R Programming By Example

Communicating available behavior with a database interface

We will start by defining the interface for databases in the Database class. This class is never intended to be instantiated itself. Its purpose is to simply provide an interface definition that must be respected by specific database implementations, like the CSVFiles implementation we will develop, and by the Storage implementation, to communicate with any database. The advantage of defining an interface such as this is that it provides a common language for these objects to talk to each other, and provides a reference for the programmer of what should be done and how methods should be named so that they work out of the box with the rest of the system. In Python, they would be called ...