August 2001 - Glasgow-haskell-users

GHCi grumbles (4)
by George Russell 15 Aug '01

15 Aug '01

If I run GHCi but leave it doing nothing and waiting for input, the process nevertheless eats CPU time, and is at the moment bringing my RealAudio relay of Gardeners' Question Time to a halt. Do the GHC Team have anything to suggest for dealing with this problem?

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GHCi grumbles (3)
by George Russell 15 Aug '01

15 Aug '01

It should be possible to change (1) the environment returned by System.getEnv (2) the arguments returned by System.getArgs (3) System.getProgName in GHCi (for example, using :set). By the way, my partial solution to grumble (1) is :def modules (\ modulesStr -> do { let { imports = Prelude.map (\ modName -> ("import "++(if modName == "+" then "Prelude" else modName)++"\n")) (Prelude.words modulesStr) ; imod = "module XYZZY where \n"++(Prelude.concat imports) } ; Prelude.writeFile "/tmp/XYZZY.hs" imod ; Prelude.return ":load /tmp/XYZZY.hs" } ) Now if only I had a Haskell function for replacing a Haskell declaration or expression using layout with the appropriate ({/;/}) functions, I could write a :def macro :code (complicated thing split over several lines) :edoc which put everything together and compiled it. Is there a contest for "Worst Abuse of :def"?

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GHCi grumbles (2)
by George Russell 15 Aug '01

15 Aug '01

It would also be nice if ghci allowed you to continue onto a new line. Otherwise writing long complicated :def scripts is tiresome . . .

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GHCi really should allow multiple modules
by George Russell 15 Aug '01

15 Aug '01

GHCi is great. But I really think it should allow you to have multiple modules in scope, since having to qualify either your favorite module or the Prelude all the time is a bore. My complete suggestion is (1) That there be a list of in-scope modules. Names are searched in each module in term, starting at the list head. (2) :module mod1 mod2 ... modn (n>=1) replaces the current list by [mod1,mod2,...,modn] :module mod1 mod2 ... modn + prepends [mod1,mod2,...,modn] to the existing list. :module displays the current list. (3) The prompt show the head of the current list, followed, if the list has more than one element, by a "+" sign. I appreciate that you can load multiple modules by creating a special file containing the relevant import declarations. Indeed, if provoked enough I suppose I might write a :def macro to do this, but it seems rather untidy and can't get at the existing list of modules.

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freshmeat project listing for The Glasgow Haskell Compiler
by jeff covey 15 Aug '01

15 Aug '01

I'm writing in reference to your project "The Glasgow Haskell Compiler". Since the time you submitted this project to us, freshmeat has adopted a new categorization system which allows much more fine-grained organization of projects. Since your project has never been recategorized under this system, our readers aren't finding your project when they browse through categories where it should be listed. We'd like to ask you to take just a few minutes to recategorize your project. You should delete any categories which begin with "Old Appindex" and add all of the new categories which apply to your project. You can edit your project listing at: http://freshmeat.net/projects/theglasgowhaskellcompiler/ with the "recategorize" function in the menu. While you're there, take a moment to make sure everything else is up-to-date. If you have any problems, please let us know at http://freshmeat.net/contact/. Thanks for listing your project in our database. Sincerely, Jeff Covey

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RE: Release schedule for GHC 5.02
by Julian Seward (Intl Vendor) 14 Aug '01

14 Aug '01

Crashing GHCi? Can you send some details? Have you filed a bug report? GHCi shouldn't crash on any platforms. Pls send more info. The same goes for all users -- if GHC and/or GHCi have crashed/ failed for you and you didn't report a bug, NOW is the time to do so! J | -----Original Message----- | From: Daan Leijen [mailto:daan@cs.uu.nl] | Sent: Tuesday, August 14, 2001 2:12 PM | To: Julian Seward (Intl Vendor); cvs-ghc(a)haskell.org | Cc: glasgow-haskell-users(a)haskell.org | Subject: Re: Release schedule for GHC 5.02 | | | > * Win32: simple one-click-install package. No requirement for | > Cygwin any longer, and you don't need to install any other | > supporting stuff either. | | Yahoo, I love the experimental version (except for the | crashing GHCi) and my windows friends at Utrecht are finally | using GHC now, especially now that the profiler works again :-) | | All the best, | Daan. | |

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Re: Release schedule for GHC 5.02
by Alex Ferguson 14 Aug '01

14 Aug '01

> * Much heroic hacking by Ken Shan to revive the Alpha port. My hero! But you don't mention an Alpha release per se -- is that going to be available elsewhere, binarywise, or is a final version still pending? Or will someone hold my hand while I try a source build? ;-) Cheers, Alex.

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ghc-5.00.2 solaris-bin-dist link problem
by Johannes Waldmann 14 Aug '01

14 Aug '01

I just installed the ghc-5.00.2 binary package for Solaris. When trying to link a program that uses -syslib data, I get this ghc: linking ... /usr/local/lib/gcc-lib/sparc-sun-solaris2.6/3.0/../../../libreadline.so: undefined reference to `tgetnum' /usr/local/lib/gcc-lib/sparc-sun-solaris2.6/3.0/../../../libreadline.so: undefined reference to `tgoto' and a few more. it looks more like a problem with our gcc installation, but still I'd like to know how to fix it effectively (I don't have any root privileges here). Best regards, -- -- Johannes Waldmann ---- http://www.informatik.uni-leipzig.de/~joe/ -- -- joe(a)informatik.uni-leipzig.de -- phone/fax (+49) 341 9732 204/252 --

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RE: Comparsion of Execution Speeds
by Simon Marlow 13 Aug '01

13 Aug '01

> Is anyone aware of publications relating the execution speeds of ghc > compiled haskell programs to say C? > > I have once heard that the difference is about a factor of 10. The difference varies wildly depending on the program. But Doug Bagely's programming language shootout has some interesting figures: http://www.bagley.org/~doug/shootout/ cheers, Simon

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Comparsion of Execution Speeds
by Stephan Reiff-Marganiec 13 Aug '01

13 Aug '01

Hi, Is anyone aware of publications relating the execution speeds of ghc compiled haskell programs to say C? I have once heard that the difference is about a factor of 10. Stephan -- ______________________________________________________________________________ Stephan Reiff-Marganiec e-mail: sreiff(a)dcs.gla.ac.uk Research Assistant / Student tel: + 44 141 339 8855 x 0048 Department of Computing Science fax: + 44 141 330 4913 University of Glasgow 8-17 Lilybank Gardens GLASGOW G12 8RZ, U.K. ______________________________________________________________________________

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