AgentId.java

/**
  * This program (working title: MAS Prover) is an automated tableaux prover
  * for epistemic logic (S5n).
  * Copyright (C) 2007  Elske van der Vaart and Gert van Valkenhoef

  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published
  * by the Free Software Foundation.

  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.

  * You should have received a copy of the GNU General Public License along
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */

package nl.rug.ai.mas.oops.formula;

/**
 * Class representing a concrete Agent
 */
public class AgentId implements Agent {
	private String d_name;
	private int d_code;
	
	/**
	 * Constructor.
	 * @param name The name for this Agent.
	 */
	public AgentId(String name, int code) {
		d_name = name;
		d_code = 2 * code;
	}

	public String toString() {
		return d_name;
	}

	/**
	 * A concrete Agent is equal only to itself.
	 */
	public boolean equals(Object other) {
		return this == other;
	}

	/**
	 * A concrete Agent matches only itself. In that case it returns the empty
	 * Substitution.
	 */
	public Substitution<Agent> match(Agent other) {
		if (equals(other)) {
			return new Substitution<Agent>();
		}
		return null;
	}

	/**
	 * Substituting yields this Agent itself.
	 */
	public Agent substitute(Substitution<Agent> s) {
		return this;
	}

	public boolean isConcrete() {
		return true;
	}

	public int code() {
		return d_code;
	}

	public int hashCode() {
		return d_code;
	}
}