The main characteristics of the application to be tested are:
the capability of performing arithmetic operations;
the correct representation in the different representation formats;
the correct representation in the different number bases.
Architecture and planning
The system architecture shown in Figure 6.2 is very simple. It is made up of
two main components: the multi-format calculator that provides all the basic
functionalities and the user interface.
Figure 6.2 Architecture
The benefit stemming from such a structure is that it is possible to change
independently the implementation of the calculator and the interface
provided to its user.
The development of the system will be carried out in two phases, each
providing a working prototype.
Prototype 1: Representation formats . The first prototype will implement
the basic features of the calculator, i.e. perform operations; in addition
it will deal with multiple representation formats. The interface of this
prototype will be a text-based command line interpreter.
Prototype 2: Number bases . The second prototype will add the manage-
ment of multiple number bases. In addition to performing more extensive
testing it should be able to read commands from a file.
Prototype 1: Representation formats
The focus of this prototype is on the execution of basic operations and on
multiple representation formats. As required in the specification of the
problem, priority is given to the fractional format.
The problem at hand can be split into two sub-problems: the calculator and
the user interface. The former problem deals with defining the computational