/*
 * CalculatorModel.java
 *
 * Created on December 5, 2002, 2:11 AM
 */

package Calculator;

import CollabUtils.*;
import java.util.GregorianCalendar;
import java.util.Iterator;
import java.util.List;

/** See the documentation for ICalculatorModel and IApplicationIdentification.
 */
public class CalculatorModel implements ICalculatorModel, IApplicationIdentification {
    
    /** Creates a new instance of CalculatorModel */
    public CalculatorModel() {
    }
    
    public String getApplicationAuthor() {
    }
    
    /** return a string (as long as desired) identifying the authors of the program.
     */
    public String getApplicationAuthorDetails() {
    }
    
    /** return the date of creation or update
     */
    public GregorianCalendar getApplicationDate() {
    }
    
    /** return a (short) description of the application.
     */
    public String getApplicationDescription() {
    }
    
    /** return a string (as long as desired) describing the application
     */
    public String getApplicationDescriptionDetails() {
    }
    
    
    /** return a string (as long as desired) giving any details of
     * usage or applicability which the author wishes to convey to
     * a user or a client.
     */
    public String getUsageInformation() {
    }
    
    /** Answer, what is the current expression?
     * @return a string with all the tokens of the original expression, in the
     * usual left-to-right infix notation.  Note that the current expression might
     * have been invalid, but this method will still return it.
     * @throws RuntimeException is no expression has yet been set.
     */
    public String currentExpression() {
    }
    
    /** Set the number base which will be assumed for integer tokens in all subsequent new
     * expressions.
     *
     * Models are free to accept or reject any base except 10, which must always
     * be accepted.
     * @return true if the model accepts the change to the desired number base.
     * @return false if the model does not accept the change.
     *     public boolean setNumberBase(int radix);
     *
     *     /** Answer, what is the value of the current expression?
     * @return the (correct) value of the current expression, if there is one,
     *         as a string with no leading
     *  or trailing whitespace and no leading zeros.  If the current expression
     * is invalid, return an empty string (not a null reference).
     * @throws RuntimeException is no expression has yet been set.
     */
    public String currentValue() {
    }
    
    /** Answer, what is the value of the latest expression?
     * The current expression is the last valid expression received.
     * Pre: a valid expressed is present.
     * Post: None of the tokens have been modified.
     * @return the integer value of the last valid expression.
     * @throws RuntimeException If no valid expression has yet been received, or the latest expression
     * was invalid, the method should throw a runtime error, with a message
     * (in the exception) describing the reason for the exception.
     */
    public int evaluateExpression() {
    }
    
    /** Set the next expression to be evaluated.
     * The previous expression is forgotten.
     * Note: it is NOT an error to set a new expression when the old one's value
     * has never been called for.
     *
     *       @param expressionTokens An iterator to a list of the tokens in the expression
     * in their original, left-to-right, infix order.  Each token is a string.
     * For example, the expression 1 + (300 - 17) would correspond to a token
     * list of: "1" "+" "(" "300" "-" "17" ")".
     * Pre: The token list is non-empty
     * Post: If the token list was valid (in all respects relative to the model's
     * ability to evaluate it), then the expression has been saved within the model.
     * @return -1 if the token list was valid.  If not valid, the return value is
     * a list position where an error was detected.  By convention, this should
     * be the position of the first error, but that need not be guaranteed.
     */
    public int setExpression(Iterator expressionTokens) {
    }
    
    /** Signal that the model will not be called upon again.
     */
    public void terminate() {
    }
    
}