@steve, I ♥ !lambda, but they can kill your performance in #Python because there's so much overhead in Python's procedure-call implementation. So #Guido would say you're supposed to use list comprehensions for that stuff at this point.
So, I'm trying to do some set fixed point recursion stuff in Scala, but I'm not exactly sure how I should set things up properly. Mutable sets? Specifically, I'm trying to find all the possible states a pushdown automaton can go to, from some state/stack pair using only epsilon transitions. Basically, I'm after the transitive closure of the transition relation starting…
@jpope: eh--I played with this a few months ago with !lambda and profiles on different sites; I just had to unsub from the old group and sub to the new one; everything ended up fine.