[Haskell-cafe] Functional version of this OO snippet

[Thomas Davie]

>
> In other words, I want to provide the same UI across multiple  
> implementations of the engine that actually processes the commands.

You can ofc make my reply somewhat more functional by removing the  
interact from run, and just making it have type IEngine a => a ->  
String -> String.  That way it will be nice and functional and  
composable and fit into a larger system.

Bob