hi, spread v0.2 now has set operations. see: https://github.com/rapido/spread/blob/master/avail/Treap.avail
the guts of every conceivable set operation is implemented via the method “___combine" . in the cases where sets are disjoint or equal, “___combine” dispatches important decisions to subclasses of 'set operation’. i think that “___combine" demonstrates that avail very much supports a higher-order functional programming style. however, i would like to know what would be a more idiomatic avail version of “___combine”? cheers, Robbert.
