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 Parser.Ambiguous, Parser.Failed {
+ public final Tree<T> expand1() throws Ambiguous, ParseFailed {
Iterator<Tree<T>> it = expand(true).iterator();
- if (!it.hasNext()) throw new Parser.Failed();
+ if (!it.hasNext()) throw new ParseFailed();
return it.next();
}
/** expand this forest into a set of trees */
- public abstract HashSet<Tree<T>> expand(boolean toss);
- public abstract boolean empty();
-
- static <T> Forest<T> singleton(Token.Location loc, Sequence creator) { return create(loc, null, new Forest[] { }, creator, false, true); }
- static <T> Forest<T> singleton(Token.Location loc, Forest<T> body, Sequence creator) { return create(loc, null, new Forest[] { body }, creator, false, true); }
- static <T> Forest<T> leaf(Token.Location loc, T tag, Sequence creator) { return create(loc, tag, null, creator, false, false); }
- public static <T> Forest<T> create(Token.Location loc, T tag, Forest<T>[] tokens, Sequence creator, boolean unwrap, boolean singleton) {
- return new MultiForest<T>(loc, tag, tokens, creator, unwrap, singleton);
+ 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>>()));
+ if (toss && ret.size() > 1) throw new Ambiguous(this);
+ return ret;
+ }
+
+ 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); }
+ public static <T> Forest<T> create(Input.Location loc, T tag, Forest<T>[] tokens, boolean unwrap, boolean singleton) {
+ return new MyBody<T>(loc, tag, tokens, unwrap, singleton);
}
// Body //////////////////////////////////////////////////////////////////////////////
- protected static class Body<T> {
+ protected static interface Body<T> {
+ HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<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); }
- private final Token.Location location;
+ private final Input.Location location;
private final T tag;
private final Forest<T>[] tokens;
- private final Sequence creator;
private final boolean unwrap;
private final boolean singleton;
- private Body(Token.Location loc, T tag, Forest<T>[] tokens, Sequence creator, boolean unwrap, boolean singleton) {
+ private MyBody(Input.Location loc, T tag, Forest<T>[] tokens, boolean unwrap, boolean singleton) {
this.location = loc;
this.tag = tag;
this.tokens = tokens==null ? emptyForestArray : new Forest[tokens.length];
if (tokens != null) System.arraycopy(tokens, 0, this.tokens, 0, tokens.length);
if (tokens != null) for(int i=0; i<tokens.length; i++) if (tokens[i]==null) throw new Error(i+"");
- this.creator = creator;
this.unwrap = unwrap;
this.singleton = singleton;
}
- private HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<T>> h) {
+ public 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 {
}
return h;
}
- void addTo(HashSet<Body> h) {
- if (!singleton) h.add(this);
- else for(Body b : (IterableForest<T>)tokens[0]) b.addTo(h);
- }
- void addTo(FastSet<Body> h) {
- if (!singleton) h.add(this, true);
- else for(Body b : (IterableForest<T>)tokens[0]) b.addTo(h);
- }
-
- private boolean rep = false;
- public String toString() {
- if (rep) return "***";
- try {
- rep = true;
- 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;
- } finally {
- rep = false;
- }
- }
+ protected String headToString() { return null; }
+ protected String headToJava() { return null; }
+ protected String left() { return "{"; }
+ protected String right() { return "}"; }
+ protected boolean ignoreSingleton() { return false; }
}
// Ref //////////////////////////////////////////////////////////////////////////////
- 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> {
- public boolean empty() {
- if (res!=null) return res.empty();
- for(Forest f : hp) if (!f.empty()) return false;
- return true;
- }
- private FastSet<Forest> hp = new FastSet<Forest>();
- private Forest res = null;
+ static class Ref<T> extends Forest<T> {
+ private FastSet<Forest<T>> hp = new FastSet<Forest<T>>();
public Ref() { }
- public void merge(Forest p) {
- if (res != null) throw new Error("already resolved!");
- if (p==null) throw new Error();
- if (p!=this) hp.add(p, true);
- }
- public Iterator<Body<T>> iterator() { return ((IterableForest<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)
- b.addTo(nh);
- res = new MultiForest(nh);
- hp = null;
- return res;
- }
- }
-
- // Implementations //////////////////////////////////////////////////////////////////////////////
+ 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();
+ }
+ };
- private static class MultiForest<T> extends IterableForest<T> {
- public boolean empty() { return results.size()>0; }
- private final FastSet<Body<T>> results;
- private MultiForest(FastSet<Body<T>> results) { this.results = results; }
- public MultiForest(Token.Location loc, T tag, Forest<T>[] tokens, Sequence creator, boolean unwrap, boolean singleton) {
- this.results = new FastSet<Body<T>>(new Body(loc, tag, tokens, creator, 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)
- ret.addAll(b.expand(toss, new ArrayList<Tree<T>>(), 0, new HashSet<Tree<T>>()));
- if (toss && ret.size() > 1) throw new Parser.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();
}
+ public Forest resolve() { return this; }
}
+
// Statics //////////////////////////////////////////////////////////////////////////////
private static Tree[] tree_hint = new Tree[0];
- private static Body[] body_hint = new Body[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; }
}