D. Notkin, W. G. Griswold, "Enhancement through Extension: The Extension Interpreter", Proceedings of the SIGPLAN '87 Symposium on Interpreters and Interpretive Techniques, SIGPLAN Notices, ACM, vol.22, (no.7):45-55, July 1987.


The ability to extend programs dynamically has clear advantages. However, providing efficient yet sufficiently flexible support for such capabilities system-wide presents significant challenges. The authors describe a design and implementation of an extension mechanism that depends heavily on interpretive techniques, including call arbitration, dynamic linking, and multilanguage extensions. They discuss these mechanisms in the context of their Extension Interpreter, which embodies their ideas and provide a framework for discussing the efficiency and generality of the implementation. The current implementation runs under BSD UNIX 4.2 and 4.3 on VAXs and SUN workstations. Extensions can be written in both C and in Icon, demonstrating our ability to address problems both of compiled and interpreted languages.