From: haskell-cafe-bounces@haskell.org [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Al Falloon
Bayley, Alistair wrote:
Al Falloon wrote:
what does withSession return if there is a DBException?
Well, whatever the handler returns, same as with any other exception handler. Note that this must have the same type as whatever withSession returns, and this constraint is enforced by the type of catch/catchDB:
Sorry, I wasn't clear. What does it return when there is an uncaught exception? It sounds like it raises an exception in IO. Is this correct?
Well, a function raising an uncaught exception doesn't really return anything - it's raised an exception. I'm not clear on the semantics of exceptions in Haskell, but if you don't catch it then eventually it reaches the RTS, which will halt your program with an uncaught exception error. If you're asking if it propagates up to the RTS, then the answer is yes. The downside is that because it's a dynamic exception, the RTS can't/won't show anything other than "uncaught dynamic exception", which isn't helpful. Alistair ***************************************************************** Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. *****************************************************************