+ public Iterable<StateNode> getPreds() { return predecessors; }
+ public void addSucc(StateNode succ) {
+ if (successors.contains(succ)) return;
+ successors.add(succ);
+ usedByNonDoomedNode += succ.state().doomed ? 0 : 1;
+ if (predecessors.size() > 1) throw new Error();
+ }
+ public void removeSucc(StateNode 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()+"->"+predPhase; }
+
+ public void check() {
+ if (successors.size()==0) destroy();
+ else if (predecessors.size()==0) destroy();
+ }
+ public void destroy() {
+ if (destroyed) return;
+ if (primordeal) return; // never destroy the "primordeal" result
+ destroyed = true;
+ while(predecessors.size() > 0)
+ for(StateNode pred : predecessors) {
+ removePred(pred);
+ pred.removeSucc(this);
+ break;
+ }
+ predecessors = null;
+ while(successors.size() > 0)
+ for(StateNode succ : successors) {
+ removeSucc(succ);
+ succ.removeResult(this);
+ break;
+ }
+ successors = null;
+ }