Does anybody know if there is some unsafe IO function that would let me do destructive assignment?
Something like:

a = 5
main = do
veryUnsafeAndYouShouldNeverEveryCallThisFunction_DestructiveAssign a 8
print a
> 8

and yes I am in fact insane...

I'm also looking for a way to make actual copies of data.
so I could do something like this:

a = Node 5 [Node 2 [], Node 5 [a]]
main = do
b <- makeCopy a
veryUnsafeAndYouShouldNeverEveryCallThisFunction_DestructiveAssign b (Node 0 [])
-- 'a' is unchanged

It would be even more fantastic, if the copy function was lazy.
I think the traverse function might actually make a copy, but I would be happier with something more general (doesn't require membership in traversable), and more explicit (was actually designed for making real copies).

Any ideas?

Thanks,

- Job