February 2007 - Glasgow-haskell-users

ghc: out of memory error while compiling huge "let"
by David Morse 06 Feb '07

06 Feb '07

I have a machine-generated source-code file that brings my computer to its knees with ghc-6.6. After an hour or so of rummaging around, ghc dies with: "ghc-6.6: out of memory (requested 1048576 bytes)". The linux machine has 1gb RAM and 2gb swap, and I don't have access to a better one. The file is of the form ------------------------------------------- module foo (a,b) where (a,b) = let ...10,300 bindings... ; in ([a1,a2,a3...a300],[b1,b2,b3...b10000]) -------------------------------------------- Is there some simple syntactic refactoring I can do to make this work? E.g. busting the local bindings out of the "let" and into to the global level? The bindings are intertwined, but I could (with some effort) reorder them so that b5000 would only reference b5001...b10000 and never b1...b4999.

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Compiling module using Data.Time with -O fails; can't find HsTime.h
by Alistair Bayley 06 Feb '07

06 Feb '07

If I try to compile this Main.hs: module Main where import Data.Time main = getCurrentTime >>= print with this ghc-6.6 command: ghc --make Main -o test -O ... I get this error: C:\DOCUME~1\bayleya\LOCALS~1\Temp\ghc728_0\ghc728_0.hc:8:20: HsTime.h: No such file or directory Is this me doing something I shouldn't, or is there something wrong with the way the library has been distributed? Alistair

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(no subject)
by Tays Soares 06 Feb '07

06 Feb '07

Hello everyone, I did at my master thesis a compiler that generates Haskell code. Now I need to measure the execution time of my generated code and I've been searched and I don't know if I'm looking with the wrong keywords but I could not find anything. I just need to measure the time of simple functions, like Ackermann and Fibonacci. Does anyone know how to measure the execution time of a Haskell program or function? Thank you, Tays __________________________________________________ Fale com seus amigos de graça com o novo Yahoo! Messenger http://br.messenger.yahoo.com/

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Re: [Haskell-cafe] Become a GHC build slave!
by Simon Marlow 06 Feb '07

06 Feb '07

dgriffi3(a)uiuc.edu wrote: > Here at ACM@UIUC we have the following that we could use: > AIX on PPC > Linux on PPC > Mac OSX on PPC > Mac OSX on x86 > OpenVMS on Alpha > Solaris on Sparc > > If needed we could also set up the following: > Solaris on x86 > BeOS on BeBox > IRIX on MIPS > Linux on Sparc > something on Itanium (Preproduciton-caliber Float support) Thanks - all of these would be useful; only the two Mac OS X builds would be duplicates, but duplicates are useful (as redundancy). Please let us know when you've set up your clients and we'll add you to the setup. Cheers, Simon

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Become a GHC build slave!
by Simon Marlow 06 Feb '07

06 Feb '07

Thanks largely to Ian Lynagh, GHC now has a BuildBot infrastructure to automate nightly builds on multiple platforms. This replaces the old set of shell scripts that we used to run nightly builds; now adding new clients to the setup is relatively easy, instructions are here: http://hackage.haskell.org/trac/ghc/wiki/BuildBot So far we have various Windows builds running, and I'll be moving over the existing Linux nightly builds in due course. If you have a spare machine or a machine that is idle overnight, and you'd like to use it to run automated GHC builds, then please take a look at the above page for how to get started. We especially need platforms that we don't use regularly (i.e. not Windows or Linux/x86/x86_64). Cheers, Simon

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Re: time profiling (was: (no subject))
by Kirsten Chevalier 05 Feb '07

05 Feb '07

On 2/5/07, Tays Soares <tayscristina(a)yahoo.com.br> wrote: > > > > Hello everyone, > > I did at my master thesis a compiler that generates Haskell code. Now I need to measure the execution time of my generated code and I've been searched and I don't know if I'm looking with the wrong keywords but I could not find anything. I just need to measure the time of simple functions, like Ackermann and Fibonacci. Does anyone know how to measure the execution time of a Haskell program or function? If you just want wallclock time, then use the standard Unix "time" command. If you want more specific data, look at the Profiling section of the GHC manual: http://www.haskell.org/ghc/docs/latest/html/users_guide/profiling.html and also at the Profiling section of the Commentary, though it's very incomplete: http://hackage.haskell.org/trac/ghc/wiki/Commentary/Profiling And feel free to ask again on this list after looking at those pages, if you still have more questions. Cheers, Kirsten -- Kirsten Chevalier* chevalier(a)alum.wellesley.edu *Often in error, never in doubt "the faith that is so easy to forget / in moment after moment of distraction" -- Ilene Weiss

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No instance for (Monad ((->) Integer))
by Chad Scherrer 05 Feb '07

05 Feb '07

I'm getting this error in ghci, and I think it should typecheck just fine. Prelude> let fs = [(+2), (*4)] Prelude> :t fs fs :: [Integer -> Integer] Prelude> :t sequence fs <interactive>:1:0: No instance for (Monad ((->) Integer)) arising from use of `sequence' at <interactive>:1:0-10 Possible fix: add an instance declaration for (Monad ((->) Integer)) I'm using ghc-6.6-3 on Ubuntu edgy, installed as described on Pupeno's web site (http://pupeno.com/2006/12/17/unstable-packages-on-ubuntu/) Could something be installed incorrectly, or am I just misreading the type info? Thanks, Chad

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ghc 6.6 for mac os x (intel)
by Ariel Apostoli 05 Feb '07

05 Feb '07

Hello, I tried to install ghc 6.6 but apparently I have done something wrong since whenever I type ghc I obtain: $ /usr/local/bin/ghc dyld: Library not loaded: /opt/local/lib/libreadline.5.1.dylib Referenced from: /usr/local/lib/ghc-6.6/ghc-6.6 Reason: image not found Trace/BPT trap can anyone help please?

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Re: GHC appears to loop
by Wouter Swierstra 04 Feb '07

04 Feb '07

On 4 Feb 2007, at 14:12, Duncan Coutts wrote: > Would you say this the same as the one described in the user guide? > > http://www.haskell.org/ghc/docs/latest/html/users_guide/ > bugs.html#bugs-ghc You're right of course. I checked Trac before hitting send, but didn't think to look any further. Thanks for the link, Wouter

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GHC appears to loop
by Wouter Swierstra 04 Feb '07

04 Feb '07

When I try to compile to the following program, GHC seems to loop: data Evil = Evil (Evil -> Evil) instance Show Evil where show _ = "t" apply :: Evil -> Evil -> Evil apply (Evil f) x = f x delta :: Evil delta = Evil (\x -> x `apply` x) omega :: Evil omega = delta `apply` delta main = print omega The program codes up a non-terminating term omega - very similar to (\x -> x x) (\x -> x x) - without using recursion. The trick is to define an Evil data type which has a negative occurrence of Evil. I realize it's a contrived example, but I wasn't sure if it's a known issue. In case it matters, I'm using GHC 6.6 on a PowerPC Mac. All the best, Wouter

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