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 prism;
  
  import parser.ast.ASTElement;
  
  public class PrismLangException extends PrismException
  {
  	public static final int MAX_ERR_STR = 20;
  	
  	protected ASTElement e = null;
  	
  	public PrismLangException(String s)
  	{
  		super(s);
  	}
  	
  	public PrismLangException(String s, ASTElement e)
  	{
  		super(s);
  		this.e =e ;
  	}
  	
  	public void setASTElement(ASTElement e)
  	{
  		this.e =e ;
  	}
  	
  	public boolean hasASTElement()
  	{
  		return e != null ;
  	}
  	
  	public ASTElement getASTElement()
  	{
  		return e ;
  	}
  	
  	public String getMessage()
  	{
  		String msg = super.getMessage();
  		if (e == null) return msg;
  		String s = null;
  		try {
  			s = e.toString();
  		} catch (Exception ex) {
  			// in case there is a problem converting the AST element to a string
  			// we ignore it
  		}
  		if (s != null && s.length() < MAX_ERR_STR) {
  			if (e.hasPosition()) msg += " (\"" + s + "\", " + e.getBeginString() +")";
  			else msg += " (\"" + s + "\")";
  		}
  		else {
  			if (e.hasPosition()) msg += " (" + e.getBeginString() +")";
  		}
  		return msg;
  	}
  	
  	public String toString()
  	{
  		return "Error: " + getMessage() + ".";
  	}
  	
  	public boolean hasLineNumbers()
  	{
  		if (hasASTElement())
  		{
  			if (e.getBeginColumn() != -1
  			 && e.getBeginLine() != -1
  			 && e.getEndLine() != -1
  			 && e.getEndColumn() != -1)
  			return true;
  		}
  		
  		return false;
  	}
  	
  	public int getBeginColumn()
  	{
  		if (hasLineNumbers())
  			return e.getBeginColumn();
  		else
  			return -1;
  	}
  	
  	public int getEndColumn()
  	{
  		if (hasLineNumbers())
  			return e.getEndColumn();
  		else
  			return -1;
  	}
  	
  	public int getBeginLine()
  	{
  		if (hasLineNumbers())
  			return e.getBeginLine();
  		else
  			return -1;
  	}
  	
  	public int getEndLine()
  	{
  		if (hasLineNumbers())
  			return e.getEndLine();
  		else
  			return -1;
  	}
  }
  
  //------------------------------------------------------------------------------
  