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.Body<T>>*/ implements Iterable<Forest.Body<T>> {
+public abstract class Forest<T> /*extends PrintableTree<Forest.Body<T>>*/ implements Visitable<Forest.Body<T>>, Iterable<Forest.Body<T>> {
+
+ public abstract <B,C> void invoke(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c);
+ private static class TreeMaker<T> extends HashSet<Tree<T>> implements Invokable<Forest.Body<T>,Boolean,Integer> {
+ public ArrayList<Tree<T>> toks = new ArrayList<Tree<T>>();
+ public void invoke(Forest.Body<T> bod, Boolean toss, Integer i) {
+ if (i==null) {
+ addAll(bod.expand(toss, 0, new TreeMaker<T>()));
+ } else {
+ bod.expand(toss, i, this);
+ }
+ }
+ }
/** assume that this forest contains exactly one tree and return it; otherwise throw an exception */
public final Tree<T> expand1() throws Ambiguous, ParseFailed {
/** expand this forest into a set of trees */
public HashSet<Tree<T>> expand(boolean toss) {
- HashSet<Tree<T>> ret = new HashSet<Tree<T>>();
- for(Body<T> b : this)
- ret.addAll(b.expand(toss, new ArrayList<Tree<T>>(), 0, new HashSet<Tree<T>>()));
+ TreeMaker<T> ret = new TreeMaker<T>();
+ invoke(ret, new Boolean(toss), null);
if (toss && ret.size() > 1) throw new Ambiguous(this);
return ret;
}
// Body //////////////////////////////////////////////////////////////////////////////
protected static interface Body<T> {
- HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<T>> h);
+ TreeMaker<T> expand(boolean toss, int i, TreeMaker<T> h);
}
- protected static class MyBody<T> extends Forest<T> implements Body<T> /* extends PrintableTree<Forest<T>> implements Iterable<Forest.Body<T>>*/ {
+ protected static class MyBody<T> extends Forest<T> implements Body<T> /* extends PrintableTree<Forest<T>> implements */,Iterable<Forest.Body<T>> {
+
+ public <B,C> void invoke(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
+ ivbc.invoke(this, b, c);
+ }
public Iterator<Body<T>> iterator() { return new SingletonIterator<Body<T>>(this); }
private final Input.Location location;
this.singleton = singleton;
}
- public HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<T>> h) {
+ public TreeMaker<T> expand(boolean toss, int i, TreeMaker<T> h) {
if (singleton) {
- for(Body<T> b : tokens[0]) b.expand(toss, toks, i, h);
+ tokens[0].invoke(h, toss, i);
} else if (i==tokens.length) {
- h.add(new Tree<T>(null, tag, toks.toArray(tree_hint)));
+ h.add(new Tree<T>(null, tag, h.toks.toArray(tree_hint)));
} else if (unwrap && i==tokens.length-1) {
if (tokens[i] != null)
- for(Body b : tokens[i])
- b.expand(toss, toks, 0, h);
+ tokens[i].invoke(h, toss, 0);
} else {
boolean hit = false;
for(Tree<T> r : tokens[i].expand(toss)) {
hit = true;
- int old = toks.size();
- toks.add(r);
- expand(toss, toks, i+1, h);
- while(toks.size() > old) toks.remove(toks.size()-1);
+ int old = h.toks.size();
+ h.toks.add(r);
+ expand(toss, i+1, h);
+ while(h.toks.size() > old) h.toks.remove(h.toks.size()-1);
}
//if (!hit) throw new Error();
}
* forests to be viewed as a forest at some later date; once
* viewed, it becomes immutable
*/
- static class Ref<T> extends Forest<T> {
+ static class Ref<T> extends Forest<T> implements Iterable<Forest.Body<T>> {
private FastSet<Forest<T>> hp = new FastSet<Forest<T>>();
public Ref() { }
public void merge(Forest p) { if (p!=this) hp.add(p, true); }
+ public <B,C> void invoke(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
+ for(Forest.Body<T> bod : this)
+ ivbc.invoke(bod, b, c);
+ }
public Iterator<Body<T>> iterator() {
final Iterator<Forest<T>> ift = hp==null ? null : hp.iterator();
return new Iterator<Body<T>>() {