Event-driven control statements

Abstract

Abstract.Charles T. Zahn has recently proposed a new and promising statement that encourages structured thinking and that may also be said to make programming become documentation. D. E. Knuth has suggested that this statement may be of importance in future languages, and it has been thoroughly discussed in the literature. However, it seems that the statement is not properly suited for problems requiring nested constructs, and it is argued that this is caused by the long implicit jumps in the statement. It is also shown that by introducing an eventvariable and by permitting different events to share actions, the statement will become even more useful. A modified statement is proposed and demonstrated on a number of standard ill-structured algorithms that normally call for the use of GOTOs.