Interactive programs in a functional language: A functional implementation of an editor

Abstract The transition from imperative programming to functional programming for problems whose mathematical nature is not immediately obvious raises two questions. First, how can the function concept be applied to such problems, and, secondly, what language concepts are most suited in this situation. This paper shows that an existing functional programming language is very well suited for the elegant implementation of interactive programs. As an example, a text editor is described. The implementation of the editor has once more demonstrated the benefits of functional programming: fast generation of short and reliable programs. This indicates that it is worth while to investigate the application fields of functional programming languages as well as their implementation, in order to try to make them into general‐purpose programming languages that can be used in a production environment.