Objectives
This section introduces a number of
extensions to the basic object model,
including meta classes, object identity,
persistence and concurrency.
Also exceptions, which may be used to deal with
abnormal events, are briefly explained.
Points to emphasize
- meta classes -- dynamic type information
- distribution -- persistence, active objects
- exceptions -- abnormal events
Hints
It is meant as a forward reference
to the material presented in part III.
Question
- What extensions to the basic object
model can you think of?
Why are these extensions needed?
Comments
Dependent on the track you wish to follow,
you must now prepare the way to introduce
the subject that is to come next.