package de.unisiegen.tpml.core.languages ;


/**
 * Thrown if an error occurs while scanning the source code for a given
 * language.
 * 
 * @author Benedikt Meurer
 * @version $Rev$
 * @see de.unisiegen.tpml.core.languages.LanguageScanner
 */
public class LanguageScannerException extends RuntimeException
{
  //
  // Constants
  //
  /**
   * The unique serialization identifier of the class.
   */
  private static final long serialVersionUID = 5806884058872318979L ;


  //
  // Attributes
  //
  /**
   * The left character position of the error.
   * 
   * @see #getLeft()
   */
  private int left ;


  /**
   * The right character position of the error.
   * 
   * @see #getRight()
   */
  private int right ;


  //
  // Constructor
  //
  /**
   * Allocates a new <code>LanguageScannerException</code> with the specified
   * <code>left</code> and <code>right</code> character offsets, and the
   * specified error <code>message</code>.
   * 
   * @param pLeft the left character offset in the input source stream.
   * @param pRight the right character offset in the input source stream.
   * @param message the error message.
   * @see #getLeft()
   * @see #getRight()
   */
  public LanguageScannerException ( int pLeft , int pRight , String message )
  {
    super ( message ) ;
    this.left = pLeft ;
    this.right = pRight ;
  }


  /**
   * Extended variant of the {@link #LanguageScannerException(int, int, String)}
   * constructor, which allows the caller to also specify an exception
   * <code>e</code> that explains the cause of the error.
   * 
   * @param pLeft the left character offset in the input source stream.
   * @param pRight the right character offset in the input source stream.
   * @param message the error message.
   * @param e the cause of the exception.
   */
  public LanguageScannerException ( int pLeft , int pRight , String message ,
      Throwable e )
  {
    super ( message , e ) ;
    this.left = pLeft ;
    this.right = pRight ;
  }


  //
  // Accessors
  //
  /**
   * Returns the left character offset of the error in the source input stream.
   * 
   * @return the left character offset in the source input stream.
   */
  public int getLeft ( )
  {
    return this.left ;
  }


  /**
   * Returns the right character offset of the error in the source input stream.
   * 
   * @return the right character offset in the source input stream.
   */
  public int getRight ( )
  {
    return this.right ;
  }
}