On Wed, Sep 22, 2010 at 3:18 AM, Mitar
What would I also like to see in Haskell is that it would be somehow possible to see which all exceptions could your function (through used functions there) throw. In this way it would be really possible to make async-exception-safe functions (as we really do not want catch-all all around). (Of course the problem with this approach is if somebody changes underlying function it could get additional possible exception(s) to be thrown.)
So it would be even better if this would be solved like pattern matching warning (so you could see if you are missing some exception through warning) or even better: that type system would enforce you to or catch or declare throwing/passing exception yourself. Similar how Java has.
Because one other major Haskell's selling point is that you (are said to) know from type if and which side-effects a function has. This is the story behind IO monad. And with exceptions you do not have this information anymore. I believe this should be visible through type system.
Something like:
http://paczesiowa.blogspot.com/2010/01/pure-extensible-exceptions-and-self.h...
For type-safe _synchronous_ exception handling we have Pepe Iborra's: http://hackage.haskell.org/package/control-monad-exception However we don't have anything similar for asynchronous exception handling. What will a type-safe asynchronous exception handling API look like? What guarantees should it provide? Regards, Bas