How will issues with MonadCatchIO affect apps build with the Snap framework in the future?

Question

I recently saw the warning about the MonadCatchIO class here.

The Snap Monad is an instance of this.

I'm wondering how any likely resolution the MonadCatchIO issue will affect webapps build on the current version of Snap. Will this mean that framework upgrades for Snap webapps will require extensive changes?

Answer 1

Yes, snap 1.0 will use monad-control. Code using MonadCatchIO should be easily ported to Control.Exception.Lifted from the lifted-base package.

The combination of moving Snap away from iteratee style and monad-control should result in a substantial reduction in the overhead associated with exception handling in the Snap monad and in monads lifted over it.