use Appendable rather than StringBuffer for toJava()

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

diff --git a/src/edu/berkeley/sbp/Tree.java b/src/edu/berkeley/sbp/Tree.java
index d2bfc4b..cce7bfe 100644 (file)
--- a/src/edu/berkeley/sbp/Tree.java
+++ b/src/edu/berkeley/sbp/Tree.java
@@ -1,62 +1,82 @@
+// Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
+
 package 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.*;
 
-/** a tree (or node in a tree); see jargon.txt for details */
-public class Tree<T>
-    extends PrintableTree<Tree<T>>
-    implements Iterable<Tree<T>>,
-               GraphViz.ToGraphViz {
-
-    private final Input.Region location;
-    private final T            head;
-    private final Tree<T>[]    children;
-    private final boolean      lift;
+/** <font color=blue>a tree (or node in a tree); see jargon.txt for details</font> */
+public class Tree<NodeType>
+    extends PrintableTree<Tree<NodeType>>
+    implements Iterable<Tree<NodeType>> {
 
-    /** the element at the head of the tree */
-    public T                 head()        { return head; }
+    private static final Tree[] emptyTree = new Tree[0];
 
-    private Tree<T> lifted() { return children[children.length-1]; }
+    private final Input.Region     location;
+    private final NodeType         ihead;
+    private final Tree<NodeType>[] children;
 
     /** the number of children the tree has */
-    public int               numChildren() {
-        return lift
-            ? (children.length-1)+lifted().numChildren()
-            : children.length;
-    }
+    public int               size() { return children.length; }
+
+    /** the element at the head of the tree */
+    public NodeType                 head()        { return ihead; }
+    public NodeType              getHead()        { return ihead; }
 
     /** the tree's children */
-    public Iterable<Tree<T>> children()    { return this; }
+    public Iterable<Tree<NodeType>> children()    { return this; }
 
     /** the tree's children */
-    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 Iterator<Tree<NodeType>> iterator()    { return new ArrayIterator(children); }
 
     /** get the <tt>i</t>th child */
-    public Tree<T> child(int i)  {
-        return lift && i >= children.length-1
-            ? children[children.length-1].child(i-(children.length-1))
-            : children[i];
-    }
+    public Tree<NodeType> child(int i)            { return children[i]; }
 
     /** get the input region that this tree was parsed from */
     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) { this(loc, head, children, false); }
-    Tree(Input.Region loc, T head, Tree<T>[] children, boolean lift) {
+    public Tree(Input.Region loc, NodeType head) {
+        location = loc;
+        ihead = head;
+        children = emptyTree;
+    }
+    public Tree(Input.Region loc, NodeType head, List<Tree<NodeType>> kids){
+        location = loc;
+        ihead = head;
+        if (kids.size() == 0)
+            children = emptyTree;
+        else {
+            children = new Tree[kids.size()];
+            kids.toArray(children);
+        }
+    }
+    public Tree(Input.Region loc, NodeType head, Tree<NodeType>[] kids) {
+        location = loc;
+        ihead = head;
+        children = (kids == null ? emptyTree : kids.clone());
+    }
+
+    // FIXME: fairly inefficient because we keep copying arrays
+    /** package-private constructor, allows setting the "lift" bit */
+    Tree(Input.Region loc, NodeType head, Tree<NodeType>[] children, boolean[] lifts) {
         this.location = loc;
-        this.head = head;
-        this.lift = lift && children != null && children.length > 0;
-        this.children = ArrayUtil.clone(children, Tree.class);
+        this.ihead = head;
+
+        int count = 0;
+        for(int i=0; i<children.length; i++)
+            count += lifts[i] ? children[i].size() : 1;
+
+        this.children = new Tree[count];
+        int j = 0;
+        for(int i=0; i<children.length; i++) {
+            if (!lifts[i])
+                this.children[j++] = children[i];
+            else
+                for(int k=0; k<children[i].size(); k++)
+                    this.children[j++] = children[i].child(k);
+        }
     }
 
 
@@ -68,7 +88,9 @@ public class Tree<T>
         if (head()==null) return null;
         if (head() instanceof ToJava) {
             StringBuffer sb = new StringBuffer();
-            ((ToJava)head()).toJava(sb);
+            try {
+                ((ToJava)head()).toJava(sb);
+            } catch (IOException e) { throw new RuntimeException(e); }
             return sb.toString();
         }
         return (head()==null?"null":("\""+StringUtil.toJavaString(head().toString())+"\""));
@@ -78,22 +100,4 @@ public class Tree<T>
     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);
-        n.label = head()==null ? "" : head().toString();
-        //n.color = "red";
-        for(Tree t : this) n.edge(t, null);
-        return n;
-    }
-    public boolean isTransparent() { return false; }
-    public boolean isHidden() { return false; }
-
-
-    // TreeFunctor /////////////////////////////////////////////////////////////////////////////
-
-    public static interface TreeFunctor<T,R> extends Functor<Iterable<Tree<T>>, R> { }
-    
 }