code: //==============================================================================
  //	
  //	Copyright (c) 2002-
  //	Authors:
  //	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford, formerly University of Birmingham)
  //	
  //------------------------------------------------------------------------------
  //	
  //	This file is part of PRISM.
  //	
  //	PRISM is free software; you can redistribute it and/or modify
  //	it under the terms of the GNU General Public License as published by
  //	the Free Software Foundation; either version 2 of the License, or
  //	(at your option) any later version.
  //	
  //	PRISM is distributed in the hope that it will be useful,
  //	but WITHOUT ANY WARRANTY; without even the implied warranty of
  //	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  //	GNU General Public License for more details.
  //	
  //	You should have received a copy of the GNU General Public License
  //	along with PRISM; if not, write to the Free Software Foundation,
  //	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  //	
  //==============================================================================
  
  package parser.ast;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Vector;
  
  import parser.visitor.ASTVisitor;
  import prism.PrismLangException;
  
  // class to store list of labels
  
  public class LabelList extends ASTElement
  {
  	// Name/expression pairs to define labels
  	private List<String> names;
  	private Vector<Expression> labels;
  	// We also store an ExpressionIdent to match each name.
  	// This is to just to provide positional info.
  	private Vector<ExpressionIdent> nameIdents;
  	
  	// Constructor
  	
  	public LabelList()
  	{
  		names = new ArrayList<String>();
  		labels = new Vector<Expression>();
  		nameIdents = new Vector<ExpressionIdent>();
  	}
  	
  	// Set methods
  	
  	public void addLabel(ExpressionIdent n, Expression l)
  	{
  		names.add(n.getName());
  		labels.addElement(l);
  		nameIdents.add(n);
  	}
  	
  	public void setLabelName(int i , ExpressionIdent n)
  	{
  		names.set(i, n.getName());
  		nameIdents.set(i, n);
  	}
  	
  	public void setLabel(int i , Expression l)
  	{
  		labels.set(i, l);
  	}
  	
  	// Get methods
  
  	public int size()
  	{
  		return labels.size();
  	}
  
  	public String getLabelName(int i)
  	{
  		return names.get(i);
  	}
  	
  	public List<String> getLabelNames()
  	{
  		return names;
  	}
  	
  	public Expression getLabel(int i)
  	{
  		return labels.elementAt(i);
  	}
  	
  	public ExpressionIdent getLabelNameIdent(int i)
  	{
  		return nameIdents.elementAt(i);
  	}
  
  	/**
  	 * Get the index of a label by its name (returns -1 if it does not exist).
  	 */
  	public int getLabelIndex(String s)
  	{
  		return names.indexOf(s);
  	}
  
  	// Methods required for ASTElement:
  	
  	/**
  	 * Visitor method.
  	 */
  	public Object accept(ASTVisitor v) throws PrismLangException
  	{
  		return v.visit(this);
  	}
  	
  	/**
  	 * Convert to string.
  	 */
  	public String toString()
  	{
  		String s = "";
  		int i, n;
  		
  		n = size();
  		for (i = 0; i < n; i++) {
  			s += "label \"" + getLabelName(i);
  			s += "\" = " + getLabel(i) + ";\n";
  		}
  		
  		return s;
  	}
  	
  	/**
  	 * Perform a deep copy.
  	 */
  	public ASTElement deepCopy()
  	{
  		int i, n;
  		LabelList ret = new LabelList();
  		n = size();
  		for (i = 0; i < n; i++) {
  			ret.addLabel((ExpressionIdent)getLabelNameIdent(i).deepCopy(), getLabel(i).deepCopy());
  		}
  		ret.setPosition(this);
  		return ret;
  	}
  }
  
  //------------------------------------------------------------------------------
  