The application uses a simple text oriented user interface. The user activates a command by entering a single character, and then follows the instructions given by the system to enter the needed data. The application should be able to deal with invalid data, give proper error message to the user so the data can be re-entered. The application also prints responses to the commands. Since we have no persistent data, we assume the program keeps running, so a session is the entire life time of the store.
Design Think about the structure of the application - the classes and their relationships.
Reuse - an important aspect of this homework is to use classes from the library, mostly for the various data structures. For this you will need to browse the library, using flat and short . You may also want to look at the eiffel library book. Extendibility - Your design should make it as easy as possible to make changes. A change should require as little modification of code as possible.