- Glasgow-haskell-users

ghc-cabal-Random
by Serge D. Mechveliani 02 Jan '12

02 Jan '12

People, I have ghc-7.4.0.20111219 made from source and tested it on the DoCon-2.12 application -- thanks to people for their help! It looks all right. This was -- with skipping the module Random. Now it remains to add the Random package. I have taken AC-Random Version 0.1 from hackage. Its installation requires Cabal: > which cabal cabal: Command not found. > And Cabal is difficult to install, it reports that such and such package versions are missing. On the other hand, Cabal is, probably, present inside ghc-7.4.0.20111219, somewhere in the installation directory. Thus I see its .a and .o files in ~/ghc/7.4.1pre/inst0/lib/ghc-7.4.0.20111219/Cabal-1.14.0/ Can you, please, tell me what is the simplest way to install Random in this situation? Thank you in advance for your explanation, ------ Sergei mechvel(a)botik.ru

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7.4.1-cand for docon
by Serge D. Mechveliani 31 Dec '11

31 Dec '11

Dear GHC team, The archive http://botik.ru/pub/local/Mechveliani/ghcBugs/ghc741candQuest.zip contains the source of the docon-2.12 application. ghc-7.0.1 compiles it and runs the test successfully. ghc-7.4.0.20111219 cannot compile it. 1. It requires to add Show a to Integral a in a certain place. It occurs that this requirement breaks the standard (?). But all right, so far, add Show a there and see what happens further. 2. It reports that certain two packages overlap at some module. This is a matter of the `build-depends' field in docon.cabal and of the import declarations. I tried to correct the build-depends list. But each time the compiler reports that a) some packages overlap or b) build-depends has a wrong line or c) it cannot find some module (for example, Random). Can you please, look into ghc741candQuest.zip and set there an appropriate build-depends ? (so that make configure make build make install finish correctly). How does the user guess of this list, what is the method? This also touches the question of the module Random ------------- Thorkil Naur <naur(a)post11.tele.dk> wrote > System.Random can be found in http://hackage.haskell.org/package/random. I do not find the Random class in Haskell-2010. Probably, DoCon imports Random from the GHC (non-standard) library. When installing ghc-7.01, I just download the source distribution, `make' it, and it installs automatically together with the module Random. Has the status of the module Random changed in ghc-7.4.1 ? What is a regular way to install ghc-7.4.1 together with the module Random ? 3. After the point (2) is fixed, there may appear some more of them ... Thank you in advance for your explanation, ------ Sergei mechvel(a)botik.ru

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"GeneralizedNewtypeDeriving"
by Matthew Farkas-Dyck 28 Dec '11

28 Dec '11

Just of curiosity, why is it spelt with a z? Is it spelt thus in Scottish English? I thought that "generalised" is written throughout Great Britain. Cheers, MFD

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Re: ANNOUNCE: GHC 7.4.1 Release Candidate 1
by Joachim Breitner 24 Dec '11

24 Dec '11

Hi, Am Samstag, den 24.12.2011, 08:28 +1100 schrieb Erik de Castro Lopo: > Joachim Breitner wrote: > > > ghc-stage2: panic! (the 'impossible' happened) > > (GHC version 7.4.0.20111219 for powerpc-unknown-linux): > > Cant do annotations without GHCi > > {libraries/vector/Data/Vector/Fusion/Stream/Monadic.hs:104:19-33} > > base:GHC.Exts.ForceSpecConstr{d rbL} > > Thats related to the problem of GHCi being broken on powerpc. Somewhat: vector uses annotations, annotation need GHCi, GHCi is disabled (because broken) on powerpc, vector is bundled by accident in GHC (and will be removed in the final release, unless I am mistaken), and the real vector package is patched in Debian to handle this (http://patch-tracker.debian.org/patch/series/view/haskell-vector/0.9-2/no_a…) My hope is that ghc will in the future ignore annotations on non-GHCi-arches (http://hackage.haskell.org/trac/ghc/ticket/4268) Once vector is unbundled, I expect the build to succeed on powerpc. I guess the other weird-arch builds would have failed at this point as well, if they had not failed due to the various other reasons earlier; I hope these get fixed in the final release. Maybe Debian should offer GHC to run buildbots (http://hackage.haskell.org/trac/ghc/wiki/Builder) on at least some of our weird arch machines, so that these problems will be noticed. earlier. But I’m not sure if the DSA team allows such a thing, as we’d be running code that is not under our control. Is someone in the Haskell team interested in finding that out? Greetings, Joachim -- Joachim "nomeata" Breitner Debian Developer nomeata(a)debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nomeata(a)joachim-breitner.de | http://people.debian.org/~nomeata

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Show and Integral
by Serge D. Mechveliani 23 Dec '11

23 Dec '11

Sorry, I have forgotten to copy to the List my last note on this subject. The on-line spec of Haskell-2010 shows Eq Show \ / Num | Real | Integral Hence, for x :: Integral a => a, it is correct to apply (show x). And ghc-7.4.0.20111219 does not allow this (show x). So, it breaks the standard, and people say, this is deliberate. I witness such a break for the first time, and this looks so strange! Well, I also diskile the edge Show / Num in the standard. But it is better to implement Show as dummy for appropriate types, -- so far, -- and to wait for the next standard. Am I missing something? Regards, ------ Sergei mechvel(a)botik.ru

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Re: Unit unboxed tuples
by Christian Höner zu Siederdissen 23 Dec '11

23 Dec '11

Hi, I have to second that. I recently "fell" over that problem when writing instances for certain kinds of tuples. In libraries, such as "tuple" there is a special 'OneTuple' constructor but I'd really appreciate a more uniform fix -- but don't know of one either... Gruss, Christian * Ganesh Sittampalam <ganesh(a)earth.li> [23.12.2011 15:39]: > On 23/12/2011 13:46, Ian Lynagh wrote: > > On Fri, Dec 23, 2011 at 01:34:49PM +0000, Simon Peyton-Jones wrote: > >> > >> Arguments Boxed Unboxed > >> 3 ( , , ) (# , , #) > >> 2 ( , ) (# , #) > >> 1 > >> 0 () (# #) > >> > >> Simple, uniform. > > > > Uniform horizontally, but strange vertically! > > It's worth mentioning that if you want to write code that's generic over > tuples in some way, the absence of a case for singletons is actually a > bit annoying - you end up adding something like a One constructor to > paper over the gap. But I can't think of any nice syntax for that case > either. > > Cheers, > > Ganesh > > _______________________________________________ > Glasgow-haskell-users mailing list > Glasgow-haskell-users(a)haskell.org > http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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build-depends
by Serge D. Mechveliani 22 Dec '11

22 Dec '11

Dear GHC team, ghc-7.4.0.20111219 puts the following problem of build-depends. docon.cabal of the DoCon project has build-depends: haskell2010, containers And ghc-7.4.0.20111219 reports DExport.hs:28:8: Could not find module `Random' It is a member of the hidden package `haskell98-2.0.0.1'. Perhaps you need to add `haskell98' to the build-depends in your .cabal file. Then, build-depends: haskell2010, haskell98, containers causes "Parse of field 'build-depends' failed". Then, build-depends: haskell98, containers causes VecMatr.hs:49:8: Could not find module `Data.List' It is a member of the hidden package `base'. Perhaps you need to add `base' to the build-depends in your .cabal file. It is a member of the hidden package `haskell2010-1.1.0.1'. Perhaps you need to add `haskell2010' to the build-depends in your .cabal file. Adding haskell2010 will cause "Parse of field 'build-depends' failed." Adding base will cause DExport.hs:26:8: Ambiguous module name `Prelude': it was found in multiple packages: base haskell98-2.0.0.1 Please, what is a reasonable way out ? Regards, ------ Sergei mechvel(a)botik.ru

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Prelude in 7.4.0.20111219
by Serge D. Mechveliani 22 Dec '11

22 Dec '11

Dear GHC developers, This is on ghc-7.4.0.20111219. Compiling --------------------------------------------------- {-# OPTIONS -fno-warn-duplicate-exports #-} module DExport (module DPrelude, module Categs, module SetGroup, module RingModule, module Z, module DPair, module Fraction, module Permut, module VecMatr, module Pol, module Residue, module LinAlg, module GBasis, module Partition, module AlgSymmF, module Complex, module Prelude, module List, module Ratio, module Random ) where import Complex import List hiding (minimum, maximum, sort, sortBy) import Prelude hiding (minimum, maximum, ) import Ratio ... --------------------------------------------------- ghc-7.4.0.20111219 reports (unlike ghc-7.0.1): ---------------------- runghc Setup.hs build Building docon-2.12... Preprocessing library docon-2.12... DExport.hs:26:8: Ambiguous module name `Prelude': it was found in multiple packages: base haskell98-2.0.0.1 ---------------------- Please, what is the best way out? Regards, ------ Sergei mechvel(a)botik.ru

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Erratic failure to specialize function
by Alexey Khudyakov 18 Dec '11

18 Dec '11

Hello! I've found a puzzling performance problem with code which uses vector library and relies heavily on GHC to perform inlining and specialization. In some cases compiler refuses to specialize function and just copies there generic version which is slow. Here is smallest test case I've manages to make: file 'test.hs' > import Criterion.Main > import qualified Data.Vector.Unboxed as U > import Boundary > > sample :: U.Vector Double > sample = U.replicate 10000 0 > > main = defaultMain > [ bench "eta" $ nf variance sample > , bench "lambda" $ nf (\x -> variance x) sample > ] file 'Boundary.hs' > {-# LANGUAGE FlexibleContexts #-} > module Boundary where > import qualified Data.Vector.Generic as G > > variance :: (G.Vector v Double) > => v Double -> Double > variance vec = G.sum vec > {-# INLINE variance #-} Here is benchmarking results: benchmarking eta - mean: 220.8042 us benchmarking lambda - mean: 24.31309 us If variance is moved to the test.hs file or eta reduced or written as lambda: varance = \vec -> G.sum vec difference goes away. What causes such behavior?

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Proposal to incorporate Haskell.org
by Don Stewart 16 Dec '11

16 Dec '11

Hello everyone. The haskell.org committee[1], in the interest of the long-term stability of the open source Haskell community infrastructure, has decided to incorporate haskell.org as a legal entity. This email outlines our recommendation, and seeks input from the community on this decision. The committee's proposal is that haskell.org incorporate as an entity under the Software Freedom Conservancy umbrella organization (the same group that Darcs joined recently): http://sfconservancy.org/ If we proceed with this move, haskell.org will be a legal entity, and registered as a non-profit, allowing us to more directly accept (US tax-deductible) donations, and to invest in assets that benefit the Haskell open source community. We welcome your feedback on the proposal attached below. -- Don Stewart (on behalf of the Haskell.org committee) ------------------------------------------------------------------------ = A proposal for the incorporation of Haskell.org = In recent years, haskell.org has started to receive assets, e.g. money from Google Summer Of Code, donations for Hackathons, and a Sparc machine for use in GHC development. We have also started spending this money: in particular, on hosting haskell.org itself. There is also interest in running fundraising drives for specific things such as Hackathon sponsorship and hosting fees. However, haskell.org doesn't currently exist as a legal entity, meaning that these assets have had to be held on our behalf by other entities, such as Galois and various universities. This leads to tricky situations, with no-one being sure who should decide how the haskell.org assets can be used. To solve these problems, we propose that haskell.org applies to become a member project of the Software Freedom Conservancy (SFC) <http://conservancy.softwarefreedom.org/>. The SFC is a non-profit organization that provides free financial and administrative services to open source projects. Additionally, it has 501(c)(3) status, meaning donations from the US are tax-deductible. The SFC would hold haskell.org's money and other assets, and would be able to accept donations on behalf of haskell.org. The haskell.org committee, as described here [2], will make decisions on spending assets and other decisions related to governing the non-profit. Before proceeding, we are inviting input from the community in the form of specific objections or queries regarding the plan. We've tried to answer some of the most likely questions: Q: Does this mean that my Haskell project must now be covered by a copyleft licence such as GPL? A: No, but Haskell projects using haskell.org resource should use an Open Source licence <http://www.opensource.org/licenses/alphabetical>. Q: Will it still be possible to use community.h.o to host non-open-source material, such as academic papers? A: An overall minority of such content, as is the current situation, is not a problem. Q: Will it still be possible to have job ads on the haskell.org mailing lists and website? A: Yes. Q: Will this affect our ability to host the Haskell Symposium <http://www.haskell.org/haskell-symposium/> and Industrial Haskell Group<http://industry.haskell.org/> webpages within haskell.org? A: No. Q: What will be the relationship between haskell.org and other organizations such as the Haskell Symposium and Industrial Haskell Group? A: Those organisations will continue to exist as separate entities. Q: If an umbrella non-profit organisation "The Haskell Foundation" was created, would haskell.org be able to join it? A: Yes. It's likely that in such a scenario, the Haskell Foundation would become the owner of the haskell.org domain name, with the cost divided between the members. The entity that is part of the SFC would be renamed "community.haskell.org" in order to avoid confusion. [1]: http://www.haskell.org/haskellwiki/Haskell.org_committee [2]: http://www.haskell.org/haskellwiki/Haskell.org_committee#Operation

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