ANNOUNCE: GHC version 6.12.1

Jost Berthold berthold at
Mon Dec 14 14:04:02 EST 2009


to use Control.Parallel, you need to download and install two packages, 
deepseq and parallel, from
Most likely this will work with cabal, or you just download the two 
tarballs .

The reason is, when packaging "parallel", this package has been removed 
from the GHC core libraries. BTW I am unsure whether this is at all 
clever, since it needs specific GHC support (at least for now - am I 
right here?)

In addition, be informed that Control.Parallel.Strategies has been 
heavily restructured just last month (splitting it into deepseq and 
parallel is one of the changes, but not the most fundamental).
If you want to try examples from GpH publications, you will certainly 
have some problems. parallel-1.x versions containing the original 
definitions are on hackage as well and should work for experiments.

Jost Berthold

PS: Loading Control.Parallel into ghci is a handy debugging procedure 
for the sequential parts of your program without any hassle, but if you 
do not compile and link your program, it will not use any parallelism 
(and run slow anyway).

> From: Luca Ciciriello <luca_ciciriello at>
> Subject: RE: ANNOUNCE: GHC version 6.12.1
> To: <marco-oweber at>, <glasgow-haskell-users at>
> Message-ID: <SNT128-W3217F8C02C7EAA2723E4339A890 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
> Installed 6.12.1 on MacOS X 10.6Now I'm unable to load in GHCi of that 
> modules containing "import Control.Parallel"I'm missing something?
> Luca
>> From: marco-oweber at
>> To: glasgow-haskell-users at
>> Date: Mon, 14 Dec 2009 15:24:48 +0100
>> Subject: RE: ANNOUNCE: GHC version 6.12.1
>> Excerpts from Luca Ciciriello's message of Mon Dec 14 15:12:45 +0100 
>> 2009:
>> > I've the 6.10.4 version installed on my MacOS X 10.6 OS. Have I to 
>> uninstall
>> > this version of GHC before installing the Mac .pkg for the 6.12.1?
>> Hi Luca,
>> You should be able to get some hints by looking at where ghc is 
>> installed.
>> By default ghc puts its libraries into directory which contains the ghc
>> release name. So libs can be installed at the same time.
>> There are also ghc(i)-pkg-$GHC_VERSION executables.
>> So it should be possible. However I don't know about Mac details.
>> But maybe someone else can give you a more accurate answer.
>> Sincerly
>> Marc Weber

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