July 2003 - Glasgow-haskell-users

your own account
by info＠account.com 15 Jul '03

15 Jul '03

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Using Template Haskell for deriving instances
by Carsten Schultz 15 Jul '03

15 Jul '03

Hi, is any workable example code for using Template Haskell to generate instance declarations available, eg the function `genEq' mentioned in the Template Haskell paper? Greetings, Carsten -- Carsten Schultz (2:40, 33:47), FB Mathematik, FU Berlin http://carsten.fu-mathe-team.de/ PGP/GPG key on the pgp.net key servers, fingerprint on my home page.

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glasgow-haskell-users找到个交友游戏网站
by sms 14 Jul '03

14 Jul '03

找到个交友游戏网站 http://www.creatonly.com

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Virus Found in message "Application"
by WinSupport 14 Jul '03

14 Jul '03

Norton AntiVirus found a virus in an attachment you (glasgow-haskell-users(a)haskell.org) sent to winsupport(a)codamusic.com. To ensure the recipient(s) are able to use the files you sent, perform a virus scan on your computer, clean any infected files, then resend this attachment. Attachment: your_details.zip Virus name: Multiple viruses found. Please see individual log messages. Action taken: Clean failed : Quarantine succeeded : File status: Still contains 1 infected items

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RE: -fdicts-strict ?
by Simon Peyton-Jones 14 Jul '03

14 Jul '03

In theory, the dictionaries passed to functions could always be passed by value. -fdicts-strict is supposed to make this happen, which should make overloaded programs a bit more efficient. I don't think it's ever been tested, though, so I'm not surprised it doesn't work properly. If you can make a reasonably small program that demonstrates the failure I'd be happy to look at it. Simon | -----Original Message----- | From: glasgow-haskell-users-admin(a)haskell.org [mailto:glasgow-haskell-users-admin@haskell.org] | On Behalf Of Johannes Waldmann | Sent: 11 July 2003 14:38 | To: glasgow-haskell-users(a)haskell.org | Subject: -fdicts-strict ? | | what exactly happens when ghc applies `-fdicts-strict' ? | | and what could then be the reason for | | Fail: Oops! Entered absent arg w_s1Bjs {GHCziBase.Ord {- tc 2c -} c {- tv a1AVd -}} | | when executing the compiled program? | | best regards, | -- | -- Johannes Waldmann ---- http://www.informatik.uni-leipzig.de/~joe/ -- | -- joe(a)informatik.uni-leipzig.de -- phone/fax (+49) 341 9732 204/209 -- | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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Undelivered Mail Returned to Sender
by MAILER-DAEMON＠isx.com 12 Jul '03

12 Jul '03

This is the Postfix program at host mailgate2.isx.com. I'm sorry to have to inform you that the message returned below could not be delivered to one or more destinations. For further assistance, please send mail to <postmaster> If you do so, please include this problem report. You can delete your own text from the message returned below. The Postfix program <A75104EC-5321-11D7-98EC-003065F4867C(a)isx.com>: host voyager.isx.com[192.77.181.66] said: 550 5.1.1 <A75104EC-5321-11D7-98EC-003065F4867C(a)isx.com>... User unknown (in reply to RCPT TO command)

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Returned mail: see transcript for details
by Mail Delivery Subsystem 12 Jul '03

12 Jul '03

The original message was received at Sat, 12 Jul 2003 01:09:41 -0400 (EDT) from grimy.research.bell-labs.com [204.178.16.57] ----- The following addresses had permanent fatal errors ----- <20010207125102R.pfps(a)research.bell-labs.com> (reason: 550 5.1.1 <20010207125102R.pfps(a)research.bell-labs.com>... User unknown) ----- Transcript of session follows ----- ... while talking to grubby.research.bell-labs.com.: >>> DATA <<< 550 5.1.1 <20010207125102R.pfps(a)research.bell-labs.com>... User unknown 550 5.1.1 <20010207125102R.pfps(a)research.bell-labs.com>... User unknown <<< 503 5.0.0 Need RCPT (recipient)

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Debian GHC packages
by Ian Lynagh 11 Jul '03

11 Jul '03

Hi all, Just a quick note to let you know what's going on with GHC packaging in Debian. As Michael Weber has been short of time to work on the GHC packages recently I have taken over the GHC packaging from him; the latest releases of ghc 5 and 6 are now in unstable. Unrelatedly, Isaac Jones has set up an apt repository for experimental Haskell packages; see the "Haskell Experimental Debian Repository" section of http://www.haskell.org/hawiki/DebianUsers for details. In the stable section you can get the latest packages compiled for a pure stable system. Thanks Ian

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-fdicts-strict ?
by Johannes Waldmann 11 Jul '03

11 Jul '03

what exactly happens when ghc applies `-fdicts-strict' ? and what could then be the reason for Fail: Oops! Entered absent arg w_s1Bjs {GHCziBase.Ord {- tc 2c -} c {- tv a1AVd -}} when executing the compiled program? best regards, -- -- Johannes Waldmann ---- http://www.informatik.uni-leipzig.de/~joe/ -- -- joe(a)informatik.uni-leipzig.de -- phone/fax (+49) 341 9732 204/209 --

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Posix library ,Concurrent Haskell and Haskell IO sub-system
by Rafael Martinez Torres 11 Jul '03

11 Jul '03

I use the Posix library since I have to communicate via a pipe with another UNIX process. Therefore I have to use fdRead :: Fd -> ByteCount -> IO (String,ByteCount) The problem is that "fdRead" , as a non Haskell-IO sub-system function, seems to block the entire STG system. The rest of the other threads are blocked too. BTW, "String" stands for non-printable bytes I can be sent for a system, '\0' included ? Alternatives: 1 .- Polling. Sleep and ask. ================================ You have to use the setFdOption fd NonblockingRead True fdReadNonBlockingSTG :: Fd -> Int -> IO (String,ByteCount) fdReadNonBlockingSTG mypipe nobytes = do (string,nobytesread) -> fdRead mypipe nobytes if (nobytesread == -1) then do threadDelay 10000 fdReadNonBlockingSTG mypipe nobytes else return (string,nobytesread) myprogram :: IO () ... setFdOption mypipe NonBlockingRead True (a,b) <- fdReadNonBlockingSTG mypipe 2 ... Problem: As you see, "1000" es an arbitrary constant maybe too short, may be too long and this affects throughput. 2.- Desired approach ======================= Ideally I would like to use the threadWaitRead :: Int -> IO() from Concurrent Haskell as ... -- setFdOption mypipe NonBlockingRead True -- should be called? threadWaitRead (fdToInt mypipe) (string,nobytes) <- fdRead mypipe 2 ... But... QUESTIONS ========== A ) is the GHC-RTS ready to dispatch the signal send by the O.S on a "Posix Fd" and make "threadWaitRead" to run as expected ? The Posix library doc warns: intToFd :: Int -> Fd -- use with care fdToInt :: Fd -> Int -- ditto B) Other approaches, like Handles... Is it possible to convert a Fd into a Handle or bypassing it to the RTS another way ?...

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