Evaluating the Expressiveness of a Multimethod Object-Oriented Programming Language
Although most popular object oriented languages use single dispatch, multiple dispatch programming languages offer more expressiveness over single dispatch languages. We developed an interpreter for a multimethod object-oriented language, TSTBC, to study the expressiveness of these languages. Compared with other multimethod languages, TSTBC features: objects that can act as classes, instances, and first-class generic functions, as well as method update. TSTBC has scoped inheritance, and the inheritance relation of an object is set at the time of its creation. The generic functions can be extended in the scope they are declared in, but only way to extend a generic function in a nested scope is to create a new generic function, assign the old generic function's methods to the new generic function and extend the new generic function. Keywords: Multimethods, generic functions, object-oriented programming languages, encapsulation, information hiding, block structure, subtyping, inheritance, TSTBC language. 1994 CR Categories: D.3.1 [Programming Languages] Formal Definitions and Theory --- semantics; D.3.2 [Programming Languages] Language Classifications --- object-oriented languages; D.3.3 [Programming Languages] Language Constructs and Features --- abstract data types, control structures, procedures, functions, and subroutines; D.3.m [Programming Languages] Miscellaneous --- multimethods, generic functions; F.3.2 [Logics and Meanings of Programs] Semantics of Programming Languages --- operational semantics; F.3.3 [Logics and Meanings of Programs] Studies of Program Constructs --- control primitives.