
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
 */
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. */
  @Override
  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;
  }

  /*-----------------------------------------------------------*/

}
