X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FForest.java;h=4f4baacb62315f466039ca27283f7366d5c1f631;hb=4eeae516c2ef96ca11d24f23fd5e80d12e7734a6;hp=0a20228acd563ee908532da57f962af4002d33ee;hpb=fc1e5069ec5401c425dd29b77b04285916b62d10;p=sbp.git

diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index 0a20228..4f4baac 100644
--- a/src/edu/berkeley/sbp/Forest.java
+++ b/src/edu/berkeley/sbp/Forest.java
@@ -7,7 +7,7 @@ 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.MyBody<T>>*/ implements Visitable<Forest.Body<T>> {
 
     /** assume that this forest contains exactly one tree and return it; otherwise throw an exception */
     public final Tree<T> expand1() throws Ambiguous, ParseFailed {
@@ -17,18 +17,31 @@ public abstract class Forest<T> extends PrintableTree<Forest.Body<T>> implements
     }
 
     /** expand this forest into a set of trees */
-    public abstract HashSet<Tree<T>>  expand(boolean toss);
+    public HashSet<Tree<T>> expand(boolean toss) {
+        TreeMaker<T> ret = new TreeMaker<T>();
+        invoke(ret, new Boolean(toss), null);
+        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 MultiForest<T>(loc, tag, tokens, unwrap, singleton);
+        return new MyBody<T>(loc, tag, tokens, unwrap, singleton);
     }
 
     // Body //////////////////////////////////////////////////////////////////////////////
 
-    protected static class Body<T> extends PrintableTree<Forest<T>> implements Iterable<Forest<T>> {
+    protected static interface Body<T> {
+        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 */ {
+
+        public <B,C> void invoke(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
+            ivbc.invoke(this, b, c);
+        }
 
         private final Input.Location    location;
         private final T                 tag;
@@ -36,7 +49,7 @@ public abstract class Forest<T> extends PrintableTree<Forest.Body<T>> implements
         private final boolean           unwrap;
         private final boolean           singleton;
 
-        private Body(Input.Location loc, T tag, Forest<T>[] tokens, 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];
@@ -46,43 +59,36 @@ public abstract class Forest<T> extends PrintableTree<Forest.Body<T>> implements
             this.singleton = singleton;
         }
 
-        private 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();
             }
             return h;
         }
 
-        void addTo(FastSet<Body> h) {
-            if (!singleton) h.add(this, true);
-            else for(Body b : tokens[0]) b.addTo(h);
-        }
-
         protected String  headToString()         { return null; }
         protected String  headToJava()           { return null; }
         protected String  left()                 { return "{"; }
         protected String  right()                { return "}"; }
         protected boolean ignoreSingleton()      { return false; }
-        public    Iterator<Forest<T>> iterator() { return new ArrayIterator<Forest<T>>(tokens); }
     }
 
 
@@ -94,43 +100,28 @@ public abstract class Forest<T> extends PrintableTree<Forest.Body<T>> implements
      *  viewed, it becomes immutable
      */
     static class Ref<T> extends Forest<T> {
-        private FastSet<Forest> hp = new FastSet<Forest>();
-        private Forest res = null;
+        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 ((Forest<T>)resolve()).iterator(); }
-        public HashSet<Tree<T>> expand(boolean toss) { return resolve().expand(toss); }
-        public Forest resolve() {
-            if (hp==null) return res;
-            FastSet<Body> nh      = new FastSet<Body>();
-            for(Forest<?> p : hp)
-                for(Body<?> b : (Forest<?>)p)
-                    b.addTo(nh);
-            res = new MultiForest(nh);
-            hp = null;
-            return res;
+        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) {
+            if (hp==null) return;
+            for(Forest<T> f : hp) f.invoke(ivbc, b, c);
         }
+        public Forest resolve() { return this; }
     }
 
-    // Implementations //////////////////////////////////////////////////////////////////////////////
-
-    private static class MultiForest<T> extends Forest<T> {
-        private final FastSet<Body<T>> results;
-        private MultiForest(FastSet<Body<T>> results) { this.results = results; }
-        public MultiForest(Input.Location loc, T tag, Forest<T>[] tokens, boolean unwrap, boolean singleton) {
-            this.results = new FastSet<Body<T>>(new Body(loc, tag, tokens, 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 Ambiguous(this);
-            return ret;
+    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) {
+                ArrayList<Tree<T>> toks = this.toks;
+                this.toks = new ArrayList<Tree<T>>();
+                bod.expand(toss, 0, this);
+                this.toks = toks;
+            } else {
+                bod.expand(toss, i, this);
+            }
         }
     }