+// (C) 2006-2007 all rights reserved; see LICENSE file for BSD-style license
+
package edu.berkeley.sbp;
-import edu.berkeley.sbp.util.*;
-import edu.berkeley.sbp.*;
-import edu.berkeley.sbp.*;
-import java.io.*;
import java.util.*;
-import java.lang.reflect.*;
-import java.lang.ref.*;
-/** <font color=green>the root superclass for all components of the grammar (terminals, nonterminals, literals, etc)</font> */
-public abstract class Element {
+/**
+ * <font color=green>
+ * the root superclass for all components of the grammar (terminals,
+ * nonterminals, literals, etc)
+ * </font>
+ */
+public abstract class Element implements SequenceOrElement {
/** sorry, you can't make up new, custom elements */
Element() { }
+ /** a more verbose version of toString() for displaying whole grammars */
abstract StringBuffer toString(StringBuffer sb);
- /** returns the Forest resulting from matching this element against the empty string */
- Forest epsilonForm() { throw new Error("element " + this + " has no epsilon form"); }
-
}