On Mon, Dec 29, 2008 at 05:07:22PM +0100, Bertram Felgenhauer wrote:
Simon Peyton-Jones wrote:
This is odd (to me). The "permanently bound" stuff applies only to *synchronous* exceptions, which thread-killing is not. Simon M will have more to say when he gets back
This is true when the exception is raised the first time. However, some exception handling functions like 'bracket' catch the exception, do their cleanup, and then throw the exception again. This is done in onException, and goes through throwIO and eventually raiseIO#. At this point the originally asynchronous exception has become a synchronous one.
We don't currently have a way to know whether an exception was thrown asynchronously or not, right? Should we actually be throwing data SomeExceptionSync = SomeExceptionSync Bool -- synchronous? SomeException with catch etc ignoring the Bool, but bracket etc handling it appropriately? Thanks Ian