- Glasgow-haskell-users

IArray (IOToDiffArray IOUArray) Bool : Why it doesn't exist ?
by Chaddaï Fouché 13 Nov '07

13 Nov '07

IOUArray Bool exists, and is even a bits array in reality (which makes it really efficient), is there any reason that DiffUArray Bool can't exist ? -- Jedaï

2 1

Binary for Vista 64-bit
by Chris Saunders 13 Nov '07

13 Nov '07

Just wondering if a binary for Vista 64-bit will be released? Regards Chris Saunders

3 2

Re[2]: ghc-6.8.1, +RTS -N2
by Bulat Ziganshin 13 Nov '07

13 Nov '07

Hello Johannes, Tuesday, November 13, 2007, 12:08:20 PM, you wrote: >> i suggest you to test it on one-threaded CPU too > I just did. The behaviour is identical > (works with -N1, segfaults with -N2) > Any ideas? - Best regards, J.W. no. just publish this into maillist, it's important to identify the problem well, in my practice the only way to make GHC crash (except for errors in GHC itself) is to use unsafePerformIO, in particular for creation global variables -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com

2 1

ghc-6.8.1, +RTS -N2
by Johannes Waldmann 13 Nov '07

13 Nov '07

what could be the reason for my program (compiled with -threaded) crashing with +RTS -N2 it seems to work fine with "-N1". I compiled with ghc-6.8.1 (installed from binary package). I am using forkIO, some MVars, some IORefs, some Channels. It seems -prof -threaded does not work: ghc-6.8.1: combination not supported: Threaded/Profiling When I run the executable under gdb I get Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0xb6afeb90 (LWP 7801)] 0x08138d8c in checkBlackHoles () This behaviour occurs both on a dual core PC and on an single core hyperthreaded PC, both running openSuse-10.3 I cannot tell whether this is an regression from 6.6 (I cannot easily backport my code). Any hints appreciated, Johannes Waldmann.

1 0

Re: GHC 6.8.1 on Mac OS X 10.5 (Leopard)
by Benedikt Huber 13 Nov '07

13 Nov '07

Manuel M T Chakravarty wrote: > A full binary distribution of GHC 6.8.1 for Mac OS X 10.5 (Leopard) > is available from > http://www.cse.unsw.edu.au/~chak/haskell/ghc-6.8.1-i386-apple-darwin.tar.bz2 Thanks, it's great you provided a binary distribution, especially since macports' ghc seems to be broken on Leopard at the moment. I had one little problem when linking with a dynamic library though (darwin9 / i386): <<< ghc --make -O -hidir build/ifaces -odir build/objs Foreign/ YicesTest.hs -o bin/YicesTest -optl "-fexceptions" -lstdc++ -lyices Linking bin/YicesTest ... ld: absolute addressing (perhaps -mdynamic-no-pic) used in ___gmpn_divexact_1 from <ghc-6.8.1-dir>/lib/ghc-6.8.1/ libgmp.a(dive_1.o) not allowed in slidable image >>> I don't know if this is a known problem and what causes it, and I'm not sure what it means; However, replacing the 'libgmp.a' you've distributed with a recently compiled one from macports (gmp 4.2.2_0) resolved the problem for me. Benedikt

2 1

Re: Extensible Records
by Barney Hilken 12 Nov '07

12 Nov '07

I think this would be a BIG mistake. Whatever system GHC settles on is almost certain to become part of the Haskell standard, and this particular system has some deep limitations which could not be got round without ripping it all out and starting again. The problem with this (and other "Flex-like") systems is that they take record extension as the basic operation of record building, rather than record merging. This means that you can only ever add or update statically determined fields of a given record. An important application which is made impossible by this approach is functions with optional arguments. For example, if you look at the definition of R (the statistics system) every function has a small number of mandatory positional arguments, and a very large number of optional named arguments, which take sensible default values. I want to be able to write: > f opts x = let vals = {Opt1 =: default1, ... } |: opts in > ... vals ... x ... where '{Opt1 =: default1, ... }' is some fixed record of default values, and '|:' is record overwrite. The type of f should be > f :: (a `Subrecord` {Opt1 :=: t1, ...}) => a -> b -> c where '{Opt1 :=: t1, ...}' is the (fixed) type of '{Opt1 =: default1, ... }' (and x::b, and c is the type of the result). The condition 'a `Subrecord` {Opt1 :=: t1, ...}' in the context of this type means that every field of 'opts :: a' must be a field of '{Opt1 :=: t1, ...}', but opts can have as few fields as you like. This is exactly what you want for optional arguments. This could never be defined in any "Flex-like" system, because these systems depend on the fact that their record types can be reduced to a type variable extended by a fixed set of labels. This is a major restriction to what you can do with them: you can never define operations like '|:' or '+:' where the second argument does not have a constant set of fields. This restriction does not hold for more flexible systems like that defined by Oleg & co using functional dependencies, or the one I proposed on this list using type families. Although these systems are much more flexible than the "scoped labels" system, they would take LESS work to add to GHC because they have less built-in syntax, and are almost entirely defined in a library. I second the call for a records system, but please don't limit us to something like scoped labels! Barney.

6 9

Extensible Records
by Voldermort 11 Nov '07

11 Nov '07

Is there any chance of seeing extensible records in GHC 6.10? There seems to be widespread agreement that the current situation is unacceptable, but the official GHC policy is that there are too many good ideas to choose from - so nothing gets done! I hence humble propose that http://www.cs.uu.nl/~daan/download/papers/scopedlabels.pdf be adapted to GHC. In my naivete, I assume that porting an existing implementation would be much easier than starting from scratch. Is this reasonable? N.B. I am aware that GHC has limited resources - many thanks to Simon & Simon and all other contributors either way.

5 7

missing Control.Monad.State
by Hal Daume III 11 Nov '07

11 Nov '07

Hi all -- Something weird just happened and I feel bad asking on the list for help (because it's a dumb question), but I've racked my brains and can't figure it out. I've been happily using ghc for some time now. My current machine died, and the computer folks gave me a new one. Both my old and new were running ubuntu. The new machine came in and I apt-get installed ghc6 ghc6-prof ghc6-docs haskell-mode ghc6-libsrc. But when I try to run ghc on a module that uses Control.Monad.State, I get: ~ ghc --make -fglasgow-exts Main.hs -o hbc Core.hs:24:7: Could not find module `Control.Monad.State': Use -v to see a list of the files searched for. If I say -v, I get: Glasgow Haskell Compiler, Version 6.6, for Haskell 98, compiled by GHC version 6.6 Using package config file: /usr/lib/ghc-6.6/package.conf wired-in package base mapped to base-2.0 wired-in package rts mapped to rts-1.0 wired-in package haskell98 mapped to haskell98-1.0 wired-in package template-haskell mapped to template-haskell-2.0 Hsc static flags: -static *** Chasing dependencies: Chasing modules from: Main.hs Core.hs:24:7: Could not find module `Control.Monad.State': locations searched: Control/Monad/State.hs Control/Monad/State.lhs *** Deleting temp files: Deleting: *** Deleting temp dirs: Deleting: Looking in /usr/lib/ghc-6.6/package.conf, I don't find any mention of Control.Monad.State (or anything with "State") for that matter. A "find" in /usr/lib/ghc-6.6 doesn't turn up anything called State, either. I presume that I'm doing something incredibly stupid, but I'd appreciate a bit of help! Thanks! - Hal -- Hal Daume III --- me AT hal3 DOT name | http://hal3.name "Arrest this man, he talks in maths." | http://nlpers.blogspot.com

3 2

GHC and dynamic linking
by Richard Giraud 11 Nov '07

11 Nov '07

I foggily remember previous versions of GHC being unable to create programs that use dynamic links to libraries. Is this the case and, if so, is it still an issue? Static linking is not an option due to licensing issues. I'm interested in GHC 6.6.1 and 6.8.1 on Windows, Mac (PowerPC and x86), and Linux (x86). Thanks in advance, Richard

2 1

ghc-6.8.1 under Solaris
by Christian Maeder 11 Nov '07

11 Nov '07

Dear Solaris Users, binary distributions for Solaris 10 ultrasparc and i383 can be found at: http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… Both distributions (like those for ghc-6.6.1) require the following dynamic libraries (among others): libreadline.so.5 libncurses.so.5 libm.so.2 libgmp.so.3 (possibly set LD_LIBRARY_PATH on your system) If configure only finds ./install-sh, you need to call: ./configure INSTALL=`pwd`/install-sh --prefix=.... gmake install (or edit Makefile-vars after configure manually: http://hackage.haskell.org/trac/ghc/ticket/1810#comment:1) Cheers Christian P.S. a build slave under Solaris would be quite useful (to improve the shell hacks).

2 1