Parallelism in 6.6 and seq vs. pseq
I just noticed, thanks to some testing of the parallelism support in 6.6 by Satnam Singh, that Control.Parallel exports seq when in fact it should probably export pseq. The difference is subtle. The semantics of seq and pseq are identical; however, GHC can see that seq is strict in both its arguments and hence could choose to evaluate them in either order, whereas pseq is only strict in its first argument as far as the strictness analyser is concerned. The point is that pseq is useful for controlling evaluation order, which is what you want for adding parallelism to a program. seq, on the other hand, is not useful for controlling evaluation order. The documentation in 6.6 is also incorrect on this point. pseq is currently not exported by Control.Parallel, this is an oversight on my part, you have to import it from GHC.Conc for now. For 6.8 we'll export pseq from Control.Parallel instead of seq. Incedentally, the fixity of par is also wrong in 6.6: it should be infixr 0, but in fact it has the default fixity of infixl 0. This means if you write an expression like 'x `par` y `seq` z', it isn't doing what you think. Workaround: either use parentheses, or define your own par with the right fixity. Cheers, Simon ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
GHC 6.6 for OS X using MacPorts
Hi, GHC 6.6 is now available for OS X systems on both Intel and PowerPC processors using the MacPorts infrastructure. The compiler is built from source, using a binary bootstrap compiler. OS X versions 10.3 (Panther) and 10.4 (Tiger) are supported for PowerPC processors; for Intel processors, version 10.4. MacPorts (formerly Darwinports) is a packaging system for managing builds of unix-compatible software on OS X. For more information on MacPorts, see http://www.macports.org/ A new ghc-devel port will soon be available for those who just have to live on the bleeding edge. Best Wishes, Greg Gregory Wright Antiope Associates LLC [EMAIL PROTECTED] ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: GHC 6.6 for OS X using MacPorts
Hi Greg, I have just been trying to install ghc 6.6 using Darwin Ports, but the search facility can't find ghc-6.6. : sudo port selfupdate DarwinPorts base version 1.320 installed Downloaded MacPorts base version 1.320 The MacPorts installation is not outdated and so was not updated selfupdate done! dhcp2940:~ cmb21$ port search ghc ghclang/ghc 6.4.2The Glorious Glasgow Haskell Compilation System ghc-devel lang/ghc-devel 6.5 The Glorious Glasgow Haskell Compilation System (development version) dhcp2940:~ cmb21$ Am I doing something wrong? Kind regards, Chris Brown, On Fri, 27 Oct 2006, Gregory Wright wrote: Hi, GHC 6.6 is now available for OS X systems on both Intel and PowerPC processors using the MacPorts infrastructure. The compiler is built from source, using a binary bootstrap compiler. OS X versions 10.3 (Panther) and 10.4 (Tiger) are supported for PowerPC processors; for Intel processors, version 10.4. MacPorts (formerly Darwinports) is a packaging system for managing builds of unix-compatible software on OS X. For more information on MacPorts, see http://www.macports.org/ A new ghc-devel port will soon be available for those who just have to live on the bleeding edge. Best Wishes, Greg Gregory Wright Antiope Associates LLC [EMAIL PROTECTED] ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: GHC 6.6 for OS X using MacPorts
On Oct 27, 2006, at 10:25 AM, C.M.Brown wrote: Hi Greg, I have just been trying to install ghc 6.6 using Darwin Ports, but the search facility can't find ghc-6.6. : sudo port selfupdate DarwinPorts base version 1.320 installed Downloaded MacPorts base version 1.320 The MacPorts installation is not outdated and so was not updated selfupdate done! dhcp2940:~ cmb21$ port search ghc ghclang/ghc 6.4.2The Glorious Glasgow Haskell Compilation System ghc-devel lang/ghc-devel 6.5 The Glorious Glasgow Haskell Compilation System (development version) dhcp2940:~ cmb21$ Am I doing something wrong? No, just give the servers a few hours to run their update scripts. Then the new portfiles will be available by selfupdate. (I confess I do not know how often these days the scripts run, but it is at least a couple of times per day, IIRC.) If by, say, UTC 28 Oct 2006 you don't see the new portfiles, let me know. Something might be wacky with the server. Sorry for the delay. Best Wishes, Greg Kind regards, Chris Brown, On Fri, 27 Oct 2006, Gregory Wright wrote: Hi, GHC 6.6 is now available for OS X systems on both Intel and PowerPC processors using the MacPorts infrastructure. The compiler is built from source, using a binary bootstrap compiler. OS X versions 10.3 (Panther) and 10.4 (Tiger) are supported for PowerPC processors; for Intel processors, version 10.4. MacPorts (formerly Darwinports) is a packaging system for managing builds of unix-compatible software on OS X. For more information on MacPorts, see http://www.macports.org/ A new ghc-devel port will soon be available for those who just have to live on the bleeding edge. Best Wishes, Greg Gregory Wright Antiope Associates LLC [EMAIL PROTECTED] ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: seq vs. pseq
Simon Marlow [EMAIL PROTECTED] wrote: The difference is subtle. The semantics of seq and pseq are identical; however, GHC can see that seq is strict in both its arguments and hence could choose to evaluate them in either order, whereas pseq is only strict in its first argument as far as the strictness analyser is concerned. The point is that pseq is useful for controlling evaluation order, which is what you want for adding parallelism to a program. seq, on the other hand, is not useful for controlling evaluation order. This is a rather weird thing, and I would consider it a bug in the Haskell Report, rather than a bug in ghc. (It bites hard when you are trying to implement something like HPC.) The very name 'seq' surely suggests that you are controlling the evaluation order. Please evaluate this thing on the left first. But that is _not_ what the Haskell Report says! Ghc takes the Report literally, and so the thing on the right is just as likely to be evaluated before the thing on the left! Surely the language designers did not intend this consequence. For Haskell-prime, can we fix this bug, and ensure that 'seq' really implies ordering of evaluation? [ If you just want strictness annotations, with the compiler free to reorder computations, I would say ($!) is a better bet, and could be redefined to use not the natural `seq`, but the strict-in-both-arguments variation. ] Regards, Malcolm ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: GHC 6.6 for OS X using MacPorts
Hello, The Portfile has made it to the servers, but installation doesn't complete successfully for me (on Intel/10.4.8). The first issue is that something happens to the dynamic library lookup path so the configure check for a working C compiler fails with a dyld error. I managed to fix this with the following: cd /usr mkdir i686-apple-darwin8 cd i686-apple-darwin8 ln -s ../lib This allows configure to complete, but then it seems to have trouble finding the bootstrap compiler. I've attached the entire output, since I think context is important. If it seems more appropriate for this discussion to continue on the MacPorts mailing list, let me know. Aaron ghc-macports.log Description: Binary data On Oct 27, 2006, at 6:59 AM, Gregory Wright wrote: Hi, GHC 6.6 is now available for OS X systems on both Intel and PowerPC processors using the MacPorts infrastructure. The compiler is built from source, using a binary bootstrap compiler. OS X versions 10.3 (Panther) and 10.4 (Tiger) are supported for PowerPC processors; for Intel processors, version 10.4. MacPorts (formerly Darwinports) is a packaging system for managing builds of unix-compatible software on OS X. For more information on MacPorts, see http://www.macports.org/ A new ghc-devel port will soon be available for those who just have to live on the bleeding edge. Best Wishes, Greg Gregory Wright Antiope Associates LLC [EMAIL PROTECTED] ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
OpenGL failing with Mac Intel 6.6 distribution
I'm attempting to build frag on Mac OS X Intel with the 6.6 distribution, and I hit the following: /tmp/ghc25850_0/ghc25850_0.hc:5:22: error: HsOpenGL.h: No such file or directory A comparison of the C include directories for 6.6 and a recent 6.5 build gives: $ diff -r /usr/local/lib/ghc-6.5.20061008/include/ /usr/local/lib/ ghc-6.6/include/ Only in /usr/local/lib/ghc-6.5.20061008/include/: HsOpenGL.h Only in /usr/local/lib/ghc-6.5.20061008/include/: HsOpenGLExt.h Only in /usr/local/lib/ghc-6.5.20061008/include/: HsOpenGLTypes.h Only in /usr/local/lib/ghc-6.6/include/: HsReadline.h Only in /usr/local/lib/ghc-6.6/include/: HsReadlineConfig.h diff -r /usr/local/lib/ghc-6.5.20061008/include/ghcautoconf.h /usr/ local/lib/ghc-6.6/include/ghcautoconf.h 130c130 #define HAVE_LIBIBERTY 1 --- /* #undef HAVE_LIBIBERTY */ Is the fact that HSOpenGL*.h is missing in 6.6 expected? Thanks, Deborah ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
