- Glasgow-haskell-users

Re: [Gtk2hs-users] cairo error: ghc.exe: unable to load package `cairo-0.12.0'
by Axel Simon 05 Apr '11

05 Apr '11

Hi Daniel, On 04.04.2011, at 16:01, Daniel wrote: > Hi list, > > I've built gtk2hs successfully for ghc-7.0.2, but if I try to load > the example > Drawing.hs from the cairo packages demo folder I get: > > > *Main> :load Drawing.hs > [1 of 1] Compiling Main ( Drawing.hs, interpreted ) > Ok, modules loaded: Main. > *Main> main > Loading package transformers-0.2.2.0 ... linking ... done. > Loading package mtl-2.0.1.0 ... linking ... done. > Loading package array-0.3.0.2 ... linking ... done. > Loading package containers-0.4.0.0 ... linking ... done. > Loading package process-1.0.1.5 ... linking ... done. > Loading package time-1.2.0.3 ... linking ... done. > Loading package random-1.0.0.3 ... linking ... done. > Loading package haskell98-1.1.0.1 ... linking ... done. > Loading package cairo-0.12.0 ... linking ... <interactive>: > C:/users/daniel/appd > ata/roaming/cabal\cairo-0.12.0\ghc-7.0.2\HScairo-0.12.0.o: unknown > symbol `_cair > o_image_surface_get_data' > ghc.exe: unable to load package `cairo-0.12.0' > > Have tried many things so far: > > * Starting with re-inited package database > * Doing a $ nm /h/Gtk+/bin/libcairo-2.dll | grep -i > cairo_image_surface_get_data > yielding 68de04d8 T _cairo_image_surface_get_data > * Temporarily renaming libcairo-2.dll (the only one found on my > setup, even > not-in-PATH ones are non-existent) yielding as expected "dll not > found" error > * as you can see there is no "literal" space in the gtk+ > installation path > (h:\Gtk+), only in the users haskell package installation path, but > that's > fairly standard with Windows I guess > * Compilable with ghc --make ... though, but that's sadly not > sufficient as > Chart package isn't installable due to this issue If ghc --make works but interactively the object cannot be found, then it might be a ghc problem rather than ours, especially since the symbol exists in the DLL. Can somebody from the ghc group shed some light on the issue? Cheers, Axel

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Re: [Haskell] Polymorphic types in RHS of type instances
by José Pedro Magalhães 04 Apr '11

04 Apr '11

Hi, [Moving to glasgow-haskell-users(a)haskell.org] I would also like to know the answer to this question. While I can imagine it has something to do with type checking/inference, it is not immediately clear to me where the problem lies. Thanks, Pedro On Sat, Feb 5, 2011 at 12:25, Steven Keuchel <steven.keuchel(a)gmail.com>wrote: > Hi list, > > I was wondering why GHC doesn't allow usage of polymorphic types in > the right-hand side of type instance declarations for type families. > The GHC user guide states: "The right-hand side of a type instance > must be a monotype (i.e., it may not include foralls) [...]", but it > doesn't state the reason. > > I stumbled upon this limitation when I was trying to generically > calculate Johann's and Ghani's interpreter (transformers) for nested > data types from their "Initial Algebra Semantics is Enough!" paper. > > Cheers, > Steven > > _______________________________________________ > Haskell mailing list > Haskell(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell >

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T3738 allocation figures for 32-bit
by Daniel Fischer 02 Apr '11

02 Apr '11

In 7.0.3's testsuite, allT in perf/should_run says: test('T3738', [stats_num_field('peak_megabytes_allocated', 1, 1), # expected value: 1 (amd64/Linux) # expected value: 12800 (x86/OS X): if_wordsize(32, stats_num_field('bytes allocated', 12700, 14000)), if_wordsize(64, stats_num_field('bytes allocated', 60000, 80000)), # expected value: 72608 (amd64/Linux) only_ways(['normal']) ], compile_and_run, ['-O']) which looks quite amazing. On my linux box I consequently get bytes allocated 60608 is more than maximum allowed 14000 *** unexpected failure for T3738(normal) which looks quite horrible. But considering that 6.12.3 allocated nearly 500,000 bytes for that, it's pretty fine. In HEAD's testsuite, the figures have been adjusted to if_wordsize(32, stats_num_field('bytes allocated', 40000, 50000)), and HEAD does that, allocating 46008 bytes. A trivial 'main = return ()' produces ./nuff +RTS -s 47,496 bytes allocated in the heap 1,376 bytes copied during GC 34,036 bytes maximum residency (1 sample(s)) 19,212 bytes maximum slop here Apparently the allocation figures drastically vary by arch and OS, it would probably be necessary to test on several such and be more generous with the limits. Cheers, Daniel

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Re: [Haskell-cafe] is ppc64 arch registerised
by Antoine Latter 01 Apr '11

01 Apr '11

On Fri, Apr 1, 2011 at 6:30 AM, Jiri Skala <jaskalnik(a)gmail.com> wrote: > Hi all, > I've read on this page > > http://hackage.haskell.org/trac/ghc/wiki/Platforms > > the ppc64 arch is registerised. > > I succeeded to build ghc-7.0.2 on ppc64 (Fedora) with > GhcUnregisterised=YES. Switching off this option currently leads to > failure. > > I'd like to know: > > - is the info about registerised ppc64 arch still valid? > > - could you provide me tips how to build it registerised? > Someone on the ghc-users list might know specifics. > Thanks > > Skalnik > > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe >

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Class constraints for associated type synonyms
by Jan-Willem Maessen 01 Apr '11

01 Apr '11

Hi all - I've been trying to construct a class declaration with an associated type synonym, but I'd like to constrain that type to belong to a particular class. Consider the following class: class Monoid m => Constructs c m | c -> m where construct :: m -> c This captures the idea that the collection c ought to be constructed using the monoid m (say if we're doing the construction using the Writer monad)--the functional dependency indicates the desire for the type c to injectively determine the choice of monoid m. For example: newtype ListBuilder a = Builder ([a] -> [a]) deriving (Monoid) instance Constructs [a] (ListBuilder a) where construct (Builder f) = f [] instance (Ord a) => Constructs (Set a) (Set a) where construct = id Now I'd like to be able to do the same thing using an associated type synonym, something like this: class Monoid (GeneratorOf a) => Generable a where type GeneratorOf a :: * -> * construct :: GeneratorOf a -> a Now, it seems I need FlexibleInstances to do this when I'm using an associated type synonym, but I don't need the flexibility when using a multiparameter type class. In both cases the instance constraint involves types that can be injectively inferred (if I have my terminology straight; work with me here) from a single type mentioned in the class head. In particular, I can imagine storing the dictionary for Monoid (GeneratorOf a) in the dictionary for Generable a, and thus allowing context reduction of (Monoid (GeneratorOf tyvar)) to (Generable tyvar). Meanwhile, I think there are things that are permitted by FlexibleInstances that I'd rather *not* have creeping into my programs. Is there a fundamental constraint I'm missing here that requires the full generality of FlexibleInstances? Do I need to use FlexibleInstances whenever I use associated types in my programs? -Jan-Willem Maessen

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ANNOUNCE: GHC version 7.0.3
by Ian Lynagh 31 Mar '11

31 Mar '11

============================================================= The (Interactive) Glasgow Haskell Compiler -- version 7.0.3 ============================================================= The GHC Team is pleased to announce a new patchlevel release of GHC. This release contains a handful of bugfixes relative to 7.0.2, so we recommend upgrading. The release notes are here: http://www.haskell.org/ghc/docs/7.0.3/html/users_guide/release-7-0-3.html How to get it ~~~~~~~~~~~~~ The easy way is to go to the web page, which should be self-explanatory: http://www.haskell.org/ghc/ We supply binary builds in the native package format for many platforms, and the source distribution is available from the same place. Packages will appear as they are built - if the package for your system isn't available yet, please try again later. Background ~~~~~~~~~~ Haskell is a standard lazy functional programming language. GHC is a state-of-the-art programming suite for Haskell. Included is an optimising compiler generating good code for a variety of platforms, together with an interactive system for convenient, quick development. The distribution includes space and time profiling facilities, a large collection of libraries, and support for various language extensions, including concurrency, exceptions, and foreign language interfaces (C, whatever). GHC is distributed under a BSD-style open source license. A wide variety of Haskell related resources (tutorials, libraries, specifications, documentation, compilers, interpreters, references, contact information, links to research groups) are available from the Haskell home page (see below). On-line GHC-related resources ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Relevant URLs on the World-Wide Web: GHC home page http://www.haskell.org/ghc/ GHC developers' home page http://hackage.haskell.org/trac/ghc/ Haskell home page http://www.haskell.org/ Supported Platforms ~~~~~~~~~~~~~~~~~~~ The list of platforms we support, and the people responsible for them, is here: http://hackage.haskell.org/trac/ghc/wiki/Contributors Ports to other platforms are possible with varying degrees of difficulty. The Building Guide describes how to go about porting to a new platform: http://hackage.haskell.org/trac/ghc/wiki/Building Developers ~~~~~~~~~~ We welcome new contributors. Instructions on accessing our source code repository, and getting started with hacking on GHC, are available from the GHC's developer's site run by Trac: http://hackage.haskell.org/trac/ghc/ Mailing lists ~~~~~~~~~~~~~ We run mailing lists for GHC users and bug reports; to subscribe, use the web interfaces at http://www.haskell.org/mailman/listinfo/glasgow-haskell-users http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs There are several other haskell and ghc-related mailing lists on www.haskell.org; for the full list, see http://www.haskell.org/mailman/listinfo/ Some GHC developers hang out on #haskell on IRC, too: http://www.haskell.org/haskellwiki/IRC_channel Please report bugs using our bug tracking system. Instructions on reporting bugs can be found here: http://www.haskell.org/ghc/reportabug

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FFI and LLVM
by Louis Wasserman 31 Mar '11

31 Mar '11

I'm curious: as I understand it, one of the purposes of the FFI is to allow bindings to "close to the metal" languages. I'm curious what would be involved in letting the FFI provide bindings to LLVM code in Haskell. While I'm at it, I'll mention the most recent reason that this thought occurred to me, which is the complaint in here<http://disciple-devel.blogspot.com/2011/03/real-time-edge-detection-in-hask…> that Haskell can't currently get access to SIMDs, while LLVM does<http://llvm.org/docs/LangRef.html#t_vector>have that access, and I'm trying to think about how I might go about gluing those together. Louis Wasserman wasserman.louis(a)gmail.com http://profiles.google.com/wasserman.louis

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Hackage buildbot: llvm
by Christian Hoener zu Siederdissen 30 Mar '11

30 Mar '11

Hi, could it be that the llvm version used for the hackage buildbot is too old? The newest version of my 'Biobase' library does not compile there: http://hackage.haskell.org/packages/archive/Biobase/0.3.1.0/logs/failure/gh… and this seems to be due to llvm being too old: http://comments.gmane.org/gmane.comp.lang.haskell.glasgow.user/19397 Gruss, Christian Options in my cabal file (for reference): ghc-options: -Odph if impl(ghc > 6.13) ghc-options: -fllvm

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warning
by Luca Ciciriello 29 Mar '11

29 Mar '11

Hi All. I've installed on my MacOS X 10.6.7 (Xcode4) the new GHC 7.0.3 (64 bit) All works fine, but every time I build my code I get the warning: ld: warning: could not create compact unwind for _ffi_call_unix64: does not use RBP or RSP based frame Is this warning something bad? Thanks. Luca.

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Fix context reduction stack overflow in dimensional
by Bas van Dijk 29 Mar '11

29 Mar '11

Dear Bjorn, Attached is a patch that fixes a context reduction stack overflow in your dimensional package. I noticed something weird though (that's why I'm CCing the ghc list). When I cabal build dimensional-0.8.2 I first get the context reduction stack overflow when I then build it again I get the error again (as expected). However when I try to build it for the third time it succeeds! Why is this? I attached the build log. Regards, Bas

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