“There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies”
—C.A.R. Hoare, 1980 ACM Turing Aware Lecture
A large program is a costly program, and not just because of the time it takes to build. Size almost always involves complexity, and complexity confuses programmers. Confused programmers, in turn, tend to introduce mistakes (bugs) into programs. A large program also provides a lot of space for these bugs to hide, making them hard to find.
Let’s briefly go back to the final two example programs in the introduction. The first is self-contained and six lines long. ...