// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
package edu.berkeley.sbp;
import edu.berkeley.sbp.*;
import edu.berkeley.sbp.util.*;
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
extends PrintableTree>
implements Iterable> {
private final Input.Region location;
private final NodeType ihead;
private final Tree[] children;
/** the number of children the tree has */
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> children() { return this; }
/** the tree's children */
public Iterator> iterator() { return new ArrayIterator(children); }
/** get the ith child */
public Tree 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, NodeType head) { this(loc, head, null); }
public Tree(Input.Region loc, NodeType head, Tree[] children) { this(loc, head, children, false); }
// FIXME: fairly inefficient because we keep copying arrays
/** package-private constructor, allows setting the "lift" bit */
Tree(Input.Region loc, NodeType head, Tree[] children, boolean lift) {
this(loc, head, children, lift, false);
}
Tree(Input.Region loc, NodeType head, Tree[] children, boolean lift, boolean liftLeft) {
this.location = loc;
this.ihead = head;
// FIXME: lift+liftLeft togheter
if (liftLeft && children != null && children.length > 0) {
Tree last = children[0];
this.children = new Tree[(children.length-1)+last.children.length];
System.arraycopy(children, 1, this.children, last.children.length, children.length-1);
if (last.children.length > 0)
System.arraycopy(last.children, 0, this.children, 0, last.children.length);
} else if (lift && children != null && children.length > 0) {
Tree last = children[children.length-1];
this.children = new Tree[(children.length-1)+last.children.length];
System.arraycopy(children, 0, this.children, 0, children.length-1);
if (last.children.length > 0)
System.arraycopy(last.children, 0, this.children, children.length-1, last.children.length);
} else {
this.children = ArrayUtil.clone(children, Tree.class);
}
}
// PrintableTree /////////////////////////////////////////////////////////////////////////////
protected String headToString() { return head()==null?null:head().toString(); }
protected String headToJava() {
// FIXME
if (head()==null) return null;
if (head() instanceof ToJava) {
StringBuffer sb = new StringBuffer();
((ToJava)head()).toJava(sb);
return sb.toString();
}
return (head()==null?"null":("\""+StringUtil.toJavaString(head().toString())+"\""));
}
protected String left() { return "{"; }
protected String right() { return "}"; }
protected boolean ignoreSingleton() { return false; }
}