- Glasgow-haskell-users

Re: [Haskell-cafe] Re: a help for install
by Wolfgang Jeltsch 19 Feb '08

19 Feb '08

Am Dienstag, 19. Februar 2008 11:36 schrieb Wolfgang Jeltsch: > Am Montag, 18. Februar 2008 19:46 schrieb Carlos Gomez A.: > > hi, my name is carlos > > > > I need information for correct install or > > > > what are dependencies on ghc ? > > > > I have a Debian System. > > Always use your distribution’s packages until they aren’t any or there is > good reason not to do so. Try “aptitude install ghc6”. > > Best wishes, > Wolfgang Sorry, this should go to glasgow-haskell-users(a)haskell.org. :-( Best wishes, Wolfgang

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a help for install
by Carlos Gomez A. 18 Feb '08

18 Feb '08

hi, my name is carlos I need information for correct install or what are dependencies on ghc ? I have a Debian System. I have this message error to install the ghc: Debian-System/haskell/ghc-6.8.2# ./configure checking build system type... i686-pc-linux-gnu checking host system type... i686-pc-linux-gnu checking target system type... i686-pc-linux-gnu Canonicalised to: i386-unknown-linux checking for ghc... no checking for ghc-pkg matching ... no checking for ghc-pkg... no checking whether ghc has readline package... no checking for nhc... no checking for nhc98... no checking for hbc... no checking for ld... /usr/bin/ld configure: error: GHC is required unless bootstrapping from .hc files. Debian-System/haskell/ghc-6.8.2# --------------------------------- ¡Capacidad ilimitada de almacenamiento en tu correo! No te preocupes más por el espacio de tu cuenta con Correo Yahoo!: http://correo.yahoo.com.mx/

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ghci feature request: partially read modules
by Johannes Waldmann 18 Feb '08

18 Feb '08

Hello. Here is one ghci feature that I find mildly annoying: If ghci (re-)reads a module that contains some error, then it considers the module loading as a complete failure, and at the prompt I get the Prelude environment. I'd like to have at least the import statements executed, and possibly the declarations that were error-free. That would help me in interactively debugging the erraneous part of the module. (Often the error is some type error, related to some imported entity; but when my module contains the error, then the imports are gone.) Perhaps I'm doing something wrong, then please educate me; or perhaps there's an easy way to implement partial reading and typechecking. (It'd be enough to have this for the "current" module, of course.) Thanks - Johannes Waldmann.

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statically linking
by Martina Seidl 17 Feb '08

17 Feb '08

Hallo, I urgently need a statically linked binary (ELF 32) of a Haskell program I have written and I could not figure out yet how to achieve this. Could anyone give me a hint please? Best regards, Martina

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slightly modified hasktags version / Who can commit it?
by Marc Weber 17 Feb '08

17 Feb '08

I've hacked on hasktags again http://mawercer.de/hasktags.hs I'd like to merge changes into the ghc distribution or ask someone to do so. changes: a) full qualified module names are added as well now b) hack: removed empty tokens so that getcons finds [..] rqBody :: RqBody, [..] c) ctag files are sorted now testcase : ============= ======================================================= -- module name should be found module A.B.testcase where -- Request, Request2 -- rqMethod, rqBody, rqPeer should be found as well data Request = Request2 { rqMethod::Method, rqBody :: RqBody, rqPeer :: Host } deriving(Show,Read,Typeable) ============= ======================================================= hasktags distributed with ghc (6.8.2): Request testcase.hs 6 Request2 testcase.hs 6 rqMethod testcase.hs 6 testcase.hs 7 <<< name is missing testcase.hs 8 <<< name is missing my modified version: A.B.testcase testcase.hs 2 <<< module name added Request2 testcase.hs 6 Request testcase.hs 6 rqMethod testcase.hs 6 rqBody testcase.hs 7 rqPeer testcase.hs 8

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building ghc-6.8.2 network library fails under gcc43
by Jens Petersen 15 Feb '08

15 Feb '08

(I know gcc-4.3 is still under development, but it is expected to be the version of gcc in Fedora 9 which will be released around the end of April.) Has anyone tried or managed to build ghc with gcc-4.3? I tried yesterday in the Fedora buildsystem and got to: Socket.hsc: In function 'main': Socket.hsc:1144: error: invalid application of 'sizeof' to incomplete type 'struct ucred' Socket.hsc:1144: error: invalid application of 'sizeof' to incomplete type 'struct ucred' Socket.hsc:1144: error: invalid application of 'sizeof' to incomplete type 'struct ucred' Socket.hsc:1150: error: invalid use of undefined type 'struct ucred' Socket.hsc:1151: error: invalid use of undefined type 'struct ucred' Socket.hsc:1152: error: invalid use of undefined type 'struct ucred' Socket.hsc:2419: error: 'NI_MAXHOST' undeclared (first use in this function) Socket.hsc:2419: error: (Each undeclared identifier is reported only once Socket.hsc:2419: error: for each function it appears in.) Socket.hsc:2420: error: 'NI_MAXSERV' undeclared (first use in this function) compiling dist/build/Network/Socket_hsc_make.c failed command was: gcc -c -D__GLASGOW_HASKELL__=608 -I/builddir/build/BUILD/ghc-6.8.2/includes -I/builddir/build/BUILD/ghc-6.8.2/gmp/gmpbuild -D__GLASGOW_HASKELL__=608 -DCALLCONV=ccall -Iinclude dist/build/Network/Socket_hsc_make.c -o dist/build/Network/Socket_hsc_make.o Preprocessing library network-2.1.0.0... The full buildlog is at http://koji.fedoraproject.org/koji/getfile?taskID=425959&name=build.log Before investigating further I just wondered if anyone has already looked at this and might have a patch or workaround? Jens

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GHC logo ideas (was: Re: ANN: Mac installer pkg for GHC - 6.8.2.20080211 trial release (Leopard, Intel))
by Tim Chevalier 15 Feb '08

15 Feb '08

On 2/14/08, Yitzchak Gale <gale(a)sefer.org> wrote: > Manuel M T Chakravarty wrote: > >> I'd also be nice to have a cool logo/icon. > > > Tim Chevalier wrote: > > I am a mediocre artist, but I'd be willing to give it a try if there > > are no better ones around. > > > Sounds great, please give it a whirl. > Well, I got bored in class, so here's a sketch: http://lafalafu.com/krc/Scratch/ghc-logo-idea.png This is still based on Yitzhak's idea of incorporating the Clyde Arc. The extra bit of the lambda that extends on the left and turns into a chip is meant to look like the bridge, though I'm not sure I got the shape right. I hereby release the above-linked image into the public domain. If anyone wants to mess with it or make something prettier that's based on the same idea, feel free. If anyone likes it, I could try to turn this into something more polished. I'm not sure to what extent GHC-land is crying out for a new logo, though... > > > I'm almost tempted to switch back to a Mac. > > > Since you have been a Mac user, you are aware of how > fidgety this platform is about aesthetics. We all appreciate Well, that was actually just in response to the "Installation instructions: nil" comment in the OP. I'd love to use something that has no installation instructions :-) Cheers, Tim -- Tim Chevalier * http://cs.pdx.edu/~tjc * Often in error, never in doubt "I do not write about nice people. I am not nice people." -- Dorothy Allison

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Some problems writing a threaded program
by John Vogel 13 Feb '08

13 Feb '08

I am running my program in WinXP with ghc 2.6.8 If you install netstat and change the parameters it should still work in linux. Why does thread # 3 dominate over the over threads int the output? Why does thread # 4 never seem to run? I can't use the sleep function in System.Process.Win32 since it puts all the threads asleep at the same time. Is there a way to put only one thread asleep? That would allow more of a chance for thread #4 to run. The simplified program: --------------------------------------------------------------- module Main where import Data.IORef import Data.List import System.IO import System.Process import Control.Concurrent import Control.Concurrent.Chan data Connection = Null | Last | Active deriving (Eq) instance Show Connection where show Null = "Null" show Last = "Last" show Active = "Active" instance Read Connection where readsPrec _ s = case take 5 s of " UDP" -> [(Active, "")] " TCP" -> [(Active, "")] "Last" -> [(Last,"")] _ -> [(Null,"")] -- ptrints one 0 and 1 main = do stop <- newIORef False cbuffer <- newChan :: IO (Chan Connection) putStr "0" (_,output,_,ph) <- runInteractiveCommand "netstat -noa 5" sequence $ map forkIO $ [(processConnections ph output cbuffer), (stopNetstat ph stop False), (printChan cbuffer),(checkStop stop "xxxx")] putStr "1" _ <- waitForProcess ph --mapM killThread ts putStrLn "\nDone" -- thread # 2 processConnections :: ProcessHandle -> Handle -> (Chan Connection) -> IO () processConnections ph hout chan = do h <- hReady hout e <- getProcessExitCode ph putStr "2" if (not h && e /= Nothing) then do writeChan chan Last >> return () else do if h then do readConnection hout >>= writeChan chan else do processConnections ph hout chan readConnection :: Handle -> IO Connection readConnection hout = do l <- hGetLine hout let c = (read l :: Connection) if (c == Null) then do (readConnection hout) else do (return c) -- thread number 3 stopNetstat :: ProcessHandle -> (IORef Bool) -> Bool -> IO () stopNetstat netstat _ True = terminateProcess netstat stopNetstat netstat gref False = putStr "3" >> yield >> readIORef gref >>= stopNetstat netstat gref --thread 4 printChan :: (Chan Connection) -> IO () printChan chan = do putStr "4" c <- readChan chan printConnection c printChan chan checkStop :: (IORef Bool) -> String -> IO () checkStop ref s = do if (take 4 s == "stop") then do (writeIORef ref True) else do (getChar >>= (\x -> checkStop ref ((tail s) ++ [x]))) printConnection :: Connection -> IO () printConnection c = case c of Null -> putStr "N" Last -> putStr "L" _ -> putStr "A"

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Array.ST is not being nice to me
by Robert van Herk 11 Feb '08

11 Feb '08

Hi all, I have a problem with regards to the speed of ST arrays. In short: a Data.Map.Map outperforms Data.Array.ST in my application, whereas as far as I understand it, the ST array should be quicker. My application is a compiler. It compiles some source code into a (huge) number of boolean equations. These equations are finally printed to stdout; they form my "byte-code". Also the equations are defined in terms of the other equations again. So, for instance, compiled byte code may look like: 1 == 5 5 == True /\ 3 3 == False To optimize the compiled code, I do some tricks like constant propagation. So, for instance, if I know that one equation always results in some constant, I substitute that constant for that equation. So above set of equations will be rewritten as: 1 == False 5 == False 3 == False ------ All in all, my compiler does the following: - It generates a set of equations for some statement in the source code - It rewrites these equations - It remembers for each equation which other equations it depends upon, such that if these are rewritten to something simple, this equation may be rewritten too. So there are a lot of lookups of the equations, especially for all the rewritings. All in all, I store quite some data for each equation, amongst which are: data EquationState = EQS {cDefinition::Equation, usedBy::Map.Map Int (), ...} First, I stored all the equations in a Data.Map.Map. Int EquationState. But then I thought it'd be more clever to put it into an ST array, seen the large number of lookups. So now i put it into an ST array. However, the code runs much, much slower now (about 4 times). The ST array does use slightly less memory though. I did some profiling. It seems that it is not the GC that is making over-hours. So my theory now is: I do a large number of lookups. Only a small number of these lookups trigger a change in the array. One EquationState is pretty big. Is it so that when you look something up from an ST array, the whole element gets deeply copied in memory, just in case you would change it in the array? Seen the size of my elements, I could imagine that that would cause a whole bunch of needless copying. Or is there some other reason for this slower behaviour of ST array? Robert

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Shared Libraries in ghci
by Bernd Brassel 11 Feb '08

11 Feb '08

Sorry to ask a C question here, but I could not find an answer on the net. How do I create a library that can be used in ghci? This is the situation: I have a c file coracle.c. I do /tmp$ cc -c -o coracle.o coracle.c /tmp$ ar rc libcoracle.a coracle.o /tmp$ ranlib libcoracle.a and then I the library is linked statically with ghc just fine: /tmp$ ghc -L/tmp -lcoracle --make COracle.hs But if I create a shared library, like this: /tmp$ cc -c -shared -o libcoracle.so coracle.c then ghci does not like the format: /tmp$ ghci -L/tmp -lcoracle COracle.hs GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help Loading package base ... linking ... done. Loading object (dynamic) coracle ... failed. Dynamic linker error message was: /tmp/libcoracle.so: only ET_DYN and ET_EXEC can be loaded Whilst trying to load: (dynamic) coracle Directories to search are: /tmp ghc-6.8.2: user specified .o/.so/.DLL could not be loaded. In the web I only find bla about which bit in the ELF-header of the library tells you that it is ET_DYN or not. But never how to build such a library. I guess it is too much to hope for a C-freak around here but I am sure a semi-freak or quarter-freak will do as well. Thanks in advance! Bernd

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