content: package java_cup.runtime;
  
  /**
   * Defines the Symbol class, which is used to represent all terminals
   * and nonterminals while parsing.  The lexer should pass CUP Symbols 
   * and CUP returns a Symbol.
   *
   * @version last updated: 7/3/96
   * @author  Frank Flannery
   */
  
  /* ****************************************************************
    Class Symbol
    what the parser expects to receive from the lexer. 
    the token is identified as follows:
    sym:    the symbol type
    parse_state: the parse state.
    value:  is the lexical value of type Object
    left :  is the left position in the original input file
    right:  is the right position in the original input file
    xleft:  is the left position Object in the original input file
    xright:  is the left position Object in the original input file
  ******************************************************************/
  
  public class Symbol {
  
  //  TUM 20060327: Added new Constructor to provide more flexible way
  //   for location handling
  /*******************************
   *******************************/
      public Symbol(int id, Symbol left, Symbol right, Object o){
          this(id,left.left,right.right,o);
      }
      public Symbol(int id, Symbol left, Symbol right){
          this(id,left.left,right.right);
      }
      public Symbol(int id, Symbol left, Object o){
          this(id,left.right,left.right,o);
      }
   /*******************************
    Constructor for l,r values
   *******************************/
  
    public Symbol(int id, int l, int r, Object o) {
      this(id);
      left = l;
      right = r;
      value = o;
    }
  
  /*******************************
    Constructor for no l,r values
  ********************************/
  
    public Symbol(int id, Object o) {
      this(id, -1, -1, o);
    }
  
  /*****************************
    Constructor for no value
    ***************************/
  
    public Symbol(int id, int l, int r) {
      this(id, l, r, null);
    }
  
  /***********************************
    Constructor for no value or l,r
  ***********************************/
  
    public Symbol(int sym_num) {
      this(sym_num, -1);
      left = -1;
      right = -1;
    }
  
  /***********************************
    Constructor to give a start state
  ***********************************/
    Symbol(int sym_num, int state)
      {
        sym = sym_num;
        parse_state = state;
      }
  
  /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
  
    /** The symbol number of the terminal or non terminal being represented */
    public int sym;
  
    /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
  
    /** The parse state to be recorded on the parse stack with this symbol.
     *  This field is for the convenience of the parser and shouldn't be 
     *  modified except by the parser. 
     */
    public int parse_state;
    /** This allows us to catch some errors caused by scanners recycling
     *  symbols.  For the use of the parser only. [CSA, 23-Jul-1999] */
    boolean used_by_parser = false;
  
  /*******************************
    The data passed to parser
   *******************************/
  
    public int left, right;
    public Object value;
  
    /*****************************
      Printing this token out. (Override for pretty-print).
      ****************************/
    public String toString() { return "#"+sym; }
  }
  
  
  
  
  
  
  