At 11:31 11/11/04 +0000, Keean Schupke wrote:
Wouldn't it be easier to simply define "once" as a common Haskell library function?
Erm, it is a library function (I provided the NamedSem library as an attachment)... Are you suggesting it would be nice to be able to do this without talking to the OS?
OK, I didn't sufficiently emphasize *common* library function. Maybe I should have said "standard". I'm not suggesting that the calling program should not use the operating system, but that it should be insulated from the details of said OS. Not all OSes have process IDs or named semaphores. This discussion has shown many ways to implement "once", and which is best may depend upon the underlying OS. #g ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact