package CSP;

/**
 * Title:        CSP_Variable
 * Description:  Define subclass to represent a specific kind of CSP variable.
 * Copyright:    Copyright (c) 2005
 * Company:      MIT
 * @author Andreas Hofmann
 * @version 1.0
 */

import java.util.*;


public class CSP_Variable
{
    CSP_Domain domain = null;
    List from_arcs = new ArrayList();
    List to_arcs = new ArrayList();

    public CSP_Variable()
    {

    }

    public CSP_Domain get_domain()
    {
	return domain;
    }

    public List get_domain_values()
    {
	return domain.domain_values;
    }

    public void assign(Object domain_value)
    {
	List values = new ArrayList();
	values.add(domain_value);
	domain.domain_values = values;  // Replaces old domain
    }

    public void restore_domain(List values)
    {
	domain.domain_values = values;  // Replaces old domain
    }

    public boolean consistent()
    {
	// Iterate over to_arcs, checking if consistent.
	ListIterator to_arc_iterator = to_arcs.listIterator();
	while (to_arc_iterator.hasNext()) {
	    CSP_Constraint to_arc = (CSP_Constraint)to_arc_iterator.next();
	    if (!(to_arc.consistent())) return false;
	}

	// Iterate over from_arcs, checking if consistent.
	ListIterator from_arc_iterator = from_arcs.listIterator();
	while (from_arc_iterator.hasNext()) {
	    CSP_Constraint from_arc = (CSP_Constraint)from_arc_iterator.next();
	    if (!(from_arc.consistent())) return false;
	}

	return true;
    }

}