Well Haskell has a well defined execution order. I think the large problem is that compiled Haskell doesn't represent the original source at all making this tricky if not impossible.

The execution order is only defined on the IO monad or when there is data dependency. Independent chunks of pure code can be executed in any order.

The key word being independent. There is still a natural baked in dependency ordering. That is all that I meant. I realize I could of phrased it better.