final class ResultNode
extends Node<StateNode> {
- private Forest.Many f = new Forest.Many();
- //private HashSet<StateNode> predecessors = new HashSet<StateNode>();
- //private HashSet<StateNode> successors = new HashSet<StateNode>();
- private FastSet<StateNode> predecessors = new FastSet<StateNode>();
- private FastSet<StateNode> successors = new FastSet<StateNode>();
- private boolean destroyed = false;
- private boolean primordeal;
- private int usedByNonDoomedNode = 0;
private Pos reduction;
- private GSS.Phase predPhase;
+ private Forest.Many f = new Forest.Many();
- public boolean predecessorsContains(StateNode n) {
- return predecessors.contains(n);
- }
+ public void merge(Forest newf) { this.f.merge(newf); }
public Pos reduction() { return reduction; }
- public void merge(Forest newf) {
- this.f.merge(newf);
- /*
- if (predecessors.contains(pred)) return;
- addPred(pred);
- if (fromEmptyReduction) return;
- n.state().invokeReductions(n.phase().getToken(), n, this);
- */
- }
-
- public boolean noSuccessors() { return successors.size()==0; }
-
- public GSS.Phase phase() { return predPhase; }
+ public boolean isDoomedState() { /* this is irrelevant */ return false; }
public Forest getForest() { return f; }
- 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 String toString() { return super.toString()+"->"+phase(); }
+ public boolean hasPathToRoot() {
+ if (predecessorPhase()==null) return true;
+ return super.hasPathToRoot();
}
- 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;
+ if (!hasSuccessors() || !hasPredecessors()) destroy();
}
-
- public void removePred(StateNode pred) {
- if (!predecessors.contains(pred)) return;
- predecessors.remove(pred);
- check();
+ protected void destroy() {
+ if (destroyed) return;
+ if (predecessorPhase()==null) return; // never destroy the "primordeal" result
+ super.destroy();
}
- public void addPred(StateNode pred) {
- if (predPhase==null) predPhase = pred.phase();
- if (predPhase != pred.phase()) throw new Error();
- predecessors.add(pred);
- pred.addSucc(this);
- if (predecessors.size() > 1) throw new Error();
+ protected void addPred(StateNode pred) {
+ super.addPred(pred);
+ // results should have at most one predecessor
+ //if (predecessors.size() > 1) throw new Error();
}
- public ResultNode() {
- this(null, null, null);
- this.primordeal = true;
- }
+ public ResultNode() { this(null, null, null); }
public ResultNode(Forest f, Pos reduction, StateNode pred) {
+ super(pred==null ? null : pred.phase(),
+ pred==null ? null : pred.phase());
this.f.merge(f);
this.reduction = reduction;
if (pred != null) addPred(pred);
}
-
-
}
\ No newline at end of file