October 2001 - Glasgow-haskell-users

RE: gtk+hs and libgmp
by Simon Marlow 01 Nov '01

01 Nov '01

> > That would be one solution, yes. On your system, if you > remove /usr/lib/libgmp.a (and /usr/lib/libgmp.so if you have > one), does it work? You only need these files if you intend > to build any software which depends on having GMP version 2, > which is unlikely since GMP 3 is source-compatible with GMP 2. > > Yes, that works. Still I would opt for the renaming to avoid this > problem in the future. It really depends on the setup of the system. > Another question: should packages like gtk+hs not add themselves to > package.conf, so that gtkhs-config is not needed? Or is this method > not yet proven. I've been discussing with Manuel how best to do this. It's not straightforward, because you still want to be able to do things like 'make install', and have several versions of gtk+hs on your system at once. Cheers, Simon

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problem compiling
by Juan Ignacio García García 31 Oct '01

31 Oct '01

hello, I installed ok the rpm-packages on linux (Mandrake 8.1), but when I try to compile something the following message appears: f2.hs:1: failed to load interface for `Prelude': Bad interface file: ./Prelude.hi does not exist Action: openFile Reason: No such file or directory File: ./Prelude.hi If I go to the directory /usr/bin (where the binary file ghc is) and I type > ghc -c /home/user/file.hs then the compilation is done without problems. Does anyone know what I have to do for compiling without problems in any folder? (The directory /usr/bin is my PATH).

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RE: gtk+hs and libgmp
by Gérard Milmeister 31 Oct '01

31 Oct '01

On Wed, 2001-10-31 at 15:49, Simon Marlow wrote: > > > Here is the output: > > 1. Main.out from a link that succeeds. > > 2. GtkHelloWorld.out, a sample program from gtk+hs, compiled with > > ghc -v -fglasgow-exts -lgtkHS GtkHelloWorld.hs `gtkhs-config > > --cflags` `gtkhs-config --libs` `gtk-config --cflags` > > `gtk-config --libs` > > > > In fact, you are right, there is a -L/usr/lib before -lgmp. > > Maybe the libgmp.a included > > with ghc should be renamed, for example libgmp_ghc.a > > That would be one solution, yes. On your system, if you remove /usr/lib/libgmp.a (and /usr/lib/libgmp.so if you have one), does it work? You only need these files if you intend to build any software which depends on having GMP version 2, which is unlikely since GMP 3 is source-compatible with GMP 2. Yes, that works. Still I would opt for the renaming to avoid this problem in the future. It really depends on the setup of the system. Another question: should packages like gtk+hs not add themselves to package.conf, so that gtkhs-config is not needed? Or is this method not yet proven. -- Gérard Milmeister Tannenrauchstr. 35 8038 Zürich gemi(a)bluewin.ch

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RE: gtk+hs and libgmp
by Simon Marlow 31 Oct '01

31 Oct '01

> Here is the output: > 1. Main.out from a link that succeeds. > 2. GtkHelloWorld.out, a sample program from gtk+hs, compiled with > ghc -v -fglasgow-exts -lgtkHS GtkHelloWorld.hs `gtkhs-config > --cflags` `gtkhs-config --libs` `gtk-config --cflags` > `gtk-config --libs` > > In fact, you are right, there is a -L/usr/lib before -lgmp. > Maybe the libgmp.a included > with ghc should be renamed, for example libgmp_ghc.a That would be one solution, yes. On your system, if you remove /usr/lib/libgmp.a (and /usr/lib/libgmp.so if you have one), does it work? You only need these files if you intend to build any software which depends on having GMP version 2, which is unlikely since GMP 3 is source-compatible with GMP 2. Cheers, Simon

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problem definind a function
by Juan Ignacio García García 31 Oct '01

31 Oct '01

hello, Does anybody know why it is not possible to define the folowing function in ghc? gggg= \x y -> (x+y - length [1..(gcd x y)] >= round ((x+1)/2)) ) The message obtained was this one: No instance for (RealFrac Int) arising from use of `round' at num-s-divs.hs:253 In the second argument of `(>=)', namely `round ((x + 1) / 2)' In a lambda abstraction: (((x + y) - (length [1 .. (gcd x y)])) >= (round ((x + 1) / 2))) Thanks in advance, J. I. García

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RE: ghc compiled program crashes
by Julian Seward (Intl Vendor) 30 Oct '01

30 Oct '01

Sven | from time to time ghc compiled programs simply crash on | my windows2000 without any meaningfull error message. I guess | this has something to do with storage management (I vaguely | remember having read something about errors durcing gc on | this list, but did not find the corresponding posts in the archive). ghc-5.02 has a known bug on Win32 only, which causes all programs compiled with it to die silently when the heap size reaches 128 megabytes. This is fixed in the upcoming 5.02.1. You did not say what version ghc you are using or give any other details. If you tell us more we might be able to help more. J

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RE: ghc --make feature request
by Simon Peyton-Jones 30 Oct '01

30 Oct '01

| Note that in GHC, the "version number" of a function can | often change for hard-to-spot reasons. You just need to | change (for example) the strictness properties of the | function, which can be very easy to do when making changes to | your code. The compiler cares about (much) more than just | the types of imported objects. I tend to expect recompiles | whenever something depends on a function I've changed, even | if I don't think the changes were very significant. But you get many many fewer such "unexpected" changes when you do not use -O or (I believe) when you use ghci. Reason: without -O ghc exports only type info across module boundaries. So I'd still like to understand why Martin is seeing so much recompilation. S

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interpreter features
by S.D.Mechveliani 30 Oct '01

30 Oct '01

Eray Ozkural <erayo(a)cs.bilkent.edu.tr> writes > Still, having come from that realm of old-school-AI-language-interpreters I > have difficulty using GHCi because I can't define functions interactively. > Would it be possible to introduce a mode to do that? > [..] > and perhaps going into "interactive" modules which would be separate > namespaces. > > And if LISP can do it, why can't you? ;) > [..] The following works in ghc-5.02: ghci ... Prelude> let {g:: Integer->Integer; g 0 = 0; g n = n+(g $ pred n)} Prelude> g 0 0 Prelude> g 3 6 But Prelude> let {type T = Int; n = 1 :: T} does not. I wonder, whether there is any good reason for such distinction. I would like too Haskell to behave like a good interpreter, with self-applicability, dynamic features, like, maybe, some Lisp systems do. ----------------- Serge Mechveliani mechvel(a)botik.ru

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GHCi -- thanks ghc team !
by Ronald Legere 29 Oct '01

29 Oct '01

OK, I admit it. I didnt play with GHCi at all when it was first available ... because I was on windows... but I have started to play with it a bit with the latest installer... and let me say: Nice Job GHC team! Cheers! __________________________________________________ Do You Yahoo!? Make a great connection at Yahoo! Personals. http://personals.yahoo.com

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RE: gtk+hs and libgmp
by Gérard Milmeister 29 Oct '01

29 Oct '01

On Mon, 2001-10-29 at 11:11, Simon Marlow wrote: > > > On Sat, 2001-10-27 at 17:27, Manuel M. T. Chakravarty wrote: > > > Gérard Milmeister <gemi(a)bluewin.ch> wrote, > > > > > > > On Thu, 2001-10-25 at 13:53, Simon Marlow wrote: > > > > > It seems very strange that the libgmp in your GHC > > installation doesn't work. How did you install GHC? Do you > > have problems linking other programs, or just gtk+hs programs? > > > > > > > > > As far as I know, it happens only with gtk+hs. Small > > programs I have > > > > written are linked alright. > > > > > > Do these small programs actually use any arbitrary precision > > > arthimetic - ie, use the type Integer? > > > > > > Manuel > > Something like this? > > > > module Main where > > > > main = print (1000000000000000000000000000000::Integer) > > > > Yes, it works. > > I know that gtk+hs adds a -L/usr/lib option to the command line, which comes originally from gtk-config. > > I'm still confused by what you said about GHC not linking with the libgmp.a in /opt/ghc, and yet it still manages to link programs using arbitrary precision integers somehow. Normally GHC won't look in /usr/local/lib for libraries, so it won't even find your GMP 3 library at all. > > Hmm. All very mysterious. I think you'll need to send us output from ghc -v for a link that failed and one that succeeded. > > Cheers, > Simon Here is the output: 1. Main.out from a link that succeeds. 2. GtkHelloWorld.out, a sample program from gtk+hs, compiled with ghc -v -fglasgow-exts -lgtkHS GtkHelloWorld.hs `gtkhs-config --cflags` `gtkhs-config --libs` `gtk-config --cflags` `gtk-config --libs` In fact, you are right, there is a -L/usr/lib before -lgmp. Maybe the libgmp.a included with ghc should be renamed, for example libgmp_ghc.a n.b. I send the message only to you, not to the mailing list because of the attachments. Regards,

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