import java.util.*;
/**
* Each Symbol object represents one entry in a SymbolTable.
* 
* @author Hyung-Joon Kim
*/
public class Symbol {
    
    //-----------------------------------------------------------------
    
	private int type;
	private String label;
	private HashMap attributes;
	
	public static final int UNKNOWN_TYPE= 0;
	public static final int KEYWORD		= 1;
	public static final int CLASSNAME	= 2;
	public static final int VARIABLE	= 3;
	public static final int METHOD		= 4;
	
    //-----------------------------------------------------------------	
    
	/**
	* Construct a new Symbol with the given name and type.
	* @param name the label by which the program being compiled
	* refers to this Symbol
	* @param t the symbol type, an int value.  Can be one of the
	* type values defined by the Symbol class or some other class
	* like Token.
	*/
	public Symbol(String name,int t) {
		label = name;
		type = t;
		attributes = new HashMap();
	}

	/**
	* Get the label attribute of this object.
	* @return the Symbol label
	*/
	public String getLabel() {
		return label;
	}

	/**
	* Set the label attribute of this object.
	* @param name the Symbol label
	*/
	public void setLabel(String name) {
		label = name;
	}

	/**
	* Get the type of this Symbol.
	* @return the Symbol type
	*/
	public int getType() {
		return type;
	}

	/**
	* Set the type of this Symbol.
	* @param t the Symbol type
	*/
	public void setType(int t) {
		type = t;
	}

	/**
	* Put an attribute in the HashMap of a Symbol.
	* @param key the name of the attribute
	* @param att the Object that holds the attribute's value
	*/
	public void putAttribute(String key,Object att) {
		attributes.put(key,att);
	}

	/**
	* Get an attribute from a Symbol.  The result is whatever kind of
	* object was stored for this attribute, so make sure your putters
	* and getters agree.
	* @param key the name of the attribute to get
	* @return the Object that holds the attribute's value
	*/
	public Object getAttribute(String key) {
		return attributes.get(key);
	}

	/**
	* Provide the String that describes this Symbol.
	*/
	public String toString() {
		StringBuffer sb = new StringBuffer(label+", type: "+Integer.toString(type));
		Set s = attributes.entrySet();
		Iterator iter = s.iterator();
		while (iter.hasNext()) {
			Map.Entry e = (Map.Entry)iter.next();
			sb.append(", "+e.getKey()+" "+e.getValue());
		}		
		return sb.toString();
	}	
}