+ public Node pred() { return pred; }
+ public void addSucc(Node succ) {
+ successors.add(succ);
+ usedByNonDoomedNode += succ.state().doomed ? 0 : 1;
+ }
+ public void removeSucc(Node succ) {
+ if (!successors.contains(succ)) return;
+ successors.remove(succ);
+ usedByNonDoomedNode -= succ.state().doomed ? 0 : 1;
+ check();
+ }
+
+ public boolean usedByAnyNode() { return successors.size() > 0; }
+ public boolean usedByNonDoomedNode() { return usedByNonDoomedNode > 0; }
+
+ public String toString() { return super.toString()+"->"+pred(); }
+
+ public void check() { if (successors.size()==0) destroy(); }
+ public void destroy() {
+ if (destroyed) return;
+ if (pred==null) return; // never destroy the "primordeal" result
+ destroyed = true;
+ pred.removeSucc(this);
+ while(successors.size() > 0)
+ for(Node n : successors) {
+ removeSucc(n);
+ n.removeResult(this);
+ break;
+ }
+ }