Hi Henk-Jan, You have come across a known, and (I'm afraid) difficult issue to fix.
While I can give an explanation below, I don't think we will be able to fix the issue. I will update the wiki to reflect the fact that this is a known problem, as this information has somehow been lost in the move from the Sourceforge.net site to the Haskell.org wiki. Best regards Jeremy On Sun, 19 Oct 2008 18:46:12 +0200, "Henk-Jan van Tuyl" <[EMAIL PROTECTED]> said: > > L.S., > > The bouncing balls demo crashes GHCi when run for the second time; to > reproduce this: > 1. Start GHCi > 2. Load BouncingBalls.hs > 3. Run main > 4. Close the BouncingBalls window > 5. Run main > > > The most minimal program that reproduces this error is: > > > module Main where > > > import Graphics.UI.WX > > > main :: IO () > > main = start myFrame > >myFrame :: IO () > > myFrame = > > do > > f <- frameFixed [text := "Crash test"] > > return () The problem is that versions of wxWidgets after 2.4.x make use of static C++ destructors which execute only when the executable is unloaded. This means that when main terminates in GHCI, the wxWidgets library is not left in a sane state (because the DLL is still loaded, and the destructors have not run). For this reason, it is not very practical to use recent versions of wxHaskell with GHCi. I took a quick look, a year or so back, at continuing to support wxWidgets 2.4.2 in wxHaskell, and I'm afraid the conclusion was that the wxHaskell team just don't have the time available to do this (many wxWidgets APIs have changed enough in the last three years that we would really be maintaining two separate branches). The alternative approach (of making this functionality work with recent versions of the wxWidgets library) is a substantial amount of work (and the work would be mainly in C, rather than Haskell!), as it would require dynamically unloading wxWidgets DLLs when main terminates and reloading them when it is run again. I'd love someone with a spare couple of months to do this! If it is absolutely essential for you to support incremental development using GHCi, the only real option is to use 0.9.4-1 (see http://sourceforge.net/project/showfiles.php?group_id=73133&package_id=73173). I fear that this may require a little work before it will build on the most recent versions of GHC. > Software used: > GHC 6.8.3 / wxWindows 0.10.3 / Windows XP The same behaviour is likely to be observed on all platforms. -- Jeremy O'Donoghue [EMAIL PROTECTED] ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ wxhaskell-devel mailing list wxhaskell-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wxhaskell-devel
