X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FTree.java;h=1b9ddfa668f8bcee675892b4c216cc7408456fac;hp=086a9bb36a8bdbd14cdb12aa969538231b525c1b;hb=c8d1c3a25e2bfa9645c4b91d3dde9c4857f636f2;hpb=2bee2b032b0422d212e17082cc4dcbf28cb897ac

diff --git a/src/edu/berkeley/sbp/Tree.java b/src/edu/berkeley/sbp/Tree.java
index 086a9bb..1b9ddfa 100644
--- a/src/edu/berkeley/sbp/Tree.java
+++ b/src/edu/berkeley/sbp/Tree.java
@@ -1,7 +1,7 @@
 package edu.berkeley.sbp;
 import edu.berkeley.sbp.*;
-import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.util.*;
+import edu.berkeley.sbp.bind.*;
 import java.io.*;
 import java.util.*;
 import java.lang.reflect.*;
@@ -12,43 +12,66 @@ public class Tree<T>
     implements Iterable<Tree<T>>,
                GraphViz.ToGraphViz {
 
-    final T           head;
-          Tree<T>[]   children;
-    final Input.Region    location;
+    private final Input.Region location;
+    private final T            head;
+    private final Tree<T>[]    children;
+    private final boolean      lift;
 
     public T                 head()        { return head; }
-    public int               numChildren() { return children.length; }
-    public Iterable<Tree<T>> children()    { return new ArrayIterator(children); }
-    public Iterator<Tree<T>> iterator()    { return new ArrayIterator(children); }
-    public Tree<T>           child(int i)  { return children[i]; }
+
+    private Tree<T> lifted() { return children[children.length-1]; }
+
+    public int               numChildren() {
+        return lift
+            ? (children.length-1)+lifted().numChildren()
+            : children.length;
+    }
+    public Iterable<Tree<T>> children()    { return this; }
+    public Iterator<Tree<T>> iterator()    {
+        return lift
+            ? new ConcatenateIterator(new ArrayIterator(children, 0, children.length-1),
+                                      children[children.length-1].iterator())
+            : new ArrayIterator(children);
+    }
+
+    public Tree<T> child(int i)  {
+        return lift && i >= children.length-1
+            ? children[children.length-1].child(i-(children.length-1))
+            : children[i];
+    }
 
     public Input.Region    getRegion() { return location; }
 
-    public Tree(Input.Region loc, T head)                   { this(loc, head, null); }
-    public Tree(Input.Region loc, T head, Tree<T>[] children) {
+    public Tree(Input.Region loc, T head)                     { this(loc, head, null); }
+    public Tree(Input.Region loc, T head, Tree<T>[] children) { this(loc, head, children, false); }
+    public Tree(Input.Region loc, T head, Tree<T>[] children, boolean lift) {
         this.location = loc;
         this.head = head;
-
-        Tree<T>[] children2 = children==null ? new Tree[0] : new Tree[children.length];
-        if (children != null) System.arraycopy(children, 0, children2, 0, children.length);
-        this.children = children2;
+        this.lift = lift && children != null && children.length > 0;
+        this.children = ArrayUtil.clone(children, Tree.class);
     }
 
-    protected String headToString() { return head==null?null:head.toString(); }
+
+    // PrintableTree /////////////////////////////////////////////////////////////////////////////
+
+    protected String headToString() { return head()==null?null:head().toString(); }
     protected String headToJava()   {
       // FIXME
-        if (head==null) return null;
-        if (head instanceof ToJava) {
+        if (head()==null) return null;
+        if (head() instanceof ToJava) {
             StringBuffer sb = new StringBuffer();
-            ((ToJava)head).toJava(sb);
+            ((ToJava)head()).toJava(sb);
             return sb.toString();
         }
-        return (head==null?"null":("\""+StringUtil.toJavaString(head.toString())+"\""));
+        return (head()==null?"null":("\""+StringUtil.toJavaString(head().toString())+"\""));
     }
     protected String left()   { return "{"; }
     protected String right()  { return "}"; }
     protected boolean ignoreSingleton() { return false; }
 
+
+    // ToGraphViz /////////////////////////////////////////////////////////////////////////////
+
     public GraphViz.Node toGraphViz(GraphViz gv) {
         if (gv.hasNode(this)) return gv.createNode(this);
         GraphViz.Node n = gv.createNode(this);
@@ -60,28 +83,9 @@ public class Tree<T>
     public boolean isTransparent() { return false; }
     public boolean isHidden() { return false; }
 
-    public static interface TreeFunctor<T,R> extends Functor<Iterable<Tree<T>>, R> {
-    }
 
-    public static class ArrayBuildingTreeFunctor<T> implements TreeFunctor<T,T[]>, ToJava {
-
-        public void toJava(StringBuffer sb) { sb.append("new Tree.ArrayBuildingTreeFunctor()"); }
-        public String toString() { return ""; }
-        
-        public T[] invoke(Iterable<Tree<T>> t) {
-            ArrayList ret = new ArrayList();
-            for(Tree tc : t) {
-                if (tc.head() != null && tc.head() instanceof Functor)
-                    ret.add(((Functor<Iterable<Tree>,Object>)tc.head()).invoke(tc.children()));
-                else if (tc.numChildren() == 0)
-                    ret.add(tc.head());
-                else {
-                    System.err.println("FIXME: don't know what to do about " + tc);
-                    ret.add(null);
-                }
-            }
-            return (T[])ret.toArray(new Object[0]);
-        }
-    }
+    // TreeFunctor /////////////////////////////////////////////////////////////////////////////
 
+    public static interface TreeFunctor<T,R> extends Functor<Iterable<Tree<T>>, R> { }
+    
 }