this document are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of Wright Laboratory or the U. S. Government. The U. S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon. This manuscript is submitted for publication with the understanding that the U. S. Government is authorized to reproduce and distribute reprints for Governmental purposes. Authors' address: School of Computer Science, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213; email: amy;wing@cs.cmu.edu. To appear, ACM Transactions on Software Engineering and Methodology (TOSEM), April 1995. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, requires a fee and/or specific permission. c fl 1995 ACM xxxx-xxxx/xx/xxxx-xxxx $xx.xx 2 \Delta A. Moormann Zaremski and J. M. Wing ware libraries successfully, especially as libraries increase in size, is the availability of good tools to organize, navigate through, and retrieve from libraries. Currently many libraries use the file system for their only organization (directories and files) and file system and editor commands for navigation and retrieval. For example, the local ML library is organized with categories of components as directories (e.g., local/lib/Container/, local/lib/Threads/); one uses ls and

The object-oriented paradigm of computing has started to have a significant influence on many areas of information and data processing, including database systems. This thesis focuses on the various issues and aspects governing the implementation design and development of the object model for TIGUKAT 1 , an object management system which is intended to be a full featured object-oriented database system on completion. The TIGUKAT object model [25] is behaviorally defined with a uniform object semantics. The model is behavioral in the sense that all access and manipulation of objects is restricted to the application of behaviors on objects, and it is uniform in that every entity within the model has the status of a first-class object. Various implementation design alternatives are discussed and the approaches that were chosen are justified. The ensuing implementation provides a robust kernel around which the rest of the system may be conveniently synthesized. 1 TIGUKAT(tee-goo-kat) i...

Inheritance with derived classes and virtual functions are key design concepts in C++. Despite this, their use can result in significant degradation of run time performance. We present a class flattening tool, which we believe will help eliminate the overhead associated with virtual functions in C++ programs. A flattener may also prove useful in the reuse, debugging, and understanding of C++ components. This report deals with the issues associated with flattening, and then presents a detailed design of such a tool.