July 2001 - Haskell-Cafe

ST Questions
by Ashley Yakeley 28 Jul '01

28 Jul '01

Two questions on module ST: <http://www.haskell.org/ghc/docs/latest/set/sec-st.html> 1. What's the 's' parameter for? 2. Do STRefs get garbage-collected once they're forgotten? For instance, if I have an action that calls newSTRef, uses the ref, and then forgets it, and I run the action repeatedly, am I at risk of running out of memory? -- Ashley Yakeley, Seattle WA

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getCh
by Michael Ackerman 27 Jul '01

27 Jul '01

Hello, In Bird's book, p 332, he writes of a "Haskell primitive function, getCh, which is similar to getChar except that the character is not echoed". I can find no reference to getCh in the Report or the docs for the libraries. How can this be defined? Thanks. - Michael Ackerman

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Re: Simple compiler question
by Wolfgang Lux 26 Jul '01

26 Jul '01

Mark Carroll wrote > Do any of the decent Haskell compilers allow you to just type function > definitions at an interpreter prompt and use them in subsequent > interactions, as you'd expect from a Lisp environment? I don't know whether you consider hbi (the interactive version of hbc) a decent compiler, but it supports entering definitions as well: > let { f x = x + x }; f :: (Prelude.Num a) => a -> a > f 3; 6 Wolfgang -- Wolfgang Lux Phone: +49-251-83-38263 Institut fuer Wirtschaftinformatik FAX: +49-251-83-38259 Universitaet Muenster Email: wlux(a)uni-muenster.de

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Simple compiler question
by Mark Carroll 25 Jul '01

25 Jul '01

Do any of the decent Haskell compilers allow you to just type function definitions at an interpreter prompt and use them in subsequent interactions, as you'd expect from a Lisp environment? I'm fed up of editing a tiny file separately and typing :reload each time, etc. Surely I'm missing something obvious? -- Mark

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embeddable haskell?
by matt hellige 25 Jul '01

25 Jul '01

is there any haskell interpreter that allows haskell to be used as an embedded scripting language in a larger application, similar to the way python or tcl, but more especially guile (the gnu scheme implementation) are often used as extension languages? i thought i remembered hearing about some way in which hugs supported this, but i'm not sure and searches turn up nothing... in any event, this would be a useful thing to be able to do, and if it isn't currently possible, i'm wondering if there is a good reason for that, or if it's just that no one's ever undertaken to do it... matt -- matt hellige matt(a)immute.net http://matt.immute.net

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transfer
by Jan Skibinski 20 Jul '01

20 Jul '01

I'll be closing the www services of Numeric Quest soon for some time. I do not know yet when the pages will reappear again. If you need them they are all best indexed and backed-up by Google. Please do not download anything en-masse now - the server is just too slow for this. But you are still welcome to peruse. Hoping to "talk to you" again, Jan Skibinski Numeric Quest Inc. Huntsville, Ontario, Canada

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Fwd: STRAW POLL: comp.lang.haskell (fwd)
by Ashley Yakeley 19 Jul '01

19 Jul '01

If it were to be gatewayed to a list, Haskell Cafe seems the obvious choice. ---------------- Begin Forwarded Message ---------------- Date: 2001-07-19 09:24 Received: 2001-07-19 15:40 From: Mark Carroll, markc(a)chiark.greenend.org.uk To: Haskell List, haskell(a)haskell.org People should be aware of this article that was recently posted to the newsgroup comp.lang.functional. ------- start of forwarded message ------- From: jeff-haskell(a)litech.org (Jeffrey M. Vinocur) Newsgroups: comp.lang.functional,news.groups Subject: STRAW POLL: comp.lang.haskell Date: Thu, 19 Jul 2001 15:31:05 +0000 (UTC) Message-ID: <9j6ufp$fil$3(a)marduk.litech.org> I'm volunteering to take a straw poll to see whether we should try proposing comp.lang.haskell as a new newsgroup, possibly gatewayed to a mailing list. Currently Haskell-related traffic is in comp.lang.functional, and some people feel that it is a sufficiently-large portion of the traffic there to warrant a separate group. Opinions should be sent to <jeff-haskell(a)litech.org>. What we're really trying to determine is how many people would respond to an eventual Call For Votes in news.groups. There would first be a discussion period to hash out the details of things like mailing list gatewaying. (There is some discussion going on in comp.lang.haskell at the moment, feel free to join in there.) Reasonable choices for opinions are "Yes", "No", "Yes, provided it's gatewayed to a mailing list", "Yes, provided it's not gatewayed to a mailing list", "Will abstain from voting but don't want it gatewayed to the mailing list", etc. Note that a perfectly rational justification for wanting a separate group is because you read comp.lang.functional and want the Haskell traffic elsewhere; you need not be interested in reading a Haskell-only group. I'll post a summary of results, mmm, early next week, perhaps. So please reply promptly. -- Jeffrey M. Vinocur jeff(a)litech.org ------- end of forwarded message ------- _______________________________________________ Haskell mailing list Haskell(a)haskell.org http://www.haskell.org/mailman/listinfo/haskell ----------------- End Forwarded Message ----------------- -- Ashley Yakeley, Seattle WA

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pipe through external process?
by John Meacham 17 Jul '01

17 Jul '01

I am trying to implement a function which takes a string, pipes it through an external command and returns the stdout of teh command utilizing the Posix library and ghc. first of all, if someone has this handy code tidbit already written then feel free to send it to me. the other thing is that I cannot figure out how to get data into and out of the process. I can create a pipe which returns a pair of Fd's but then i cannot pass these into runProcess since it expects handles. also I have no ability to wait for the termination of the command that runProcess starts... it is always possible i am just overlooking a few key functions in Posix... John -- --------------------------------------------------------------------------- John Meacham - California Institute of Technology, Alum. - john(a)repetae.net ---------------------------------------------------------------------------

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blindness people
by jiro hiraike 14 Jul '01

14 Jul '01

Dear Sirs, I am in Japanese university's(Rikkyo University in Tokyo) master course of mathmatics. And I am helping one blindness undergraduate student as part-time job. This is in the class of aplied mathmatics, and we use haskell to learn algorizm and so on. The problem is he (the blindness student) cannot use haskell in his home, becouse of his "reading-out-software" for blindness people. The school's reading-out-software "outSpoken" is available for haskell, but his one is not. So, I want to know the available reading out software. If you know, PLEASE tell me. Or some other information that you know, PLEASE tell me. Sincerly yours, jiro hiraike.

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Good for a laugh!
by Kirk 04 Jul '01

04 Jul '01

Thought you'd like to take a break and laugh a little. The following site is updated daily and has funny news articles, quotes, and sections like Dog Thoughts and Headlines. It even has a Webcam! I'm sure you'll find something to enjoy. http://www.laundryday.com Spread the smiles. P.S. Please do not respond to this email. It's a one time mailing. :-)

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