X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FForest.java;h=34982bd11d935d2e238e059e29c1eb305af18ae4;hb=61a0c83fd40b98292b2dfe1eaba237eb804b2cb4;hp=bd3b46a996fc4addea796528fd17c3864b4d4474;hpb=280e93a7eec101178dc81f8009eedb2916271f09;p=sbp.git
diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index bd3b46a..34982bd 100644
--- a/src/edu/berkeley/sbp/Forest.java
+++ b/src/edu/berkeley/sbp/Forest.java
@@ -1,78 +1,105 @@
+// Copyright 2006 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.*;
/**
+ *
* An efficient representation of a collection of trees (Tomita's
* shared packed parse forest).
+ *
*/
-public abstract class Forest implements GraphViz.ToGraphViz {
+public abstract class Forest implements GraphViz.ToGraphViz {
/** assume that this forest contains exactly one tree and return it; otherwise throw an exception */
- public abstract Tree expand1() throws Ambiguous;
+ public abstract Tree expand1() throws Ambiguous;
/** expand this forest into a set of trees */
- public void expand(HashSet> ht) { expand(ht, new HashSet>(), null); }
-
- /** create a new forest */
- public static Forest create(Input.Region loc, T head, Forest[] children, boolean lift) {
- return new One(loc, head, children, lift);
+ public Iterable> expand() {
+ HashSet> ht = new HashSet>();
+ expand(ht, new HashSet>(), null);
+ return ht;
}
+ /** returns the input Region which this Forest was parsed from */
+ public abstract Input.Region getRegion();
+
// Package-Private //////////////////////////////////////////////////////////////////////////////
- abstract void expand(HashSet> ht, HashSet> ignore, Tree bogus);
- abstract void gather(HashSet> ignore);
- abstract void edges(GraphViz.Node n);
- boolean ambiguous() { return false; }
+ static Forest create(Input.Region region, NodeType head, Forest[] children,
+ boolean lift) {
+ if (region == null) throw new RuntimeException("invoked Forest.create(region=null) -- this should never happen");
+ return new One(region, head, children, lift);
+ }
+
+ static Forest create(Input.Region region, NodeType head, Forest[] children,
+ boolean lift, boolean liftLeft) {
+ if (region == null) throw new RuntimeException("invoked Forest.create(region=null) -- this should never happen");
+ return new One(region, head, children, lift, liftLeft);
+ }
+ /** create a new forest */
+ public static Forest create(Input.Region region, NodeType head, Forest[] children) {
+ return Forest.create(region, head, children, false); }
+ abstract void expand(HashSet> ht, HashSet> ignore, Tree bogus);
+ abstract void gather(HashSet> ignore);
+ abstract void edges(GraphViz.Node n);
+ boolean ambiguous() { return false; }
+
// One //////////////////////////////////////////////////////////////////////////////
/** A "single" forest with a head and child subforests */
- private static class One extends Forest {
+ private static class One extends Forest {
private final Input.Region location;
- private final T head;
- private final Forest[] children;
+ private final NodeType head;
+ private final Forest[] children;
/** if true, the last child's children are considered children of this node */
private final boolean lift;
+ private final boolean liftLeft;
- private One(Input.Region loc, T head, Forest[] children, boolean lift) {
+ public Input.Region getRegion() { return location; }
+
+ private One(Input.Region loc, NodeType head, Forest[] children, boolean lift) {
+ this(loc, head, children, lift, false);
+ }
+ private One(Input.Region loc, NodeType head, Forest[] children, boolean lift, boolean liftLeft) {
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 expand1() throws Ambiguous {
- Tree[] ret = new Tree[children.length];
+ public Tree expand1() throws Ambiguous {
+ Tree[] ret = new Tree[children.length];
for(int i=0; i(location, head, ret, lift);
+ return new Tree(location, head, ret, lift, liftLeft);
}
- void gather(HashSet> hf) {
+ void gather(HashSet> hf) {
hf.add(this);
- for(Forest f : children) f.gather(hf);
+ for(Forest f : children) f.gather(hf);
}
- void expand(HashSet> ht, HashSet> ignore, Tree bogus) {
+ void expand(HashSet> ht, HashSet> ignore, Tree 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[] ta, HashSet> ht, HashSet> ignore, Tree bogus) {
+ private void expand(final int i, Tree[] ta, HashSet> ht, HashSet> ignore,
+ Tree bogus) {
if (i==children.length) {
- ht.add(new Tree(location, head, ta, lift));
+ ht.add(new Tree(location, head, ta, lift, liftLeft));
} else {
- HashSet> ht2 = new HashSet>();
+ HashSet> ht2 = new HashSet>();
children[i].expand(ht2, ignore, bogus);
- for(Tree tc : ht2) {
+ for(Tree tc : ht2) {
ta[i] = tc;
expand(i+1, ta, ht, ignore, bogus);
ta[i] = null;
@@ -116,26 +143,27 @@ public abstract class Forest implements GraphViz.ToGraphViz {
// Many //////////////////////////////////////////////////////////////////////////////
/** An "ambiguity node"; this is immutable once it has been "looked at" */
- static class Many extends Forest {
+ static class Many extends Forest {
- HashSet parents = new HashSet();
- private FastSet> hp = new FastSet>();
+ private FastSet> hp = new FastSet>();
private boolean touched = false;
public Many() { }
- public Tree expand1() throws Ambiguous {
+ public Input.Region getRegion() { return hp.iterator().next().getRegion(); } // all should be identical
+
+ public Tree expand1() throws Ambiguous {
touched();
if (hp.size() > 1) {
- HashSet> hf0 = new HashSet>();
- Iterator> ih = hp.iterator();
+ HashSet> hf0 = new HashSet>();
+ Iterator> ih = hp.iterator();
ih.next().gather(hf0);
- for(Forest f : hp) {
- HashSet> hf1 = new HashSet>();
+ for(Forest f : hp) {
+ HashSet> hf1 = new HashSet>();
f.gather(hf1);
hf0.retainAll(hf1);
}
- HashSet> ht = new HashSet>();
+ HashSet> ht = new HashSet>();
expand(ht, hf0, new Tree(null, "*"));
throw new Ambiguous((Forest>)this,
(HashSet>)(Object)ht);
@@ -143,20 +171,28 @@ public abstract class Forest implements GraphViz.ToGraphViz {
return hp.iterator().next().expand1();
}
- void gather(HashSet> ht) {
+ void gather(HashSet> 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 f : hp) f.gather(ht);
+ for(Forest f : hp) f.gather(ht);
}
private void touched() {
if (touched) return;
touched = true;
/*
- FastSet> f2 = new FastSet>();
+ FastSet> f2 = new FastSet>();
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)f))
f2.add(ff);
hp = f2;
*/
@@ -177,10 +213,10 @@ public abstract class Forest implements GraphViz.ToGraphViz {
return true;
}
- void expand(HashSet> ht, HashSet> ignore, Tree bogus) {
+ void expand(HashSet> ht, HashSet> ignore, Tree bogus) {
touched();
if (ignore.contains(this)) { ht.add(bogus); return; }
- for (Forest f : hp) f.expand(ht, ignore, bogus);
+ for (Forest f : hp) f.expand(ht, ignore, bogus);
}