| gvSIG desktop 1

/**

 * Interface that all the operators of an expression to be parsed

 * has to implement

 * @author Pepe Vidal Salvador - jose.vidal.salvador@iver.es

 */

	/**

	 * Returns true if the expression is correctly evaluated using the

	 * HashTable for that

	 * @param symbol_table

	 * @return

	 * @throws ExpressionException

	public Object evaluate() throws ExpressionException;

	/**

	 * Returns an String containing the pattern for the operator. That is, the

	 * @return String with the pattern

	 */

	public String getPattern();

	/**

	 * Adds an argument (which is an Expression) to the operator in the

	 * ith position.

	 * @param i position where the argument will be added

	 * @param arg argument to be added

	 */

	public void addArgument(int i, Expression arg);

	/**

	 * Obtains the arguments of the Expression

	 * @return ArrayList with the arguments

	 */

	public ArrayList<Expression> getArguments() ;

	/**

	 * Sets the arguments of the Expression

	 * @param arguments

	 */

	public void setArguments(ArrayList<Expression> arguments);

	/**

	 * Checks if the semantic of the Expression is correct using for that

	 * the values of the HashTable if it is necessary

	 * @param symbol_table which contains the symbols

	 * @throws ExpressionException

	 */

}