that it was a useful feature, so | why was it | removed? | | bye | iavor | | _______________________________________________ | Haskell mailing list | Haskell(a)haskell.org http://www.haskell.org/mailman/listinfo/haskell |

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ScanMail Message: To Recipient virus found and action taken.
by System Attendant 31 Dec '01

31 Dec '01

ScanMail for Microsoft Exchange has detected virus-infected attachment(s). Sender = Louise Finch Recipient(s) = haskell(a)haskell.org Subject = <no subject> Scanning Time = 12/31/2001 10:39:28 Action on virus found: The attachment HAMSTER.DOC.pif exists WORM_BADTRANS.B virus. ScanMail has Moved it. The attachment was moved to Y:\Program Files\Trend\Smex\Virus\HAMSTER.DOC3c3086b0f.pif_. Warning to recipient. ScanMail detected a virus in an email attachment. The attachment will be cleaned if possible. If the attachment cannot be cleaned , it will be stripped.

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Re:
by Louise Finch 31 Dec '01

31 Dec '01

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Call for Papers: Annals of Software Engineering Special Volume
by asespec＠serg.ing.unisannio.it 30 Dec '01

30 Dec '01

CALL FOR PAPERS -------------------------------------------------------------- Our apologies if you received multiple copy of this. -------------------------------------------------------------- Annals of Software Engineering: Special Volume on "Computational Intelligence In Software Engineering" http://manta.cs.vt.edu/ase The Annals of Software Engineering journal seeks articles for a special volume on "Computational Intelligence In Software Engineering". The constantly evolving technological infrastructure of the modern world presents a great challenge of developing software systems with increasing size and complexity. Software engineers and researchers are striving to meet these and other continuously growing challenges by developing and implementing useful software engineering methodologies. However, despite the introduction of some important and useful paradigms in the software engineering discipline, their technological transfers on a larger scale has been extremely gradual and limited. The recent emergence of the field of Computational Intelligence (CI) in Software Engineering provides a software development team with an opportunity by taking advantage of the currently developed, documented, and mature CI technologies such as fuzzy logic, artificial neural networks, genetic and artificial intelligence based computational systems, expert knowledge based systems, and case based reasoning. These and other computational intelligence technologies have been used to resolve issues arising from the ever-increasing complexity and size of software systems. The aim and scope of this special issue is focused on the current research trends of introducing and implementing CI techniques to address the various software engineering needs arising during different phases of software development and analysis. This special issue is intended to serve as a comprehensive collection of some of the current state-of-the-art CI in software engineering technologies. Topics of Interest Topics of particular interest on "Computational Intelligence In Software Engineering" include but are not limited to: * Neural Networks * Fuzzy Logic * Genetic Algorithms & Programming * Case Based Reasoning * Data Mining Techniques * Adaptive Computing Systems * Knowledge Based Systems * Software Cost Estimation * Software Reliability Modeling * Formal Verification Methods * Software Testing & Software Validation * Expert Software Systems * Software Requirements & Specifications Engineering * Machine Learning Techniques * Hybrid Intelligent Systems Editor Professor Taghi M. Khoshgoftaar Department of Computer Science & Engineering Florida Atlantic University Boca Raton, Florida 33433, U.S.A. Tel: +1-561-297-3994 Fax: +1-561-297-2800 Email: taghi(a)cse.fau.edu Annals of Software Engineering imposes virtually no length limitation on the submitted papers. A paper's length is judged with respect to the quality of its content. Submitted papers must not have been previously published or be currently under consideration for publication elsewhere. All papers will be rigorously refereed. The complete manuscript in PDF or postscript format should be submitted to the editor on or before April 1, 2002. Submission Submission of a manuscript to the Annals of Software Engineering journal is a representation that the manuscript: (a) has not been previously published, (b) is not currently under consideration for publication elsewhere, and (c) will not be submitted elsewhere until a decision is made regarding its suitability for publication in Annals of Software Engineering. Submission is also the representation that the work has been approved for open publication if performed under an official sponsorship requiring such an approval.

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Importing in ghci
by Konst Sushenko 28 Dec '01

28 Dec '01

Hello, I just started using GHCI and I am having trouble importing modules except for these in the "imports/std" directory. I am using windows, and my GHC installation directory is "d:/ghc/ghc-5.02.1". I tried starting ghci with the -i option: ghci -I"d:/ghc/ghc-5.02.1" to no avail... Tried it with quotes, without quotes, tried relative path, no help. 'ghc-pkg -l' reports that the module that I import is indeed in an installed package, and as far as I understand as long as the module is in an installed package, GHC should be happy. What am I missing? Thanks konst

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punning in GHC?
by Iavor S. Diatchki 26 Dec '01

26 Dec '01

hi there, i just discovered that GHC does not support punning with the -fglasgow-exts option. is there another flag to turn this on or has it been completely removed? if so could we have it back - i really like the feature (in patterns anyways) and use it (hugs -98 supports it). i don't particularly care that it is not in haskell 98 as i rarely write haskell 98 programs. by the way before posting this i did a search on "punning" through the mailing list archive to see if someone asked this already. i couldnt find anything but it seems that since 1997 there were 7 posts on "punning" and all of them seemed to agree that it was a useful feature, so why was it removed? bye iavor

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A question about "Putting Type Annotations to Work"
by Diego Dainese 24 Dec '01

24 Dec '01

Hi, I am not sure whether this is the right place to ask this question: I don't understand how to compute the least upper bound of 2 (or N) substitutions in the MGI algorithm of the paper mentioned in the subject (see Figure 4 on page 10, rules (->) and (T)). Any hint is welcomed. Thanks in advance and merry Christmas, -- Diego To reply remove the 2 `x' from the address.

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