1. A Survey of Object-Oriented Concepts, by Oscar Nierstrasz Reviewed by Odd Petter N. Slyngstad for DT8100, 27/1/2005

2. Overview Argues that the fundamental concept in object-oriented systems is encapsulation (all OO systems exploit this in some way) Also attempt to show that other concepts depend on encapsulation (instantiation, inheritance, polymorphism, genericity etc.)

3. Object-Oriented Programming Languages #1 – Simula (computer simulations) Smalltalk – ”objects useful for prototyping and app.dev. too” Definition of OO-language: ”Any language which provides mechanisms to exploit encapsulation is (to some degree) object- oriented” (not either or, but to which degree) Operations form visible interface, while implementation is hidden

4. OO-languages-cont’d Reusability (encapsulation of programs and data) with a short explanation of basic concepts such as: –Instantiation and Object classes –Inheritance (static, dynamic, etc.) –Polymorphism and overloading –Generic classes Object Types – type checking and conformance Concurrency – direct vs. indirect communication, synchronization

5. Object-Oriented Systems Object mgmt. –run-time issues (object-naming, persistence, concurrency, distribution, version control, security, etc., etc.) –examples of C++, Smalltalk, Lisp OO programming environments –tools to aid design, selection, reuse and evolution management of objects

6. Summary ”Object-oriented refers to any approach which exploits encapsulation or packaging in designing or building software” Article provides a survey of object-oriented techniques in prog. Languages, as well as issues related to run-time object support and programming environments. Questions, comments ??