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
extends PrintableTree>
implements Iterable>,
GraphViz.ToGraphViz {
private final Input.Region location;
private final T head;
private final Tree[] children;
private final boolean lift;
/** the element at the head of the tree */
public T head() { return head; }
private Tree lifted() { return children[children.length-1]; }
/** the number of children the tree has */
public int numChildren() {
return lift
? (children.length-1)+lifted().numChildren()
: children.length;
}
/** the tree's children */
public Iterable> children() { return this; }
/** the tree's children */
public Iterator> iterator() {
return lift
? new ConcatenateIterator(new ArrayIterator(children, 0, children.length-1),
children[children.length-1].iterator())
: new ArrayIterator(children);
}
/** get the ith child */
public Tree child(int i) {
return lift && i >= children.length-1
? children[children.length-1].child(i-(children.length-1))
: 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[] children) { this(loc, head, children, false); }
/** package-private constructor, allows setting the "lift" bit */
Tree(Input.Region loc, T head, Tree[] children, boolean lift) {
this.location = loc;
this.head = head;
this.lift = lift && children != null && children.length > 0;
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; }
// 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();
for(Tree t : this) n.edge(t, null);
return n;
}
public boolean isTransparent() { return false; }
public boolean isHidden() { return false; }
}