Ownership Confinement Ensures Representation Independence for Object-Oriented Programs

for data abstraction and justifies reasoning by simulation. Representation independence has been shown for a variety of languages and constructs but not for shared references to mutable state; indeed it fails in general for such languages. This paper formulates representation independence for classes, in an imperative, object-oriented language with pointers, subclassing and dynamic dispatch, class oriented visibility control, recursive types and methods, and a simple module. An instance of a class is considered to implement an abstraction using private fields and so-called representation objects. Encapsulation of representation objects is expressed by a restriction, called confinement, on aliasing. Representation independence is proved for programs satisfying the confinement condition. A static analysis is given for confinement that accepts common designs such as the observer and factory patterns. The formalization takes into account the usual interface between a client and a class tha...

• Type: Journal
• Year: 2002
• Where: CORR
• Authors: Anindya Banerjee, David A. Naumann
• Keywords: Abstraction, CORR 2002, Education, Representation Independence, Representation Objects