X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FElement.java;h=27a3ee64edc3220951fd1bb88e3833bd9d46fefe;hp=16ae2f04e1a874dac968f0c2b65e375cab537387;hb=dc9bb3a45ed306e2e35549076842b3e74efecb48;hpb=111166986ad83b54d0cae5c03c2304d23e332f29 diff --git a/src/edu/berkeley/sbp/Element.java b/src/edu/berkeley/sbp/Element.java index 16ae2f0..27a3ee6 100644 --- a/src/edu/berkeley/sbp/Element.java +++ b/src/edu/berkeley/sbp/Element.java @@ -1,21 +1,20 @@ +// (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.*; -/** the root superclass for all components of the grammar (terminals, nonterminals, literals, etc) */ +/** + * + * the root superclass for all components of the grammar (terminals, + * nonterminals, literals, etc) + * + */ 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"); } - }