- Haskell - Haskell.org

Data.Hashtable operations in IO?
by ROBERT DOUGLAS HOELZ 20 Feb '07

20 Feb '07

I was reading the docs for Data.Hashtable, and quickly noticed that operations on a hashtable are of the IO monad. Why is this? I should think that the operations would look like this: insert :: Hashtable -> key -> val -> Hashtable lookup :: Hashtable -> key -> a etc. Thanks, Rob Hoelz

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GHC/ Fortress -Parallel Computing
by Gottfried F. Zojer 20 Feb '07

20 Feb '07

Hallo to all, Just curious after reading a posting on the internet. Is somebody using Fortress in combination with Haskell ( GHC) in a parallel setup. http://en.wikipedia.org/wiki/Fortress_programming_language >From Sun Microsystems : http://research.sun.com/projects/plrg/faq/index.html http://fortress.sunsource.net/ Thanks for any feedback Regards Gottfried www.wirtschaftswunder.co.uk www.5152.eu

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cabal-upload build problem
by Paul Johnson 19 Feb '07

19 Feb '07

I want to upload a package to Hackage. I tried installing cabal-upload, but got the following error: ! Preprocessing executables for cabal-upload-0.2... ! Building cabal-upload-0.2... ! ! src/CabalUpload.hs:7:7: ! Could not find module `Distribution.Compat.FilePath': ! it is hidden (in package Cabal-1.1.6) I tried "ghc-pkg expose Cabal-1.1.6" without success. I have ghc-6.6 installed on Linux (Fedora Core 6), including Cabal-1.1.6. (BTW I know I will also need a user id and password. That was going to be my next step). Paul.

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ANNOUNCE: cabal-make version 0.1
by Conal Elliott 19 Feb '07

19 Feb '07

Cabal-make is a GNU make include file to be used with Cabal in creating and sharing Haskell packages. A few highlights: * Web-based, cross-package links in Haddock docs * Syntax coloring via hscolour, with per-project CSS * Links from the Haddock docs to hscolour'd code and to wiki-based user comment pages. See http://haskell.org/haskellwiki/Cabal-make for description, tips, and download. Comments, suggestions, welcome (especially on the cabal-make wiki talk page). Cheers, - Conal

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FUN IN THE AFTERNOON: this Wednesday, Nottingham
by Graham Hutton 19 Feb '07

19 Feb '07

Dear all *** FUN IN THE AFTERNOON, WED 21 FEB, NOTTINGHAM, UK *** Fun in the Afternoon is a termly seminar on functional programming and related topics. The next meeting will take place in Nottingham this week, on the afternoon of Wednesday 21st February, and include talks by James McKinna, Jeremy Gibbons, Nils Anders Danielsson, and Lennart Augustsson. Further details are available from: http://sneezy.cs.nott.ac.uk/fun We hope you and your students will be able to attend! Please feel free to pass this message on to your colleagues and students. Best wishes, Graham and Conor +---------------------------------------------------------------------+ | Dr Graham Hutton Email : gmh(a)cs.nott.ac.uk | | School of Computer Science and IT | | University of Nottingham Web : www.cs.nott.ac.uk/~gmh | | Jubilee Campus, Wollaton Road | | Nottingham NG8 1BB, UK Phone : +44 (0)115 951 4220 | +---------------------------------------------------------------------+ This message has been checked for viruses but the contents of an attachment may still contain software viruses, which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation.

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Converting to Foreign types
by ROBERT DOUGLAS HOELZ 17 Feb '07

17 Feb '07

Hello, I want to convert a Haskell Integer (Data.Int.Int32) to a C long (Foreign.C.Types.CLong), but it seems this code here doesn't work: intToLong :: Int32 -> Clong intToLong num = let maybelong = cast num in if isNothing maybelong then 0 else fromJust maybeLong (It always returns 0) Could anyone give me a hint as to what the problem is? Thanks!

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ANNOUNCE: Hardware Design and Functional Languages 2007 - Call for Participation
by Andy Martin 16 Feb '07

16 Feb '07

Dear Member of the Haskell Community, Carl Seger, Mary Sheeran and I are very pleased to announce the upcoming workshop on Hardware Design and Functional Languages, to be held on March 24-25 in Braga Portugal, as a satellite event of ETAPS 2007. We have a very exciting two-day programme consisting of fourteen talks from industry and academia. For more information, and the full, printable call for participation, please visit the workshop website at http://www.hflworkshop.org. To register, please visit the ETAPS 2007 website at http:// www.di.uminho.pt/etaps07 We would be very grateful if you would circulate this call amongst your colleagues and post it where appropriate. Since there is a long history of the use of Haskell for hardware design, we felt this workshop would be of interest to the Haskell community, and benefit from your participation. Please accept my apologies if your receive this email more than once, or if this email is unwanted. Regards, Andy Martin

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Finding pointer size
by Rob Hoelz 15 Feb '07

15 Feb '07

I'm working with the Foreign module, and I need to allocate a pointer to a pointer (in C, a char **). The problem is, I don't know how to find out the size of a char * in Haskell. Here's the basic layout of the code: allocaBytes len $ \ array -> ... -- len is the size of the char ** to be allocated times sizeof(char *). Thanks, Rob Hoelz

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How does "do" know when to stop?
by Rob Hoelz 15 Feb '07

15 Feb '07

When I define a function and I use do to string functions together, how does it know when my list of functions has come to an end? For example: foo = do bar baz other_func bar = ... How does it know to stop at other_func? Thanks, Rob Hoelz

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Haskell-mode 2.3
by Stefan Monnier 14 Feb '07

14 Feb '07

A few minor typos/thinkos plagued Haskell-mode 2.2, so here's 2.3. http://www.iro.umontreal.ca/~monnier/elisp/ No significant change, apart from the inclusion of a haskell-cabal-mode for Cabal description files (doesn't do anything useful, tho, other than highlight comments). Stefan

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