June 2004 - Glasgow-haskell-users

Executing external program
by Gerd M 06 Jun '04

06 Jun '04

Is there a simple way to execute a different process from a Haskell program, waiting for it's termination and then continuing with the next IO action? Or does one have to use the forkIO & waiting for the child process - stuff? regards _________________________________________________________________ STOP MORE SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail

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Parallel
by Goran Topic 03 Jun '04

03 Jun '04

Hello. I am a newcomer to functional programming, and I would like to learn it very much. However, I'm also starting to deal with parallel programming, and I thought I'd combine my two interests. So I grabbed the Debian ghc6 package (v6.2), and (after a lot of searching) found out that I lack the "mp" way. Then I tried grabbing the sources, and compiling them with WAYS=mp, but when the compiler is compiling the "mp" way, it does so with the -parallel switch, which requires the "mp" include files - the very ones I am trying to compile! Now, several people tried telling me that GpH is a separate project, but 1) it's very out of date 2) ghc source has a ton of PVM references 3) the ghc user manual mentions parallel code ...so I kind of figured that GpH got integrated into ghc. The problem is that I just can't get it to run! Can anyone tell me what I am doing wrong? Goran Topic

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F#
by John Sharley 03 Jun '04

03 Jun '04

I note this remark on the Microsoft Research site (http://research.microsoft.com/projects/ilx/fsharp.aspx) <quote> Purely functional languages like Haskell are excellent within certain niches, but unfortunately some simple programming exercises can quickly turn into problems that require a PhD. to solve. </quote> Are the Microsoft Research people working on GHC or anyone else on this list also of this opinion? If so, why? What if anything does the quoted remark mean for the prospects of seeing a production Haskell compiler from Microsoft?

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RE: deriving Typeable
by Simon Peyton-Jones 03 Jun '04

03 Jun '04

You can just write the instance of Typeable by hand instance Typeable1 e => Typeable (Y e) where ... (Use the instances in the library as a guide.) Yes, GHC could do this for you, but it would then stumble when e had kind ((*->*) -> *). We need kind polymorphism! Simon | -----Original Message----- | From: glasgow-haskell-users-bounces(a)haskell.org [mailto:glasgow-haskell-users- | bounces(a)haskell.org] On Behalf Of John Meacham | Sent: 02 June 2004 21:53 | To: glasgow-haskell-users(a)haskell.org | Subject: deriving Typeable | | newtype Y e = Y { unY :: (e (Y e)) } | deriving(Data,Typeable,Show,Read,Eq) | | gives | E.hs:64: | Can't make a derived instance of `Typeable (Y e)' | (`Y' is parameterised over arguments of kind other than `*') | When deriving instances for type `Y' | | Is there any way around this limitation other than manually expanding Y | everywhere I want to use it (which I really don't want to do)? Is the | limitation inherent to the way Typeable works, or is it just that no one | has implemented it yet? | | -- | John Meacham - ⑆repetae.net⑆john⑈ | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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deriving Typeable
by John Meacham 02 Jun '04

02 Jun '04

newtype Y e = Y { unY :: (e (Y e)) } deriving(Data,Typeable,Show,Read,Eq) gives E.hs:64: Can't make a derived instance of `Typeable (Y e)' (`Y' is parameterised over arguments of kind other than `*') When deriving instances for type `Y' Is there any way around this limitation other than manually expanding Y everywhere I want to use it (which I really don't want to do)? Is the limitation inherent to the way Typeable works, or is it just that no one has implemented it yet? -- John Meacham - ⑆repetae.net⑆john⑈

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Handrolled linker?
by David Brown 02 Jun '04

02 Jun '04

Any estimates on the difficulty of changing Linker.c to be able to use standard dynamic link calls (dlopen, ...) rather than having to be customized for every target platform. I'm considering making this work on powerpc-linux, but I'm thinking it might be a more useful task to make the linker more portable, rather than just hacking in another platform. There are a few platforms (linux alpha, linux powerpc) where the compiler wasn't very difficult to get working, but ghci doesn't work because of the linker problem. Dave

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RE: ghc web page
by Simon Marlow 02 Jun '04

02 Jun '04

On 01 June 2004 18:00, John Meacham wrote: > server side includes are no longer being processed on the ghc web > server making the web page sort of not usable. perhaps someone > changed the .htaccess or apache config? Well spotted. Now fixed, thanks. > also, I no longer seem to have access to the fptools cvs repository, > my ssh login no longer works, should I resend my public key to > someone to get it fixed? thanks. I'll re-activate your account. What was your username? Cheers, Simon

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ghc web page
by John Meacham 01 Jun '04

01 Jun '04

server side includes are no longer being processed on the ghc web server making the web page sort of not usable. perhaps someone changed the .htaccess or apache config? also, I no longer seem to have access to the fptools cvs repository, my ssh login no longer works, should I resend my public key to someone to get it fixed? thanks. John -- John Meacham - ⑆repetae.net⑆john⑈

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http://cvs.haskell.org nonresponsive
by herington, dean 01 Jun '04

01 Jun '04

The last couple of days, http://cvs.haskell.org <http://cvs.haskell.org> has been barely functional for me (pardon the pun). Does anybody know what's up? Dean

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RE: AMD64
by Simon Marlow 01 Jun '04

01 Jun '04

On 31 May 2004 20:53, scott west wrote: > Well, I just poked and proded the build a bit more, and got it to > complete and install, with the same result as you. Seg faults > immediately and that's it. Hmm, any else had any experience with this? The amd64 port isn't really there yet. It works unregisterised, but the registerised support need some more work (as you discovered). You also need a non-broken version of gcc (3.3.3 or 3.4.0). Don Stewart was working on this recently; I'm not sure how far he got. Cheers, Simon

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