AP/S++: Case-study of a MOP for Purposes of Software Evolution

Cristina Videira Lopes (Northeastern University & Xerox PARC) and Karl Lieberherr (Northeastern University)

We study a recent programming paradigm known as Adaptive Programming (AP) as an ideal candidate for a metaobject protocol (MOP) for object-oriented programming languages; we call it the APMOP. The major benefit of the APMOP is to provide a mechanism for writing base-level programs in a structure-shy manner. Doing so, the programs are more robust to changes in the structural aspects of the applications. We describe AP/S++, an implementation of the APMOP using the Scheme-based, object-oriented language S++. AP/S++ is a compile-time MOP and has no negative effects on the run-time performance of programs.

The contributions of this paper are: (i) to show a new application for reflection; (ii) to clearly identify the abstraction boundaries of AP; and (iii) to propose an implementation of the APMOP that can easily be reproduced in many object-oriented programming languages.

lopes@parc.xerox.com
demeter@ccs.neu.edu