import java.lang.reflect.*;
/** a tree (or node in a tree); see jargon.txt for details */
-public class Tree<T> {
+public class Tree<T> extends PrintableTree<Tree<T>> implements Iterable<Tree<T>> {
final T head;
Tree<T>[] children;
- final Token.Location location;
+ final Input.Location location;
- public T head() { return head; }
+ public T head() { return head; }
public int numChildren() { return children.length; }
- public Iterable<Tree<T>> children() { return new ArrayIterator(children); }
- public Tree<T> child(int i) { return children[i]; }
+ public Iterable<Tree<T>> children() { return new ArrayIterator(children); }
+ public Iterator<Tree<T>> iterator() { return new ArrayIterator(children); }
+ public Tree<T> child(int i) { return children[i]; }
- public Token.Location getLocation() { return location; }
+ public Input.Location getLocation() { return location; }
- public Tree(Token.Location loc, T head) { this(loc, head, null); }
- public Tree(Token.Location loc, T head, Tree<T>[] children) {
+ public Tree(Input.Location loc, T head) { this(loc, head, null); }
+ public Tree(Input.Location loc, T head, Tree<T>[] children) {
this.location = loc;
this.head = head;
Tree<T>[] children2 = children==null ? new Tree[0] : new Tree[children.length];
this.children = children2;
}
- /** append Java code to <tt>sb</tt> which evaluates to this instance */
- public void toJava(StringBuffer sb) {
- sb.append("new Tree(null, ");
- sb.append(head==null ? "null" : "\"" + StringUtil.toJavaString(head+"") + "\"");
- sb.append(", new Tree[] { ");
- for(int i=0; i<children.length; i++) {
- if (children[i]==null) sb.append("null");
- else children[i].toJava(sb);
- if (i<children.length-1) sb.append(",\n ");
- }
- sb.append("})");
- }
-
+ /** since Tree instances are immutable, we can cache this to make pretty-printing MUCH faster */
public String toString() {
- StringBuffer ret = new StringBuffer();
- for(int i=0; i<children.length; i++) {
- String q = children[i]==null ? "null" : children[i].toString();
- if (q.length() > 0) { ret.append(q); ret.append(" "); }
- }
- String tail = ret.toString().trim();
- String h = (head!=null && !head.toString().equals("")) ? (tail.length() > 0 ? head+":" : head+"") : "";
- if (tail.length() > 0) tail = "{" + tail + "}";
- return h + tail;
+ if (toString!=null) return toString;
+ return toString = super.toString();
}
+ private String toString = null;
-
+ protected String headToString() { return head==null?null:head.toString(); }
+ protected String headToJava() { return head==null?null:StringUtil.toJavaString(head+""); }
+ protected String left() { return "{"; }
+ protected String right() { return "}"; }
+ protected boolean ignoreSingleton() { return false; }
}