On Fri, 2008-07-18 at 11:19 -0400, Brandon S. Allbery KF8NH wrote:
On 2008 Jul 18, at 11:05, Ian Lynagh wrote:
On Thu, Jul 17, 2008 at 09:16:36AM -0400, Isaac Dupree wrote:
I'm not entirely happy with this particular sketch of a proposal, but do people think that my initial issue is something to be concerned about at all? (I'd be glad to be disproved :-)
It's hard to say if it'll be a problem in practice - we don't have any experience with writing exception hierarchies.
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. Duncan