package edu.stanford.rt.datatype;

import edu.stanford.rt.util.*;

/**
 * @author Ninghui Li, Sandra Qiu <br>
 * 
 * A SingletonValueSet object is a value set that 
 * conatins a single value of <code>SimpleType</code>.
 */
public class SingletonValueSet extends ValueSet
{
    private DataValue value;

    /**
     * Constructor for SingletonValueSet.
     */
    public SingletonValueSet(SimpleType type, DataValue value)
    {
        super(type);
        if (! type.isValidValue(value)) 
        {
            throw new IllegalArgumentException("Value type does not match");
        }
        this.value = value;
    }

	/**
	 * Method getValue.
	 * @return DataValue
	 */
    public DataValue getValue()
    {
        return this.value;
    }
    
	/* (non-Javadoc)
	 * @see edu.stanford.rt.datatype.ValueSet#toString(String)
	 */
    public String toString(String indent)
    {
        String thisIndent = indent + "  ";
        StringBuffer sb = new StringBuffer();
        sb.append(thisIndent).append("SingletonValueSet: \n");
        sb.append(thisIndent+"  ").append(getType().toString()).append("\n");
        sb.append(thisIndent+"  ").append(value.toString());
        return sb.toString();
    }
    
}