A functional pattern system for object-oriented design

This book integrates key areas of object-orientation, functional programming, design patterns, and language design. It introduces six design patterns that encapsulate essential concepts from functional programming: FUNCTION OBJECTS (black-box behavior parameterization), LAZY OBJECTS (evaluation-by-need semantics), VALUE OBJECTS (immutable values), VOID OBJECTS (abandoning null references), TRANSFOLD (combining internal and external iteration), and TRANSLATOR (homomorphic mapping with generic functions). These patterns can enhance software design in any object-oriented language, forming a collaborative system that references each other and established design patterns. The first part of the book presents an introduction to object-orientation, functional programming, and design patterns, comparing the two paradigms conceptually and on a calculus level. The second part focuses on the functional pattern system, which integrates the functional paradigm into object-oriented software design, allowing practitioners to leverage advantages typically found in functional languages. Even existing functional concepts in object-oriented software can be seen as specialized applications of these broader function patterns. The theoretical discussion of multi-paradigm language design culminates in an evaluation of the pattern system's implications for language design, proposing a new distribution of responsibilities between languages and their