+// 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.*;
/** <font color=blue>a tree (or node in a tree); see jargon.txt for details</font> */
-public class Tree<T>
- extends PrintableTree<Tree<T>>
- implements Iterable<Tree<T>> {
-
- private final Input.Region location;
- private final T head;
- private final Tree<T>[] children;
- private final boolean lift;
+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 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 size() {
- return lift
- ? (children.length-1)+lifted().size()
- : 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); }
+ public Tree(Input.Region loc, NodeType head) { this(loc, head, new Tree[0]); }
+ public Tree(Input.Region loc, NodeType head, Tree<NodeType>[] children) { this(loc, head, children, new boolean[children==null?0:children.length]); }
+ // FIXME: fairly inefficient because we keep copying arrays
/** package-private constructor, allows setting the "lift" bit */
- Tree(Input.Region loc, T head, Tree<T>[] children, boolean lift) {
+ 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);
+ }
}