import java.lang.reflect.*;
/** an efficient representation of a collection of trees (Tomita's shared packed parse forest) */
-public abstract class Forest<T> {
+public abstract class Forest<T> extends PrintableTree<Forest.Body<T>> implements Iterable<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 {
// Body //////////////////////////////////////////////////////////////////////////////
- protected static class Body<T> {
+ protected static class Body<T> extends PrintableTree<Forest<T>> implements Iterable<Forest<T>> {
private final Input.Location location;
private final T tag;
private HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<T>> h) {
if (singleton) {
- for(Body<T> b : (IterableForest<T>)tokens[0]) b.expand(toss, toks, i, h);
+ for(Body<T> b : tokens[0]) b.expand(toss, toks, i, h);
} else if (i==tokens.length) {
h.add(new Tree<T>(null, tag, toks.toArray(tree_hint)));
} else if (unwrap && i==tokens.length-1) {
if (tokens[i] != null)
- for(Body b : (IterableForest<T>)tokens[i])
+ for(Body b : tokens[i])
b.expand(toss, toks, 0, h);
} else {
void addTo(FastSet<Body> h) {
if (!singleton) h.add(this, true);
- else for(Body b : (IterableForest<T>)tokens[0]) b.addTo(h);
+ else for(Body b : tokens[0]) b.addTo(h);
}
- public String toString() {
- StringBuffer ret = new StringBuffer();
- for(int i=0; i<tokens.length; i++) {
- String q = tokens[i]==null ? "null" : tokens[i].toString();
- if (q.length() > 0) {
- ret.append(q);
- ret.append(" ");
- }
- }
- String tail = ret.toString().trim();
- String head = (tag!=null && !tag.toString().equals("")) ? (tail.length() > 0 ? tag+":" : tag+"") : "";
- if (tail.length() > 0) tail = "{" + tail + "}";
- return head + tail;
- }
+ protected String headToString() { return null; }
+ protected String headToJava() { return null; }
+ protected String left() { return "{"; }
+ protected String right() { return "}"; }
+ protected boolean ignoreSingleton() { return false; }
+ public Iterator<Forest<T>> iterator() { return new ArrayIterator<Forest<T>>(tokens); }
}
// Ref //////////////////////////////////////////////////////////////////////////////
- private static abstract class IterableForest<T> extends Forest<T> implements Iterable<Forest.Body<T>> {
- public abstract Iterator<Forest.Body<T>> iterator();
- }
-
/**
* This class represents a partially complete collection of
* forests to be viewed as a forest at some later date; once
* viewed, it becomes immutable
*/
- static class Ref<T> extends IterableForest<T> {
+ static class Ref<T> extends Forest<T> {
private FastSet<Forest> hp = new FastSet<Forest>();
private Forest res = null;
public Ref() { }
if (p==null) throw new Error();
if (p!=this) hp.add(p, true);
}
- public Iterator<Body<T>> iterator() { return ((IterableForest<T>)resolve()).iterator(); }
+ public Iterator<Body<T>> iterator() { return ((Forest<T>)resolve()).iterator(); }
public HashSet<Tree<T>> expand(boolean toss) { return resolve().expand(toss); }
- public String toString() { return resolve().toString(); }
public Forest resolve() {
if (hp==null) return res;
FastSet<Body> nh = new FastSet<Body>();
for(Forest<?> p : hp)
- for(Body<?> b : (IterableForest<?>)p)
+ for(Body<?> b : (Forest<?>)p)
b.addTo(nh);
res = new MultiForest(nh);
hp = null;
// Implementations //////////////////////////////////////////////////////////////////////////////
- private static class MultiForest<T> extends IterableForest<T> {
+ private static class MultiForest<T> extends Forest<T> {
private final FastSet<Body<T>> results;
private MultiForest(FastSet<Body<T>> results) { this.results = results; }
public MultiForest(Input.Location loc, T tag, Forest<T>[] tokens, boolean unwrap, boolean singleton) {
this.results = new FastSet<Body<T>>(new Body(loc, tag, tokens, unwrap, singleton));
}
public Iterator<Body<T>> iterator() { return results.iterator(); }
-
public HashSet<Tree<T>> expand(boolean toss) {
HashSet<Tree<T>> ret = new HashSet<Tree<T>>();
for(Body<T> b : results)
if (toss && ret.size() > 1) throw new Ambiguous(this);
return ret;
}
-
- // Display //////////////////////////////////////////////////////////////////////////////
-
- private String toString = null;
- public String toString() {
- if (toString != null) return toString;
- StringBuffer ret = new StringBuffer();
- if (results.size()==1) {
- for(Forest.Body<T> r : results)
- ret.append(r);
- return toString = ret.toString();
- }
- ret.append("<?");
- boolean first = true;
- for(Forest.Body<T> r : results) {
- if (!first) ret.append(' ');
- first = false;
- ret.append(r);
- }
- ret.append("?>");
- return toString = ret.toString();
- }
}
// Statics //////////////////////////////////////////////////////////////////////////////
private static Tree[] tree_hint = new Tree[0];
private static final Forest[] emptyForestArray = new Forest[0];
+
+ protected String headToString() { return null; }
+ protected String headToJava() { return null; }
+ protected String left() { return "<?"; }
+ protected String right() { return "?>"; }
+ protected boolean ignoreSingleton() { return true; }
}
projects / sbp.git / blobdiff