Untrusted code

[Chris Angus]

Hi,

I was wondering if there was any way to run code which possibly
threw an error in any version of Haskell.

e.g.

efficient3rdPartyAlgorithm :: Int -> Int
myOwnSlowAlgorithm :: Int -> Int

i.e. the idea is you run the efficent version and if 
falls over you run your own version.

Cheers

Chris