On Jul 18, 2008, at 12:04 , Duncan Coutts wrote:
On Fri, 2008-07-18 at 11:19 -0400, Brandon S. Allbery KF8NH wrote:
I'm going to ask a possibly silly question: has anyone thought about this vis-a-vis Simon's proposal of a new signals API? It's not that unusual for signals (usually SIGUSR1/SIGUSR2, often SIGINT, SIGHUP, sometimes SIGABRT, SIGQUIT) to be used as asynchronous triggers --- which might be best represented in the "Haskell world" as special exceptions. Likewise, it often makes sense to treat SIGPIPE, SIGHUP, SIGINT as exceptions instead of signals.
SIGINT will be an exception in ghc-6.10. It will throw an async exception to the main thread. We're just trying to think of the details though, eg how to programs like ghci ignore ^C and can it be done in a portable way.
SIGPIPE can be ignored because we get a sync exception when we write to a pipe with no reader.
I think I was more getting at (a) reserving an exception "class" for remapped signals, and (b) optionally providing a convenience function to install a signal handler for a given signal that maps it to the equivalent exception. This should be possible as a separate library, if the extensible exceptions are designed right... -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH