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.MyBody<T>>*/ implements Visitable<Forest.Body<T>> {
/** 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>>()));
+ final HashSetTreeConsumer<T> ret = new HashSetTreeConsumer<T>();
+ visit(new TreeMaker2<T>(toss, ret), null, null);
if (toss && ret.size() > 1) throw new Ambiguous(this);
return ret;
}
+ public static interface TreeConsumer<T> {
+ public void addTree(Tree<T> t);
+ }
+ public static class HashSetTreeConsumer<T> extends HashSet<Tree<T>> implements TreeConsumer<T> {
+ public void addTree(Tree<T> t) { super.add(t); }
+ }
+
static <T> Forest<T> singleton(Input.Location loc) { return create(loc, null, new Forest[] { }, false, true); }
static <T> Forest<T> singleton(Input.Location loc, Forest<T> body) { return create(loc, null, new Forest[] { body }, false, true); }
static <T> Forest<T> leaf(Input.Location loc, T tag) { return create(loc, tag, null, false, false); }
// Body //////////////////////////////////////////////////////////////////////////////
protected static interface Body<T> {
- HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<T>> h);
+ void expand(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>>*/ {
- public Iterator<Body<T>> iterator() { return new SingletonIterator<Body<T>>(this); }
+ protected static class MyBody<T> extends Forest<T> implements Body<T> /* extends PrintableTree<Forest<T>> implements */ {
+
+ public <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
+ ivbc.invoke(this, b, c);
+ }
private final Input.Location location;
private final T tag;
this.singleton = singleton;
}
- public HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<T>> h) {
+ public void expand(final int i, final TreeMaker<T> h) {
if (singleton) {
- for(Body<T> b : tokens[0]) b.expand(toss, toks, i, h);
+ tokens[0].visit(h, null, i);
+ return;
+ }
+ if (i==0) h.start(tag, location);
- } else if (i==tokens.length) {
- h.add(new Tree<T>(null, tag, toks.toArray(tree_hint)));
+ if (i==tokens.length) {
+ h.finish(tag, location);
} else if (unwrap && i==tokens.length-1) {
if (tokens[i] != null)
- for(Body b : tokens[i])
- b.expand(toss, toks, 0, h);
+ tokens[i].visit(h, null, 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);
- }
- //if (!hit) throw new Error();
+ tokens[i].visit(new TreeMaker<T>(h.toss) {
+ public void start(T head, Input.Location loc) { }
+ public void addTree(Tree<T> t) { toks.add(t); }
+ public void finish(T head, Input.Location loc) {
+ int old = h.toks.size();
+ h.addTree(new Tree<T>(loc, head, toks.toArray(tree_hint)));
+ expand(i+1, h);
+ while(h.toks.size() > old) h.toks.remove(h.toks.size()-1);
+ }
+ }, null, null);
}
- return h;
}
protected String headToString() { return null; }
private FastSet<Forest<T>> hp = new FastSet<Forest<T>>();
public Ref() { }
public void merge(Forest p) { if (p!=this) hp.add(p, true); }
- public Iterator<Body<T>> iterator() {
- final Iterator<Forest<T>> ift = hp==null ? null : hp.iterator();
- return new Iterator<Body<T>>() {
- Iterator<Body<T>> ibt = ift==null ? null : ift.hasNext() ? ift.next().iterator() : null;
- public void remove() { throw new RuntimeException("not supported"); }
- public boolean hasNext() {
- if (ibt==null) return false;
- if (ibt.hasNext()) return true;
- ibt = ift.hasNext() ? ift.next().iterator() : null;
- return hasNext();
- }
- public Body<T> next() {
- return ibt.next();
- }
- };
-
+ public <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
+ if (hp==null) return;
+ for(Forest<T> f : hp)
+ f.visit(ivbc, b, c);
}
public Forest resolve() { return this; }
}
+ public abstract <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c);
+ private static class TreeMaker2<T> extends TreeMaker<T> {
+ private TreeConsumer<T> tc;
+ public TreeMaker2(boolean toss, TreeConsumer<T> tc) { super(toss); this.tc = tc; }
+ public void finish(T head, Input.Location loc) { tc.addTree(new Tree<T>(loc, head, toks.toArray(tree_hint)));; }
+ public void start(T head, Input.Location loc) { }
+ public void addTree(Tree<T> t) { toks.add(t); }
+ }
+ private static abstract class TreeMaker<T> implements Invokable<Forest.Body<T>,Boolean,Integer>, TreeConsumer<T> {
+ public ArrayList<Tree<T>> toks = new ArrayList<Tree<T>>();
+ private boolean toss;
+ protected T head;
+ public TreeMaker(boolean toss) { this.toss = toss; }
+ public abstract void start(T head, Input.Location loc);
+ public abstract void finish(T head, Input.Location loc);
+ public abstract void addTree(Tree<T> t);
+ public void invoke(Forest.Body<T> bod, Boolean o, Integer i) {
+ if (i==null) {
+ ArrayList<Tree<T>> toks = this.toks;
+ this.toks = new ArrayList<Tree<T>>();
+ bod.expand(0, this);
+ this.toks = toks;
+ } else {
+ bod.expand(i, this);
+ }
+ }
+ }
// Statics //////////////////////////////////////////////////////////////////////////////
projects / sbp.git / blobdiff