Software Engineering for Students A Programming Approach

16.3 A specification of this kind only specifies the method names and their
parameters. It does not specify any more closely what a method does –
other than via any comments.
16.4 interface Clock {
void init();
void waitSeconds(int seconds);
int getHours();
int getMinutes();
int getSeconds();
}
interface Display {
void init();
void flashLight();
void unflashLight();
void soundKlaxon();
void unsoundKlaxon();
void displayMessage(String message);
void clearScreen();
}
interface Heart {
int readRate();
int readPressure();
}
interface Lungs {
int readRate();
}
interface Temp {
int readTemp();
}
16.5 public class Circle implements Displayable
Further reading 235
Further reading
•A good collection of papers from the computer science literature which critically evaluate
and compare these three programming languages: A. Feuer and N. Gehani, Comparing
and Assessing Programming Languages, Ada, Pascal and C, Prentice Hall, 1984.
An excellent text for students wishing to explore further the fundamental principles
underlying programming languages: B.J. Maclennan, Principles of Programming
Languages: Design, Evaluation and Implementation, Dryden Press, 1987.