After seeing set_size and thinking it redundant (thought it returned the capacity of the set until I checked), I realized set_count would be a much better name (set_count (node->successors) in qfcc does make much more sense).
Now that qfcc actually supports them properly.
I'd written Set.[rh] after the big rewrite so never noticed the access error.
This includes both normal functions and a Set class (and SetIterator class). Most of the methods are implemented as builtins.
Bill Currie