java_cup.symbol_part Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of javacup Show documentation
A fork of the Java Cup parser generator with some bug fixes and enhancements. (Forked at version 11b)
The newest version!
package java_cup;

/**
 * This class represents a part of a production which is a symbol (terminal
 * or non terminal).  This simply maintains a reference to the symbol in
 * question.
 *
 * @author Scott Hudson
 * @version last updated: 11/25/95
 * @see java_cup.production
 */
public class symbol_part extends production_part {

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

    /**
     * Full constructor.
     *
     * @param sym the symbol that this part is made up of.
     * @param lab an optional label string for the part.
     */
    public symbol_part(symbol sym, String lab) throws internal_error {
        super(lab);

        if (sym == null)
            throw new internal_error(
                    "Attempt to construct a symbol_part with a null symbol");
        _the_symbol = sym;
    }

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

    /**
     * Constructor with no label.
     *
     * @param sym the symbol that this part is made up of.
     */
    public symbol_part(symbol sym) throws internal_error {
        this(sym, null);
    }

  /*-----------------------------------------------------------*/
  /*--- (Access to) Instance Variables ------------------------*/
  /*-----------------------------------------------------------*/

    /**
     * The symbol that this part is made up of.
     */
    protected symbol _the_symbol;

    /**
     * The symbol that this part is made up of.
     */
    public symbol the_symbol() {
        return _the_symbol;
    }

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

    /**
     * Respond that we are not an action part.
     */
    public boolean is_action() {
        return false;
    }

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

    /**
     * Equality comparison.
     */
    public boolean equals(symbol_part other) {
        return other != null && super.equals(other) &&
                the_symbol().equals(other.the_symbol());
    }

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

    /**
     * Generic equality comparison.
     */
    public boolean equals(Object other) {
        if (!(other instanceof symbol_part))
            return false;
        else
            return equals((symbol_part) other);
    }

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

    /**
     * Produce a hash code.
     */
    public int hashCode() {
        return super.hashCode() ^
                (the_symbol() == null ? 0 : the_symbol().hashCode());
    }

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

    /**
     * Convert to a string.
     */
    public String toString() {
        if (the_symbol() != null)
            return super.toString() + the_symbol();
        else
            return super.toString() + "$$MISSING-SYMBOL$$";
    }

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

}