- public String toString() { return "state["+idx+"]"; }
-
- public int compareTo(Table.State s) { return idx==s.idx ? 0 : idx < s.idx ? -1 : 1; }
- }
-
- /**
- * the information needed to perform a reduction; copied here to
- * avoid keeping references to <tt>Element</tt> objects in a Table
- */
- public class Reduction {
- // FIXME: cleanup; almost everything in here could go in either Sequence.Position.getRewrite() or else in GSS.Reduct
- public final int numPop;
- /*private*/ final Position position;
- private final Forest[] holder; // to avoid constant reallocation
- public int hashCode() { return position.hashCode(); }
- public boolean equals(Object o) {
- if (o==null) return false;
- if (o==this) return true;
- if (!(o instanceof Reduction)) return false;
- Reduction r = (Reduction)o;
- return r.position == position;
- }
- public Reduction(Position p) {
- this.position = p;
- this.numPop = p.pos;
- this.holder = new Forest[numPop];
- }
- public String toString() { return "[reduce " + position + "]"; }
-
- private Forest zero = null;
- public Forest zero() {
- if (zero != null) return zero;
- if (numPop > 0) throw new Error();
- return zero = position.rewrite(null);
- }
-
- public Forest reduce(GSS.Phase.Node parent) {
- if (numPop==0) return finish(parent, zero(), parent.phase());
- return reduce(parent, numPop-1, null, parent.phase());
- }
-
- public Forest reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild) {
- if (numPop<=0) throw new Error("called wrong form of reduce()");
- int pos = numPop-1;
- holder[pos] = parent.pending();
- if (pos==0) {
- System.arraycopy(holder, 0, position.holder, 0, holder.length);
- return finish(onlychild, position.rewrite(parent.phase().getLocation()), parent.phase());
- }
- return reduce(onlychild, pos-1, null, parent.phase());
- }
-
- // FIXME: this could be more elegant and/or cleaner and/or somewhere else
- private Forest reduce(GSS.Phase.Node parent, int pos, Forest rex, GSS.Phase target) {
- if (pos<0) return finish(parent, rex, target);
- holder[pos] = parent.pending();
- if (pos==0 && rex==null) {
- System.arraycopy(holder, 0, position.holder, 0, holder.length);
- rex = position.rewrite(target.getLocation());