Agora

Abstract

Agora is a framework for exploring object-oriented languages. In this paper we will discuss a particular prototype-based instance of Agora that features a general mixin-based approach to (multiple) inheritance. One of the major innovations of Agora is that many important features of object-orientation including inheritance, slot access, reification, cloning and inline objects are introduced by means of message passing rather than by ordinary programming structures.The syntax and semantics of Agora is explained and illustrated with examples. Furthermore, an FTP-site is given where a Smalltalk implementation of Agora can be found.

A formal foundation for object-oriented software evolution

“…To cope with the latter two problems, the reuse contracts technique has been introduced [13]. Reuse contracts have been applied to evolving object-oriented class hierarchies [1], collaborating classes [6], UML interaction diagrams [9,10], software architectures [11] and even evolving software requirements [2].…”