The command dispatcher is the centerpiece of the calculator. As the controller in the MVC framework, the command dispatcher is responsible for the entire business logic of the application. This chapter addresses not only the specific design of the command dispatcher module for the calculator but also, more broadly, the flexible design of a loosely coupled command infrastructure.
4.1 Decomposition of the Command Dispatcher
The first question
we asked when decomposing the stack was, “Into how many components should the stack be divided?” We ask the same question now for the command ...