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newbie conceptual question
by Cagdas Ozgenc 25 Jul '01

25 Jul '01

Greetings, I have been programming with imperative languages for 15 years. Now I started learning Haskell, and functional programming (and I am very determined to learn it well). It seems to me that I can still use functional programming paradigm with an imperative language. How can I benefit more from a functional programming language (i.e.Haskell)? In other words, is having built-in language constructs for functional programming the only reason for using a functional programming language(I can use polymorpim, and generic programming in imperative languages, as well). Thanks

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RE: lexical description problem in language report?
by Simon Peyton-Jones 25 Jul '01

25 Jul '01

I agree with Thomas's suggestion: a) Change the definition of lexeme b) Move lexical discussion from 5.5.1 to 2.4 It also looks that Christian is correct in revising the details of (a). Thomas, do you agree? Would this resolve the various lexical issues? Thanks for your help. Simon | -----Original Message----- | From: Christian Sievers [mailto:sievers@ips.cs.tu-bs.de] | Sent: 24 July 2001 20:45 | To: haskell(a)haskell.org | Subject: Re: lexical description problem in language report? | | | Thomas Hallgren wrote: | | > program -> {lexeme | whitespace } | > lexeme -> varid | conid | varsym | consym | literal | special | | > reservedop | reservedid | > | > There is no reference to qualified names here. I thought | the purpose | > of | > these productions were to say that a Haskell program is | correct on the | > lexical level iff there is a derivation of it in the | lexical grammar, | > starting from the nonterminal "program". Since qualified | names are not | > part of this grammar, they are not part of the lexical | syntax, which | > contradicts the text in section 5.5.1. | > | > So, I repeat my improvment suggestions: include qvarid, | qconid, etc, | > in | > the production for lexeme. Move the explanation of the lexical | > properties of qualified names from section 5.5.1 to section 2.4. | | You could still parse a qualified name as three lexemes. | Of course you don't want this, as this would allow white | space between them. For the same reason, you want backquoted | functions and constructors to be only one lexeme. In order to | achieve this, just use qop instead of qvarsym and qconsym. | And we need opencom, as the report says {- is a lexeme. | | So I suggest: | | lexeme -> qvarid | qconid | qop | | literal | special | reservedop | reservedid | opencom | | | It's all not new. See: | http://www.dcs.gla.ac.uk/mail-| www/haskell/msg01596.html | | http://www.dcs.gla.ac.uk/mail-www/haskell/msg01730.html All the best Christian Sievers _______________________________________________ Haskell mailing list Haskell(a)haskell.org http://www.haskell.org/mailman/listinfo/haskell

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IFL 2001 call for registration
by thomas＠cslab.ericsson.se 25 Jul '01

25 Jul '01

IFL 2001 13th International Workshop on the IMPLEMENTATION OF FUNCTIONAL LANGUAGES Stockholm Sweden September 24 - 26, 2001 ============================================================= Registration deadline 15 August 2001 <<-- Submission deadline 1 September 2001 http://www.ericsson.com/cslab/ifl2001/ email: thomas(a)cslab.ericsson.se ============================================================= We have had problems with our web server. In case you registered and did not get a response, please register again. Due to this inconvenience registration will be possible until August 15! Please register before August 15, either via the web site or by returning the following information to me: name: affiliation=: address: country: phone: fax: email: web: talk: yes/no talktitle: attending Erlang User Conference (27/9): yes/no arrival: 24 Sept (or different date) departure: 27 Sept (or different date) diet: The registration fee is 1000 sek (about 100 euro) and should be paid on arrival. The hotel you should arrange yourself. See the web page for a list of hotels. A number of rooms is reserved in Globe Hotel. For the reduced price of 995 sek, to be obtained by giving the reference number MK 1636. http://www.globehotel.se/ phone: +46 8 686 6320 +46 8 686 6300 fax: +46 8 686 6301 mailto:bokning.globe@quality.choicehotels.se Best regards Thomas --- Thomas Arts Ericsson Computer Science Laboratory Box 1505 125 25 Stockholm Sweden thomas(a)cslab.ericsson.se

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ICALP 2002 Call for Papers
by José Luis Triviño 25 Jul '01

25 Jul '01

We apologize for possible multiple postings. In http://www.lcc.uma.es/icalp2002/c4p-jul01.pdf you can find a pdf version of this call for paper. +++++++++++++++++++++++++++++++++++++ Call for Papers ICALP 2002 29th International Colloquium on Automata, Languages and Programming July 8-13, 2002, Málaga, Spain Camera Ready: April 16, 2002 The 29th annual meeting of the European Association of Theoretical Computer Science will be held in Málaga, Spain, July 8-13, 2002 (at the E.T.S. Ingeniería Informática). As with the Journal Theoretical Computer Science (TCS), the scientific program of the Colloquium will be split into two parts: Track A of the meeting will correspond to Algorithms, Automata, Complexity and Games, while Track B to Logic, Semantics and Theory of Programming. SUBMISIONS: Authors are invited to submit extended abstract of their papers, presenting original contributions to the theory of computer science. Detailed instructions for paper submissions will be found on the conference webpage (http://www.lcc.uma.es/icalp2002) and in future calls for papers. Submissions should consist of: a cover page, with the author's full name, address, fax number, e-mail address, a 100-word abstract, keywords and to which track (A or B) the paper is being submitted and an extended abstract describing original research. At least one author of an accepted paper should be available to present it at the conference. Simultaneous submission to other conferences with published proceedings is not allowed. Further information (dates and instructions for submissions, workshops, registration, location and travel) will be provided in future announcements. ORGANIZING COMMITEE: Buenaventura Clares (University of Granada), Ricardo Conejo (University of Málaga), Inmaculada Fortes (University of Málaga), Llanos Mora (University of Málaga), Rafael Morales (co-Chair, University of Málaga), Marlon Nuñez (University of Málaga), José Luis Pérez de la Cruz (University of Málaga), Gonzalo Ramos (University of Málaga), Francisco Triguero (co-Chair, University of Málaga), José Luis Triviño (University of Málaga). IMPORTANT DATES: Workshops proposal: November 8, 2001 Submissions: January 14, 2002 Notification: March 20, 2002 CONFERENCE CO-CHAIRS Prof. Francisco Triguero Prof. Rafael Morales Universidad de Málaga E.T.S. Ingeniería Informática Dept. Lenguajes y Ciencias de la Computación Bulevar Louis Pasteur, 35 29071 - Málaga (SPAIN) e-mail: icalp2002(a)informatica.uma.es PROGRAM COMMITEE Track A Ricardo Baeza-Yates (U. Chile) Volker Diekert (U. Stuttgart) Paolo Ferragina (U. Pisa) Catherine Greenhill (U. Melbourne) Torben Hagerup (U. Frankfurt) Johan Håstad (KTH, Stockholm) Gabriel Istrate (Los Alamos) Claire Kenyon (U. Paris XI) Der-Tsai Lee (Acad. Sinica, Taipei) Heikki Mannila (Nokia, Helsinki) Elvira Mayordomo (U. Zaragoza) Helmut Prodinger (U. Witwatersrand, South Africa) Jan van Leeuwen(U. Utrecht) Paul Vitányi (CWI, Amsterdam) Peter Widmayer (ETH Zürich) (Chair) Gerhard Woeginger (T.U. Graz) Christos Zaroliagis (U. Patras) Track B Martín Abadi (Bell Labs Research, Lucent) Roberto Amadio (U. Provence) Gilles Barthe (INRIA-SophiaAntipolis) Manfred Droste (University of Technology Dresden) Cédric Fournet (Microsoft Cambridge) Matthew Hennessy (U. Sussex) (Chair) Furio Honsell (U. Udine) Peter O'Hearn (Queen Mary & W. C. London) Fernando Orejas (U.P.Catalunya) Ernesto Pimentel (U. Málaga) David Sands (Chalmers University of Technology and Göteborg University) Dave Schmidt (U. Kansas) Gheorghe Stefanescu (U. Bucharest) Vasco Vasconcelos (U. Lisbon) Thomas Wilke (U. Kiel)

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Machine bit representations
by pachinko＠magicaldesk.com 25 Jul '01

25 Jul '01

Hello, Is it possible in Haskell to access the underlying machine bit representation of a Float or Double value? I need to be able to be able to send this bit representation as a list of bytes in network byte order to a process running on a different platform (with a different host byte order to my platform). For reference, I run Haskell under Linux on Intel. The processes I want to communicate with run under Sun Solaris, Hitachi HPUX and Java everywhere. Any suggestions, for any Haskell translator much appreciated. Thanks. _____________________________________________________________ Global Virtual Desktop http://www.magicaldesk.com

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by video2flash＠boldyonline.com 25 Jul '01

25 Jul '01

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Re: Machine bit representations
by Ashley Yakeley 25 Jul '01

25 Jul '01

At 2001-07-24 16:51, pachinko(a)magicaldesk.com wrote: >Is it possible in Haskell to access the underlying machine bit >representation of a Float or Double value? If you mean the _actual_ bit representation, then I hope not! But maybe there should be (or are) functions for converting such values to _standard_ platform-independent bit representations... -- Ashley Yakeley, Seattle WA

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newbie syntax question
by Cagdas Ozgenc 24 Jul '01

24 Jul '01

Hi, I am extremely new to Haskell. This will be my first question, so go easy. I have just read Chapter 1 on Simon Thompson's book. for example a function declaration is given as follows scale : : Picture -> Int -> Picture If the first two types are input variables why does the syntax require me to use arrows twice? I mean isn't the following syntax more readable (hypothetically)? scale : : Picture , Int -> Picture Is there a specific reason not to be able to distinguish the input parameters from the output parameter? Thanks

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RE: newbie syntax question
by Memovich, Gary 24 Jul '01

24 Jul '01

Actually, all functions in Haskell take only one argument, although the people writing the program usually don't think of it this way. scale could alternatively have been defined with type scale :: (Picture, Int) -> Picture which looks more like what we would expect in a function of two arguments. But even here there is actually only a single argument, which happens to be a pair of values. The given declaration scale :: Picture -> Int -> Picture is written in 'curried' form. This means that scale is a function of one argument, 'Picture', and that its return value is a new function with type Int -> Picture. That new function can immediately be applied to an int value so that it appears as if you called scale with two values instead of just one. instead of writing scale pic 3 for example, you could have written (scale pic) 3 or even let x = scale pic in x 3 Which might make it a little easier to see what is actually happening. Hope this helps, -- Gary -----Original Message----- From: Cagdas Ozgenc [mailto:co19@cornell.edu] Sent: Tuesday, July 24, 2001 1:07 PM To: haskell(a)haskell.org Subject: newbie syntax question Hi, I am extremely new to Haskell. This will be my first question, so go easy. I have just read Chapter 1 on Simon Thompson's book. for example a function declaration is given as follows scale : : Picture -> Int -> Picture If the first two types are input variables why does the syntax require me to use arrows twice? I mean isn't the following syntax more readable (hypothetically)? scale : : Picture , Int -> Picture Is there a specific reason not to be able to distinguish the input parameters from the output parameter? Thanks

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Re: hGetContents and laziness in file io
by Hal Daume 24 Jul '01

24 Jul '01

Okay, I understand the problem. I would do something like the solution you propose, except that in the input file, trees span multiple lines. So the input file looks something like: (:cat S :subs ((() (:cat NP :subs ((() (:surf "John"))))) (() (:cat VP :subs ((() (:surf "bought")) (() (:cat NP :subs ((() (:surf "two")) (() (:surf "cars")))))))) (() (:surf ".")))) and then there will be another one directly following it (i detect the breaks because each one is completely surrounded in parens). So a line-by-line parse solution won't really do the job...

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