- Glasgow-haskell-users

Re[2]: [Haskell-cafe] GHC including System.Time but not Data.Time?
by Bulat Ziganshin 15 Apr '09

15 Apr '09

Hello John, Wednesday, April 15, 2009, 5:35:00 PM, you wrote: > I agree. Is there any chance of 6.10.3 reverting the change? both 6.6 and 6.8 had last releases at spring, so i don't expect new 6.10.* at all -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com

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where is ghcautoconf.h, DerivedConstants.h and GHCConstants.h
by Jake L 14 Apr '09

14 Apr '09

following wiki to make an unregistered build of ghc 6.6.1 on openbsd-powerpc-current target = powerpc_unknown_openbsd host = x86_64_unknown_linux with ghc-6.10.2 "Copy <T>/includes/ghcautoconf.h, <T>/includes/DerivedConstants.h, and <T>/includes/GHCConstants.h to <H>/includes. Note that we are building on the host machine, using the target machine's configuration files. This is so that the intermediate C files generated here will be suitable for compiling on the target system." looking in the target tree after doing ./configure --enable-hc-boot --enable-hc-boot-unregisterised those 3 files doesn't exist, what step am I missing? Jake

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RE: [Haskell] deriving Show for GADT?
by Simon Peyton-Jones 14 Apr '09

14 Apr '09

Yes, indeed, see http://hackage.haskell.org/trac/ghc/ticket/3012 Incidentally, the main Haskell list isn't the right place for GHC-specific questions. glasgow-haskell-users(a)haskell.org is the place Simon | -----Original Message----- | From: haskell-bounces(a)haskell.org [mailto:haskell-bounces@haskell.org] On Behalf Of | Norman Ramsey | Sent: 14 April 2009 05:28 | To: haskell(a)haskell.org | Subject: [Haskell] deriving Show for GADT? | | I've got a fairly large GADT for which I wished to use | deriving (Show) | but I got a mysterious error message: | | Exp.hs:13:11: | Can't make a derived instance of `Show (Exp a)' | (`Exp' has non-Haskell-98 constructor(s)) | In the data type declaration for `Exp' | | | This is from GHC. Does anybody know a compiler option or other trick | that will coax the compiler into producing a Show instance. | (I know I can write one by hand, but I'd rather not bother.) | | | Norman | _______________________________________________ | Haskell mailing list | Haskell(a)haskell.org | http://www.haskell.org/mailman/listinfo/haskell

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GHC threading bug in QSem
by Neil Mitchell 08 Apr '09

08 Apr '09

Hi I believe the following program should always print 100: import Data.IORef import Control.Concurrent main = do sem <- newQSem (-99) r <- newIORef 0 let incRef = atomicModifyIORef r (\a -> (a+1,a)) sequence_ $ replicate 100 $ forkIO $ incRef >> signalQSem sem waitQSem sem v <- readIORef r print v Unfortunately, it doesn't seem to. Running on a 2 processor machine, with +RTS -N3 I usually get 100, but have got answers such as 49, 82, 95. With +RTS -N2 it doesn't seem to fail, but it does with -N4. This is using GHC 6.10.2 on Windows. Using GHC 6.8.3, I get answers /= 100 roughly every other time. >From reading the implementation of QSem, it doesn't seem that negative availability was considered. I think it would be need to be changed as: -- Invariant: avail >= 1 ==> null blocked waitQSem :: QSem -> IO () waitQSem (QSem sem) = do (avail,blocked) <- takeMVar sem -- gain ex. access if avail > 0 then putMVar sem (avail-1,[]) else do block <- newEmptyMVar putMVar sem (avail, blocked++[block]) -- changed line takeMVar block signalQSem :: QSem -> IO () signalQSem (QSem sem) = do (avail,blocked) <- takeMVar sem -- changed below if null blocked || avail < 0 then putMVar sem (avail+1,blocked) else putMVar sem (avail, tail blocked) putMVar (head blocked) () Writing parallel code is hard, so I could have easily got this wrong. I haven't looked at QSemN, which may need similar fixes (or may already deal with this) Thanks Neil

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Re: ANNOUNCE: GHC version 6.10.2
by Benjamin L.Russell 05 Apr '09

05 Apr '09

On Wed, 1 Apr 2009 18:48:13 -0700, Lyle Kopnicky <lists(a)qseep.net> wrote: >Great! But what happened to the time package? It was in 6.10.1. Has it been >intentionally excluded from 6.10.2? Then I should probably hold off on installing the new version for now. Any estimate on when this problem will be fixed? -- Benjamin L. Russell -- Benjamin L. Russell / DekuDekuplex at Yahoo dot com http://dekudekuplex.wordpress.com/ Translator/Interpreter / Mobile: +011 81 80-3603-6725 "Furuike ya, kawazu tobikomu mizu no oto." -- Matsuo Basho^

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doCorePass
by Colin Paul Adams 01 Apr '09

01 Apr '09

Between 6.8 and 6.11, function doCorePass in module SimplCore has changed types from: CoreToDo -> HscEnv -> UniqSupply -> RuleBase -> ModGuts -> IO (SimplCount, ModGuts) to: CorePass (== CoreToDo) -> ModGuts -> CoreM ModGuts and it isn't easy for me to figure out the relationship between the two types. Is there some sort of formula I can follow to convert a function with the first type to the second? -- Colin Adams Preston Lancashire

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ANNOUNCE: GHC version 6.10.2
by Ian Lynagh 01 Apr '09

01 Apr '09

============================================================== The (Interactive) Glasgow Haskell Compiler -- version 6.10.2 ============================================================== The GHC Team is pleased to announce a new patchlevel release of GHC. This release contains a number of bugfixes relative to 6.10.1, including some performance fixes, so we recommend upgrading. Release notes are here: http://haskell.org/ghc/docs/6.10.2/html/users_guide/release-6-10-2.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; the current language version is Haskell 98, agreed in December 1998 and revised December 2002. 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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Unable to compile ghc from darcs
by Colin Paul Adams 01 Apr '09

01 Apr '09

I was getting errors somewhere in haddock about some ambiguous function, so I did a darcs pull to see if that would pull in a fix for the problem (unfortunately I didn't make a note of the errors). But now the compile fails earlier with errors in deSugar/DsMeta.hs: deSugar/DsMeta.hs:471:48: Not in scope: type constructor or class `TH.InlineSpecQ' deSugar/DsMeta.hs:504:16: Not in scope: type constructor or class `TH.TyVarBndr' deSugar/DsMeta.hs:538:50: Not in scope: type constructor or class `TH.TyVarBndr' deSugar/DsMeta.hs:640:29: Not in scope: type constructor or class `TH.Kind' etc. Is the code in darcs supposed to be compilable normally? And what can I do about such situations? Just report them here? -- Colin Adams Preston Lancashire

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GADTs with strict fields?
by Conal Elliott 01 Apr '09

01 Apr '09

Do strict fields work with GADTs? If so, what's the syntax for the strictness annotations? - Conal

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spurious "non-exhaustive" pattern warnings?
by Conal Elliott 31 Mar '09

31 Mar '09

-- Why do I get warnings about non-exhaustive pattern matches in the -- following code? Is the compiler just not clever enough to notice that -- the uncovered cases are all type-incorrect? (ghc 6.11.20090115) {-# LANGUAGE TypeFamilies, EmptyDataDecls, TypeOperators , GADTs, KindSignatures , FlexibleInstances, FlexibleContexts #-} {-# OPTIONS_GHC -Wall #-} import Control.Applicative (Applicative(..)) data Z data S n infixr 1 :< data Vec :: * -> * -> * where ZVec :: Vec Z a (:<) :: a -> Vec n a -> Vec (S n) a -- todo: infix op for SVec instance Functor (Vec n) where fmap _ ZVec = ZVec fmap f (a :< u) = f a :< fmap f u instance Applicative (Vec Z) where pure _ = ZVec ZVec <*> ZVec = ZVec -- Warning: Pattern match(es) are non-exhaustive -- In the definition of `<*>': -- Patterns not matched: -- (_ :< _) _ -- ZVec (_ :< _) instance Applicative (Vec n) => Applicative (Vec (S n)) where pure a = a :< pure a (f :< fs) <*> (x :< xs) = f x :< (fs <*> xs) -- Warning: Pattern match(es) are non-exhaustive -- In the definition of `<*>': -- Patterns not matched: -- ZVec _ -- (_ :< _) ZVec

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