From 3998af3d6daba1f9dd81e0b1a42955a501968606 Mon Sep 17 00:00:00 2001
From: adam <adam@megacz.com>
Date: Sun, 22 Jan 2006 04:17:33 -0500
Subject: [PATCH] checkpoint

darcs-hash:20060122091733-5007d-0b11eabc1366ad4fcd4f1d731069b1445a7b9a43.gz
---
 src/edu/berkeley/sbp/Forest.java |   50 ++++++++++++++++++++++++++------------
 1 file changed, 34 insertions(+), 16 deletions(-)

diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index 34759e3..748c435 100644
--- a/src/edu/berkeley/sbp/Forest.java
+++ b/src/edu/berkeley/sbp/Forest.java
@@ -7,7 +7,19 @@ 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<T> /*extends PrintableTree<Forest.Body<T>>*/ implements Iterable<Forest.Body<T>> {
+public abstract class Forest<T> /*extends PrintableTree<Forest.Body<T>>*/ implements Visitable<Forest.Body<T>>, Iterable<Forest.Body<T>>  {
+
+    public abstract <B,C> void invoke(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c);
+    private static class TreeMaker<T> extends HashSet<Tree<T>> implements Invokable<Forest.Body<T>,Boolean,Integer> {
+        public ArrayList<Tree<T>> toks = new ArrayList<Tree<T>>();
+        public void invoke(Forest.Body<T> bod, Boolean toss, Integer i) {
+            if (i==null) {
+                addAll(bod.expand(toss, 0, new TreeMaker<T>()));
+            } else {
+                bod.expand(toss, i, this);
+            }
+        }
+    }
 
     /** assume that this forest contains exactly one tree and return it; otherwise throw an exception */
     public final Tree<T> expand1() throws Ambiguous, ParseFailed {
@@ -18,9 +30,8 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.Body<T>>*/ implem
 
     /** expand this forest into a set of trees */
     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>>()));
+        TreeMaker<T> ret = new TreeMaker<T>();
+        invoke(ret, new Boolean(toss), null);
         if (toss && ret.size() > 1) throw new Ambiguous(this);
         return ret;
     }
@@ -35,10 +46,14 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.Body<T>>*/ implem
     // Body //////////////////////////////////////////////////////////////////////////////
 
     protected static interface Body<T> {
-         HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<T>> h);
+        TreeMaker<T> expand(boolean toss, int i, TreeMaker<T> h);
     }
 
-    protected static class MyBody<T> extends Forest<T> implements Body<T> /* extends PrintableTree<Forest<T>> implements Iterable<Forest.Body<T>>*/ {
+    protected static class MyBody<T> extends Forest<T> implements Body<T> /* extends PrintableTree<Forest<T>> implements */,Iterable<Forest.Body<T>> {
+
+        public <B,C> void invoke(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
+            ivbc.invoke(this, b, c);
+        }
         public Iterator<Body<T>> iterator() { return new SingletonIterator<Body<T>>(this); }
 
         private final Input.Location    location;
@@ -57,26 +72,25 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.Body<T>>*/ implem
             this.singleton = singleton;
         }
 
-        public HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<T>> h) {
+        public TreeMaker<T> expand(boolean toss, int i, TreeMaker<T> h) {
             if (singleton) {
-                for(Body<T> b : tokens[0]) b.expand(toss, toks, i, h);
+                tokens[0].invoke(h, toss, i);
 
             } else if (i==tokens.length) {
-                h.add(new Tree<T>(null, tag, toks.toArray(tree_hint)));
+                h.add(new Tree<T>(null, tag, h.toks.toArray(tree_hint)));
 
             } else if (unwrap && i==tokens.length-1) {
                 if (tokens[i] != null)
-                    for(Body b : tokens[i])
-                        b.expand(toss, toks, 0, h);
+                    tokens[i].invoke(h, toss, 0);
 
             } else {
                 boolean hit = false;
                 for(Tree<T> r : tokens[i].expand(toss)) {
                     hit = true;
-                    int old = toks.size();
-                    toks.add(r);
-                    expand(toss, toks, i+1, h);
-                    while(toks.size() > old) toks.remove(toks.size()-1);
+                    int old = h.toks.size();
+                    h.toks.add(r);
+                    expand(toss, i+1, h);
+                    while(h.toks.size() > old) h.toks.remove(h.toks.size()-1);
                 }
                 //if (!hit) throw new Error();
             }
@@ -98,10 +112,14 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.Body<T>>*/ implem
      *  forests to be viewed as a forest at some later date; once
      *  viewed, it becomes immutable
      */
-    static class Ref<T> extends Forest<T> {
+    static class Ref<T> extends Forest<T> implements Iterable<Forest.Body<T>> {
         private FastSet<Forest<T>> hp = new FastSet<Forest<T>>();
         public Ref() { }
         public void merge(Forest p) { if (p!=this) hp.add(p, true); }
+        public <B,C> void invoke(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
+            for(Forest.Body<T> bod : this)
+                ivbc.invoke(bod, b, c);
+        }
         public Iterator<Body<T>> iterator() {
             final Iterator<Forest<T>> ift = hp==null ? null : hp.iterator();
             return new Iterator<Body<T>>() {
-- 
1.7.10.4