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.