import java.lang.reflect.*;
/** an efficient representation of a collection of trees (Tomita's shared packed parse forest) */
-public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ implements Visitable<Forest.Body<T>> {
+public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ implements Visitable<Forest.Body<T>>, IntegerMappable {
+
+ private static int master_idx = 0;
+ private final int idx = master_idx++;
+ public int toInt() { return idx; }
/** assume that this forest contains exactly one tree and return it; otherwise throw an exception */
public final Tree<T> expand1() throws Ambiguous, ParseFailed {
static class Ref<T> extends Forest<T> {
private FastSet<Forest<T>> hp = new FastSet<Forest<T>>();
public Ref() { }
+ public int toInt() {
+ if (hp.size()==1) return hp.iterator().next().toInt();
+ return super.toInt();
+ }
public void merge(Forest p) { if (p!=this) hp.add(p, true); }
public <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
if (hp==null) return;
Forest[] holder = new Forest[r.pos];
if (r.pos<=0) throw new Error("called wrong form of reduce()");
int pos = r.pos-1;
- Forest old = holder[pos];
- holder[pos] = n.pending();
- if (pos==0) {
- System.arraycopy(holder, 0, r.holder, 0, holder.length);
- Forest rex = null;
- if (r.pos==1) rex = singularReductions.get(this, r);
- if (rex==null) {
- rex = r.rewrite(n.phase().getLocation());
- if (r.pos==1) singularReductions.put(this, r, rex);
- }
- n2.finish(r, rex, n.phase(), holder);
- } else {
- n2.reduce(r, pos-1, n.phase(), holder);
- }
- holder[pos] = old;
+ n.reduce(r, pos, n.phase(), holder, n2);
}
}
- public void reduce(Position r, int pos, Phase target, Forest[] holder) {
+ public void reduce(Position r, int pos, Phase target, Forest[] holder) { reduce(r, pos, target, holder, null); }
+ public void reduce(Position r, int pos, Phase target, Forest[] holder, Node only) {
Forest old = holder[pos];
holder[pos] = this.pending();
if (pos==0) {
System.arraycopy(holder, 0, r.holder, 0, holder.length);
for(int i=0; i<r.pos; i++) if (r.holder[i]==null) throw new Error("realbad");
Forest rex = null;
- if (r.pos==1) rex = singularReductions.get(this, r);
+
+ // FIXME: I'm unsure about this -- basically we want to deal with the case where
+ // there are two nodes, each of whose Ref points to the same Forest instance.
+ // Some node in the next phase has both of these as parents. This might happen
+ // since the same reduction can appear in more than one state.
+ if (r.pos==1) rex = singularReductions.get(this.pending(), r);
if (rex==null) {
rex = r.rewrite(phase().getLocation());
- if (r.pos==1) singularReductions.put(this, r, rex);
+ if (r.pos==1) singularReductions.put(this.pending(), r, rex);
}
- for(Node child : this.parents()) child.finish(r, rex, target, holder);
+ if (only != null) only.finish(r, rex, target, holder);
+ else for(Node child : this.parents()) child.finish(r, rex, target, holder);
} else {
- for(Node child : this.parents()) child.reduce(r, pos-1, target, holder);
+ if (only != null) only.reduce(r, pos-1, target, holder);
+ else for(Node child : this.parents()) child.reduce(r, pos-1, target, holder);
}
holder[pos] = old;
}