September 2002 - Glasgow-haskell-users

unsafePerformIO
by David Sabel 20 Sep '02

20 Sep '02

In read your paper ""Tackling the Awkward Squad: monadic input / output, concurrency, exceptions, and foreign-language calls in Haskell", and have a question about unsafePerformIO. In your operational semantic of the IO-Monad you tell nothing about, how 'unsafe' IO actions are performed, is there another paper / documentation about this available, or can you - or someone else - give me a review about that? David JWGU Frankfurt

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ObjectIO
by Serguey Zefirov 18 Sep '02

18 Sep '02

Hello glasgow-haskell-users, First, it would be good to have examples somewhere around ObjectIO main page. I've figured out how to download source code for examples only after third or fourth try. I know, that the question about examples and source code should be directed to the author, but it seem to be unreachable from behind our firewall for some unknown reason. Also, package.conf says: ------------------ {name = "objectio", import_dirs = ["$libdir/imports/ObjectIO"], ------------------ but directory $libdir/imports/ObjectIO contains no ObjectIO.hi file! It contains, however, Graphics/UI and only there floats ObjectIO.hi. So the only example I've downloaded fails. Even "import ObjectIO.Graphics.UI.ObjectIO" instead "import ObjectIO" couldn't help. It seem... unfair to me. ;) -- Best regards, Serguey mailto:sz@uc.ru PS Also, I cannot access cvs from behind our firewall, and there is no source archive to build from. Otherwise I wouldn't write such a complaining letter.

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RE: IO-System
by Simon Marlow 17 Sep '02

17 Sep '02

> I'd settle for that kind of indiscriminate flushing -- as is, > trivial I/O examples such as > > main = do > putStr "What is your name? " > ls <- getLine > putStrLn ("Hello " ++ ls ++ "!") > > fail to behave as expected. That depends on what you expect... :-) The Haskell report says nothing about triggering a flush on stdout when reading from stdin. I disagree that introducing this ad-hoc flush would be the right thing. A workaround for a common misconception, yes; but not the right thing in general. IMHO, it's better that programmers learn about buffering early because they'll get bitten by it later on anyhow. Suppose we were to implement this, when exactly should it be enabled? All the time? When stdin is a terminal? When stdin and stdout are both connected to the same terminal? For every output handle connected to the same terminal as stdin? Should it happen for a socket too? (if not, won't that be confusing for users?) Cheers, Simon

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RE: IO-System
by Simon Marlow 17 Sep '02

17 Sep '02

> The previous impl had facilities for controlling this - you > could label handles > as being connected (i.e., read() on one caused flushes on the > other.) By > default, stdin was connected to stdout and stderr. If that > turned out to > be troublesome, the connection could be broken (I could be mistaken, > but I believe the implementation of hConnectTo didn't provide this; > trivial to add.) My guess is that most of _your_ users > wouldn't want to > modify that default. As a data point, I cannot remember this > ever being reported as a problem. Yes, I'm aware of hConnectTo. It was a conscious decision not to re-implement it in the new IO library. There are really two separate issues: - Should we provide hConnectTo? I can only think of one reason why not: it adds a small but non-zero overhead to lots of I/O operations. - Should stdin and stdout/stderr be connected by default? Defaulting to connecting stdin and stdout is not always the right thing: consider the case when the input and output are connected to different pipes. This is a dynamic property, so the program itself would have to include code to check whether stdin and stdout are connected to the same terminal and disable the hConnectTo if not. Doing the right thing in general is hard - suppose the program opens /dev/stdin itself and starts to read from it, should this cause a flush of stdout? You're probably right that we get more bug reports the way it is just now, but it has the advantage of being simple and consistent. Cheers, Simon

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RE: meta-haskell-branch
by Simon Peyton-Jones 17 Sep '02

17 Sep '02

I have seen this before and it puzzled the hell out of me too. To be honest I have forgotten the exact cause, but it's something to do with the fact that you haven't done a new 'autoconf' or a new 'configure' or something. Much the easiest thing is to start from scratch. Check out an entirely new tree, and work from there. Odd things sometimes happen when you have an old tree lying around, esp after a big update. Simon | -----Original Message----- | From: Saswat Anand [mailto:saswat@comp.nus.edu.sg] | Sent: 17 September 2002 10:05 | To: Simon Peyton-Jones | Cc: glasgow-haskell-users(a)haskell.org | Subject: RE: meta-haskell-branch | | | Thanks for the pointer. I still get the following error, when I do gmake. | | > echo '#!/bin/sh' >>ghc-inplace | > echo exec /root/fptools/ghc/compiler/ghc-5.05 '-B/root/fptools' '"$@"' | > >>ghc-inplace | > chmod 755 ghc-inplace | > ------------------------------------------------------------------------ | > ==fptools== gmake all -wr; | > in /root/fptools/ghc/rts | > ------------------------------------------------------------------------ | > ../../ghc/compiler/ghc-inplace -optc-O -optc-Wall -optc-W | > -optc-Wstrict-prototypes -optc-Wmissing-prototypes | > -optc-Wmissing-declarations -optc-Winline -optc-Waggregate-return | > -optc-Wbad-function-cast -optc-I../includes -optc-I. -optc-Iparallel | > -optc-DCOMPILING_RTS -optc-fomit-frame-pointer -ldl -O2 -static -c | > Adjustor.c -o Adjustor.o | > gmake[2]: *** [Adjustor.o] Error 1 | > gmake[1]: *** [all] Error 1 | > gmake[1]: Leaving directory `/root/fptools/ghc' | > gmake: *** [all] Error 1 | | | It seems ghc-inplace has some problem: | | > sh-2.05# ../../ghc/compiler/ghc-inplace -c Adjustor.c -o Adjustor.o | > sh-2.05# ls *.o | > ls: *.o: No such file or directory | | What might be wrong? | | Saswat | | |

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RE: meta-haskell-branch
by Simon Peyton-Jones 17 Sep '02

17 Sep '02

On Friday I merged the meta-haskell branch onto the HEAD. So abandon the meta-haskell branch, and use the HEAD instead. (cvs up -A) As to the configure thing, you first need to run configure in the GHC directory. See Section 7.4 of the building guide http://haskell.cs.yale.edu/ghc/docs/latest/html/building/sec-building-fr om-source.html Simon | -----Original Message----- | From: Saswat Anand [mailto:saswat@comp.nus.edu.sg] | Sent: 16 September 2002 10:39 | To: glasgow-haskell-users(a)haskell.org | Subject: meta-haskell-branch | | Hi | I am trying to compile the meta-haskell-branch of ghc from cvs. I get the | following error messages. Please help me with some hints. | | Thanks, | Saswat | | # when I do ./configure in fptools directory, It ends with the following | error: | | configuring in ghc | running /bin/sh | ./configure --prefix=/root/fptools/prefix --cache-file=.././config.cache -- | srcdir=. | ./configure: ./configure: No such file or directory | configure: error: ./configure failed for ghc | | # when I went ahead to do ./make in fptools dir, it dies with: | | echo '#!/bin/sh' >>ghc-inplace | echo exec /root/fptools/ghc/compiler/ghc-5.05 '-B/root/fptools' | '"$@"'>>ghc-inplace | chmod 755 ghc-inplace | ------------------------------------------------------------------------ | ==fptools== make all -wr; | in /root/fptools/ghc/rts | ------------------------------------------------------------------------ | ../../ghc/compiler/ghc-inplace -optc-O -optc-Wall -optc-W -optc-Wstrict-prot | otypes -optc-Wmissing-prototypes -optc-Wmissing-declarations -optc-Winline - | optc-Waggregate-return -optc-Wbad-function-cast -optc-I../includes -optc-I. | -optc-Iparallel -optc-DCOMPILING_RTS -optc-fomit-frame-pointer -ldl -O2 -sta | tic -c Adjustor.c -o Adjustor.o | make[2]: *** [Adjustor.o] Error 1 | make[1]: *** [all] Error 1 | make[1]: Leaving directory `/root/fptools/ghc' | make: *** [all] Error 1 | | | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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RE: Problem to compile -parallel
by Simon Peyton-Jones 17 Sep '02

17 Sep '02

For parallel Haskell you need the GPH mailing list, not Glasgow-haskell-users. You can find details of that list at http://www.cee.hw.ac.uk/~dsg/gph/ Meanwhile, you're suffering from a compiler version shift: the new compiler can't read the old compiler's Foo.hi files. Just rm *.hi and try again. But I am pretty certain that there is no Parallel Haskell version of 5.04 Simon | -----Original Message----- | From: XSet [mailto:xset@mail.ru] | Sent: 17 September 2002 08:09 | To: glasgow-haskell-users(a)haskell.org | Subject: Problem to compile -parallel | | Hi! | | I try to see how parallel Haskell works with GHC-5.04 under Windows98. | I have installed PVM, and compile simple fibonachi example. | But when I compile using command line | | ghc -parallel -id:\ghc\imports\lang -id:\ghc\imports\concurrent -id:\ghc\imports\base - | fno-hi-version-check -o | main main.hs | | I get messages: | mismatched interface file versions: expected 5040mp, found 5040 | | Please. Tell me what I should do with interface files? Download other versions ? | | Thank you | Real XSet | | | | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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Re: ANN: C->Haskell 0.10.16 "Altocumulus Stratiformis Perlucidus Undulatus"
by Manuel M T Chakravarty 17 Sep '02

17 Sep '02

Manuel M T Chakravarty <chak(a)cse.unsw.edu.au> wrote, > I am pleased to announce version 0.10.16 "Altocumulus > Stratiformis Perlucidus Undulatus" of the C interface > generator C->Haskell. The web site http://www.cse.unsw.edu.au/~chak/haskell/c2hs/ now also has a binary rpm that is compiled for GHC 5.04.1. Moreover, Oliver Braun has updated the FreeBSD port to 0.10.16. Cheers, Manuel

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Problem to compile -parallel
by XSet 17 Sep '02

17 Sep '02

Hi! I try to see how parallel Haskell works with GHC-5.04 under Windows98. I have installed PVM, and compile simple fibonachi example. But when I compile using command line ghc -parallel -id:\ghc\imports\lang -id:\ghc\imports\concurrent -id:\ghc\imports\base -fno-hi-version-check -o main main.hs I get messages: mismatched interface file versions: expected 5040mp, found 5040 Please. Tell me what I should do with interface files? Download other versions ? Thank you Real XSet

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ANNOUNCE: GHC version 5.04.1 released
by Simon Marlow 17 Sep '02

17 Sep '02

============================================================== The (Interactive) Glasgow Haskell Compiler -- version 5.04.1 ============================================================== We are pleased to announce a new patchlevel release of the Glasgow Haskell Compiler (GHC), version 5.04.1. This is a bugfix-only release. For all the changes since 5.02.3, see the release notes: http://www.haskell.org/ghc/docs/latest/users_guide/release-5-04.html How to get it ~~~~~~~~~~~~~ The easy way is to go to the WWW page, which should be self-explanatory: http://www.haskell.org/ghc/ We supply binary builds in the native package format for various flavours of Linux and BSD, and in InstallShield form for Windows folks. Binary builds for other platforms are available as a .tar.gz which can be installed wherever you want. The source distribution is also available from the same place. Once you have the distribution, please follow the pointers in the README file to find all of the documentation about this release. Background ~~~~~~~~~~ Haskell is a standard lazy functional programming language; the current language version is Haskell 98, agreed in December 1998. 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/ Haskell home page http://www.haskell.org/ comp.lang.functional FAQ http://www.cs.nott.ac.uk/~gmh/faq.html System requirements ~~~~~~~~~~~~~~~~~~~ To compile programs with GHC, you need a machine with 64+MB memory, GCC and perl. This release is known to work on the following platforms: * i386-unknown-{linux,*bsd,mingw32} * sparc-sun-solaris2 * alpha-dec-osf3 * powerpc-apple-darwin (MacOS/X) Ports to the following platforms should be relatively easy (for a wunderhacker), but haven't been tested due to lack of time/hardware: * hppa1.1-hp-hpux{9,10} * i386-unknown-solaris2 * mips-sgi-irix{5,6} * {rs6000,powerpc}-ibm-aix The builder's guide on the web site gives a complete run-down of what ports work; it can be found at http://www.haskell.org/ghc/docs/latest/building/building-guide.html 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/ Please report bugs using our SourceForge page at http://sourceforge.net/projects/ghc/ or send them to glasgow-haskell-bugs(a)haskell.org. GHC users hang out on glasgow-haskell-users(a)haskell.org. Bleeding edge CVS users party on cvs-ghc(a)haskell.org.

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