001/*
002 *                    BioJava development code
003 *
004 * This code may be freely distributed and modified under the
005 * terms of the GNU Lesser General Public Licence.  This should
006 * be distributed with the code.  If you do not have a copy,
007 * see:
008 *
009 *      http://www.gnu.org/copyleft/lesser.html
010 *
011 * Copyright for this code is held jointly by the individual
012 * authors.  These should be listed in @author doc comments.
013 *
014 * For more information on the BioJava project and its aims,
015 * or to join the biojava-l mailing list, visit the home page
016 * at:
017 *
018 *      http://www.biojava.org/
019 *
020 */
021package org.biojava.utils.bytecode;
022
023/**
024 * A Label used to mark a position in byte code.
025 *
026 * <p>
027 * Labels are used as the targets for jumps, and for exception handlers. Labels
028 * can be named. They implement CodeGenerator, which allows them to be added
029 * to things like an InstructionVector. The writeCode method takes care of
030 * marking the label with the context.
031 * </p>
032 *
033 * @author Thomas Down
034 * @author Matthew Pocock
035 */
036public class Label implements CodeGenerator {
037  public String name;
038  
039  public Label() {
040    name = null;
041  }
042  
043  public Label(String name) {
044    this.name = name;
045  }
046  
047  public String toString() {
048    if (name != null)
049      return name;
050    return super.toString();
051  }
052  
053  public void writeCode(CodeContext ctx) throws CodeException {
054    ctx.markLabel(this);
055  }
056  
057  public int stackDepth() {
058    return 0;
059  }
060  
061  public int stackDelta() {
062    return 0;
063  }
064}