- Glasgow-haskell-users

GADT problems
by Mitchell, Neil 15 Sep '08

15 Sep '08

Hi The following code works in GHC 6.8.3, works in GHC 6.9.20071111, but doesn't work in GHC HEAD. {-# LANGUAGE GADTs, ScopedTypeVariables #-} module Test where data E x = E x data Foo where Foo :: Gadt a -> Foo data Gadt a where GadtValue :: Gadt (E a) f (Foo GadtValue) = True f _ = False Under GHC HEAD I get the error: GADT pattern match with non-rigid result type `t' Solution: add a type signature In the definition of `f': f (Foo GadtValue) = True Adding a type signature to f fixes this problem: f :: Foo -> Bool But I haven't found anywhere other than the top level f to add a type signature. When the match is in a list comprehension, it becomes much harder. While playing further I discovered this example: foos = undefined g = [() | Foo GadtValue <- foos] This code doesn't compile under GHC HEAD, but does under 6.8.3. However, adding the type signature: g :: [()] Makes the code compile. This is surprising, as [()] isn't a GADT type, so shouldn't need stating explicitly. Any help on what these errors mean, or how they can be fixed with local type annotations? Thanks Neil ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================

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Building GHC with time package
by Mitchell, Neil 15 Sep '08

15 Sep '08

Hi, I want to build GHC HEAD with the time package. I figured out how to do it by editing packages and removing the word extralibs, but that doesn't seem to be the correct way. I suspected I might be able to get time included by giving some incantation to ./darcs-all, but I couldn't figure out what - commands such as help and --help to darcs all were little use. What is the correct way to add a library into the GHC build? If someone tells me I'll add it to the wiki somewhere. I tried looking here: http://hackage.haskell.org/trac/ghc/wiki/Building Thanks Neil ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================

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Re: Is FPH implemented in GHC?
by Wolfgang Jeltsch 15 Sep '08

15 Sep '08

Am Sonntag, 14. September 2008 16:11 schrieben Sie: > | To implement all this stuff, I had to do quite a bit of code obfuscation. > | That is, I introduced a lot of trivial functions only to give them an > | explicit impredicative/rank 2 type signature. > > But impredicative is not the same as rank-2. GHC has done higher-rank > types for ages; but impredicative instantiation is a different story. Are > you sure that's the bit you need? Can you give an example? > > Simon Hello Simon, I know that rank 2 is something different. I need both, rank 2 and impredicativity. I already mentioned the (impredicative) type SSignal t (forall t'. SignalFun t' a). The full type of my switch operator is SSignal t (forall t'. SignalFun t' a) -> SignalFun t a. Some of the trivial functions, I mentioned above, have rank 2 types, some have impredicative types. The latter ones typically have types of the form f (forall t. signal t a) -> f (forall t. signal' t a') where f is some specific functor. And as far as I understood, FPH brings advantages for both rank n and impredicativity. Am I wrong at this point? Best wishes, Wolfgang

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How to directly strip ghc generated binaries
by leledumbo 15 Sep '08

15 Sep '08

Sometimes it's annoying to call strip --strip-all <program name> everytime after compilation. Is there anything like gcc's -s so that debugging symbols aren't included? -- View this message in context: http://www.nabble.com/How-to-directly-strip-ghc-generated-binaries-tp194870… Sent from the Haskell - Glasgow-haskell-users mailing list archive at Nabble.com.

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Windows build failure
by Mitchell, Neil 15 Sep '08

15 Sep '08

Hi, I've just tried building GHC HEAD using GHC 6.8.3 on Windows following the instructions on the wiki (http://hackage.haskell.org/trac/ghc/wiki/Building/Windows) I initially got a failure about cc1 not being found when executing 6.8.3's gcc, which I worked around by adding c:/ghc/ghc-6.8.3/gcc-lib at the end of the path (i.e. last priority) After this error I get a problem with include files, see the attached log file. It looks like include files are going wrong between Mingw and 6.8.3. My current $PATH variable is: /cygdrive/c/mingw/bin:/usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin:/cygdr ive/c/WI NNT/Microsoft.NET/Framework/v2.0.50727:/cygdrive/c/local/MikTex/texmf/mi ktex/bin :/cygdrive/c/Perl/site/bin:/cygdrive/c/Utils/mks/MKSNT:/cygdrive/c/WINNT /system3 2:/cygdrive/c/WINNT:/cygdrive/c/WINNT/System32/Wbem:/cygdrive/c/CSsystem :/cygdri ve/c/Utils:/cygdrive/c/Program Files/Sybase.12/OCS-12_0/bin:/cygdrive/c/ghc/ghc- 6.8.3:/cygdrive/c/ghc/ghc-6.8.3/bin:/cygdrive/c/bin:/cygdrive/c/Program Files/Ha skell/bin:/cygdrive/f/ImslNT.30/CNL/Bin:/cygdrive/c/Utils/mks/mksnt:/cyg drive/f/ Fame/76:/cygdrive/c/Utils/mks/MKSNT:/cygdrive/c/ghc/ghc-6.8.3/gcc-lib Thanks Neil ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================

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How to print output and ask input on the same line
by leledumbo 15 Sep '08

15 Sep '08

This is my main function: main = do putStr "What's the value that each equation must satisfy? " c <- readLn putStr "How many unknowns are there? " n <- readLn sequence_ (result c n) Using runhugs / winhugs / ghci, I can see every output of putStr before it stops for readLn. But compiling it with ghc, it just stops for readLn and putStr output is printed together with sequence_' one. So, instead of: What's the value that each equation must satisfy? <stop for readLn> How many unknowns are there? <stop for readLn> <output of sequence_> I got: <stop for readLn> <stop for readLn> What's the value that each equation must satisfy? How many unknowns are there? <output of sequence_> Hope that's clear enough. -- View this message in context: http://www.nabble.com/How-to-print-output-and-ask-input-on-the-same-line-tp… Sent from the Haskell - Glasgow-haskell-users mailing list archive at Nabble.com.

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Is FPH implemented in GHC?
by Wolfgang Jeltsch 13 Sep '08

13 Sep '08

Hello, is FPH implemented in GHC? If yes, will it be part of GHC 6.10.1? Best wishes, Wolfgang

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gcc-looking error when building GHC 6.8.3 from source - "directives may not be used inside a macro argument"
by Jeff Evans 13 Sep '08

13 Sep '08

Hi everyone, I am trying to build GHC 6.8.3 from source in a slightly nonstandard environment (mostly with regard to the filesystem). The build setup, however, is fairly standard (32-bit x86 RHEL, gcc 3.4, glibc 2.3). I managed to get the bootstrap installation from the "ghc-6.6.1-x86_64-unknown-linux" tarball (downloaded from http://www.haskell.org/ghc/download_ghc_661.html#x86linux) working without much trouble. Now I'm trying to use that to build 6.8.3 from source. But I am hitting an error in the build target, apparently for this rts component. Output snippet here: http://hpaste.org/10252 The first of the ghc errors is "RtsFlags.c:1120:1: directives may not be used inside a macro argument" which is followed by many more (I think this is the real cause though). I searched around and it seems like a gcc "limitation" (not supporting something that is not part of the C standard but people still wanted). But even then it has supposedly been supported since gcc 3.2, and I'm using 3.4. To be honest, I don't know anything about the interaction between ghc and gcc at this juncture so I'm a bit in the dark. Any advice is appreciated. I can also provide more complete output/details if it would be useful. Thank you!

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Making GHC work on BSD
by Simon Peyton-Jones 12 Sep '08

12 Sep '08

Dear BDS hackers We'd like GHC to be buildable on BSD, but at the moment it isn't. We support GHC on Linux, Windows, Mac, but we really need help with BSD. Alas, we didn't get much response to Simon's message below. (One, I think -- thank you to that person! I think it was Kili, but I'm not sure.) So this message is to say: if you'd like GHC on BSD, please help! No help probably means no GHC. Time is short before GHC 6.10. "Help" means more than "can offer a remote login", but less than "solve it by yourself". We'll try hard to support you if you can invest a bit of time at your end. Many thanks Simon -----Original Message----- From: glasgow-haskell-users-bounces(a)haskell.org [mailto:glasgow-haskell-users-bounces@haskell.org] On Behalf Of Simon Marlow Sent: 02 September 2008 13:37 To: GHC Users Mailing List Cc: cvs-ghc(a)haskell.org Subject: *BSD GHC hackers needed... While perusing the tickets in the 6.10.1 milestone I spotted 3 that look to be FreeBSD-specific: 2476 internal error: awaitEvent: descriptor out of range 2502 segfault with GHC.Handle.fdToHandle' 2511 unix package doesnt load in ghci on freebsd/amd64 It's unlikely that we'll get to these in time for 6.10.1. Any FreeBSD hackers out there want to take a look? Help/advice is available as usual. There's also one NetBSD-specific ticket: 2351 NetBSD defines ELF_ST_TYPE (that one is easy), and one that I think applies to all the *BSDs: 2063 Breackage on OpenBSD due to mmap remap (actually the latter one is a top priority, because without it GHCi can't work, so we need it fixed for 6.10.1). Cheers, Simon _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users(a)haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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(no subject)
by Mitchell, Neil 08 Sep '08

08 Sep '08

Hi Claus, I was reading your instructions on the GHC wiki page, http://hackage.haskell.org/trac/ghc/wiki/Building/Windows, and they are wonderful - exactly what I wanted. However, they don't work. When downloading Cygwin you are told to add haskell.org/ghc/cygwin as a path so it can pick up the setup.ini file. However, in the latest version of Cygwin it obvious wants signatures for all the .ini files: --------------------------- Cygwin Setup --------------------------- Unable to get http://www.haskell.org/ghc/cygwin/setup.ini.sig from <http://www.haskell.org/ghc/cygwin> --------------------------- OK --------------------------- Could someone please add the appropriate signature file? Thanks Neil ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================

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