The STL++ Coordination Language

Abstract

With the experience of STL, it turned out that in ECM the separation of code cannot always be easily maintained. Although the blackbox process model of ECM is a good attempt to separate coordination and computation code, dynamic properties proved to be difficult to be expressed in a separate language.

This consideration led us to initiate the development of our new coordination language called STL++ [SCKH98] [SCH99], [SCK+99]. Starting from the experience acquired with STL, a single language approach has been adopted: STL++ implements the conceptual model of ECM by embedding it in a given object-oriented language (namely C++ [Str97]) with coordination primitives realized in a library.

This chapter is organized as follows. In this introduction, we expose the principal design decisions of STL++ and give an overview of an STL++ application. Sections 6.2 to 6.6 give a semi-formal presentation of STL++. Section 6.7 discusses a tutorial example implemented in STL++. Section 6.8 sketches the main characteristics of a prototype implementation of STL++. Section 6.9 concludes the chapter with a discussion. Appendix A systematically presents the core interface of STL++.