Hi I'm a hard working contractor struggling with my current customer's legacy C application (1-2 million lines worth) in a project to apply OO techniques to enable re-engineering without re-writing. The trick is to keep the train on the rails (running smoothly and well maintained) while re-engineering to make it possible to maintain and extend with less risk of regressions. My current issue is how to map an ISAM file system (OpenVMS RMS and Informix C-ISAM) to a C++ interface. My current thinking is along the lines of files as containers and indices as iterators - then make it look as much like the C++ library as possible. This causes a few problems when concurrency has to be implemented, perhaps a few extra operations on the contained type to handle "optimistic locking" and record update. -------------------------- mailto:WSomerville@datastream.com ---- CategoryHomePage