cleanups, reorg, and commenting

[sbp.git] / src / edu / berkeley / sbp / Element.java

diff --git a/src/edu/berkeley/sbp/Element.java b/src/edu/berkeley/sbp/Element.java
index 33bfd8d..27a3ee6 100644 (file)
--- a/src/edu/berkeley/sbp/Element.java
+++ b/src/edu/berkeley/sbp/Element.java
@@ -1,18 +1,20 @@
+// (C) 2006-2007 all rights reserved; see LICENSE file for BSD-style license
+

 package edu.berkeley.sbp;
 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.util.*;

-import java.lang.reflect.*;
-import java.lang.ref.*;

 
 

-/** the root superclass for all components of the grammar (terminals, nonterminals, literals, etc) */
-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 {

 
 

-    abstract StringBuffer toString(StringBuffer sb);
+    /** sorry, you can't make up new, custom elements */
+    Element() { }

 
 

-    /** if this element always matches exactly one token, return a topology covering exactly those possible tokens, otherwise <tt>null</tt> */
-    Forest epsilonForm() { return null; }
+    /** a more verbose version of toString() for displaying whole grammars */
+    abstract StringBuffer toString(StringBuffer sb);

 
 }
 
 }