1 // Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
3 package edu.berkeley.sbp;
4 import edu.berkeley.sbp.*;
5 import edu.berkeley.sbp.util.*;
8 import java.lang.reflect.*;
10 /** <font color=blue>a tree (or node in a tree); see jargon.txt for details</font> */
11 public class Tree<NodeType>
12 extends PrintableTree<Tree<NodeType>>
13 implements Iterable<Tree<NodeType>> {
15 private final Input.Region location;
16 private final NodeType ihead;
17 private final Tree<NodeType>[] children;
19 /** the number of children the tree has */
20 public int size() { return children.length; }
22 /** the element at the head of the tree */
23 public NodeType head() { return ihead; }
24 public NodeType getHead() { return ihead; }
26 /** the tree's children */
27 public Iterable<Tree<NodeType>> children() { return this; }
29 /** the tree's children */
30 public Iterator<Tree<NodeType>> iterator() { return new ArrayIterator(children); }
32 /** get the <tt>i</t>th child */
33 public Tree<NodeType> child(int i) { return children[i]; }
35 /** get the input region that this tree was parsed from */
36 public Input.Region getRegion() { return location; }
38 public Tree(Input.Region loc, NodeType head) { this(loc, head, null); }
39 public Tree(Input.Region loc, NodeType head, Tree<NodeType>[] children) { this(loc, head, children, false); }
41 // FIXME: fairly inefficient because we keep copying arrays
42 /** package-private constructor, allows setting the "lift" bit */
43 Tree(Input.Region loc, NodeType head, Tree<NodeType>[] children, boolean lift) {
46 if (lift && children != null && children.length > 0) {
47 Tree<NodeType> last = children[children.length-1];
48 this.children = new Tree[(children.length-1)+last.children.length];
49 System.arraycopy(children, 0, this.children, 0, children.length-1);
50 if (last.children.length > 0)
51 System.arraycopy(last.children, 0, this.children, children.length-1, last.children.length);
53 this.children = ArrayUtil.clone(children, Tree.class);
58 // PrintableTree /////////////////////////////////////////////////////////////////////////////
60 protected String headToString() { return head()==null?null:head().toString(); }
61 protected String headToJava() {
63 if (head()==null) return null;
64 if (head() instanceof ToJava) {
65 StringBuffer sb = new StringBuffer();
66 ((ToJava)head()).toJava(sb);
69 return (head()==null?"null":("\""+StringUtil.toJavaString(head().toString())+"\""));
71 protected String left() { return "{"; }
72 protected String right() { return "}"; }
73 protected boolean ignoreSingleton() { return false; }