parse_reduce_table.java

package java_cup;


/**
 * This class represents the complete "reduce-goto" table of the parser. It has
 * one row for each state in the parse machines, and a column for each terminal
 * symbol. Each entry contains a state number to shift to as the last step of a
 * reduce.
 * 
 * @see java_cup.parse_reduce_row
 * @version last updated: 11/25/95
 * @author Scott Hudson
 */
@SuppressWarnings (
{ "all" } )
public class parse_reduce_table
{

  /*-----------------------------------------------------------*/
  /*--- Constructor(s) ----------------------------------------*/
  /*-----------------------------------------------------------*/
  /**
   * Simple constructor. Note: all terminals, non-terminals, and productions
   * must already have been entered, and the viable prefix recognizer should
   * have been constructed before this is called.
   */
  public parse_reduce_table ()
  {
    /* determine how many states we are working with */
    _num_states = lalr_state.number ();
    /* allocate the array and fill it in with empty rows */
    under_state = new parse_reduce_row [ _num_states ];
    for ( int i = 0 ; i < _num_states ; i++ )
      under_state [ i ] = new parse_reduce_row ();
  }


  /*-----------------------------------------------------------*/
  /*--- (Access to) Instance Variables ------------------------*/
  /*-----------------------------------------------------------*/
  /** How many rows/states in the machine/table. */
  protected int _num_states;


  /** How many rows/states in the machine/table. */
  public int num_states ()
  {
    return _num_states;
  }


  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */
  /** Actual array of rows, one per state */
  public parse_reduce_row [] under_state;


  /*-----------------------------------------------------------*/
  /*--- General Methods ---------------------------------------*/
  /*-----------------------------------------------------------*/
  /** Convert to a string. */
  public String toString ()
  {
    String result;
    lalr_state goto_st;
    int cnt;
    result = "-------- REDUCE_TABLE --------\n";
    for ( int row = 0 ; row < num_states () ; row++ )
    {
      result += "From state #" + row + "\n";
      cnt = 0;
      for ( int col = 0 ; col < parse_reduce_row.size () ; col++ )
      {
        /* pull out the table entry */
        goto_st = under_state [ row ].under_non_term [ col ];
        /* if it has action in it, print it */
        if ( goto_st != null )
        {
          result += " [non term " + col + "->";
          result += "state " + goto_st.index () + "]";
          /* end the line after the 3rd one */
          cnt++ ;
          if ( cnt == 3 )
          {
            result += "\n";
            cnt = 0;
          }
        }
      }
      /* finish the line if we haven't just done that */
      if ( cnt != 0 )
        result += "\n";
    }
    result += "-----------------------------";
    return result;
  }
  /*-----------------------------------------------------------*/
}