+// Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
+
package edu.berkeley.sbp;
-import edu.berkeley.sbp.*;
-import edu.berkeley.sbp.Sequence.Position;
import edu.berkeley.sbp.util.*;
import java.io.*;
import java.util.*;
-import java.lang.reflect.*;
/**
+ * <font color=blue>
* An efficient representation of a collection of trees (Tomita's
* shared packed parse forest).
+ * </font>
*/
-public abstract class Forest<T> implements GraphViz.ToGraphViz {
-
+public abstract class Forest<NodeType> implements GraphViz.ToGraphViz {
/** assume that this forest contains exactly one tree and return it; otherwise throw an exception */
- public abstract Tree<T> expand1() throws Ambiguous;
+ public abstract Tree<NodeType> expand1() throws Ambiguous;
/** 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 */
- public static <T> Forest<T> create(Input.Region loc, T head, Forest<T>[] children, boolean unwrap) {
- return new One<T>(loc, head, children, unwrap);
+ public Iterable<Tree<NodeType>> expand() {
+ HashSet<Tree<NodeType>> ht = new HashSet<Tree<NodeType>>();
+ expand(ht, new HashSet<Forest<NodeType>>(), null);
+ return ht;
}
+ /** returns the input Region which this Forest was parsed from */
+ public abstract Input.Region getRegion();
// 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 static <NodeType> Forest<NodeType> create(Input.Region region, NodeType head, Forest<NodeType>[] children) {
+ return create(region, head, children, new boolean[children==null ? 0 : children.length]); }
+ public static <NodeType> Forest<NodeType> create(Input.Region region, NodeType head, Forest<NodeType>[] children, boolean[] lifts) {
+ if (region == null) throw new RuntimeException("invoked Forest.create(region=null) -- this should never happen");
+ return new One<NodeType>(region, head, children, lifts);
+ }
+ abstract void expand(HashSet<Tree<NodeType>> ht, HashSet<Forest<NodeType>> ignore, Tree<NodeType> bogus);
+ abstract void gather(HashSet<Forest<NodeType>> ignore);
+ abstract void edges(GraphViz.StateNode n);
+ boolean ambiguous() { return false; }
+
// One //////////////////////////////////////////////////////////////////////////////
/** A "single" forest with a head and child subforests */
- public static class One<T> extends Forest<T> {
+ private static class One<NodeType> extends Forest<NodeType> {
private final Input.Region location;
- private final T head;
- private final Forest<T>[] children;
+ private final NodeType head;
+ private final Forest<NodeType>[] children;
/** if true, the last child's children are considered children of this node */
- private final boolean unwrap;
+ private final boolean[] lifts;
+
+ public Input.Region getRegion() { return location; }
- private One(Input.Region loc, T head, Forest<T>[] children, boolean unwrap) {
+ private One(Input.Region loc, NodeType head, Forest<NodeType>[] children, boolean[] lifts) {
this.location = loc;
this.head = head;
+ if (head==null) throw new RuntimeException("invoked Forest.create(,null,,,) -- this should never happen");
this.children = children==null ? emptyForestArray : new Forest[children.length];
if (children != null) System.arraycopy(children, 0, this.children, 0, children.length);
if (children != null) for(int i=0; i<children.length; i++) if (children[i]==null) throw new Error(i+"");
- this.unwrap = unwrap;
+ this.lifts = lifts;
}
- public Tree<T> expand1() throws Ambiguous {
- Tree<T>[] ret = new Tree[children.length];
+ public Tree<NodeType> expand1() throws Ambiguous {
+ Tree<NodeType>[] ret = new Tree[children.length];
for(int i=0; i<children.length; i++) ret[i] = children[i].expand1();
- return new Tree<T>(location, head, ret, unwrap);
+ return new Tree<NodeType>(location, head, ret, lifts);
}
- public void gather(HashSet<Forest<T>> hf) {
+ void gather(HashSet<Forest<NodeType>> hf) {
hf.add(this);
- for(Forest<T> f : children) f.gather(hf);
+ for(Forest<NodeType> f : children) f.gather(hf);
}
- public void expand(HashSet<Tree<T>> ht, HashSet<Forest<T>> ignore, Tree<T> bogus) {
+ void expand(HashSet<Tree<NodeType>> ht, HashSet<Forest<NodeType>> ignore, Tree<NodeType> bogus) {
if (ignore.contains(this)) { ht.add(bogus); return; }
expand(0, new Tree[children.length], ht, ignore, bogus);
}
- private 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<NodeType>[] ta, HashSet<Tree<NodeType>> ht, HashSet<Forest<NodeType>> ignore,
+ Tree<NodeType> bogus) {
if (i==children.length) {
- ht.add(new Tree<T>(location, head, ta, unwrap));
+ ht.add(new Tree<NodeType>(location, head, ta, lifts));
} else {
- HashSet<Tree<T>> ht2 = new HashSet<Tree<T>>();
+ HashSet<Tree<NodeType>> ht2 = new HashSet<Tree<NodeType>>();
children[i].expand(ht2, ignore, bogus);
- for(Tree<T> tc : ht2) {
+ for(Tree<NodeType> tc : ht2) {
ta[i] = tc;
expand(i+1, ta, ht, ignore, bogus);
ta[i] = null;
public boolean isTransparent() { return false; }
public boolean isHidden() { return false; }
- public GraphViz.Node toGraphViz(GraphViz gv) {
+ public GraphViz.StateNode toGraphViz(GraphViz gv) {
if (gv.hasNode(this)) return gv.createNode(this);
- GraphViz.Node n = gv.createNode(this);
+ GraphViz.StateNode n = gv.createNode(this);
n.label = headToString()==null?"":headToString();
n.directed = true;
edges(n);
return n;
}
- boolean edges = false;
- public void edges(GraphViz.Node n) {
+ boolean edges = false; // FIXME ??
+ public void edges(GraphViz.StateNode n) {
if (edges) return;
edges = true;
for(int i=0; i<children.length; i++) {
- if (i==children.length-1 && unwrap && !children[i].ambiguous()) {
+ if (lifts[i] && !children[i].ambiguous()) {
children[i].edges(n);
} else {
n.edge(children[i], null);
// Many //////////////////////////////////////////////////////////////////////////////
/** An "ambiguity node"; this is immutable once it has been "looked at" */
- public static class Many<T> extends Forest<T> {
+ static class Many<NodeType> extends Forest<NodeType> {
- HashSet<GSS.Phase.Node> parents = new HashSet<GSS.Phase.Node>();
- private FastSet<Forest<T>> hp = new FastSet<Forest<T>>();
+ private FastSet<Forest<NodeType>> hp = new FastSet<Forest<NodeType>>();
private boolean touched = false;
public Many() { }
- public Iterator<One<T>> iterator() {
- touched();
- return (Iterator<One<T>>)hp.iterator(); // FIXME: fastset's iterator is not safe!
- }
+ public Input.Region getRegion() { return hp.iterator().next().getRegion(); } // all should be identical
- public Tree<T> expand1() throws Ambiguous {
+ public Tree<NodeType> expand1() throws Ambiguous {
touched();
if (hp.size() > 1) {
- HashSet<Forest<T>> hf0 = new HashSet<Forest<T>>();
- Iterator<Forest<T>> ih = hp.iterator();
+ HashSet<Forest<NodeType>> hf0 = new HashSet<Forest<NodeType>>();
+ Iterator<Forest<NodeType>> ih = hp.iterator();
ih.next().gather(hf0);
- for(Forest<T> f : hp) {
- HashSet<Forest<T>> hf1 = new HashSet<Forest<T>>();
+ for(Forest<NodeType> f : hp) {
+ HashSet<Forest<NodeType>> hf1 = new HashSet<Forest<NodeType>>();
f.gather(hf1);
hf0.retainAll(hf1);
}
- HashSet<Tree<T>> ht = new HashSet<Tree<T>>();
+ HashSet<Tree<NodeType>> ht = new HashSet<Tree<NodeType>>();
expand(ht, hf0, new Tree(null, "*"));
throw new Ambiguous((Forest<?>)this,
(HashSet<Tree<?>>)(Object)ht);
return hp.iterator().next().expand1();
}
- public void gather(HashSet<Forest<T>> ht) {
+ void gather(HashSet<Forest<NodeType>> ht) {
touched();
+
+ // FIXME: do something more sensible here
+ if (ht.contains(this)) {
+ System.err.println("WARNING: grammar produced a circular forest\n" + this);
+ //throw new Error("grammar produced a circular forest:\n" + this);
+ return;
+ }
+
ht.add(this);
- for(Forest<T> f : hp) f.gather(ht);
+ for(Forest<NodeType> f : hp) f.gather(ht);
}
private void touched() {
if (touched) return;
touched = true;
- FastSet<Forest<T>> f2 = new FastSet<Forest<T>>();
+ /*
+ FastSet<Forest<NodeType>> f2 = new FastSet<Forest<NodeType>>();
for(Forest f : hp)
if (f instanceof Forest.One) f2.add(f);
- else for(Forest ff : ((Forest.Many)f))
+ else for(Forest ff : ((Forest.Many<NodeType>)f))
f2.add(ff);
hp = f2;
+ */
}
public boolean contains(Forest f) {
touched();
return true;
}
- public void expand(HashSet<Tree<T>> ht, HashSet<Forest<T>> ignore, Tree<T> bogus) {
+ void expand(HashSet<Tree<NodeType>> ht, HashSet<Forest<NodeType>> ignore, Tree<NodeType> bogus) {
touched();
if (ignore.contains(this)) { ht.add(bogus); return; }
- for (Forest<T> f : hp) f.expand(ht, ignore, bogus);
+ for (Forest<NodeType> f : hp) f.expand(ht, ignore, bogus);
}
public boolean isTransparent() { return hp.size()==1; }
public boolean isHidden() { return hp.size()==0; }
- public void edges(GraphViz.Node n) {
+ public void edges(GraphViz.StateNode n) {
if (hp.size()==1) { hp.iterator().next().edges(n); return; }
for(Forest f : hp) f.edges(n);
}
- public GraphViz.Node toGraphViz(GraphViz gv) {
+ public GraphViz.StateNode toGraphViz(GraphViz gv) {
if (hp.size()==1) return hp.iterator().next().toGraphViz(gv);
if (gv.hasNode(this)) return gv.createNode(this);
- GraphViz.Node n = gv.createNode(this);
+ GraphViz.StateNode n = gv.createNode(this);
n.label = "?";
n.color = "red";
for(Forest f : hp) n.edge(f, null);
projects / sbp.git / blobdiff