import java.util.*;
import java.lang.reflect.*;
-/** an efficient representation of a collection of trees (Tomita's shared packed parse forest) */
+/**
+ * An efficient representation of a collection of trees (Tomita's
+ * shared packed parse forest).
+ */
public abstract class Forest<T> implements GraphViz.ToGraphViz {
/** expand this forest into a set of trees */
public void expand(HashSet<Tree<T>> ht) { expand(ht, new HashSet<Forest<T>>(), null); }
- /** create a new forest node */
+ /** create a new forest */
public static <T> Forest<T> create(Input.Region loc, T head, Forest<T>[] children, boolean unwrap) {
- return new Body<T>(loc, head, children, unwrap);
+ return new One<T>(loc, head, children, unwrap);
}
+
// Package-Private //////////////////////////////////////////////////////////////////////////////
abstract void expand(HashSet<Tree<T>> ht, HashSet<Forest<T>> ignore, Tree<T> bogus);
abstract void gather(HashSet<Forest<T>> ignore);
+ boolean ambiguous() { return false; }
public abstract void edges(GraphViz.Node n);
- public boolean ambiguous() { return false; }
- // Body //////////////////////////////////////////////////////////////////////////////
- private static class Body<T> extends Forest<T> /* extends PrintableTree<Forest<T>> implements */ {
+ // One //////////////////////////////////////////////////////////////////////////////
+
+ /** A "single" forest with a head and child subforests */
+ public static class One<T> extends Forest<T> {
private final Input.Region location;
private final T head;
private final Forest<T>[] children;
+
+ /** if true, the last child's children are considered children of this node */
private final boolean unwrap;
- private Body(Input.Region loc, T head, Forest<T>[] children, boolean unwrap) {
+ private One(Input.Region loc, T head, Forest<T>[] children, boolean unwrap) {
this.location = loc;
this.head = head;
this.children = children==null ? emptyForestArray : new Forest[children.length];
public Tree<T> expand1() throws Ambiguous {
Tree<T>[] ret = new Tree[children.length];
- for(int i=0; i<children.length; i++)
- ret[i] = children[i].expand1();
+ for(int i=0; i<children.length; i++) ret[i] = children[i].expand1();
return new Tree<T>(location, head, ret, unwrap);
}
+
public void gather(HashSet<Forest<T>> hf) {
hf.add(this);
for(Forest<T> f : children) f.gather(hf);
if (ignore.contains(this)) { ht.add(bogus); return; }
expand(0, new Tree[children.length], ht, ignore, bogus);
}
- public void expand(final int i, Tree<T>[] ta, HashSet<Tree<T>> ht, HashSet<Forest<T>> ignore, Tree<T> bogus) {
+ private void expand(final int i, Tree<T>[] ta, HashSet<Tree<T>> ht, HashSet<Forest<T>> ignore, Tree<T> bogus) {
if (i==children.length) {
ht.add(new Tree<T>(location, head, ta, unwrap));
} else {
}
- // Ref //////////////////////////////////////////////////////////////////////////////
+ // Many //////////////////////////////////////////////////////////////////////////////
+
+ /** An "ambiguity node"; this is immutable once it has been "looked at" */
+ public static class Many<T> extends Forest<T> {
- /**
- * 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 Forest<T> {
- public HashSet<GSS.Phase.Node> parents = new HashSet<GSS.Phase.Node>();
+ HashSet<GSS.Phase.Node> parents = new HashSet<GSS.Phase.Node>();
private FastSet<Forest<T>> hp = new FastSet<Forest<T>>();
+ private boolean touched = false;
- public Ref() { }
+ public Many() { }
public Tree<T> expand1() throws Ambiguous {
+ touched();
if (hp.size() > 1) {
HashSet<Forest<T>> hf0 = new HashSet<Forest<T>>();
Iterator<Forest<T>> ih = hp.iterator();
}
public void gather(HashSet<Forest<T>> ht) {
+ touched();
ht.add(this);
for(Forest<T> f : hp) f.gather(ht);
}
- public Forest resolve() { return this; }
- public void expand(HashSet<Tree<T>> ht, HashSet<Forest<T>> ignore, Tree<T> bogus) {
- if (ignore.contains(this)) { ht.add(bogus); return; }
- for (Forest<T> f : hp) f.expand(ht, ignore, bogus);
+ private void touched() {
+ touched = true;
+ }
+ public boolean contains(Forest f) {
+ touched();
+ return hp.contains(f);
}
- public boolean contains(Forest f) { return hp.contains(f); }
- public void merge(Forest p) { if (p!=this) hp.add(p, true); }
- public boolean ambiguous() {
+ public void merge(Forest p) {
+ if (touched) throw new RuntimeException("attempt to merge() on a Forest.Many that has already been examined");
+ if (p==this) throw new RuntimeException("attempt to merge() a Forest.Many to itself!");
+ hp.add(p, true);
+ }
+ boolean ambiguous() {
+ touched();
if (hp.size()==0) return false;
if (hp.size()==1) return hp.iterator().next().ambiguous();
return true;
}
- // GraphViz, ToInt //////////////////////////////////////////////////////////////////////////////
- /*
- public int toInt() {
- if (hp.size()==1) return hp.iterator().next().toInt();
- return super.toInt();
+ public void expand(HashSet<Tree<T>> ht, HashSet<Forest<T>> ignore, Tree<T> bogus) {
+ touched();
+ if (ignore.contains(this)) { ht.add(bogus); return; }
+ for (Forest<T> f : hp) f.expand(ht, ignore, bogus);
}
- */
+
+
+ // GraphViz, ToInt //////////////////////////////////////////////////////////////////////////////
+
public boolean isTransparent() { return hp.size()==1; }
public boolean isHidden() { return hp.size()==0; }
public void edges(GraphViz.Node n) {
for(Forest f : hp) f.edges(n);
}
public GraphViz.Node toGraphViz(GraphViz gv) {
- //if (hp.size()==0) return null;
if (hp.size()==1) return hp.iterator().next().toGraphViz(gv);
if (gv.hasNode(this)) return gv.createNode(this);
GraphViz.Node n = gv.createNode(this);
projects / sbp.git / blobdiff