X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FForest.java;h=5807545eb981c564a3f9be9839a2d66bc8d14b0c;hp=e4572ec0d598721017d5ff5a3679e232ee2eb330;hb=76bc0ff98c5e67f4fe6fa2593bffdf31b6db437a;hpb=6a2ea790f843e058c7e67d3c7d1deebadcfe1fd5

diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index e4572ec..5807545 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> {
+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 +17,34 @@ public abstract class Forest<T> {
     }
 
     /** expand this forest into a set of trees */
-    public abstract HashSet<Tree<T>>  expand(boolean toss);
+    public HashSet<Tree<T>> expand(boolean toss) {
+        final HashSet<Tree<T>> hs = new HashSet<Tree<T>>();
+        TreeMaker<T> ret = new TreeMaker<T>(toss) {
+            public void add(Tree<T> t) { hs.add(t); }
+        };
+        visit(ret, null, null);
+        if (toss && hs.size() > 1) throw new Ambiguous(this);
+        return hs;
+    }
 
     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> {
+    protected static interface Body<T> {
+        TreeMaker<T> expand(int i, TreeMaker<T> h);
+    }
+
+    protected static class MyBody<T> extends Forest<T> implements Body<T> /* extends PrintableTree<Forest<T>> implements */, Invokable<Tree<T>, TreeMaker<T>, Integer> {
+
+        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;
@@ -36,7 +52,7 @@ public abstract class Forest<T> {
         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];
@@ -46,127 +62,80 @@ public abstract class Forest<T> {
             this.singleton = singleton;
         }
 
-        private HashSet<Tree<T>> expand(boolean toss, ArrayList<Tree<T>> toks, int i, HashSet<Tree<T>> h) {
+        public TreeMaker<T> expand(final int i, final TreeMaker<T> h) {
             if (singleton) {
-                for(Body<T> b : (IterableForest<T>)tokens[0]) b.expand(toss, toks, i, h);
+                tokens[0].visit(h, null, 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 : (IterableForest<T>)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 add(Tree<T> r) {
+                        int old = h.toks.size();
+                        h.toks.add(r);
+                        expand(i+1, h);
+                        while(h.toks.size() > old) h.toks.remove(h.toks.size()-1);
+                    }
+                }, null, null);
             }
             return h;
         }
-
-        void addTo(FastSet<Body> h) {
-            if (!singleton) h.add(this, true);
-            else for(Body b : (IterableForest<T>)tokens[0]) b.addTo(h);
+        public void invoke(Tree<T> r, TreeMaker<T> h, Integer i) {
+            //hit = true;
+            int old = h.toks.size();
+            h.toks.add(r);
+            expand(i+1, h);
+            while(h.toks.size() > old) h.toks.remove(h.toks.size()-1);
+            //ivbc.invoke(this, b, c);
         }
 
-        public String toString() {
-            StringBuffer ret = new StringBuffer();
-            for(int i=0; i<tokens.length; i++) {
-                String q = tokens[i]==null ? "null" : tokens[i].toString();
-                if (q.length() > 0) {
-                    ret.append(q);
-                    ret.append(" ");
-                }
-            }
-            String tail = ret.toString().trim();
-            String head = (tag!=null && !tag.toString().equals("")) ? (tail.length() > 0 ? tag+":" : tag+"") : "";
-            if (tail.length() > 0) tail = "{" + tail + "}";
-            return head + tail;
-        }
+        protected String  headToString()         { return null; }
+        protected String  headToJava()           { return null; }
+        protected String  left()                 { return "{"; }
+        protected String  right()                { return "}"; }
+        protected boolean ignoreSingleton()      { return false; }
     }
 
 
     // Ref //////////////////////////////////////////////////////////////////////////////
 
-    private static abstract class IterableForest<T> extends Forest<T> implements Iterable<Forest.Body<T>> {
-        public abstract Iterator<Forest.Body<T>> iterator();
-    }
-
     /**
      *  This class represents a partially complete collection of
      *  forests to be viewed as a forest at some later date; once
      *  viewed, it becomes immutable
      */
-    static class Ref<T> extends IterableForest<T> {
-        private FastSet<Forest> hp = new FastSet<Forest>();
-        private Forest res = null;
+    static class Ref<T> extends Forest<T> {
+        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 ((IterableForest<T>)resolve()).iterator(); }
-        public HashSet<Tree<T>> expand(boolean toss) { return resolve().expand(toss); }
-        public String toString() { return resolve().toString(); }
-        public Forest resolve() {
-            if (hp==null) return res;
-            FastSet<Body> nh      = new FastSet<Body>();
-            for(Forest<?> p : hp)
-                for(Body<?> b : (IterableForest<?>)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 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; }
     }
 
-    // Implementations //////////////////////////////////////////////////////////////////////////////
-
-    private static class MultiForest<T> extends IterableForest<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;
-        }
-        
-        // Display //////////////////////////////////////////////////////////////////////////////
-        
-        private String toString = null;
-        public String toString() {
-            if (toString != null) return toString;
-            StringBuffer ret = new StringBuffer();
-            if (results.size()==1) {
-                for(Forest.Body<T> r : results)
-                    ret.append(r);
-                return toString = ret.toString();
-            }
-            ret.append("<?");
-            boolean first = true;
-            for(Forest.Body<T> r : results) {
-                if (!first) ret.append(' ');
-                first = false;
-                ret.append(r);
+    public abstract <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c);
+    private static abstract class TreeMaker<T> implements Invokable<Forest.Body<T>,Boolean,Integer> {
+        public ArrayList<Tree<T>> toks = new ArrayList<Tree<T>>();
+        private boolean toss;
+        public TreeMaker(boolean toss) { this.toss = toss; }
+        public abstract void add(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);
             }
-            ret.append("?>");
-            return toString = ret.toString();
         }
     }
 
@@ -174,4 +143,10 @@ public abstract class Forest<T> {
 
     private static Tree[] tree_hint = new Tree[0];
     private static final Forest[] emptyForestArray = new Forest[0];
+
+    protected String  headToString()    { return null; }
+    protected String  headToJava()      { return null; }
+    protected String  left()            { return "<?"; }
+    protected String  right()           { return "?>"; }
+    protected boolean ignoreSingleton() { return true; }
 }