package java_cup;

import java.util.Hashtable;
  
/**
 * This class represents a terminal symbol in the grammar. Each terminal has a
 * textual name, an index, and a string which indicates the type of object it
 * will be implemented with at runtime (i.e. the class of object that will be
 * returned by the scanner and pushed on the parse stack to represent it).
 *
 * @version last updated: 7/3/96
 * @author Frank Flannery
 */
public class terminal extends symbol {

  /*-----------------------------------------------------------*/
  /*--- Constructor(s) ----------------------------------------*/
  /*-----------------------------------------------------------*/

  /**
   * Full constructor.
   * 
   * @param nm the name of the terminal.
   * @param tp the type of the terminal.
   */
  public terminal(String nm, String tp, int precedence_side, int precedence_num) {
    /* superclass does most of the work */
    super(nm, tp);

    /* add to set of all terminals and check for duplicates */
    Object conflict = _all.put(nm, this);
    if (conflict != null)
      // can't throw an execption here because this is used in static
      // initializers, so we do a crash instead
      // was:
      // throw new internal_error("Duplicate terminal (" + nm + ") created");
      (new internal_error("Duplicate terminal (" + nm + ") created")).crash();

    /* assign a unique index */
    _index = next_index++;

    /* set the precedence */
    _precedence_num = precedence_num;
    _precedence_side = precedence_side;

    /* add to by_index set */
    _all_by_index.put(Integer.valueOf(_index), this);
  }

  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */

  /**
   * Constructor for non-precedented terminal
   */

  public terminal(String nm, String tp) {
    this(nm, tp, assoc.no_prec, -1);
  }

  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */

  /**
   * Constructor with default type.
   * 
   * @param nm the name of the terminal.
   */
  public terminal(String nm) {
    this(nm, null);
  }

  /*-----------------------------------------------------------*/
  /*-------------------  Class Variables  ---------------------*/
  /*-----------------------------------------------------------*/

  private int _precedence_num;
  private int _precedence_side;

  /*-----------------------------------------------------------*/
  /*--- (Access to) Static (Class) Variables ------------------*/
  /*-----------------------------------------------------------*/

  /**
   * Table of all terminals. Elements are stored using name strings as the key
   */
  protected static Hashtable<String,terminal> _all = new Hashtable<>();

  // Hm Added clear to clear all static fields
  public static void clear() {
    _all.clear();
    _all_by_index.clear();
    next_index = 0;
    EOF = new terminal("EOF");
    error = new terminal("error");
  }

  /** Access to all terminals. */
  public static Iterable<terminal> all() {
    return _all.values();
  }

  /** Lookup a terminal by name string. */
  public static terminal find(String with_name) {
    if (with_name == null)
      return null;
    else
      return _all.get(with_name);
  }

  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */

  /** Table of all terminals indexed by their index number. */
  protected static Hashtable<Integer,terminal> _all_by_index = new Hashtable<>();

  /** Lookup a terminal by index. */
  public static terminal find(int indx) {
    Integer the_indx = Integer.valueOf(indx);

    return _all_by_index.get(the_indx);
  }

  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */

  /** Total number of terminals. */
  public static int number() {
    return _all.size();
  }

  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */

  /** Static counter to assign unique index. */
  protected static int next_index = 0;

  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */

  /** Special terminal for end of input. */
  public static terminal EOF = new terminal("EOF");

  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */

  /** special terminal used for error recovery */
  public static terminal error = new terminal("error");

  /*-----------------------------------------------------------*/
  /*--- General Methods ---------------------------------------*/
  /*-----------------------------------------------------------*/

  /** Report this symbol as not being a non-terminal. */
  @Override
  public boolean is_non_term() {
    return false;
  }

  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */

  /** Convert to a string. */
  @Override
  public String toString() {
    return super.toString() + "[" + index() + "]";
  }

  /* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . */

  /** get the precedence of a terminal */
  public int precedence_num() {
    return _precedence_num;
  }

  public int precedence_side() {
    return _precedence_side;
  }

  /** set the precedence of a terminal */
  public void set_precedence(int p, int new_prec) {
    _precedence_side = p;
    _precedence_num = new_prec;
  }

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

}
