[Haskell-cafe] Unsafe IO and Wash

On a related note, Wash seems to be preserving all sorts of unnecessary "state" from previous screens a user visited. I don't understand why it doesn't pass only the parameters to the next screen; that should be easily determined to be all that is necessary. On that same topic, I've used Wash's unsafe_io some places with no ill effects. (Note that this has no relationship to unsafePerformIO, which is a different beast entirely.) Can anyone tell me why unsafe_io in Wash is unsafe, and in which situations it could blow up in my face? Thanks, John