X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FForest.java;h=a8c44f018f7c2eb49faae221e8adefad01364df1;hb=92e027ee41d33f590ede1e23e27224712980c533;hp=ec3da782bf7a8378c944092accb9ce59cb239262;hpb=ef9c08962db99929febe84197e9162e6867f942d;p=sbp.git

diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index ec3da78..a8c44f0 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 {
@@ -17,25 +17,38 @@ 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) {
-            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>>()));
-            if (toss && ret.size() > 1) throw new Ambiguous(this);
-            return ret;
-        }
+    public HashSet<Tree<T>> expand(boolean toss) {
+        final HashSetTreeConsumer<T> ret = new HashSetTreeConsumer<T>();
+        visit(new TreeMaker2<T>(toss, ret), null, null);
+        if (toss && ret.size() > 1) throw new Ambiguous(this);
+        return ret;
+    }
+
+    public static interface TreeConsumer<T> {
+        public void addTree(Tree<T> t);
+    }
+    public static class HashSetTreeConsumer<T> extends HashSet<Tree<T>> implements TreeConsumer<T> {
+        public void addTree(Tree<T> t) { super.add(t); }
+    }
 
     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>(new Body<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> {
+        void expand(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 visit(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;
@@ -43,7 +56,7 @@ 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];
@@ -53,35 +66,32 @@ 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 void expand(final int i, final TreeMaker<T> h) {
             if (singleton) {
-                for(Body<T> b : tokens[0]) b.expand(toss, toks, i, h);
+                tokens[0].visit(h, null, i);
+                return;
+            }
+            if (i==0) h.start(tag, location);
 
-            } else if (i==tokens.length) {
-                h.add(new Tree<T>(null, tag, toks.toArray(tree_hint)));
+            if (i==tokens.length) {
+                h.finish(tag, location);
 
             } else if (unwrap && i==tokens.length-1) {
                 if (tokens[i] != null)
-                    for(Body b : tokens[i])
-                        b.expand(toss, toks, 0, h);
+                    tokens[i].visit(h, null, 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);
-                }
-                //if (!hit) throw new Error();
+                tokens[i].visit(new TreeMaker<T>(h.toss) {
+                    public void start(T head, Input.Location loc) { }
+                    public void addTree(Tree<T> t) { toks.add(t); }
+                    public void finish(T head, Input.Location loc) {
+                        int old = h.toks.size();
+                        h.addTree(new Tree<T>(loc, head, toks.toArray(tree_hint)));
+                        expand(i+1, h);
+                        while(h.toks.size() > old) h.toks.remove(h.toks.size()-1);
+                    }
+                }, null, null);
             }
-            return h;
-        }
-
-        void addTo(FastSet<Body<T>> h) {
-            /*if (!singleton)*/ h.add(this, true);
-            //else for(Body b : tokens[0]) b.addTo(h);
         }
 
         protected String  headToString()         { return null; }
@@ -89,7 +99,6 @@ public abstract class Forest<T> extends PrintableTree<Forest.Body<T>> implements
         protected String  left()                 { return "{"; }
         protected String  right()                { return "}"; }
         protected boolean ignoreSingleton()      { return false; }
-        public    Iterator<Forest<T>> iterator() { return new ArrayIterator<Forest<T>>(tokens); }
     }
 
 
@@ -104,30 +113,40 @@ public abstract class Forest<T> extends PrintableTree<Forest.Body<T>> implements
         private FastSet<Forest<T>> hp = new FastSet<Forest<T>>();
         public Ref() { }
         public void merge(Forest p) { if (p!=this) hp.add(p, true); }
-        public Iterator<Body<T>> iterator() {
-            final Iterator<Forest<T>> ift = hp==null ? null : hp.iterator();
-            return new Iterator<Body<T>>() {
-                Iterator<Body<T>> ibt = ift==null ? null : ift.hasNext() ? ift.next().iterator() : null;
-                public void remove() { throw new RuntimeException("not supported"); }
-                public boolean hasNext() {
-                    if (ibt==null) return false;
-                    if (ibt.hasNext()) return true;
-                    ibt = ift.hasNext() ? ift.next().iterator() : null;
-                    return hasNext();
-                }
-                public Body<T> next() {
-                    return ibt.next();
-                }
-            };
-
+        public <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
+            if (hp==null) return;
+            for(Forest<T> f : hp)
+                f.visit(ivbc, b, c);
         }
         public Forest resolve() { return this; }
     }
 
-    private static class MultiForest<T> extends Forest<T> {
-        private final FastSet<Body<T>> results = new FastSet<Body<T>>();
-        public MultiForest(Body<T> b) { results.add(b); }
-        public Iterator<Body<T>> iterator() { return results.iterator(); }
+    public abstract <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c);
+    private static class TreeMaker2<T> extends TreeMaker<T> {
+        private TreeConsumer<T> tc;
+        public TreeMaker2(boolean toss, TreeConsumer<T> tc) { super(toss); this.tc = tc; }
+        public void finish(T head, Input.Location loc) { tc.addTree(new Tree<T>(loc, head, toks.toArray(tree_hint)));; }
+        public void start(T head, Input.Location loc) { }
+        public void addTree(Tree<T> t) { toks.add(t); }
+    }
+    private static abstract class TreeMaker<T> implements Invokable<Forest.Body<T>,Boolean,Integer>, TreeConsumer<T> {
+        public ArrayList<Tree<T>> toks = new ArrayList<Tree<T>>();
+        private boolean toss;
+        protected T head;
+        public TreeMaker(boolean toss) { this.toss = toss; }
+        public abstract void start(T head, Input.Location loc);
+        public abstract void finish(T head, Input.Location loc);
+        public abstract void addTree(Tree<T> t);
+        public void invoke(Forest.Body<T> bod, Boolean o, Integer i) {
+            if (i==null) {
+                ArrayList<Tree<T>> toks = this.toks;
+                this.toks = new ArrayList<Tree<T>>();
+                bod.expand(0, this);
+                this.toks = toks;
+            } else {
+                bod.expand(i, this);
+            }
+        }
     }
 
     // Statics //////////////////////////////////////////////////////////////////////////////