Parasitic Methods: An Implementation of Multi-Methods for Java

In an object-oriented programming language, method selection is (usually) done at run-time using the class of the receiver. Some object-orientedlanguages(such as CLOS) have multi-methods which comprise several methods selected on the basis of the run-time classes of all the parameters, not just the receiver. Multi-methods permit intuitive and typesafe de nition of binary methods such as structural equality, set inclusion and matrix multiplication, just to name a few. Java as currently de ned does not support multimethods. This paper de nes a simple extension to Java that enables the writing of \encapsulated" multi-methods through the use of parasitic methods, methods that \attach" themselves to other methods. Encapsulated multi-methods avoid some of the modularity problems that arise with fully general multi-methods. Furthermore, this extension yields for free both covariant and contravariant specialization of methods (besides Java's current invariant specialization). P...

• Type: Conference
• Year: 1997
• Where: OOPSLA
• Authors: John Boyland, Giuseppe Castagna
• Keywords: Binary Methods, Multi-methods, Object-oriented Programming Language, OOPSLA 1997, Security Privacy