checkpoint

[sbp.git] / src / edu / berkeley / sbp / Forest.java

diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index 786ffad..a8c44f0 100644 (file)
--- a/src/edu/berkeley/sbp/Forest.java
+++ b/src/edu/berkeley/sbp/Forest.java
@@ -18,12 +18,19 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ impl
 
     /** expand this forest into a set of trees */
     public HashSet<Tree<T>> expand(boolean toss) {
-        TreeMaker<T> ret = new TreeMaker<T>();
-        visit(ret, new Boolean(toss), null);
+        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); }
@@ -34,17 +41,14 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ impl
     // Body //////////////////////////////////////////////////////////////////////////////
 
     protected static interface Body<T> {
-        TreeMaker<T> expand(boolean toss, int i, TreeMaker<T> h);
+        void 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>>*/ {
+    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);
         }
-        public <B,C> void invoke(Tree<T> ivbc, B b, C c) {
-            //ivbc.invoke(this, b, c);
-        }
 
         private final Input.Location    location;
         private final T                 tag;
@@ -62,30 +66,32 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ impl
             this.singleton = singleton;
         }
 
-        public TreeMaker<T> expand(boolean toss, int i, TreeMaker<T> h) {
+        public void expand(final int i, final TreeMaker<T> h) {
             if (singleton) {
-                tokens[0].visit(h, toss, i);
+                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, h.toks.toArray(tree_hint)));
+            if (i==tokens.length) {
+                h.finish(tag, location);
 
             } else if (unwrap && i==tokens.length-1) {
                 if (tokens[i] != null)
-                    tokens[i].visit(h, toss, 0);
+                    tokens[i].visit(h, null, 0);
 
             } else {
-                boolean hit = false;
-                //tokens[i].visit(this, 
-                for(Tree<T> r : tokens[i].expand(toss)) {
-                    hit = true;
-                    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();
+                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;
         }
 
         protected String  headToString()         { return null; }
@@ -109,22 +115,36 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ impl
         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);
+            for(Forest<T> f : hp)
+                f.visit(ivbc, b, c);
         }
         public Forest resolve() { return this; }
     }
 
     public abstract <B,C> void visit(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> {
+    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>>();
-        public void invoke(Forest.Body<T> bod, Boolean toss, Integer i) {
+        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(toss, 0, this);
+                bod.expand(0, this);
                 this.toks = toks;
             } else {
-                bod.expand(toss, i, this);
+                bod.expand(i, this);
             }
         }
     }