Yes this was also very very confusing for me because I had the same idea about that. I almost gave up on learning Haskell because of that (I wanted to practice stuff from the SOE book using the latest versions), until I suddenly found out that GHC *did* work. Here's the explanation: "On Fri, 2007-06-15 at 23:15 +0200, bf3@telenet.be wrote:
I'm learning Haskell using Paul Hudak's book SOE.
I'm using GHC 6.6 under Windows XP.
GHC on Windows does not seem to come with HGL (is this correct?), so I used Gtk2HS, which contains a SOE implementation.
I noticed that most programs hang when using GHCI, but they work fine with GHC.
It's not GHCi's fault as such. The reason it does not work well in GHCi at the moment is a bit technical. The Gtk2Hs SOE implementation currently uses Haskell threads. Like most GUI toolkits, Gtk+ is single threaded and requires special attention to use it from multiple OS threads. Currently, by default, GHC produces executables that use the single-threaded runtime system, and this works fine with multiple Haskell threads because they get multiplexed on the same OS thread. GHC can however produce executables that use the multi-threaded runtime system and ghci.exe itself is such a program. So when you use SOE with GHCi it's actually using multiple threads to access Gtk+ an not in a safe way, so it goes wrong in a myriad of ways. I'll take another look at trying to make the SOE stuff work with the threaded runtime system by using the primitives Gtk2Hs provides to use Gtk+ safely from multiple threads. Duncan" -----Original Message----- From: David House [mailto:dmhouse@gmail.com] Sent: Wednesday, June 20, 2007 6:42 PM To: peterv Cc: 'David House'; haskell-cafe@haskell.org Subject: RE: [Haskell-cafe] Haskell mode for emacs - some questions peterv writes:
Yes, but I can only use GHCI for error checking, because I'm using GTK2HS/SOE which does not work well with GHCI under Windows, it only runs when using GHC.
Why is this? I'm not that familiar with Gtk2Hs, but I don't understand why it wouldn't work with GHCi if it works with GHC. They use the same code to compile it. On the other hand, you could always just set up a Makefile (which is pretty trivial) and use M-x compile (which you should bind to a key if you use it a lot). -- -David House, dmhouse@gmail.com