An abstract machine for an object-oriented language with top-level classes

Abstract

Object-oriented programming languages where classes are top-level, i.e. not first-class citizens, are better suited for compilation than completely dynamic languages like SMALLTALK or SELF. In O'SMALL, a language with top-level classes, the compiler can statically determine the inheritance hierarchy. Due to late binding, the class of the receiver of a message must be determined at run time. After that a direct jump to the corresponding method is possible. Method lookup can thus be done in constant time. We present an abstract machine for O'SMALL based on these principles. It is a concise description of a portable O'SMALL implementation.